Tire smokin' performance

[ultravorx]

I know, i know, not all of us want to smoke our tires :nono: but many people were saying with the 4.30 gears, i should be able to roast them off the rims. However this is not the case. I have DR SCT program for the 4.30's and the ford gears, yet of the line, at full throttle, no braking, i just get a little chirp. Im not saying i want to bake my tires, but i just thought that with the 4.30's and the tune i would be able to. The car launches like a bat out of hell :bounce: thats no issue, the only way i get any spinning action is if i power brake ( i havent done this yet with the new gearing). Is there something im missing, or was i just expecting too much.
On a plus side, last night i was on the highway doing 75 on a straightaway and i nailed it and it actually started to spin, granted the roads were a bit wet, it was still impressive to start spining at those speeds.

[2003 MIB]

[QUOTE=ultravorx] Is there something im missing, or was i just expecting too much. [QUOTE]

Hmmm, I dunno. From a dead stop, I get more than "a little chirp" when the tires are cold and can chirp 1-2 with 4.10s. Smoke? Nope. Road surface and temp. seems to be a factor as well as tire temp.

[merc]

install a torque converter and you will bake the rear tires with those gears :pimp:

[Macon Marauder]

Strange. My old 300A with DR chip, 180 stat, Denso plugs, and STOCK rear gear would spin pretty good from a dead stop. And chirp 1st to 2nd sometimes (at will if I manually shifted).

Maybe some tweaking of the program is in order?

[Paul T. Casey]

A funny thing I've seemed to notice, it seems to "spin" a little better off a very slow roll than a standstill.

[TripleTransAm]

I noticed the same thing, Paul, but on other cars than just the Marauder. Sometimes I wonder if it's a timing issue, since this seemed to improve when the weather got cooler. Perhaps too great a throttle opening at once results in a momentary lean mixture that is likely to pre-ignite.

[Paul T. Casey]

Solving this little "bog," if you could even call it that, should also work to improve 60' times. I noticed last time on the track, my best 60' times were when I got a little tire spin. During the run, I figured that these particular runs would have been the worst. I think I launched at about the same rpm, plus or minus <100, but results were noticably different.

[ultravorx]

Strange. My old 300A with DR chip, 180 stat, Denso plugs, and STOCK rear gear would spin pretty good from a dead stop. And chirp 1st to 2nd sometimes (at will if I manually shifted).

Maybe some tweaking of the program is in order?
I definatly get the 1-2 tire chirp, with out manually shifting :rock: , but when i do manually shift 1-2, it will actually kick me sideways :eek: so, i think my programming should be fine, i hope!
Frank

[Paul T. Casey]

Sounds like the same "bog." I get the 1-2 chirp, even noticed a 3-4 if I'm really on it (scared me the first time, 85mph or more and the tires break loose). I'm not sure about a solution to the low RPM smoke 'em from a stop thing though. I'm also not sure if it's a real problem, especially when the track starts to get greasy.

[woaface]

Well it's warm over there about now right? That might be why...try it at night see what happens. This is probably a good thing. Think about it, it doesn't happen ALL the time, but if you ask it too (brake torquing) it'll go.

But I get what you mean. Very cool though:up:

[merc406]

Wait a minute, 4:30's and no smoke show :burnout: , somethin's wrong! :cry:

Go to 4:56's :up:

[Smokie]

Ultra, there seems to be a fairly large difference in how our cars respond to the same mods, your car's mileage could be a factor, the condition of your rear tires. One thing I remember distinctly is that before I had my computer reprogramed, take off from a dead start had a noticeable pause before the car launched, afterwards the pause was gone and the launch is hard right away. I don't know if my tires have ever produced smoke, but a couple of times I had the rears break loose and spin right thru the 1-2 shift. Regardless of pavement type or temp. they now always produce more than a chirp. I wonder if there is a difference between the flash Dennis used back in '03 compared to what he uses now.

[SergntMac]

The smoke you were expecting to see from your wheel wells, was smoke blown up you azz, and I am disappointed that our resident engineers never caught on to this. It's like watching a magic show, where the magician's gestures point you away from where he doesn't want you to watch. "Nothing up my sleeve...Presto! Look HERE!" Audience..."gasp!"

There is no radical "stupendeous" change from gear ratio to gear ratio, never was. As you step through the ratio upgrade, from the OEM 3:55 to BillyG's 4:56, you will see (and feel) quicker launches and improved performance, i.e. lower 60' times and lower 1320 ETs. You will find a confortable ratio that delivers your best overall performance and best overall MPG. You will NOT roast the tires from the rims with any of them, with the drive-away launch you described in your opening post here.

If you want to do a smoke show, even with the 3:55 gears, lock the tranny in 1st gear. Brake torque until the tires break loose (2500 RPM?), and keep 'em spinning. Pull the RPMs up to 3500 max, and hold everything there as long as you want. Now, look out your mirrors, and watch 3-4K of mileage disappear from your tires every ten seconds or so. Moreover, be careful driving away from this scene, you may encounter a fire department response if you lingered too long.

Any first year mechanical engineer could have told you that gears do not create power that isn't there to begin with, and damnit, they should have. Whatever...

Only custom tuning creates more power to the rear wheels. Other mods we discuss here, such as pulleys, and torque converter, only reduce driveline loss of that power, as it travels to the rear gears. Once that power gets to the gears, they will deliver that power to the rear wheels, nothing more.

What I'm explaining here, is that even a bone stock MM can do a tire destroying smoke show, but a Stage 1 improved MM can do it easier, sooner, and more often. The mods you have in place contribute nothing towards melting your tires on the rims, other than easier, and sooner.

I estimate that you may have shaved .3 to .5 seconds off your 1/4 mile ET., while reducing your 60' time from 2.2 to maybe 1.99. Impressive results, but both work towards reducing smoke shows, not building them.

If you really want to melt your tires off the rims, you need to invest in a Vortech supercharger, but I digress.

Others here claim a lot and I apologize about that. I'd rather not disagree with them or get into that junk. But, if you read the fine print here, there is not a lot of rear wheel / real world tire spinning going on at all. For the real time racers, it's not ideal results. For the non-racers, it's bullsnit bravado chest beating garbage. Smoke shows are really a failure for the serious owner, kinda like pumping up on steroids...K? Can't really lift anything, and can't get hard, K?

I say this because I'm the only owner here with 3 sets of "legally bald" Pirelli tires resting in his garage, and I earned them the hard way with real time traction issues. I don't put on smoke shows, but I drive my MM to it's full potential almost everyday. I still haven't found grip, yet all these other guys boasting about smoking 'em up, well, none of them are posting in the "I need tires" threads, eh?

Go figure?

[Redster]

all those sixties muscle cars that were smoking tires when a lot of us were in high school were on itty-bitty tires that don't compare with what's available now. I bet if you put a set of "tiger paws" on your MM you would get all the smoke you wanted.

[sailsmen]

I took my car out at 1:00am on Sunday to a run where I could do some 1/4 mile gmeter comparisons on some different tunes.

After 5 tries I gave up due to too much wheel spin from a dead stop to get consistant readings to compare tunes with. I tried from an idle roll but one tune is @1,000 rpm and another one @600 rpm.

[ultravorx]

Thanks sarge for the great insight on it. I dont really care about "roasting" my tires, i just thought (from what people say) i should be able to spin them easier. Granted, its not something you want to do while racing, its mostly just for showing off/bragging rights. Im glad i have the traction i have, so im not complaining. I have "smoked" a couple shots up and down streets with my stock setup, it just happen to catch right and break free.
Again, thanks for the insight, its greatly appreciated!!!!! :bows:
Frank

[TripleTransAm]

I agree that gears cannot create power that isn't there, but they can multiply torque. Power remains constant because the speed it's being delivered at is lowered by the same proportion as what's being multiplied.

While the torque delivered to the driveshaft in 1st gear with the converter in full stall remains the same regardless of diff ratio, the amount of torque delivered to the axle shafts is multiplied by 4.30 in this case instead of 3.55 . The axle shafts see about 21% more torque at any given time with 4.30s than 3.55s.

At the tires, there's a given threshold of standing (static) friction that needs to be surpassed in order to break traction. This threshold is a function of the weight on that contact patch and the tire material itself. The force required to overcome that traction is determined by F= coefficient x weight... the stickier the tire, the greater the coefficient of static friction and hence more force required to break traction.

The force delivered to the contact patch is obtained directly from the torque at the axle shafts. Since Torque = force x (distance from rotating point), the bigger the distance between the axle and the contact patch, the more torque required to deliver a certain force (ie. why taller tires are harder to break loose).

So if the axle shafts have 21% more torque on them at any given time, that also means that the contact patches will have 21% more force on them at any given time.


Is this enough to break traction much easier? Looks like a stock-ish Marauder 4.6l DOHC may not have what it takes at stock stall speed to deliver the goods. But you definitely get better acceleration, since F = mass x acceleration.

[CRUZTAKER]

Is your car still young? I mean under the 15,000 mile maturity age?

Maybe it's still learning. I am actually jealous, with just 4:10's, at this point I wish the tires wouldn't break loose every time I get on it.

All that aside...perhaps a real tune is what should be next on your list.

[ultravorx]

Is your car still young? I mean under the 15,000 mile maturity age?

Maybe it's still learning. I am actually jealous, with just 4:10's, at this point I wish the tires wouldn't break loose every time I get on it.

All that aside...perhaps a real tune is what should be next on your list.
My car is a 06/02 build, with about 23000 miles. Dennis gave me the updated pcm version as well when i bought his SCT, so every little bit helps.
Frank

[woaface]

Sarge and BillyGMan needs an award for most posts with actual substance. Not dissing anyone else, but it's sure making me thing that it really helps those "wow there's a lot of information" comments from new members.

[Macon Marauder]

Maybe the difference here is semantics - we all have different definitions of burning rubber. My '03 would never roast tires like a supercharged Marauder, of course, but it would "get a wheel" as we say down here. I haven't tried it with the '04.

An older friend was disappointed when I took him for a ride in the '03. He said "Dig out!" and I did. The car 'got a wheel' and said "eeeeeerch!" or similar and we were off. "That's it?" my friend said, "That's all?!" Yep. That's all - It's supposed to hook up.

Heck, my '97 TBird 4.6 SOHC did much better burn outs.

[Ross]

all those sixties muscle cars that were smoking tires when a lot of us were in high school were on itty-bitty tires that don't compare with what's available now. I bet if you put a set of "tiger paws" on your MM you would get all the smoke you wanted.

Not only that, but "back in the day" a lot more cars were still equipped with standard trannies. It's always easier to rev up the RPM's and pop the clutch in a standard and get some spinning tires.

[Go Mifuni]

all those sixties muscle cars that were smoking tires when a lot of us were in high school were on itty-bitty tires that don't compare with what's available now. I bet if you put a set of "tiger paws" on your MM you would get all the smoke you wanted.
With the snows on my stock MM I could blow it sideways off the launch and at the 1-2 shift (What a BLAST :rock: ). The BFG's are too wide and soft to let me get away with that kind of stuff :cry: . I still get a little "chirp" from 1-2 if I shift manually though.