Can any fast guys comment on this? Joey Schilling around these forums? Janzen/Dyck you ever run it at a ProSolo?

Looks like I'm running my car in DC now. I want to cut the best 60' possible while minimizing my chances of shattering the rear differential. What do you guys do?

I learned to "drag race" with my 11 sec AWD Talon at the strip years back. I could do a 1.7 60' on street tires with that car with a slight clutch burn technique. The s2000 is...well...a bit different My current autox technique is also a slight clutch burn technique starting at around 5k, quickly but gradually feeding in throttle and releasing the clutch for just a bit of wheelspin and then it grips. It grabs around 4500 rpm (I guess a pseudo bog) but I'm maintaining max "grip." Would it generate a faster 60' / 100' time by launching more agressively and spinning the tires out of the hole/keeping it in the powerband? Or am I just waisting time spinning?

AP2 guys feel free to comment as well.

Thanks,

 

In my 08 I launch at between 6 and 6500 depending on surface conditions and let the tires spin some. I consistently turned 2.1's 60' times at Toledo last year. I just side step the clutch so no slipping.

 

Getting the tires spinning is the key to not being (too) hard on the diff.

In my AP2 I launch at around 6-6500 and sidestep, just like Keifla123. It allows me to be super consistent on launches since it is always the same once I figure out how many revs to use on the surface. It seems to work best to get the tires spinning into VTEC then lift just a tiny bit so they hook up then get right back on it.

 

In the AP1, rev it high and drop the clutch. How high depends on how much traction you have.

The key with the AP1 is to spin the tires. If you slip the clutch it will overheat and refuse to grab. If you let the clutch out without breaking traction you will bog horribly. Let the clutch all the way out and modulate the throttle to stay in the powerband and then when the wheels finally do hook up, you can floor it and be on your way.

On a warm day with Hoosiers on a good surface I've had to drop at over 8k, so don't be afraid to get on it!

 

Never done a Pro nor any timed launches. I drop the clutch as I pass through the target RPM* with the throttle floored or nearly floored.

I think I have the reasoning for the hard launch figured out though: The idea is to get the tires spinning before weight transfers rearward. Hence the hard clutch drop. If weight transfers rearward before the clutch is fully engaged then the clutch will slip. Jeff's 02 needs a faster clutch drop than my 01 does. I spun the clutch once in his as I let the clutch out too slowly. Oops...

Basically you need the clutch fully engaged plus enough HP to keep the tires spinning once they're fully loaded by weight tranfer. It's much easier to break the tires free when the car is at rest than after there has been some dynamic weight transfer.

* Target RPM = good luck. We learned at each new surface. Better to go a little too high than too low, you can always modulate wheelspin with the throttle. We were launching at full throttle and 9k when running V710s on rough local concrete. V710s needed a LOT more throttle/rpm to keep them spinning than Hoosiers. We were launching around 7k at Nationals (Lincoln, on Hoosiers) and had to feather the throttle pretty gently.

 

Alright folks I'll do that. This is a bit hair-raising, at is the exact opposite technique of launching an AWD dsm! I'll have a go and use the highrpm clutch dump technique with a contingency plan to get the car home in case it goes kaboom.

Thx guys.

 

The safest way is a progressive clutch let-out at 3k rpm at light throttle. But that's boring!

I carry a spare diff and axles to out-of-town events. Knock on wood - I haven't needed them yet over two years (with two drivers) of autocross launches on Hoosiers and V710s.

 

I'm gonna play with launch control at the next local event on the FlashPro - should be fun

I'm thinking 4k and sidestep should work for street tires...

 

+1 on my AP2 in BS form. On asphalt(Mineral Wells/HPT) it was closer to 6k, good concrete(Peru), closer to 6500. Somewhere in that range I could fine a spot where I could side-step it while flooring the throttle, and get the tires to slip such that the engine carried about 6500-7000rpm all the way til they fully grabbed, and I was still on the cam when they did. I would never lift off the throttle if I got it right. I could get consistent low 2.1's and the rare 2.09 with this method.

If you think that's nuts, I remember watching Fiedler launch his AP1 from the neutral limiter with a clutch drop...eeesh.

 

https://www.s2ki.com/forums/index.php?showt...&#entry16742208

-Marc