launch RPMs- there is something wrong with the common knowledge here

[AJ]

i did some searching on the board and i got the impression that most people are launching at 1500-2000 rpms for maximum acceleration out of the hole on street tires.. ???

what i dont undestand is that those rpms are too low. i played for a while with my friend's g-tech and obtained the best 0-60 with a launch at 3000-3500 rpms and very slight clutch slip. if i launch that way eventually around 4500 rpms i get traction and then just bang second at around 5500 rpms (i assume that the tach is slow and in reality it is more like 6000 rpms), if done right i would spin a bit in 2nd, but quickly gain traction and proceed to shift into 3rd where i can just barely bark the tires. no powershifting.

it was in the 60s, clean tarmac (parking lot) and i made sure the tires are warm.

am i missing something? launching at 1500-2000 rpms although almost without spining the tires was not nearly as fast to 60 as was the one i described above...

alex
02 gts
few other cars



<FONT COLOR="#ff0000" SIZE="1" FACE="Verdana, Arial">This message has been edited by AJ on 05-03-2002 at 01:49 PM</font>

 

[King GTS]

Everyone races differently & has different tecniques for what works best for them & their car.

 

[treynor]

With street tires, I'm also a converted believer in the "hold revs and launch with the clutch" technique. I finally broke into the 1.9s on stock 18"s using this technique, and I'm still improving. With the "dump at 1200" technique I'd get consistent 2.05-2.08s

What kind of 0-60 times were you seeing?

 

[Chuck 98 RT/10]

Don't forget, tire setup make a big difference. Many are still on the old MXX3s. The new Pilots like yours grip better for dragracing.

 

[MES]

I find that on the street I can launch much harder & at higher RPM than at the track. Most of the posts you found were probably referring to launching at the track so maybe that's why they were lower, just a guess

BTW what 0-60 times were you getting

 

[motor602]

HEy yeah i was wondering the same thing. Today i went out and for the first time tried a drop clutch start. I revved it to about 1750 and feathered the clutch, however, i was too scared to punch the throttle. Is that how you do it? Feather the clutch and mash the throttle? cuz with 450 horses Im a little worried about SERIOUS wheelspin. Should i go like 3/4 throttle or all the way? i really wanna get this down so any help would be appreciated

 

[Motor City Mad Man]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by AJ:
i played for a while with my friend's g-tech and obtained the best 0-60 with a launch at 3000-3500 rpms and very slight clutch slip. launching at 1500-2000 rpms although almost without spining the tires was not nearly as fast to 60 as was the one i described above...

alex
02 gts
few other cars

<HR></BLOCKQUOTE>


Alex, I have used the G-Tech Pro also to measure my 0-60 times. What I have found is that when you launch with a lot of wheelspin the 0-60 time tends to be more innaccurate and makes you think you ran faster than you did. I tested the G-Tech out at the track and it shows on average .2 of a second faster on the G-tech than what my time slip says in the 1/4. I had one particular run though where I spun my wheels reallly bad at launch and the G-Tech said I ran a 12.08 at 130 MPH but the timeslip said 12.575 at 116.8. For some reason the more you spin your tires at launch the more innaccurate the reading is. So, if I were you I would try your launch technique at a track and you will probably find that those runs where it looks like you are getting a really good 0-60 are actually not good runs at all. If you are spinning your tires a lot at launch you are not getting a good 60 foot time. And if I launch above 2,500 RPMs or so I always spin the tires real bad. By the way I think the best 0-60 runs I have had with the G-Tech are like 4.0 seconds.

 

[Mike Brunton]

Alex,

You are absolutely right... 3000-3500rpm's is where you need to be for a GOOD launch. You can launch at 1800 or 2000 all you want, but if you want to get the really good times, you need to rev hard enough so you dont bog the motor and use the clutch to control the power. You will find that all the guys who run truly fast times do this to get their great 60' times that lead to a good 1/4 time.


Chuck,

I think you are wrong on the Sports having more traction - I ran a 1.69 60' time on MXX3's with 20k miles on them. I know alot of the drag racing guys prefer the MXX's for their stock racing since the new sports don't stick as well.