launching an M5 3.8???

[njspder]

hey gang,
i have a friend who is tryin to improve his track times a bit. right now his biggest problem is in teh first 60ft. what kind of rpm are you guys leaving from? any technique tips?
the car has 275 tires on ss wheels, so it has a bit more traction than stock(still a peg leg, so not much).

thanks
tim

[Ender2664]

I have a stock one, with stock tires etc. I can do a no spin launch a little above 3,000 and i get a 2.25 60 ft. With that sive tire i would try and feather out at 3,500rpm no spin, that will net a good 60ft.

[Messi4h]

pop it at 5K [img]graemlins/rofl.gif[/img] [img]graemlins/rofl.gif[/img]

[lord_gufi]

I left at 2500 any more and my pegleg 3.23 would spin. tell him to slip the clutch a little from 3000 let the car roll a little and gun it. That is just about the same technique for launching my car ( only I launch at a surge between 5200 and 5700 )

[awesomeame]

i'm running stock engine & wheels, m5, 3.23, LSD, and pull 2.0-2.1 60' consistantly...no water box ever, no burnouts before the run.

when the white ready light comes on, floor the pedal, when the middle yellow lights up, dump the clutch. i get a bit of spin, but not much...

--matt

[Riles]

I had been dumping the clutch at like 2000-2500 for a while, and it was a great technique for bracket racing because it was very consistent, but it only gave me 2.2-2.4 60 foot times.

Then, at the american iron shootout, I tried feathering the clutch out at 3000 rpms, and I finally got 60 foot times in the 2.0's.

So, I'd say to feather it from 3000.

[Craig Griffis]

Thanks guys, I'll try 3000 and see how it goes. My first run a couple of weeks ago was 16.5 @ 86. Plan on running again on Nov 1. Just ordered new Centerforce dual friction clutch too and hope to have it installed by then.

[Ender2664]

Remember, DONT DUMB THE CLUTCH!. That is very important. You need to feather it out, i have it up at 3k and start the feather and gradually increase the gas, by the time that i am fully off the clutch i am about 3.5k. This method is very good. When i did it at the track, and messed it up pretty bad on my bone stock non Y86 i pulled a 2.25 with no burn out. If you have a bigger contact patch, do a burn out, and pull the start right a 2.2-2.15 is more than within your reach, and that is without LSD.

[Craig Griffis]

Well, Virginia pulled off a best of 15.567 @ 89.12 with a 60ft of 2.218 tonight on the second run. Believe it or not, on my best time I bounced the rev limiter on first gear. Feathering at 3000 rpm seems to have worked but I am running on a worn stock clutch. Will soon have centerforce installed and hope to get around 2.0 60ft. Thanks for your help everyone.

Full slips...
R/T .105 .053 -.027
60 2.214 2.218 2.289
330 6.524 6.511 6.584
1/8 10.083 10.011 10.148
MPH 68.52 69.91 68.53
990 13.060 12.948 13.137
1/4 15.704 15.567 15.790
MPH 88.43 89.12 88.12

[Ender2664]

Not a problem.