Proper Launching a GTR

[tokes]

I have a question about launching, I dont know much about manual driving, I am just learning on my GTR.

When your launching and reving your engine to 3 - 3500 RPM
do you drop your clutch quickly, as in just drop your foot? or do you need to float around the friction point while your reving, and slowly engage the club as of moving it an inch a second type thing. what is the best way to go about this.

Are you racing or just driving around? Just driving around obviously you're going to want to slip it.

For racing I found 4500 RPM's and a little bit of feather to get the car rolling and then side-stepping the clutch resulted in the hardest acceleration. It also resulted in my needing a new clutch after owning my car for 2 weeks, so be warned.

[GGTTSS-44]

I am just daily driving. So would I just drop the clutch fast, burn tires alittle and then take off?

I don't race ever and I don't wanto wear out my clutch so I dont imagine I'll ever try it, I would like to know how though.

I think just starting from a stand still is more then fast enough! without launching.

[Bruizer]

OS Giken twin

To the guys using these clutches, I'm almost certain you will regret saving $200 on this clutch rather than a nismo twin if you know the nismo twin. It's a bit heavier pedal and it chatters like mad. But hey, that's just my point from using a OS giken twin and going to a nismo. $200-300 more is like nothing for the peace of mind I get now ( no annoying chattering lol)

[tokes]

I got my OS Giken twin for 700 bucks on this board. Saved 1400 dollars over a coppermix twin. I'm a full time student, 1400 bucks is a full paycheck for me. 'Nuff said.

[cobrAA]

So when you launch.

-Rev it at 5000rpm or higher?
-Gear? 1 or 2?

I don't plan on lauching my gtr as my tranny already need love and I don't want to f*ck it more. but I would still like to know .

[bignate]

So when you launch.

-Rev it at 5000rpm or higher?
-Gear? 1 or 2?

I don't plan on lauching my gtr as my tranny already need love and I don't want to f*ck it more. but I would still like to know .

1st gear, lots of revs, drop the clutch.

[m_melen]

I have seen a few guys think they were spinning their tires when it was their clutch and blew the flywheel (great way to lose a foot).


Jon.

I'm scurred now, I floored it in second yesterday with the clutch disengaged and my car SHOOK when it started to take off. I hope it wasn't my clutch getting screwed, I'm pretty sure my clutch and tranny took alot of abuse before I bought this car.

[Dragon Humper]

Well now that I have some decent seat time I can tell you that a twin (or tripple, I don't know yet) is really hard on stuff. It's going to take some restraint to not bang gears in this thing on a daily basis.

The launch is the easiest part, aprox. 7000rpm while pumping the throttle ( let off fully to WOT to off fully...etc) gives me a nice hard trouble free AWD spinning launch. Banging gears though is very rough (might be solid disks). Hope she holds up to the rest of the summer. Ran an 11.20ish at 128mph on an unprepaired track with no burnout so a good prep with better tires should be good for 10.80's, hope nothing goes KaBoom.

The hugeass turbo gives me nothing below 5000rpm, so a 7000rpm launch is manditory. Really scares the hell out of people the first time they feel the G's.



Jon.

[Dragon Humper]

I'm scurred now, I floored it in second yesterday with the clutch disengaged and my car SHOOK when it started to take off. I hope it wasn't my clutch getting screwed, I'm pretty sure my clutch and tranny took alot of abuse before I bought this car.

A sidestep in second most likely gave you wheel hop (axel tramp). With the AWD turned off I get that sometimes in 1st and 2nd with a clutch drop while moving. Not a good thing for pretty much everything south of the tranny. Try to avoid that, it breaks alot of stuff.

My rear subframe mounts are a little tired and my diff mounts are quite sloppy. That is most likely the source of my wheel hop when I am not in AWD. Must fix that soon.


Jon.

[bignate]

A sidestep in second most likely gave you wheel hop (axel tramp). With the AWD turned off I get that sometimes in 1st and 2nd with a clutch drop while moving. Not a good thing for pretty much everything south of the tranny. Try to avoid that, it breaks alot of stuff.

My rear subframe mounts are a little tired and my diff mounts are quite sloppy. That is most likely the source of my wheel hop when I am not in AWD. Must fix that soon.


Jon.

Sounds like somebody needs some solid subframe bushings and adjustable traction rods.

[Oakville]

Bog?

feathering?

[Terrh]

Wow there seems to be a ton of different ways people use to launch this car!

I will say that it totally varies based on what turbos you are running, what kind of clutch, what tires, and the road surface/temperature. Other stuff matters too, suspension, etc - everyones car is different.



What I have found works for me, stock turbos with MBC set at 1.3 bar, stock suspension:

At the track, hot prepped surface, BFG R1's this got me a 1.5 60' and several 1.6's:

~6500RPM to WOT as I am releasing the clutch - quick drag. Resulted in a ton of foreward thrust with very little spin or wheelhop.

On the street (unprepared) - 4500-5000 with a quick drag works well. More revs on sticky tires, less when it's cold out.

Prepared street seemed to stick as well as the track, even when it got cool.
Street we used was old concrete - yours may vary.

I /NEVER/ dump the clutch from a stop if I'm trying to take off fast- this almost always results in either a bog or spinning horribly followed by wheelhop.

I did try a 7000 dump at the track once on soft, sticky street tires - I broke one pass. side trans mount bolt and ripped the other out of the floor.

Always remember to take all the slack out of the driveline before launching the car - just let the clutch out enough to creep the car foreward a TINY bit - you don't have to go any distance at all, the goal is just to take the slack out of the driveline.

If the car ever bogs it seems to be too much clutch too early - these have a reasonable amount of torque but nothing can overcome an agressive clutch on a turbo car. Fool around with it until you figure out your cars sweet spot. It probably takes 50+ passes before the car is being driven perfectly every time.

[Dragon Humper]

Sounds like somebody needs some solid subframe bushings and adjustable traction rods.

I've got the AMS alum. subframe bushings and the poly Energy Suspension diff. bushings, just need to get off my a$$ and put them in. Some one had the forsight to put in Nismo traction rods. The car only shook twice on me (once in 1st, once in 2nd) both times in RWD so I don't do that anymore.

AWD is nice and smooth. Mmmmmm...smoking 4 tires rocks.



Jon.

[Skym]

If you shift torque split to more of a rwd spilt via Veilside hydraulic torque split control handle that you pump or electronic torque split controller, you'll get higher et, mph but sacrifice stability.

The trick with GTR is the rearend, dial out the camber when rear wheels squat to get best traction in the rear. HT R32GTR dragcar did this and went from low 10sec to high 9sec.

Another trick is hold onto the gear over the line to keep engine at peak power instead of changing gear before the line. It's an old trick with low capacity motors but makes GTR's go from low 11sec to high 10sec. Watch top fuel dragcars and you'll notice they launch, then floor the throttle before they hit the line.

Another trick in Japan is boost control in each gear. Apexi AVC-R has gear dependant boost control. Dial out high boost in 1st gear for best launch and just add more boost in each gear.

For launching, use 2 step on PowerFC Pro -

http://www.youtube.com/watch?v=SIFNA7_2mGU

or

ECU launch control on some aftermarket ECU's.

or

MSD 2 step launch control -

http://www.youtube.com/watch?v=QBE9QT1p0bg&feature=related

[owennh]

depending on the surface and what is done to your car are numerous was of launching a gtr.


If on a stock clutch there is no "right" way as it will die regardless.
runing story is about 7-9 near redline launches and it is done, beginning with a brand new one of course. Testing has confirmed this once;-)

I run a nismo copper mix , I find best results on good surface @ 6500 wait for a little spool , drop , hang on , enjoy.