Gear Vendors tranny overdrive

[usafsniper]

http://www.gearvendors.com/hrford4s.html

I saw a post on this a while back but haven't seen any reports of a purchase. Has anyone actually used one of the gear splitters or know of anyone who has used one enough to comment on the item? Seems to be a fairly inexpensive way to add roughly 40HP/60TQ in a reliable manner that won't void factory or extended warranties, plus increase fuel economy. Dennis, if you're still around after yesterday's BS, how hard would it be to work a program for these? I gotta think one of these with a S/C would be incredible.

[juno]

I sent them an e-mail about the 4r70w but never got a response. Maybe you have better luck?

[usafsniper]

I sent them an e-mail about the 4r70w but never got a response. Maybe you have better luck?
I'll give it a try. I can't afford the price of a supercharger, and can't see the justification since I bought mine for long term collector value and not necessarily track use. This seems like a close second in terms of reliability and function at about half the cost. I'll let you know what comes of my try at contact.

[Two Hawks]

...that won't void factory or extended warranties... :confused:

I wouldn't bet on that.

I think Ford looks for any possible excuse to void warranties. :(

[usafsniper]

I sent them an e-mail about the 4r70w but never got a response. Maybe you have better luck?Well, here's the bottom line. Rough estimate of cost is $2695.00 for kit plus roughly $600 for install. Requires about two inches to be cut off the output shaft as well for the system to fit. Closest local dealer/installer for this area is Gary's Driveline in Holly Hill FL., 386-672-2900.

[427435]

Although there may be a few things nice about a ratio in between our current ratios, once in a while, there's a couple of things that don't pass the "smell" test of this old engineer.

1) No way that it will add horsepower at the rear wheels----if anything it will reduce rear wheel horsepower as the power will be going through more gear meshes. Second gear in over might provide more torque than 3rd gear direct but not more horsepower (horsepower = torque x RPM) as it will be turning the final drive slower than when in 3rd direct.

2) I also don't see why the transmission would be running much (if any) cooler. Most of the heat build up in a transmission is from the torque converter (a splitter wouldn't have much effect on that) and the "windage" caused by the gears turning in oil. The same gears are going to be turning in the same oil at close to the same speeds most of the time. Maybe if you were running in 3rd over instead of 3rd direct for a long time pulling a big trailer, you might see a temperature difference, but how many of us do that? If we're cruising down the road, it's in OD anyway. And who needs "double" OD?

Given the 2 things above, save your money until you can afford a supercharger of some kind (Note: I'm not going to start another supercharger thread) :D :D

[snowbird]

I took a look and my curiosity is not satisfied. All above points are valid. The heat issue if any can be solve with a cooler, and yes, i doubt there is more power.

But, looking at the trend coming from Europe, all big sedans are getting 6 and 7 speed automatics boxes.

So if they could made our cars 8 speeds trannys for 32-35 hundreds, i wonder what would be the end feel and gains ?

Always on the sweet spot power, less correct ratio hunt, faster ETs, more ultimate top speed ? Maybe it is worth to dig this a bit more.

[RF Overlord]

427435 beat me to it...there are only two ways to get more power to the ground: make the ENGINE put out more power, or reduce driveline loss. This product does neither. Whether you get an increase in performance due to keeping the engine in the power band sounds plausible, like the effect 4.10s have.

[FordNut]

Will it even fit in the driveshaft tunnel?

[torinodan]

Will it even fit in the driveshaft tunnel?I'm close enough to take a visit and find out. The place to have it done out here is in El Cajon CA. Not a far drive.

[David Morton]

I looked at it before and it's still on the plate of possibilities for me as I see no downside as such but I'm sure of one thing, it's gonna need a flip-chip. Two programs will be needed as the net effect of a gear splitter is to make the PCM have to work with two final drive ratios and the only way I know to make that happen is with a flip-chip. I guess you could put the gear switch and flip-chip on the same relay.


Or maybe a four position chip...
1) Low gear ratio and pump gas
2) High gear ratio and pump gas
3) Low gear ratio and racing gas
4) High gear ratio and racing gas

Yeeehah! NOW we're cookin' with gas! :banana2:

['03BlkMM]

Although there may be a few things nice about a ratio in between our current ratios, once in a while, there's a couple of things that don't pass the "smell" test of this old engineer.

1) No way that it will add horsepower at the rear wheels----if anything it will reduce rear wheel horsepower as the power will be going through more gear meshes. Second gear in over might provide more torque than 3rd gear direct but not more horsepower (horsepower = torque x RPM) as it will be turning the final drive slower than when in 3rd direct.

2) I also don't see why the transmission would be running much (if any) cooler. Most of the heat build up in a transmission is from the torque converter (a splitter wouldn't have much effect on that) and the "windage" caused by the gears turning in oil. The same gears are going to be turning in the same oil at close to the same speeds most of the time. Maybe if you were running in 3rd over instead of 3rd direct for a long time pulling a big trailer, you might see a temperature difference, but how many of us do that? If we're cruising down the road, it's in OD anyway. And who needs "double" OD?

Given the 2 things above, save your money until you can afford a supercharger of some kind (Note: I'm not going to start another supercharger thread) :D :D
Actually it will make more avg HP at the wheels if its used in between gears as the mfg suggests. This being due to the fact that the engine RPM's won't drop off as dramatically when the shift occurs. Currently my car drops to approx 4000 rpms after a shift at 6000 rpms. If this unit was installed and used between gears I would only drop to say 5000 rpms between shifts. The stock car makes considerably more HP at 5000 RPM's(approx 40hp more) than it does at 4000. So the avg HP put to the wheels will be higher at wide open throttle. If you read their sales info more closely you can tell that this is what they are getting at.

Who needs a double OD??? With gas prices the way they are I DO!

Another benefit I see is shortening the stock DS 2". This should help to eliminate the stock DS flex the MM suffers from, thus alleviating the need for a high dollar replacement DS.

[427435]

Actually it will make more avg HP at the wheels if its used in between gears as the mfg suggests. This being due to the fact that the engine RPM's won't drop off as dramatically when the shift occurs. Currently my car drops to approx 4000 rpms after a shift at 6000 rpms. If this unit was installed and used between gears I would only drop to say 5000 rpms between shifts. The stock car makes considerably more HP at 5000 RPM's(approx 40hp more) than it does at 4000. So the avg HP put to the wheels will be higher at wide open throttle. If you read their sales info more closely you can tell that this is what they are getting at.

Who needs a double OD??? With gas prices the way they are I DO!

Another benefit I see is shortening the stock DS 2". This should help to eliminate the stock DS flex the MM suffers from, thus alleviating the need for a high dollar replacement DS.


Yes, it may help to keep the engine nearer it's HP peak, but every extra shift will also cost you a little extra time. I'll bet you'll won't get much net improvement (maybe worse) in a quarter mile. And don't forget that the extra gear mesh will cost you 1-2% in HP to the rear wheels.

I also doubt that dropping the RPM to under 2000 at cruising speed will do much for the gas mileage.

Again, save your money, buy a supercharger.

['03BlkMM]

Yes, it may help to keep the engine nearer it's HP peak, but every extra shift will also cost you a little extra time. I'll bet you'll won't get much net improvement (maybe worse) in a quarter mile. And don't forget that the extra gear mesh will cost you 1-2% in HP to the rear wheels.

I also doubt that dropping the RPM to under 2000 at cruising speed will do much for the gas mileage.

Again, save your money, buy a supercharger.

I don't agree with you on the 1/4 mi improvement, but until somebody buys one and tries it I guess its all theory.

On the subject of gas mileage. I was thinking more of those that had aftermarket gears. You could run a 4.30 rear gear and still maintain a cruise RPM that was the equivalent of a 3.27 with the stock .71 OD.

[juno]

Actually, you can run 4.56's with stock tires and increase about 20 rpm at 85. For me, I do a lot of cruising at 80-85, so steep gears with the standard tranny are hard to swallow. I am about 90% done with a gear chart to show the rpms at all speeds and shifts.
I have to finish some real work first though. :)
As many of you have said, it doesn't 'make' ponies, but it damn sure will put you in a better sweet spot over the curve. And a shorter drive shaft will twist less and put more power to the pumpkin. Whether these will make up for the line losses remains to be seen.
Does that make it more practical for a centri blower?

Seeing as our stock motors are limited to about 450 hp for any longevity and our NVM Al block is limited to about 600 hp (per SH), unless you want to build a motor, this could be a good way to get all that power to the wheels.

Will the PCM be able to control the shifts?

4.56's will get these heavy pigs out of the hole rather nicely, and it would probably pay for itself over the lifetime of the car as opposed to installing 4.10s or 4.30's on the stock tranny.

I guess there is only one way to find out! Anyone want to donate towards an experiment? :)

[BigCars4Ever]

Actually, you can run 4.56's with stock tires and increase about 20 rpm at 85. For me, I do a lot of cruising at 80-85, so steep gears with the standard tranny are hard to swallow. I am about 90% done with a gear chart to show the rpms at all speeds and shifts.
I have to finish some real work first though. :)
As many of you have said, it doesn't 'make' ponies, but it damn sure will put you in a better sweet spot over the curve. And a shorter drive shaft will twist less and put more power to the pumpkin. Whether these will make up for the line losses remains to be seen.
Does that make it more practical for a centri blower?

Seeing as our stock motors are limited to about 450 hp for any longevity and our NVM Al block is limited to about 600 hp (per SH), unless you want to build a motor, this could be a good way to get all that power to the wheels.

Will the PCM be able to control the shifts?

4.56's will get these heavy pigs out of the hole rather nicely, and it would probably pay for itself over the lifetime of the car as opposed to installing 4.10s or 4.30's on the stock tranny.

I guess there is only one way to find out! Anyone want to donate towards an experiment? :)
I see a 250 rpm increase at 75 with my 4:10's over the stock 3:55's. With 3:55's at 75 mph I could average 24 mpg with the 4:10's I almost get to 20 under the same driving conditions. With 50/50 driving I average 17.5 mpg when I used to average 19mpg. I average 270 miles per week or about 14k miles per year. The stock gears save me 65 gallons a year or at $3 a gallon about $195 a year. At a cost of 3k it would take 15 years to see a payoff at current gas prices. 7 years if gas doubled.

I see two real performace gains here. The ability to go over 90mph safely without risking the drivetrain and keeping the motor in its powerband.

['03BlkMM]

I guess there is only one way to find out! Anyone want to donate towards an experiment? :)

I'll donate the 1st dollar! :D

['03BlkMM]

I see a 250 rpm increase at 75 with my 4:10's over the stock 3:55's. With 3:55's at 75 mph I could average 24 mpg with the 4:10's I almost get to 20 under the same driving conditions. With 50/50 driving I average 17.5 mpg when I used to average 19mpg. I average 270 miles per week or about 14k miles per year. The stock gears save me 65 gallons a year or at $3 a gallon about $195 a year. At a cost of 3k it would take 15 years to see a payoff at current gas prices. 7 years if gas doubled.

I see two real performace gains here. The ability to go over 90mph safely without risking the drivetrain and keeping the motor in its powerband.

You are basing your figures on the assumption that gas mileage will return to stock. I personally think it will be even better than stock, especially with 4.10's on the hwy. Although it might still take 10 yrs to get a payback, at least your getting a payback. There are not many mods that will pay you back!

[David Morton]

If I get one it won't be for gas mileage. It'll be for pure performance. An effective 4.56 gear for the track, and a 2.92 for long-legged, 130 mph and downshift to second gear for passing potential, in Montana or Canada.

[torinodan]

I'll donate the 1st dollar! :D
I'll donate the 2nd dollar if we use my car.:P

[juno]

I see a 250 rpm increase at 75 with my 4:10's over the stock 3:55's. With 3:55's at 75 mph I could average 24 mpg with the 4:10's I almost get to 20 under the same driving conditions. With 50/50 driving I average 17.5 mpg when I used to average 19mpg. I average 270 miles per week or about 14k miles per year. The stock gears save me 65 gallons a year or at $3 a gallon about $195 a year. At a cost of 3k it would take 15 years to see a payoff at current gas prices. 7 years if gas doubled.

I see two real performace gains here. The ability to go over 90mph safely without risking the drivetrain and keeping the motor in its powerband. Well, I don't get that kind of HWY mileage with the stock 3.55's, so you are doing something right. :)

Anyway, here is the chart I promised earlier. Basically this + tranny keeps the MM right in the power wheelhouse. I have no idea how smooth the shifts will be and how much loss there is, but a lot of people are using them in race and towing applications far beyond what we are running in our cars.
The chart indicates a stock tranny and gears on the left and this plus tranny with overdrives and 4.56's on the right. It indicates that a higher stall converter might not be required with this set up, so that may be a savings also. Again, this is just theory and math so any real world experience/comments are welcome.

[juno]

OK, an update. :)

I wanted to compare the gear vendor overdrives with 4.56's with the standard tranny/3:55's and look at power under the curve. I used the info from the previous charts (shift speeds/rpms) and borrowed data from a MM dyno. (sorry, I cannot remember who it was) It was a car with 280 rwhp and 300 rwt after a few mods.

I made a table and a graph.

The table shows HP at MPH/RPM for each.

The next table compares the HP at MPH for each set-up.

Then I graphed it. The yellow indicates the increase/decrease in power under the curve.
If my math was right, the Gear vendor unit averaged 30 extra ponies to the wheels from 200 - 6200 rpm or up to 125 MPH.

If you look at the graph and take out only the areas where the power gain/loss was zero, it was an impressive 40 hp average.

So their claims of 30 -40 hp at the wheels appear pretty close.

And it was 45 hp average right out of the hole which is a big deal with these cars.

Again, how does it shift????