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

[jongreene]

Is your clutch slipping in the higher gears?

 

[2gdanny]

yeah.. im not sure ### it showld feel like when the clutch is sliping but its really hard to shift i have to press on the clutch all the way down to be abel to put it in gear and i feel like the car only pulls after its rolling, it feels like theres a delay on the gas i dont know if it makes sens ### im saying but i cant really xplain it that good i drove my friends car they are all fwd and my friends sti they all have after market clutches and they all have 2 steps and i just feel like they all grab rigth off the line so much better then my my takes a long time to grab and start rolling but theres is right there and out

 

[jongreene]

ok, i sent you a 2nd PM that might help a little.

 

[turbotooslow]

Eh, I know this is a bit late in the thread, but for a stock motor/stock clutch, what is the safest point to launch? Not even dumping the clutch, just slipping it..? Just picked up my 95 tsi awd and I really dont want to risk anything from my differential/tranny/clutch

 

[gsx219]

ok I know this is a really bad newb question. well I've had my gsx since about may and Im kinda scared to launch it. So my questions are how strong are the stock cv axles and how much can they hold? Transmission are they known for breaking and how much power can they hold before upgrading? What rpm should i launch at and weather to feather the clutch or just drop it? Ive been to the track once on street tuned didn't change the settings for drag so i was just running 22psi tried launching at 4k and 4500 before i got kicked off the track cause they said if I learned how to launch it not only would i need a helmet ill have to install a rollcage. At the track i had a .9 react time, 2.9 60', missed 3rd like crazy and still ran a 13 flat at 112mph so any help on how i should launch with out breaking anything would greatly help!!! thanks

Also if you wanna check out my run its on my myspace www.myspace.com/powers219

 

[19Eclipse90]

http://www.vfaq.net/DSM/mods/10faq.html

Straight from:
>>The Correct Way To Launch Your

All Wheel Drive T/E/L
Hold the RPM at 4500 while sitting on the line, and then slip the clutch out very quickly while adding throttle at the same rate.
Credited to: David Buschur [email protected]
Front Wheel Drive T/E/L
Well, there's been some talk recently about how to get the FWDs to hook-up at the line. Aside from spending big bucks converting to an AWD system, there are a few things you can do to get somewhat respectable 60' times at the track. Here's what *I* think (cocky college kid mode ON):
First of all, it's very important to have tires with tread on them (as I found out last weekend :-( ). Seriously though, the tires you choose to run are EXTREMELY important. Throw out those GT+4's and get a nice set of performance tires. It seems that as far as street tires go, the Dunlop SP8000's, and Goodyear GS-C's are pretty sticky tires that will give you decent all-season performance. I currently have some Dunlop D40M2's, and although they lasted a long time and I've had numerous 2.0-2.1 60' times with them, they just break away too easily. I'm currently in the process of getting myself some BFG R1 tires, but I don't expect them to last over 10K miles on the street. After more than 100 runs, I'm pretty confident that sub-2.0 60' times are just not possible with your typical "street" tire. I'll see what both R1 and slicks can do at the ShootOut! While I'm on the subject of tires, inflation is key to getting the power to the ground. At the track, I've experimented with tire pressures in front from 10lbs to 30lbs. If the pressure is too high, you'll just sit and spin and hop. If it's too low, you'll lose optimal contact with the track, and it will slow you down at higher speeds. I've found that the best pressures are around 15lbs in the front, and 55lbs in the rear (reduces drag). Now we get to weight transfer. What you want to do is keep as much of the weight in the front of the car when launching. I'm sure you've noticed that the front wheels seem to lift up under hard acceleration as the weight "transfers" towards the rear of the car.
What I have done is to install GAB adjustable struts/shocks and Eibach springs on my car. The GAB's can be adjusted to virtually prevent weight transfer, while the springs lower the cars center of gravity. I'll be cutting a coil or two off of the front springs to give the car a "raked" attitude to further reduce transfer in the coming month. I've found that the optimal setting for the GABs is 8 in back(full stiff) while leaving the front struts on setting 1(full soft). This seems to let the tires bite into the track more as the front suspension gives a little, while the rear doesn't move. Another benefit of these suspension upgrades is that I have NOT had wheel hop since putting these on. Another thing you can do that I have not tried, is to experiment with "air bags" in the rear shocks. These clever little things let you inflate them inside of the coil to stiffen up the rear shocks even more. They're affordable too if you can't get the GABs. Needless to say, take EVERYTHING out of the hatch (spare, jack, seats, carpet, tools, etc...).
Finally there's the actual launching technique. Believe me, his takes a LOT of practice! Here's what has worked best for me (I think): When you get to the line, bring the RPM's up to 3000. I don't believe that dialing the boost down is the answer to getting a clean launch, rather it's careful use of the gas.
When you launch, DON'T let the RPMs jump up on you, and DON'T take off at full throttle in first gear! I don't know about you guys, but if I get a bad launch, I'll smoke the tires all through 1st, 2nd, and 3rd.
OK, the light turns green. Now when you feel the clutch start to grab, keep it at half-throttle and gently slip the clutch until it's all the way out, preventing the tires from smoking(keeping it around 3500). Now you have to be very careful with the throttle. It takes some practice, but after awhile you can feel when the tires are on the brink of spinning. Keep depressing the gas SLOWLY as you gain speed, keeping in mind when you feel that your tires are about to let loose. It's very easy to get anxious and floor it, but resist the temptation.
The 1-2 shift is critical to your success at the track. If you've launched right, you should be able to get through 1st without spinning until around 6000. When you go to make this shift keep in mind that if you just floor it, I guarantee that you'll spin all through 2nd and you'll have to get off the gas and bog down. Also remember not to go completely WOT in 1st gear. Any spinning that you're doing when you make the 1-2 shift will just make for a sloppy spinning 2nd gear.
As you go into 2nd, keep the RPMs steady at around 4000. Slip the clutch out until the tires bite, then start giving it some serious gas. Don't go WOT until you're sure that the tires are biting well. At around 6200 RPMs (any higher and you'll start spinning again if you have modified your car), shift into third quickly and don't let the RPMs drop below 4500. Give it full throttle as soon as you let the clutch out.
After you've gone into 3rd you should be set to "speed shift" into 4th in a few seconds (don't take your foot off the gas, but shift VERY fast). The optimal shift point from 3rd to 4th seems to be about 5500 for the stock turbo, and around 6800 for the 16G. I don't know if I've cleared this up, or if I've just further complicated things. It's hard to describe how the car should "feel" as you near the point of spinning. After a few runs you'll see what I mean. Slipping the clutch and careful use of the gas is very important, so I'd also heartily reccomend a CFDF clutch if you're going to do this.
Credited to: Jim McKenna [email protected]
>>

 

[gsx219]

tried the 4500 launch it jump and fell straight on its face, it bogged down really bad till the turbo boosted back up.

 

[19Eclipse90]

Sounds like you didn't slip the clutch, sounds like you dropped it. Slipping the clutch correctly shouldn't let the RPM drop much at all and should certainly yield better results than a 2.9 - that is unbelievably bad.

 

[gsx219]

yeah it was really bad did you see my video

 

[19Eclipse90]

yeah it was really bad did you see my video

I just watched it... you sure you didn't kill it on the line Honestly, rev it up and slowly let the clutch out. It looks like you revved it up and just dropped the clutch. Go practice some more. You are the only one who can make it better - us talkin about it won't make you automatically pull sub 2 second 60's.

 

[bighroder]

you could get a auto. some people have a lot of problems with the 4-5 syncro and some people have problems with 3rd. you should probably upgrade to a stage 2 tranny at about 300 hp roughly, i am no expert.

 

[gsx219]

trust me i would love to along with new drive shaft and stage 2 cv axles but cash is a problem when your trying to buy a new house.

 

[toybreaker]

I'm not an expert, tease: by any stretch of the imagination ) but this works for me in an awd car.

Pull around the burnout box!

Stage

Bring the rpm's up to ~4500~

Pull the handbrake up

Let the clutch out 'till it just starts to bite and load the driveline/suspension

On the green/Release the handbrake/Nail the throttle/Hard slip the clutch

Wave bye-bye to the guy in the other lane

It takes a few runs to get the hang of it, but preloading the drivetrain allows you to miminise the shock load on the transmission/axles/c.v.'s. Minimising shock loads will go along way towards minimising driveline failures.

The partial engagement of the clutch (for less than 1/2 a second) will allow you to build a little boost, and will keep you from bogging. (it will also piss your clutch off...so don't do back to back to back runs without giving it a chance to cool down.)

Everyone has to find their own technique, so don't be afraid to experiment with different rpm's/clutch engagement techniques!

(and don't forget your AAA towing card!)

 

[Detail]

You know...you can rev a little more too if you need to. 4500 works great on some cars. I've used to rev to 5250. 1.6 sec 60's allllllllllll day. Let the cluctch cool between rounds. And yes, the clutch lasted probably 300 launches (mostly street not track) before the throw out bearing of all things came apart.

 

[gsx219]

thanks for the info, tried it and im still gonna have to work on it!

 

[redeclipse7782]

Do not use the handbrake to launch, its unnecessary and only give you an excuse to change your ebrake brakes. Rev the car to 5500 instead (4500 is too low) don't try and rush off the clutch, let it out slowly until you feel it grab then let it out quicker but don't just drop the clutch, and don't let it out too slow. Once you do it once correctly you should understand how to do it better.

 

[toybreaker]

Do not use the handbrake to launch, its unnecessary and only give you an excuse to change your ebrake brakes.

Launching without preloading the driveline of an awd car means higher shock loads to the drive line ...period, end of discussion...

This shock load puts the center diff and axles at a much higher risk of catastrophic failure.

In addition, without something holding the car in place, it's really easy to roll thru the beam, and red lite.

If you're really pulling the brake up hard enough to break a cable,...ummmm,... you're doing something wrong. It doesn't take much, just enough to keep the car from moving as you preload the driveline.

And, it will not wear the brake shoes. The vehicle is not moving, so how could they wear?
From a soft slip, loaded against the brake, you release the brake/hard slip/throttle up... the brake comes off before the car moves...

Without the handbrake, the car will creep as soon as you try and soft slip, you break the beam and red light.

Launching an awd car has some risks.

I'd rather have control over the operation, and a nice smooth take off, than a high rpm/boost/slip/hope nothing breaks style launch that leaves nothing on the table.

I like to make multiple passes, and breaking something in the driveline is not very condusive to making multiple passes.

A catastrophic axle/diff failure can also free rev/zing the motor and scatter expensive engine internals, so it's best left to people who can afford to shell a motor or two along the way. ( this counts me out! )

Unless you're talking a full on stutterbox/race clutch launch in a built car, with a built ($) bulletproof driveline, on the way to a 9 second pass, leaving a hundreth or two at the line seems to work well for everyone I know.

//Disclaimer; I'm not a drag racer, nor do I pretend to be one. I'm just an old guy who hates to see people tear their equipment up. //

Everybody has to find their own technique, so if ~5500rpm/no brake works for you, I'd say that's cool. (it's certainly fast)

But, the O.P. is just starting out, and trying high rpm/boost launches for the first couple of times, and one bodged launch will=smoked clutch/broken driveline...



Btw, we are talking about the track, right?

A full on launch on the street can go really wrong, really fast. These cars, stock, will be going stupid fast, before you even get half a block. Are you sure that little kid isn't going to chase his dog (that the revving motors/screeching tires scared) out into the street?

...it only takes one time...

 

[Detail]

Currently running on transfer case # 2 (free from dealer)

Been through a few clutches, none as good as the ACT 2600

Stock trans made it to 178k. Then the front diff pin backed out and hosed the rest.

5500, slip it...and don't grab second like its a mustang.

 

[mach4g63t]

I'm having some trouble with my 1g and launching. In my old 95 I would just slip it to the grab point and once it started to lunge forward let go and away she went. This one, I do the same technique and she pulls and goes, but I always get a very faint burnt clutch smell afterwards. I don't know why it's burning up the clutch. My only idea is that maybe the clutch is worn out and these launches are too hard on it? To my knowledge it has about 40-50k on it (hard miles, I'm sure). It was in 'decent' condition when I did my motor swap so I just stuck with it. It drives fine and have no complaints until I go to launch it and it gets that little burnt clutch smell. Anyone have any input? Maybe it's too worn out to handle launches?

 

[spinninfwdlaser]

I only made about 4 passes on the TSi, before I shut her down. It was actualy my first time ever at the drag strip (dsm shootout, norwalk) and being nervous sure didnt help matters.
I would rev the car to around 5, and slip the clutch (all while the other dude is staging or whatever) until the car starts to roll slightly. I would then yank the ebrake quickly.... I would wait for my light, let the ebrake down and do my clutching at the same time, while adding fuel. I would cut 1.65s on crappy G009 tires, duralast clutch, gutted hatch area, stock shafts, and a 16g. It would actualy spin a tad, but would net some good 60s for my first ever day of racing.

 

[vinnybean]

Question. My rpm between my tachometer and logger are different. by ALOT. On the tach at about 5000rpm i am at 6800 on the logger. Which one should i follow to launch at.

 

[gsx ftw]

haven't tried the pre-loading technique, i think i'll give that a go

 

[diambo4life]

I'm having some trouble with my 1g and launching. In my old 95 I would just slip it to the grab point and once it started to lunge forward let go and away she went. This one, I do the same technique and she pulls and goes, but I always get a very faint burnt clutch smell afterwards. I don't know why it's burning up the clutch. My only idea is that maybe the clutch is worn out and these launches are too hard on it? To my knowledge it has about 40-50k on it (hard miles, I'm sure). It was in 'decent' condition when I did my motor swap so I just stuck with it. It drives fine and have no complaints until I go to launch it and it gets that little burnt clutch smell. Anyone have any input? Maybe it's too worn out to handle launches?

You are slipping it for too long. You will burn up the disc in not time if you haven't already. Release the clutch a little quicker but not too quickly to bog it down.

 

[bmoha2]

It has been so long since I have been able to launch the Talon under boost that I've been bogging it pretty bad. Kinda embarrassing. I used to launch it at 7500 chirp all four for a sec and then take off like a bat out of hell. That was on the T25. Since then I have put on the FP BigT28, DNP exhaust manifold, Aeromotive afpr, 190 lph pump, 550 cc injectors. I am not running any kind of fuel management system just yet. DSMlink is in the works. I am just running 17psi of boost as it sits. I have done a lot of softer launches and it does fine but as soon as I try launching on it harder at higher rpm like 4k I takes right off but bogs down.

 

[PieEyedPiper]

Cool story.

But I kinda tweaked when you said you used to launch at 7500rpm.