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merc
10-22-2007, 06:30 PM
Tq. Converter Stall Speed

Switching to a higher stall-speed torque converter can provide the benefit of increased launch RPM and better low-speed acceleration. Once your vehicle is up and moving, though, a different converter will have little effect. Like any other performance tuning variable, converter stall-speed should be closely matched to your vehicle and power-train requirements. Also, a torque converter may not necessarily deliver the advertised stall speed due to differences in engine torque output and vehicle chassis conditions. After-market torque converters vary greatly in their quality and coupling efficiency. However, no converter should have to reach its advertised stall RPM just to back out of your driveway or accelerate in city traffic, as is a common misconception about higher-stall-speed torque converters. In fact, a properly designed mild after-market converter (i.e. 2500 RPM stall-speed) should not feel much different than its OEM counterpart in everyday driving.

Stall speed should be selected so that the torque converter will reach its stall speed just before the engine starts it power-band (when torque output begins increasing sharply). Too much stall RPM will actually slow a car down by wasting part of the engine's useful power curve. A stock torque converter in an AOD equipped Mustang will produce a stall speed of about 1800RPM, while the stock 5.0L H.O. engine enters its power-producing stage slightly later. Therefore, a stall speed of 2500 RPM is best for most stock and mildly modified 5.0L HO applications. Stock 5.0L Mustang AOD-E torque converters stall at about 2400 RPM, and will provide significant improvements over an AOD converter. Vehicles with significantly altered valve events (i.e. large camshafts and/or huge valves) may benefit from stall speeds as high as 3000RPM or more depending upon configuration and torque curve. In such cases, it is best to consult your camshaft supplier or engine builder for best results.

For AOD transmissions (as well as C-4 and C-6 applications) there are a number of vendors providing high quality torque converters in many different configurations. As mentioned in the AOD section, Art Carr's converters require use of their special input shaft for the AOD and are available in a variety of stall speeds and sizes. Precision Industries also makes converters in both "lockup" and "non-lockup" varieties for the AOD with stall speeds to order. Baumann Engineering can also furnish high quality custom built converters for Ford transmissions at competitive prices. Before purchasing any torque converter, we suggest that you get objective recommendations from other performance enthusiasts and avoid using purchase price as the sole selection criteria.

As with the E4OD and A4LD transmissions, few vendors have yet to produce higher stall-speed torque converters for the AOD-E/4R70W transmission. However, Baumann Engineering can provide a custom-built torque converter for these and most other applications. In the case of converter clutch style transmissions, such as the AOD-E/4R70W, E4OD and A4LD, we rarely advocate removing the lockup clutch assembly from the torque converter. Therefore, they provide their converters with new heavy-duty lockup clutch assemblies. This allows you to selectively control converter lockup with the Baumannator TCS™ or even external switches if desired, thereby providing maximum efficiency and versatility with no adverse effect on vehicle performance.

How do I choose the right stall speed?
Under ideal circumstances you should select a converter that stalls approx 700 rpm below peak torque. This will set the converter and the transmission's gearing to do their job, until you reach peak hp or shift points.

For street use we never recommend a stall speed higher than 3000 to 3500 rpm depending on the rear end ratio and your normal driving rpm. If your normal 55 to 60 mph cruising rpm is at 2500 rpm, you don't want a convertor that is any higer. What you do want is the convertor to be highered up at that speed in order to avoid the heat buildup a converer generates when it is working.

It is a general misunderstanding that a vehicle will not move until the stall speed is reached. This is not the case. With a 3000 rpm stall this vehicle is drivable at any rpm, it may seem a bit sluggish or lazy until you reach 3000 rpm.

The SC makes peak torque somewhere from 2500-3000 rpm depending on what mods you have. This calls for a 1800-2300rpm stall for most applications. Unlike naturally aspirated motors, the SC makes all of it's power down low. By stalling the motor ABOVE IT'S EFFECTIVE POWER BAND, you are wasting most of it's effective power through slippage in the torque convertor.

I suggest 2,800 rpm stall converter in a SC only if you wish to drive at or above the peakTorque rmp of the engine. In other words I would not recommend a high stall converter in a SC if you intend to use it as a dailydriver. It is nearly impossible to keep the rear end from breaking loose. I am exchanging it for the 2,200 rpm converter. http://www.protorque.com, Precission Industries

Do you agree with the above statement. If not please tell me why.

Zack
10-22-2007, 06:36 PM
I have a 3500 from Darrin, feels way grippier at the low rpm's compared to the PI.

ImpalaSlayer
10-22-2007, 06:49 PM
thanks for the info. still very confusing though

MarauderTJA
10-22-2007, 07:01 PM
I have a 3500 from Darrin, feels way grippier at the low rpm's compared to the PI.

I have found the exact same thing with mine. Absolutley no comparision to the 3000 PI I had previously in the car. I think due to the larger surface area of his converters.

MarauderTJA
10-22-2007, 07:41 PM
BTW Merc, an excellent and informative thread:up:. My new BC Auto 3500 stall converter is far superior than my previous PI 3000 Stallion, hands down.

merc
10-23-2007, 06:18 AM
Since we are on the subject of converters lets use the illustration below to help us understand the parts involved.

http://www.mercurymarauder.net/showcase/files/2/3/8/Torque-Converter-callouts.jpg

merc
10-23-2007, 06:25 AM
I have found the exact same thing with mine. Absolutley no comparision to the 3000 PI I had previously in the car. I think due to the larger surface area of his converters.

http://www.mercurymarauder.net/showcase/files/2/3/8/ClutchTQ.jpg

When towing or hauling a heavy load, the stock torque converter clutch can slip while in lockup mode, which causes excessive lockup clutch wear and transmission heat. Some aftermarket valve bodies overcome this problem by boosting transmission line pressure past the limit of the transmission seals, which can cause leaks. Some Torque Converter’s lockup surface are lined with a special carbon-ceramic material that withstands heat and resists slippage better than the stock cellulose-based paper material that is used in the PI convertor. Additionally, the clutch surface area is increased for truck applications, allowing a stronger lockup at safe line pressures.

gonzo50
10-23-2007, 06:45 AM
Tq. Converter Stall Speed

The SC makes peak torque somewhere from 2500-3000 rpm depending on what mods you have. This calls for a 1800-2300rpm stall for most applications. Unlike naturally aspirated motors, the SC makes all of it's power down low. By stalling the motor ABOVE IT'S EFFECTIVE POWER BAND, you are wasting most of it's effective power through slippage in the torque convertor.

I suggest 2,800 rpm stall converter in a SC only if you wish to drive at or above the peakTorque rmp of the engine. In other words I would not recommend a high stall converter in a SC if you intend to use it as a dailydriver. It is nearly impossible to keep the rear end from breaking loose. I am exchanging it for the 2,200 rpm converter.
Do you agree with the above statement. If not please tell me why.
I have the 3000 rpm stall converter from PI, so what you're saying is when I decide to go S/C, I lose all streetabilty driving due to not being able to get any grip. :confused:

Will I have to also change out my converter ? :dunno:

merc
10-23-2007, 06:47 AM
Edited duplicate thread. Admin please delete.

merc
10-23-2007, 06:51 AM
thanks for the info. still very confusing though

Torque converter 101

The basic function of the torque converter is to multiply the turning force of an engine while at the same time replacing the clutch found in manual transmissions. The engine is connected to the torque converter by means of the crankshaft. The crankshaft ends in the torque converter, which is also where the main input or transmission shaft ends as well. However, these two shafts are not connected to each other so there isn’t any physical connection between the engine and transmission in any way. The two shafts have the slightest gap between them and are immersed in transmission fluid.

The transmission shaft is turned by the crankshaft by means of a process called hydraulic coupling. As all fluids are not easily compressed, this property is utilized in the automatic transmission. The hydraulic fluid used is the automatic transmission fluid (ATF) which fills the entire transmission and torque converter. The one downside to utilizing hydraulic coupling is that is causes automatic transmissions to be slightly more inefficient than their manual counterparts. The fluid connection between the crankshaft and transmission shaft allows some slippage to occur. As a result, there is a two to eight percent loss in energy transferred from one shaft to the other. This is the reason why automatic cars generally get slightly worse fuel economy than the manual version of the same car model.

Inside the torque converter casing, there are three main components: the impeller (pump), stator (guide wheel) and turbine. Hydraulic coupling is also at work within the torque converter itself, and to improve the efficiency of energy transfer, both the impeller and turbine have blades which are designed to increase the surface area that the fluid can act on.

Inside the transmission fluid filled torque converter, the impeller is located on the engine side while the turbine is situated on the transmission side. When the impeller starts to spin, the turbine wheel spins in tandem with it through hydraulic coupling. As this happens, centrifugal forces cause the fluid to move towards the outer edges of the blades, where the stator redirects the fluid towards the turbine side of the torque converter. This continuous flow of transmission fluid is what causes the torque converter to multiply the turning power applied by the engine.

The majority of modern torque converters will also include a lock-up feature through the use of a torque converter clutch. The highly pressurized fluid flowing through the transmission is channeled through the transmission shaft as the speed of the vehicle nears forty miles an hour. When this happens, the torque converter clutch or a metal pin, physically ‘locks’ or connects the turbine to the impeller. The pin remains connected until either the vehicle slows down below forty miles an hour or a gear-shift occurs. This feature was developed and incorporated into the modern torque converter to improve the highway fuel economy.

KillJoy
10-23-2007, 07:01 AM
Interesting.

Could it possibly be that you just need to relearn how to "drive" the car when you get a higher stall TC???

:dunno:

KillJoy

merc
10-23-2007, 07:05 AM
I have the 3000 rpm stall converter from PI, so what you're saying is when I decide to go S/C, I lose all streetabilty driving due to not being able to get any grip. :confused:

Will I have to also change out my converter ? :dunno:

Lidio wrote this back in 04-02-2003. In conversation with him he prefers the Marauder stock 04 converter over any high stall unit on the market. Lidio has since sold his Marauder but still provides aftermarket performance parts to our community.

I’d also like to note that at the end of the ¼ mile the rpms in 3d gear were only at about 4600rpm! This is not optimal for a drag racer when the engine shifts at 6000 ish. We would usually like to see a trap rpm of about 6000+ on this type of set up. This would probablly produce about a 2-3 tenth increase in ET but traction would become a much more serious problem with out a tire upgrade. This is why I’m suggesting leaving the 3.55’s in the rear for now if the Trilogy blower is in your Marauder’s future. Also the stock torque converter stall speed is perfect for the blower application. Once again a change here would only produce greater traction problems and if loosened up to much can cause a drivability concern around town when locking and unlocking.

Dennis Reinhart
10-23-2007, 07:09 AM
Tq. Converter Stall Speed

Switching to a higher stall-speed torque converter can provide the benefit of increased launch RPM and better low-speed acceleration. Once your vehicle is up and moving, though, a different converter will have little effect. Like any other performance tuning variable, converter stall-speed should be closely matched to your vehicle and power-train requirements. Also, a torque converter may not necessarily deliver the advertised stall speed due to differences in engine torque output and vehicle chassis conditions. After-market torque converters vary greatly in their quality and coupling efficiency. However, no converter should have to reach its advertised stall RPM just to back out of your driveway or accelerate in city traffic, as is a common misconception about higher-stall-speed torque converters. In fact, a properly designed mild after-market converter (i.e. 2500 RPM stall-speed) should not feel much different than its OEM counterpart in everyday driving.

Stall speed should be selected so that the torque converter will reach its stall speed just before the engine starts it power-band (when torque output begins increasing sharply). Too much stall RPM will actually slow a car down by wasting part of the engine's useful power curve. A stock torque converter in an AOD equipped Mustang will produce a stall speed of about 1800RPM, while the stock 5.0L H.O. engine enters its power-producing stage slightly later. Therefore, a stall speed of 2500 RPM is best for most stock and mildly modified 5.0L HO applications. Stock 5.0L Mustang AOD-E torque converters stall at about 2400 RPM, and will provide significant improvements over an AOD converter. Vehicles with significantly altered valve events (i.e. large camshafts and/or huge valves) may benefit from stall speeds as high as 3000RPM or more depending upon configuration and torque curve. In such cases, it is best to consult your camshaft supplier or engine builder for best results.

For AOD transmissions (as well as C-4 and C-6 applications) there are a number of vendors providing high quality torque converters in many different configurations. As mentioned in the AOD section, Art Carr's converters require use of their special input shaft for the AOD and are available in a variety of stall speeds and sizes. Precision Industries also makes converters in both "lockup" and "non-lockup" varieties for the AOD with stall speeds to order. Baumann Engineering can also furnish high quality custom built converters for Ford transmissions at competitive prices. Before purchasing any torque converter, we suggest that you get objective recommendations from other performance enthusiasts and avoid using purchase price as the sole selection criteria.

As with the E4OD and A4LD transmissions, few vendors have yet to produce higher stall-speed torque converters for the AOD-E/4R70W transmission. However, Baumann Engineering can provide a custom-built torque converter for these and most other applications. In the case of converter clutch style transmissions, such as the AOD-E/4R70W, E4OD and A4LD, we rarely advocate removing the lockup clutch assembly from the torque converter. Therefore, they provide their converters with new heavy-duty lockup clutch assemblies. This allows you to selectively control converter lockup with the Baumannator TCS™ or even external switches if desired, thereby providing maximum efficiency and versatility with no adverse effect on vehicle performance.

How do I choose the right stall speed?
Under ideal circumstances you should select a converter that stalls approx 700 rpm below peak torque. This will set the converter and the transmission's gearing to do their job, until you reach peak hp or shift points.

For street use we never recommend a stall speed higher than 3000 to 3500 rpm depending on the rear end ratio and your normal driving rpm. If your normal 55 to 60 mph cruising rpm is at 2500 rpm, you don't want a convertor that is any higer. What you do want is the convertor to be highered up at that speed in order to avoid the heat buildup a converer generates when it is working.

It is a general misunderstanding that a vehicle will not move until the stall speed is reached. This is not the case. With a 3000 rpm stall this vehicle is drivable at any rpm, it may seem a bit sluggish or lazy until you reach 3000 rpm.

The SC makes peak torque somewhere from 2500-3000 rpm depending on what mods you have. This calls for a 1800-2300rpm stall for most applications. Unlike naturally aspirated motors, the SC makes all of it's power down low. By stalling the motor ABOVE IT'S EFFECTIVE POWER BAND, you are wasting most of it's effective power through slippage in the torque convertor.

I suggest 2,800 rpm stall converter in a SC only if you wish to drive at or above the peakTorque rmp of the engine. In other words I would not recommend a high stall converter in a SC if you intend to use it as a dailydriver. It is nearly impossible to keep the rear end from breaking loose. I am exchanging it for the 2,200 rpm converter. http://www.protorque.com, Precission Industries

Do you agree with the above statement. If not please tell me why.


for a 4000lb car on the street N/A or SC a 3000/3500 works out fine, I had a 4500 in my Mark 8 and yes that was a bit much to drive on the street, PI makes a very good converter

merc
10-23-2007, 07:21 AM
Interesting.

Could it possibly be that you just need to relearn how to "drive" the car when you get a higher stall TC???

:dunno:

KillJoy

This is a good question Killjoy. Just dropping in a high stall converter with out optimizing the lockup schedules and shift points would cause some driver frustration. In my personal experience I have had 3 difference tunes that effected my transmission. I was happiest with Injected Engineering tune when I was N/A. They got my transmission singing a different song. Currently I have the stock Lidio tune for the basic 3.4 pulley setup. I find that I have to regulate my foot to have smooth highway shifts and I hate hearing the transmission lock and unlock between 60 and 70 miles per hour. I will be addressing that problem in the near future with a different tune.

merc
10-23-2007, 07:28 AM
for a 4000lb car on the street N/A or SC a 3000/3500 works out fine, I had a 4500 in my Mark 8 and yes that was a bit much to drive on the street, PI makes a very good converter

Thanks Dennis for chiming in on this thread. You have a ton of real world experience that would be helpful to share. I don't intend for this conversation to be a debate. At the end of the day we can all learn and formulate better questions with the wisdom of understanding.

sailsmen
10-23-2007, 11:38 AM
I had a 3,000 PI N/A w/ 4:10 and a 3,500 PI S/C w/o issues.

My max torque is around 4,100 or 600 more than the stall.

merc
10-23-2007, 11:47 AM
I had a 3,000 PI N/A w/ 4:10 and a 3,500 PI S/C w/o issues.

My max torque is around 4,100 or 600 more than the stall.

That's good information but could you include the date of purchase and the date you changed the stall. Also could you add the turn around time. It looks like most people are going with 3,500 stall speed vs 2800 or 3000.

magindat
10-23-2007, 12:05 PM
With 4.10's, and 20" wheels with 713 rev/mi (stock is 724)...WOT

I shift
1-2 45MPH 6227 RPM
puts me at 3398 in 2nd
2-3 82MPH 6193RPM
puts me at 3995 in 3rd
3-4 127MPH 6188 RPM
puts me at 4331 in 4th

Seems like the 3500 is just what the doctor ordered.

:dunno:

ctrlraven
10-23-2007, 01:09 PM
I've got a PI 3500 with 3.55, lots of headaches and slower 1/4 times even after a new tune file. 4.10s going in soon and another new tune and see where I am at.

merc
10-23-2007, 01:30 PM
I've got a PI 3500 with 3.55, lots of headaches and slower 1/4 times even after a new tune file. 4.10s going in soon and another new tune and see where I am at.

Thanks for the feedback. So lets talk about stall torque ratio.

Stall Torque Ratio is one of the most misunderstood aspects of torque converter construction.It's often called stall torque ratio: torque multiplier. The stall torque ratio is the amount of engine torque that the torque converter can multiply at a particular rpm level. By definition, stall torque ratio is when the turbine is at 0 RPMs and the converter is at maximum designed stall. This will produce a positive push on the turbine to increase the torque to the input shaft of the transmission, multiplied by the designed stall torque ratio of the torque converter. For example, a stall torque ratio of 2.0 would multiply 200 lb. ft. of engine torque to 400 lb. ft. of torque at the transmission input-shaft.

The misconception of stall torque ratio is that more must be better. This is not always the case. High stall torque ratio applications, typically are for industrial equipment or engines with limited low rpm engine torque as the case with the Mercury Marauder. With high stall toque ratio converters, there are important trade-offs. What you take at one end you give up on the other. Typically, a torque converter with a very high stall torque ratio, such as 2.0-2.5, will be much less efficient above its rated stall speed. There is a sacrifice in higher rpm efficiency to achieve high stall torque ratios. That lower efficiency translates into less horsepower transmitted to the tires over an RPM range.

The problem with a high stall torque ratio converter is that it is only high while the car is not moving. Maximum stall torque ratio occurs at wide open throttle (WOT) with no rotation of the transmission input shaft. As the input shaft starts to rotate with vehicle forward movement, the stall torque ratio will become non-existent much sooner than a converter of the same stall, with a lower stall torque ratio. A converter with a stall torque ratio of 2.2 for example, would display that at the starting line, but it would drop off much sooner than a converter with a lower stall torque ratio.

Brake Stall vs. Flash Stall:

Flash stall is the maximum your engine's torque can stall a torque converter. In essence flash stall and full stall are nearly identical. If you had a transbrake, you could find full stall by putting your foot to the floor and reading your tach. For argument sake, let's say we're testing a 3500 stall PI. If you had a transbrake, you would see around 3500 rpms. If your motor was at idle and then you suddenly floored the throttle, you might see slightly more (maybe 100 rpm more) stall for a half second as the momentum of the motor's internals "flashed" the converter a small bit above its true stall rating.

Brake stall, on the other hand is a very subjective thing. For most, it's the highest stall you can achieve before your tires spin. This varies greatly based on many factors: Traction, gearing, brake clamping force, and engine torque. With a PI 3500 Stallion, you may only be able to get 2200rpm "brake stall" on the street with street tires...any higher rpm and the motor torque would overwhelm the tires. But if I was at the track with racing slicks on the starting line, I might be able to get 3200 brake stall before the motor torque overwhelmed the tires. See...brake stall is very subjective.

Zack
10-23-2007, 01:42 PM
I've got a PI 3500 with 3.55, lots of headaches and slower 1/4 times even after a new tune file. 4.10s going in soon and another new tune and see where I am at.

Your car has high mileage and has been abused since day 1 right?
I would look to the internals of the trans, not the converter.
Might just be an eeeery coincidence the car slowed down after the converter install.

Are you sure the converter is seated all the way?

merc
10-23-2007, 01:51 PM
While we are on the subject of converters, have you ever wondered what's the differance between a stock 11' converter and a performance 9.5 inch. Two different sized converters can have the same stall speed, but the efficiencies will vary greatly. A converter pump will tend to have a higher efficiency when its blades have a positive angle to them. The positive angle feeds the most amount of fluid to the turbine. The more fluid you feed the turbine, the harder it pushes on it. The harder the turbine is pushed, the more torque is transferred to the transmission.

For a 11" converter that normally stalls at 1600, to be converted to a 2600 stall, most converter builders will bend the pump blades back to a negative angle to feed less fluid to the turbine. This means the pump will have to turn more rpms to force the turbine with the same amount of fluid as before. As you can imagine, the efficiency starts to drop off rapidly as you bend the blades more and more negative. You will lose rwhp.

A 9.5" converter stalls higher because it generates less fluid by virtue of it's smaller size. It takes more stall to achieve the same amount of hydraulic force of a larger 11" converter. Good thing about a 9.5" converter is that you can achieve very high efficiency in higher stall applications because the pump blades still maintain a very forward pitch to them (positive angle). So in essence, by bending the blades negative on a 11" converter, you are turning it into a heavy, inefficient, higher stall converter in comparison to a smaller diameter converter.

ctrlraven
10-23-2007, 02:00 PM
PM sent Zack

rumble
10-24-2007, 03:10 PM
http://www.mercurymarauder.net/showcase/files/2/3/8/ClutchTQ.jpg

Some aftermarket valve bodies overcome this problem by boosting transmission line pressure .......... Some Torque Converter’s lockup surface are lined with a special carbon-ceramic material that withstands heat and resists slippage better than the stock cellulose-based paper material that is used in the PI convertor. Additionally, the clutch surface area is increased for truck applications, allowing a stronger lockup at safe line pressures.

Does a "tune" increase this pressure or only valve body mods?

What is the best solution for clutchs for high output engines? 450HP+

And thanks for all the great info. Good job!!:2thumbs:

merc
10-24-2007, 05:55 PM
Most tuners like to add line pressure to increase the positive shift feeling that the customer enjoys. Too much line pressure will cause problems many years down the road. After such time the tuner blames the transmission for failures in performance.


Does a "tune" increase this pressure or only valve body mods?

What is the best solution for clutchs for high output engines? 450HP+

And thanks for all the great info. Good job!!:2thumbs:

SCT Tuning

Line Pressure
Entering higher numbers on the Y axis (Y axis = MPH) at each throttle position(X axis = TP) will firm up the shift at that TP) (these values might differ depending on which gears you have)

trans tv press 1-2
X 0 0 0 0 0 52 400 600 1020
Y 5 5 5 5 5 10 17 46 56
trans tv press 2-3
X 0 0 0 28 52 252 400 600 1020
Y -5 -5 -5 -5 0 8 8 27 42

Shift Time

scalar value
trans_tv_adder_12 16
trans_tv_adder_12_time 0
trans_tv_adder_23 16
trans_tv_adder_23_time 0
trans_tv_adder_34 20
trans_tv_adder_34_time 1
trans_min_tp_for_torque_mod 900 (to disable)
trans_torq_control_min-ECT 250 (to disable)

Tom Doan
10-25-2007, 06:22 AM
I used the famous trans builders Performance Automatics, garenteed for 750hp and for life. My trans was in and out so many times I needed Velcro fasteners.
DR did it last year and it has held up well. Very disappointed with PA, nice people,nice place,just couldn't make it work. Tom

FordNut
10-25-2007, 06:40 AM
My tq converter experience...

This may be useful to some in their decision-making.

While NA, about 300 rwhp, I put in a 2800 stall single-plate PI. It was very streetable and worked well on the strip. I was running 13.5 in the 1/4 then. Had I gone to a 3200 or 3500 I may have picked up a couple of tenths.

I went SC, about 475 rwhp, stayed with the same converter. It worked well at that power level.

Built motor, over 650 rwhp, same converter just blew away the tires. Couldn't launch for crap. Changed to a 2600 stall triple plate so the stall speed was lower than the rpm where I went into boost and it worked very well. So I agree SC or high rwhp cars are better off with a lower stall. The triple plate converter makes a lot more noise than the single plate, but when it locks it's like a straight shift car's clutch with absolutely no slipping.

Zack
10-25-2007, 06:51 AM
I have a 3600 stall with the KB, couldnt be happier :up:

merc
10-25-2007, 07:44 AM
My tq converter experience...

This may be useful to some in their decision-making.

While NA, about 300 rwhp, I put in a 2800 stall single-plate PI. It was very streetable and worked well on the strip. I was running 13.5 in the 1/4 then. Had I gone to a 3200 or 3500 I may have picked up a couple of tenths.

I went SC, about 475 rwhp, stayed with the same converter. It worked well at that power level.

Built motor, over 650 rwhp, same converter just blew away the tires. Couldn't launch for crap. Changed to a 2600 stall triple plate so the stall speed was lower than the rpm where I went into boost and it worked very well. So I agree SC or high rwhp cars are better off with a lower stall. The triple plate converter makes a lot more noise than the single plate, but when it locks it's like a straight shift car's clutch with absolutely no slipping.

Neal Chance Bolt Together Torque Converter and Neal Racing Transmissions Pro-Glide Powerglide make racing transmission for some big names.

Q: WHY WOULD I WANT A BOLT TOGETHER
A: For Many Reasons

You'll never outgrow it. By purchasing another component, the converter can be changed to virtually any stall you want.

You can do your own preventive maintenance and freshen ups. Allowing you to keep your converter "new" virtually forever!

It is completely accessible at any time. If you suspect a problem, you don't have to send it half way around the country and take someone's word on repair and costs and then when it's all said and done - wondering IF there even was a problem. Instead, you can take the converter apart in minutes and see for yourself!

Let's say you're out of town at a big race and you break a transmission! If you don't build your own trans, there's probably a dozen guys at a big race who can. But the converter needs CLEANED and not even a power flusher can get all the contamination and debris out of a converter, especially the bearings! But with your Neal Chance Bolt Together you can take the converter apart, clean it, inspect it, and put it back together in just a matter of minutes!

You can have extra parts for different stalls. It's like having two or three converters in one! Ideal for racers who race at high and low altitude track and/or have more than one engine for their car, or simply fine tune your combo,etc.!

If you don't want to do your own annual maintenance, NCRC will service and check your Bolt Together for only $79.00! Meaning there is NO reason not to keep your converter in tip top shape.

For those Marauder Members with a large budget a Bolt together vs. a wielded converter seem like an interesting idea.

http://www.transmission-specialties.com/catalog/images/834_bolt_med.gif

10" Caddie Northstar Bolt Together 1400 - 2500 HP $2,399.00

gmtech
10-25-2007, 09:13 AM
[quote=FordNut;545398]My tq converter experience...

This may be useful to some in their decision-making.

While NA, about 300 rwhp, I put in a 2800 stall single-plate PI. It was very streetable and worked well on the strip. I was running 13.5 in the 1/4 then. ]



did you have to have a specific tune for the 2800 stall ?

FordNut
10-25-2007, 09:19 AM
[quote=FordNut;545398]My tq converter experience...

This may be useful to some in their decision-making.

While NA, about 300 rwhp, I put in a 2800 stall single-plate PI. It was very streetable and worked well on the strip. I was running 13.5 in the 1/4 then. ]



did you have to have a specific tune for the 2800 stall ?

No, but the 2800 was installed when the car was tuned.

MarauderSM
10-27-2007, 01:39 AM
So SC can either go up or down on stall speed, it's just preference.

What have you guys run and what speed.

rumble
10-27-2007, 09:11 AM
SCT Tuning

Line Pressure
Entering higher numbers on the Y axis (Y axis = MPH) at each throttle position(X axis = TP) will firm up the shift at that TP) (these values might differ depending on which gears you have)

trans tv press 1-2
X 0 0 0 0 0 52 400 600 1020
Y 5 5 5 5 5 10 17 46 56
trans tv press 2-3
X 0 0 0 28 52 252 400 600 1020
Y -5 -5 -5 -5 0 8 8 27 42

Shift Time

scalar value
trans_tv_adder_12 16
trans_tv_adder_12_time 0
trans_tv_adder_23 16
trans_tv_adder_23_time 0
trans_tv_adder_34 20
trans_tv_adder_34_time 1
trans_min_tp_for_torque_mod 900 (to disable)
trans_torq_control_min-ECT 250 (to disable)

Uh, that looks like it might be Chinese arithmetic. It's about 7 miles over my head.
Maybe I can ask this another way. When should the TC lock up at partial throttle normal driving and
at WOT.

What should we look for in a clutch material?
Please remember, you are dealing with a mental midget here when it come to tuning values.

That's very good info on stall speeds for S/C cars. I was unaware of that. To many times we
think that more always equates to better.

RR|Suki
10-27-2007, 10:04 AM
My tq converter experience...

This may be useful to some in their decision-making.

While NA, about 300 rwhp, I put in a 2800 stall single-plate PI. It was very streetable and worked well on the strip. I was running 13.5 in the 1/4 then. Had I gone to a 3200 or 3500 I may have picked up a couple of tenths.

I went SC, about 475 rwhp, stayed with the same converter. It worked well at that power level.

Built motor, over 650 rwhp, same converter just blew away the tires. Couldn't launch for crap. Changed to a 2600 stall triple plate so the stall speed was lower than the rpm where I went into boost and it worked very well. So I agree SC or high rwhp cars are better off with a lower stall. The triple plate converter makes a lot more noise than the single plate, but when it locks it's like a straight shift car's clutch with absolutely no slipping.

when you were at 475whp were you locking the converter at WOT?

merc
10-27-2007, 04:59 PM
Uh, that looks like it might be Chinese arithmetic. It's about 7 miles over my head.
Maybe I can ask this another way. When should the TC lock up at partial throttle normal driving and
at WOT.

What should we look for in a clutch material?
Please remember, you are dealing with a mental midget here when it come to tuning values.

That's very good info on stall speeds for S/C cars. I was unaware of that. To many times we
think that more always equates to better.

You asked serveral questions I will tray to answer the first one for starters.

1.) Depending on your tuner the actual 1-2 shift is going to be around 1000rpms off, from the setting you enter. The 2-3 shift is around 500rpms off from the set WOT shift point. So if u want the actual 1-2 WOT shift to happen at 5900 rpms, you would enter 4900rpms for the 1-2 WOT shift, and so on. This is dependant on which gears you are running.. SO the higher the gear( 410's-up) might require an even more drastic change.

2.) There are many types of clutch materials and surface areas sizes. It depends on the manufacture of the converter. Most venders will not include the exact design or material used. We as a collective rely on word of mouth and testimonials to identify the good from the bad. I perfer carbon-ceramic material.

rumble
10-28-2007, 10:55 AM
Cool! Thank you.

FordNut
10-28-2007, 07:16 PM
when you were at 475whp were you locking the converter at WOT?

Sort of. The lockup speed was well above what I could do in the 1/4, but on the highway at high speeds it would lock up.

RR|Suki
10-28-2007, 07:26 PM
Sort of. The lockup speed was well above what I could do in the 1/4, but on the highway at high speeds it would lock up.

How come no lock? too much for the single disk? that's what I have and I was thinking of locking it at WOT after the stall speed :confused:

FordNut
10-28-2007, 07:38 PM
How come no lock? too much for the single disk? that's what I have and I was thinking of locking it at WOT after the stall speed :confused:

I was told not to lock it at WOT by several tuners, not sure if it breaks the tranny or the TC clutch.

RR|Suki
10-28-2007, 08:05 PM
I was told not to lock it at WOT by several tuners, not sure if it breaks the tranny or the TC clutch.

yeah I've been told 2 different things :lol: 1. don't lock it 2. lock it only if the TC can take it, so yeah i'll be safe and stick to unlocked I guess :-)

merc
10-29-2007, 05:56 AM
Lock up stock style converters. These are usually 12" converters that have a lock up clutch in them. Modified versions can have a stall speed of 2600-2800 rpm, depending on the construction. The lockup clutch is engaged under light throttle situations (cruise), which allows for greater efficiency, less heat generation and slightly better mpg. When racing, you can lock the clutch under WOT with a switch or with a race chip. This practice will gain about a tenth in the 1/4, but will eventually wear out the clutch.

Non-lockup converters. Available in various diameters. The most popular version of these is a 9" converter that stalls in the 3000-3200 range. There is no lockup clutch, so at cruise there is some slippage (200-300 rpm usually). They work very well on Super Charger/turbo combos. You trade off some heat generation (from the slippage) and efficiency losses, for the responsiveness gained. You need to make more HP to gain enough advantage in staying in the "sweet spot" of the RPM/torque/HP band to overcome the slippage losses and reduced efficiency.

9" and 9.5" lockup converters. These are hybrids that try to combine the best of both worlds. They allow for the higher stall and responsiveness. However, due to the smaller size, there isn't as much clutch surface available, so if they are locked up under WOT you can burn up clutches fairly quickly. Newer 9.5" converters are built with more clutch area to counteract this, while still allowing 3200-3500 brake stall.

The non-lockup style converters have more "slippage" by design. A properly operating clutch converter will have less slippage (even unlocked, due to its lower stall speed). Going to a higher stall converter is usually necessitated by the owner also installing a bigger Super Charger and/or Turbo. Therefore, before you buy a new converter, discuss your combination with the potential vendor to decide which converter is best for you.

rumble
11-01-2007, 12:31 PM
Ok, let me try this question. Is their any way to install a switch to
manualy unlock the TC clutc? Like we do with the Overdrive button.

Then if we were feeling frisky (but less than WOT) we could unlock it and save some wear and tear.

Darrin
11-01-2007, 12:36 PM
Sorry I haven't been able to be on here lately. I really need to remind myself to make the time to stop in. I haven't been on the internet much this last couple of weeks..

On the switch, you can do that but the computer isn't going to like it at all. You will end up throwing codes and getting a flashing OD light.

So, I wouldn't do it.

Darrin

Darrin
11-01-2007, 12:49 PM
Also, you guys don't want to be locking up those PI single plate converters at WOT. Not that it's a bad product at all, it just wasn't designed for that type of abuse.

Darrin

rumble
11-01-2007, 02:49 PM
Also, you guys don't want to be locking up those PI single plate converters at WOT. Not that it's a bad product at all, it just wasn't designed for that type of abuse.

Darrin


Then that means you sure don't want to lock up a stock one at WOT.

I guess my point is that lots of times we "get on it" at less than WOT
but still enough to stress the dive line. At what point should it lock or
not lock. That is the question.

I assume the "tune" tells this when and how to happen.
I would think the only time you would want it locked would
be a cruising and high manifold vacuum. Any low manifold
vacuum readings would immediately unlock it.

Is manifold vacuum in the tune equation

Thanks again, this is super info.

Darrin
11-02-2007, 06:29 AM
The computer looks at many things, but throttle position and MPH are the key factors that determine converter lock schedules.

Darrin

Svashtar
02-26-2008, 02:13 AM
Also, you guys don't want to be locking up those PI single plate converters at WOT. Not that it's a bad product at all, it just wasn't designed for that type of abuse.

Darrin

I'm sorry, (and sorry to resurrect this old thread; I'm trying to educate myself), but what does this mean? I have a PI 3000. My logic in getting it was that I thought it would work for me better than a higher stall when and if I went SC.

How does one lock up at WOT? It unlocks at 3000 RPM right? So by _not_ preloading the TC and launching from a standing start at just idle I have been stressing the TC? What if I'm tooling along at 70 mph and 2600 RPM on the freeway and floor it? Guess that would be like preloading it?

Sorry to be so clueless. :confused:


Tnx.

Norm

sailsmen
02-26-2008, 05:33 AM
Stall speed and locking are 2 different things.

There are thousands of PI out there running around as we speak w/out any problems.

I put 150+ races on my PI had it inspected and it was a ok.:)

Svashtar
02-26-2008, 12:16 PM
Stall speed and locking are 2 different things.

There are thousands of PI out there running around as we speak w/out any problems.

I put 150+ races on my PI had it inspected and it was a ok.:)

I've read so much on this my head is spinning. I'm sure the PI will hold up, esp. as I've been babying mine, except for three 0-60 WOT's starting from idle the other day. I'm just trying to understand this.

Q: how does one (incorrectly) lockup the TC at WOT? From what I understand the PI is locked at lower RPM, right?

Q: when I retest my 0-60 times, I should hold the brake and the gas at the same time, and let the car break free for the best time, correct? Should I take the RPM just up to or past 3000 RPM?

Thanks as always.

Norm

Darrin
02-26-2008, 12:27 PM
On the website for Precision Industries it very clearly states this.

"***Note the multi-disc converters are a MUST for applications that are locking-up the torque converter under WOT."

http://www.converter.com/stallion.htm

That part is very clear and straight from the horse's mouth so to speak. Locking up their single disk converter at WOT is not something that you should do and they tell you this. The tiny clutch surface area isn't capable of withstanding lockup at WOT.

Again, not that it's a bad product in any way. For what it is designed for its a great little product. It just simply isn't designed to do lockup at WOT and the manufacturer was certain enough of it that they felt the need to put it in print on their web page that if you plan to do this you MUST use their multi plate converter.

I know that all this torque converter stuff gets very confusing for most and it can take a long while to get even a small handle on it. There is a butt ton of misinformation out there and you need to be careful on what you listen to. But, when the manufacturer says no then you had better not do it. Nobody better knows the capabilities of their products than the people that build them.

Darrin

Local Boy
02-26-2008, 12:48 PM
Hey Darin,

I've got your T/C...can it handle being locked at WOT with a S/C'ed motor?

Thanks...

ALOHA

Svashtar
02-26-2008, 01:20 PM
On the website for Precision Industries it very clearly states this.

"***Note the multi-disc converters are a MUST for applications that are locking-up the torque converter under WOT."

http://www.converter.com/stallion.htm

That part is very clear and straight from the horse's mouth so to speak. Locking up their single disk converter at WOT is not something that you should do and they tell you this. The tiny clutch surface area isn't capable of withstanding lockup at WOT.

Again, not that it's a bad product in any way. For what it is designed for its a great little product. It just simply isn't designed to do lockup at WOT and the manufacturer was certain enough of it that they felt the need to put it in print on their web page that if you plan to do this you MUST use their multi plate converter.

I know that all this torque converter stuff gets very confusing for most and it can take a long while to get even a small handle on it. There is a butt ton of misinformation out there and you need to be careful on what you listen to. But, when the manufacturer says no then you had better not do it. Nobody better knows the capabilities of their products than the people that build them.

Darrin

AAARRGHHH!!!

1) The PI 3000 is a single disk converter correct?

2) CAN SOMEONE please tell me how you "lockup a single disk torque converter at WOT???" BECAUSE I'm trying to avoid doing this based on what you have said in this thread! When I want to take the car to WOT how do I avoid locking up the TC? Do I take it up to or past 3000 RPM first? At what RPM is it safe to launch the car with full pedal to the floor? Am I correct in assuming that since the TC is locked below 3000 RPM that the car should be at that RPM (at least) before I release the brake to launch?

I have gone WOT probably a half dozen times from 800 RPM up to 6100 RPM with this TC. Hopefully I haven't fried anything.

Thanks for bearing with me!

Svashtar
02-26-2008, 01:28 PM
Stall speed and locking are 2 different things.

There are thousands of PI out there running around as we speak w/out any problems.

I put 150+ races on my PI had it inspected and it was a ok.:)

OK, I understand, and thank you. But did you launch from an idle or with the engine spooled up close to the TC stall speed first? Evidently that is the difference.

P.S. I may be asking the wrong questions. In reading Lidio's sticky, it appears that with his tune the TC isn't locked at all with OD off, and is locked with the OD on up to 63 mph. All my 0-60 runs have been with the OD off. I have DR's tune, and am assuming he must be doing something similar. Maybe this thing hasn't been locked at all...? Enough. I'll give PI a call.

Local Boy
02-26-2008, 01:40 PM
what tune do you have?

Svashtar
02-26-2008, 02:05 PM
what tune do you have?

I have Dennis' standard 91 octane tune. I didn't ask him about an upgrade when I changed out the PI, and it seems to be shifting fine. Only minor complaint after the tranny rebuild and PI 3000 is a very firm "thump" now on the 1-2 shift at lower around town speeds, but I've got used to it. Shifts and kicks very hard at WOT and pulls hard.

Whenever I horse around I _always_ take the OD off.

Darrin
02-26-2008, 02:32 PM
Hey Darin,

I've got your T/C...can it handle being locked at WOT with a S/C'ed motor?

Thanks...

ALOHA
Oh yeah!

Just take a look at that 10.90 run that Tom just threw down. Locked up all the way baby.

No worries.

Darrin

Local Boy
02-26-2008, 02:34 PM
Sorry not familiar with DR's tune...Don't know, if or when, he has the T/C locked...

It is in the tune...You (user) cannot adjust on your own...only the tuner himself...

You can, however, feel for it while driving...Try driving slow while slowly accelerating (open safe road)...watch you tach...when the tach drops and slowly moves while accelerating -- motor lugs) your T/C is locked...

when you accelerate and your motor spools up (tach moves in relation to throttle position)...your T/C in unlocked...

Hope this helps

ALOHA

EDIT: Did not see Darin's response^^^...OH Yeah Baby!!! Thanks Darin...I'll be locked and loaded soon!!!

Darrin
02-26-2008, 02:44 PM
AAARRGHHH!!!

1) The PI 3000 is a single disk converter correct?

2) CAN SOMEONE please tell me how you "lockup a single disk torque converter at WOT???" BECAUSE I'm trying to avoid doing this based on what you have said in this thread! When I want to take the car to WOT how do I avoid locking up the TC? Do I take it up to or past 3000 RPM first? At what RPM is it safe to launch the car with full pedal to the floor? Am I correct in assuming that since the TC is locked below 3000 RPM that the car should be at that RPM (at least) before I release the brake to launch?

I have gone WOT probably a half dozen times from 800 RPM up to 6100 RPM with this TC. Hopefully I haven't fried anything.

Thanks for bearing with me!


1) Yes, that one is single disk unless you asked for and purchased a multi plate.

2) Locking the TC at WOT is done via the tune. But, it only happens in 2nd gear or later depending on the tune. You are not going to get the converter locked up in 1st no matter whose tune you are running. So it isn't locked off the line until after a shift takes place since it only locks up in later gears when the PCM commands it.

From your questions it seems that you aren't catching the principles here. I know it's really a tough thing to get your head around at times. Stall and lockup are 2 entirely different things and completely unrelated other than that they relate to a torque converter. The lockup portion is an actual clutch. Stall is the point at which the converter overcomes the capability of the engine to rev any higher. Not the point at which the engine overcomes the brakes and tires. That usually happens well earlier in the rpm's than stall, so you can have a 4600 stall converter that can break the tires loose at 2200 with your foot on the brake. The point at which the tires breaks loose will likely go up with the installation of a higher stall converter, but that makes it even harder to reach the true stall of the converter by foot braking.

Trust me, I know this is a tough subject. MUCH to learn and little good info on the net to learn from.

Darrin

2,4shofast
02-26-2008, 04:35 PM
That is a good read!!! I think it might take me a few weeks to sort it all out, that is extremely informative. Thanks:beer:

Svashtar
02-28-2008, 01:25 PM
1) Yes, that one is single disk unless you asked for and purchased a multi plate.

2) Locking the TC at WOT is done via the tune. But, it only happens in 2nd gear or later depending on the tune. You are not going to get the converter locked up in 1st no matter whose tune you are running. So it isn't locked off the line until after a shift takes place since it only locks up in later gears when the PCM commands it.

From your questions it seems that you aren't catching the principles here. I know it's really a tough thing to get your head around at times. Stall and lockup are 2 entirely different things and completely unrelated other than that they relate to a torque converter. The lockup portion is an actual clutch. Stall is the point at which the converter overcomes the capability of the engine to rev any higher. Not the point at which the engine overcomes the brakes and tires. That usually happens well earlier in the rpm's than stall, so you can have a 4600 stall converter that can break the tires loose at 2200 with your foot on the brake. The point at which the tires breaks loose will likely go up with the installation of a higher stall converter, but that makes it even harder to reach the true stall of the converter by foot braking.

Trust me, I know this is a tough subject. MUCH to learn and little good info on the net to learn from.

Darrin


Darrin, thanks for taking the time to explain. At what I spent you are right and it is indeed a single-plate converter. Others tried to tell me the same thing but I wasn't getting it, confusing stall with lockup.

I called PI and they gave some of the same info, and confirmed that to their knowledge with this tune I am not locked up with the OD off. They also said that at freeway speeds with OD on that if I go WOT in an emergency to pass or something I should be OK. I am assuming I would be in 3rd gear by then. I've just gotten into the habit, pounded into me by Sergeant Mac a few years ago here, to just go OD OFF whenever I put the gas down, no matter what speed I'm traveling at.

I've done a lot to my car, but am a total newbie about understanding a lot of this; I appreciate your educating me, or at least trying to. Thank you.

Norm

Svashtar
02-28-2008, 01:26 PM
Sorry not familiar with DR's tune...Don't know, if or when, he has the T/C locked...

It is in the tune...You (user) cannot adjust on your own...only the tuner himself...

You can, however, feel for it while driving...Try driving slow while slowly accelerating (open safe road)...watch you tach...when the tach drops and slowly moves while accelerating -- motor lugs) your T/C is locked...

when you accelerate and your motor spools up (tach moves in relation to throttle position)...your T/C in unlocked...

Hope this helps

ALOHA

EDIT: Did not see Darin's response^^^...OH Yeah Baby!!! Thanks Darin...I'll be locked and loaded soon!!!


It does help, and I'll try it, thanks!

Norm

FormulaMarauder
05-18-2009, 01:26 AM
great info, this NEEDS to be bumped

Dobs
05-18-2009, 07:52 PM
Should be sticky in the transmission section IMO.