How do i launch my AWD [Merged 6-7]

[noboost4you]

how would you suggest launching with an A/T and AWD?

 

[CycloneAWD]

Originally posted by noboost4you
how would you suggest launching with an A/T and AWD?

Left foot on the brake...Right on the gas...Build Boost...then let 'er rip...

 

[wastefuldreamer]

5.5-6k slip with act 2600

 

[TazzSLC]

Originally posted by CycloneAWD
Left foot on the brake...Right on the gas...Build Boost...then let 'er rip...

hahaha good job ECU raping ya and stoppin' at 3k =/

 

[DSMNightmare]

Originally posted by TazzSLC
hahaha good job ECU raping ya and stoppin' at 3k =/

What do you mean, I used to launch my A/T at over 3K.

As for my stick I would make sure you go with a 4 spider diff and get a Gabor clutch from AMS. I am literally able to rev to 6500 and sidestep the pedal. This is good for consistant 1.7-1.8 launches. Then again I have built up my tranny. I would not recommend this for a stock setup.

 

[The Wave]

How much does it cost to build up the tranny? Im starting to get a bad feeling on mine. The transfer case went awhile back and the wheels locked up = lot's of stress on tranny/driveshaft ect.

 

[DSMNightmare]

Originally posted by The Wave
How much does it cost to build up the tranny? Im starting to get a bad feeling on mine. The transfer case went awhile back and the wheels locked up = lot's of stress on tranny/driveshaft ect.

I think TRE has a base price of like 1300-1400 bucks for thier rebuilds. That is pretty much what most shops charge. That does not include if there is heavy damage to the tranny.

 

[Colossus]

Sheperd Racing does a racing prep rebuild for 895. http://www.shep-racing.com I think that's the right address? Either that or remove the dash.

 

[allwheelTSI]

actually the link is www.shepracing.com no hyphen.
and yeah,for $895,you can't beat it.

 

[jtmcinder]

Having the car revved up to 5000+ is good, because it means that the engine will be producing decent torque. But, assuming that the engine is turning over very fast and the car is not moving, you know that something has to give. The car cannot accelerate from zero to 30 mph in an instant.

There are three things that could give. (1) The tires could break free, but as soon as they are turning more than 20% faster than you are actually moving, they are providing less and less grip and, so, less and less forward acceleration. (2) Some part of the drivetrain could break. This, by defintion, would - how do I say this? - suck. Or (3) the clutch could slip. Hopefully, on purpose. This is what you should aim for. That's what it was designed to do. Yeah, sure, the stock clutch isn't going to put up with sort of thing for long, but that's when you replace it with something that can.

(FYI: I launch hard on my stock clutch once every two weeks in the summer ... last competition run of the day when autoXing. I've been doing this for two years. Still holds. I think that only doing it once and letting it completely cool down afterwards - for an hour or more - is why it still functions.)

In any event, you do not want to rev up and dump the clutch. The tires breaking free is not only a less-efficient way to launch, but if and when they suddenly catch, then Option #2 happens and you spend the next twenty minutes picking up little pieces of your drivetrain. And then the long tow home.

- Jtoby

 

[DSMNightmare]

In any event, you do not want to rev up and dump the clutch. The tires breaking free is not only a less-efficient way to launch, but if and when they suddenly catch, then Option #2 happens and you spend the next twenty minutes picking up little pieces of your drivetrain. And then the long tow home.

This is exactly what I do. Rev it to 6000 rpm or so and side step the pedal. Like I said it's about putting the right clutch on a good 4 spider diff. My Feramic disk(no thats not a mispell) and my stock pressure plate are good for 1.7s maybe better. If you plan to launch hard or do better than 13s I would recommend the 4spider to anyone. TRE sells the best one I have seen.

 

[GSXlaunch]

Well, I tried my first launch yesterday while driving down a deserted back road yesterday. I revved it to 4500 then popped the clutch. The rpms jumped to 5500-6000rpm before it really dug in and grabbed. I shifted hard into second and got up to maybe 50-55mph before coasting down to a slower speed. I could smell burnt rubber...and a little burnt clutch My question is why did I spin the tires? I know I am not running too much power. My car is pretty much stock...and I am only running about 8-10psi of boost. I do have used Firehawk GTA 215-50's up front and Goodyear Eagle RS-A 225-50's out back. I am running with about 30psi at all four corners. Do I need to go down to 28-or 26psi to make up for the lack of flex? Do these awd cars need the taller tires to flex a bit more on launch? Maybe I need to launch at 4k rpm??? Here is exactly what I did...(I know I need practice but I'd really hate to break something)

Came to a complete stop: Revved to 4400-4600rpm: Popped the clutch: Feathered the throttle a little then nailed it...tires spun for maybe 1-2 seconds before it grabbed (once it grabbed it took off like mad) If I had been racing I would have lost all or most of my awd advantage with that launch.

Thanks for the help.

Tony

 

[jtmcinder]

You have an AWD car with front and rear tires of different diameters and you're out doing dump-clutch launches. Did your car steal your girlfriend or something?

- Jtoby

 

[GSXlaunch]

Actually, and I may be wrong...but I think the diameters are all the same being that they are 50's. The width is what is different. Either way, this will be addressed after the hollidays...but what about the wheel spin? I know that isnt causing it?

 

[CowPimp]

It's always a good idea to use tires of the same diameter with AWD models, as the previous poster mentioned.

Are you positive that all 4 tires spun? It is possible something in your AWD system is not working properly and your car is acting as a RWD/FWD car.

I can't really understand why your tires spin. I can't get my tires to spin no matter how good of a launch I pull, and I have a Big28 in mine. The front tires will sometimes chirp on a launch, but that is the closest I have come to spinning wheels.

I also have a more thoroughly upgraded suspension, but I couldn't get my tires to spin even before more of my suspension mods were done. Even with nearly bald, crappy, stock Eagle tires I wasn't able to spin wheels. I do have a 2G, but the AWD system is similar (If not the same) in both vehicles.

 

[Gula]

AWD does not guarantee a great launch, but it is better than RWD or FWD. Just like a 2 wheel drive system, AWD still has it's limits. An equal launch compared AWD vs 2 wheel will obviously favor the AWD. But you still have to fine tune an AWD launch, with proper clutch use, good tires and launch rpms. Practice, practice.

 

[Gula]

Originally posted by GSXlaunch
Actually, and I may be wrong...but I think the diameters are all the same being that they are 50's. The width is what is different. Either way, this will be addressed after the hollidays...but what about the wheel spin? I know that isnt causing it?

No, they are different heights. the 50 is a sidewall height (which will directly affect overall height) of the tire. The first # ie 215 is the width in mm (with some tolerances applied from tire manufacturer to another). The 50 stands for 50% of the 215. So a 50 series of the 225 will be slightly taller than the 215.

 

[V8BWARE]

keep in mind your front tires are primary in our AWD setup,(80/20 or 90/10 i cant remember.) so a good hard launch will spin the front tires quite a bit.

running 2 different size tires is a definate no no with these cars, and that COULD cause more problems than just your traction issues down the road.

also you might be smelling/hearing/seeing your clutch baking more than anything (anyone remember that vid of the F-body making TONS and TONs of smoke but the rear wheels arent moving? )

 

[GSXlaunch]

Well, I am not 100 percent sure if 4 tires are spinning. It sure seemed like it. I do know the awd system is pushing out power to all four corners. I actually use to own a FWD 95 talon (same color as yours)...so I know what its like to launch a FWD. I use to own a Mustang and Conquest RWD so I also have a decent understanding of what its like to launch an RWD. This launch was unlike either and I could feel the car grab hard after a second or two. I am beginning to think my clutch just slipped...perhaps I should slip the clutch a little and launch from a higher rpm...maybe 5-5500rpm?

 

[GSXlaunch]

You guys are freaking me out a little here. I had someone local tell me that as long as the tires were all the same xx series it would be fine. Maybe I should use my lunch hour today to go buy some 225-50 16's for the front to match the 225-50-16's out back. Is that what should be done????

 

[nc_99_99]

[QUOTE I am beginning to think my clutch just slipped...perhaps I should slip the clutch a little and launch from a higher rpm...maybe 5-5500rpm? [/B][/QUOTE]

This was my first thought when I read your post. If you are using a stock pressure plate don't expect it to put up with much launching.

 

[MikesDSM]

dont pop the clutch out, slip or "feather" it out

 

[jtmcinder]

Originally posted by GSXlaunch
You guys are freaking me out a little here. I had someone local tell me that as long as the tires were all the same xx series it would be fine. Maybe I should use my lunch hour today to go buy some 225-50 16's for the front to match the 225-50-16's out back. Is that what should be done????

Yes.

Profile is a percentage. It's how tall the sidewall is as a percentage of the tire's width.

- Jtoby

 

[GSXlaunch]

Okay, I will try to slip it a little..and yes I think it is the stock pressure plate....now what about the tire size? Do I really need to change the fronts? If so I'd like to know asap as I will do this on my lunch hour today...if I dont have to I'd rather wait until January but if you think running 215-50's up front and 225-50's in the rear is causing problems I will change them out. Thanks again.

 

[GSXlaunch]

Cool..I am changing these out today. This may explain the whining noise in third and fourth gears...?

TT