At a recent local event, I was told that Jason Saini was launching at 3500-4000 RPM while still beating everyone at the Peru NT. One suspicion was that he knew he wasn't being threatened and relaxed on the launch to save the car.

(Edit: Toledo, not Peru)

Not wanting to believe that we're all slower than he, I tried some 4k launches and found my times still getting better. The start was slightly confounded by a sweeping curve onto the straightaway causing me to chicken out slightly and not keep my foot planted in 1st gear. Now, it's possible that I could have done better yet by a stiffer launch but have we (Jason, to be exact) found a new secret to good times? Is the launch at an autocross not as important as many of us believe? Obviously a "sufficient" turn after the start makes a drag race launch impractical but what about those that are straight(er)? One thought is that because we're not doing 0-60 mph times, the launch is less important.

Anyone (Jason, especially) want to pitch a theory? I've been a believer of high-RPM launches but this has me thinking (usually a bad decision)...

 

I've been told high rpm lanches don't really do anything for you. But that is just at local events. The really fast guys never seem to launch at high rpm's in any car though...

 

Honestly I've found my best launches to be in the 4-5000 range with enough clutch slip to keep the engine torque up all the while decreasing wheelspin with increased clutch engagment. I've never launched at high rpm even with race rubber on.

 

Saini wasn't at the Peru NT this year. Maybe you're thinking of Toledo which had 2 right angle starts.

Can't really see a 4000 rpm launch being very good, since you'll bog pretty badly out of VTEC. Trying to slip the clutch in an S2000 could be a dangerous proposition too. Very easy to fry it.

On starts where we can go full throttle (most), my co-driver and I drop the clutch at 6000 to 7000 rpm, and use the throttle to control wheelspin. We want to be in VTEC when the tires hook-up.

Kris

 

Yer right - Toledo, not Peru.

Jason, whatcha got to say for yourself?

 

Yeah, what he said!! Umm - it was mainly because there was a pretty sharp corner almost immediately after the start. I did vary it a little bit, trying to use the launch wheelspin to create 'rotation' around that first 90, but that's a low percentage maneuver. I did make it stick once, maybe from about 5000rpm.

With launches and solo2 starts, I find what works for me is whatever makes sense for the situation, and secondly whatever I don't have to think about. If I concentrate too much on the launch and it takes me a couple corners to get in the groove it's just not worth it.

YMMV, but I say launch for solo2 only when practical - but have at it when it's practical. And as for ProSolos? That's the fun part! I was launching from 7800 at Oscoda and getting my first EVER 2.0x 60' times. Yahoo!

 

Not having been at the event, I was unaware of the proximity of the first turn. So, it seems that your technique more-or-less matches mine although mine likely doesn't work as well (you have no fear of me showing up and somehow whuppin' yer butt).

Dang! And to think I was onto something new...

 

Mark Daddio usually leaves the line pretty gently. I've had plenty of chances to observe him at local events here in CT over the years. Autocross starts are set back from where the timing begins. The idea is to cross the line at the best combo of speed and control for the course after the timing begins. So a hard turn right after the timer starts needs to be accomodated. Some folks like to leave harder to get more heat into the rear tires too, so there are some other POVs here.

You know how in the quarter mile your launch can affect the final MPH? With somewhat lesser starts leading to more MPH but a worse ET? Same basic concept. Except in drag racing you start on the line, with only a short run out (inches) until you break the light beam.

If you launch super hard off the line you'll often cross the timing lights at a lower speed than a more moderate takeoff! It will take you a hair longer to get there, yes, but that is during the untimed portion of the course leading up to the lights. It can also be harder to control things if there is an immediate turn.

I've played around with this at local autocrosses using my AP-22 to study the first 20-30 feet of a run. Ultimate launches at non pro solos don't help. They hurt a bit. Just get a good solid autocross launch and not a great drag racing one.

Stan

 

My experience has been that the type of launch makes a large difference in times (~.25 second or more). The clubs I autoX with allow a fairly high number of runs (typically 3 practice morning runs and 3-4+ official runs in the afternoon). I usually do a very mild launch in the morning and than more aggressive launch in the official afternoon runs. As I said, the type of launch can be worth .25 second or more as there is a huge difference between a mild launch (~3000 rpm, some clutch slip, some slight bog with no real wheelspin) and a competitive launch (~5500 rpm, fast clutch letup, moderate wheelspin with no bog). Perhaps the fastest drivers don't have to do these harder launchs because they are so fast on the rest of the course but for us mere mortals, launch will make a difference. It seems pretty starightforward to me, the quicker you get your car up to speed the better, anything less and you are losing time. JMHO.

 

hey TubeDriver -

3 additional runs on a course for me are worth more than .25

I guess that means I need to work on my course walking skills because launching didn't make the difference for me - getting in rhythm and being 100% confident in what I was going to do and when (on the 6th run) made a huge difference.