more times, deciphering problem

[TheBeast]

tonight was bracket racing, got a few runs in before it started raining. here goes:
2.22 60' 15.49 @ 86.81
2.24 60' 15.51 @ 86.86
2.21 60' 15.49 @ 86.59
too bad the track closed before the actual eliminations started or else i would've gotten me a trophy! :D

anyways, the reason my MPH was down was due to a terrible headwind. ive still concluded though that the switch to 3.42/LSD has done completely crap for my times. take this logic of mine and see if it makes any sense: ive got 17" SLP WS6 style chrome wheels, with 275/40/zr17 tires. these are some hefty wheels/tires. with the 3.08/open setup i managed a 60' of 2.27 and a 15.411 @ 87mph. i think the only reason i managed that was because with the open diffy all the power was put to spinning that one rear wheel which got it goin good with little spin. switching to the LSD/3.42 divided the power between the two back wheels which in turn does not deliver enough punch to get these wheels movin like before. soooo i either need some smaller/less wide rims/tires for the track, or i need to get some 3.73s in there to offset the wheels/tires i have on now. anyone agree? ALL of the time I am losing happens within the first 330'. I compared my times with NBMA4V6, his best beats me by .432 in the first 330', only like .03 between 330' and 1/8, and .07 in the last 1/8.

Also, could these be other culprits?
1) bad install (although a pontiac dealership did install)
2) bad set of gears (they WERE used before i got them)

[ March 21, 2002: Message edited by: TheBeast ]</p>

[Slow-N-ugly]

This is only a guess, From what I can tell from your post you had the same wheel combo for all the times listed. Given that you can see the differance in the 3.08/3.42 on the top end in mph and a little E.T. So if you are launching at the same RPM your motor is bogged however more slightly off the line(even though you your 60' is a little quicker). Try changing your launch RPM a little, all other things (weather and track conditions) being equal, the 3.42's should make you quicker. I know you said a head wind slowed you down, but our F-bodies have such a low C.D. that I think air and track temps may have been a bigger factor....Damn that barametric pressure.

[Slow-N-ugly]

One last thing......this may be trivial however my best runs have come when I was behind a dragster or door slamer, I lined up on the sticky patch of rubber they just laid down and LAUNCHED just give more revs!

[TheBeast]

I've tried launching at 2k, 1.7k, 1.2k, all the same outcomes. I think the only reason I ran the 15.356 with the 3.42/LSD was because I was running a stripped interior, and when I ran the 15.411 with the 3.08/open I wasn't.

[Pro Stock John]

<blockquote>quote:</font><hr>Originally posted by TheBeast:
2.22 60'
2.24 60'
2.21 60'<hr></blockquote>

Are you an A4 or a M5?

I think you are an M5...

1) If you are spinning, you need to come up with a technique to get to 2.0's on street tires. Try 2000 and releasing the clutch fast, but don't dump it. If you still spin try 1600 rpms. I would prefer to come out at 2500, I'd release the clutch fast and nail it once you are rolling.

2) If you are bogging you need to come out at a higher rpm with an M5.

I would shoot for a 1.95 - 2.05 on street tires...

Change one aspect of your technique on each pass.

I think you can run 14.9's no problem as you sit.

Once you get the launch down try different shift techniques.

My best on ET Streets is a 1.51, took me about 10 passes to figure out how to do that.

[TheBeast]

nope I'm an A4 :(

[nino]

who gets 2.0 60s on street tires? i can not get better than 2.2 either on my street tires. i have DRs i havent tried yet, but i hope to break 2.0. never would have thought doing that on street tires was possible.

[W68Firebird97]

I along w/ Mike24 have both hit 2.0 60' on street tires. Make sure you smoke the tires some and launch around 2000rpms thats where I launch from. my best is a 2.076 and Mike24 is a 2.051 that makes a big differance in your E/T and MPH.
good luck [img]graemlins/burnout.gif[/img]

[TheBeast]

alright I'm goin back to the track tomorrow night, but this time im swapping out my rims/tires with Jeff (NBMA4V6) who has stock chrome 16's with 235/55 rubber. we'll see how it goes

[NBMA4V6]

nate dont jinx my tires..i cut 2.0's on these tires everytime i go...

when i get LSD i will cut 1.9's i hope..that my goal :D BTW right now on an open rear i cut 2.04's consistently...

DONT MESS UP MY RIMS WITH YOUR 15's Nate [img]tongue.gif[/img]

Jeff W

[MustangEater8251]

Did you have the same tire size with the old rear end?

you guys launch at 2k? hell I launch 4-5k, course I have exhaust off and cuts my torque down a bit but jeez, don't your cars bog off the line? Learn to feather your clutch.

i cut a 2.106 on crappy crappy street tires(cheapest tires at a god year place) with my 3.42s and LSD. If you had problems with your differential, you would hear it. they will hurt you a little topo end, but the help down low more then makes up for it.

[99Camaro99]

You don't want to rev up to hi. I've only went to the track once and got 3 runs. My 2.3 60' came off a 3K launch and my other two runs I launced at 1,700 for a 2.1 60'. BTW, mine is an A4. Anyone want to help me shave off another .1 so I can hit a 2.0? [img]smile.gif[/img]

[Slow-N-ugly]

You may try dropping you psi a little for the better bite....annybody got a # for him?

[TheBeast]

Ya, I had the same wheels with my 3.08/open setup. I usually drop the psi to about 29 or so in the rear, even tried down to about 25. I will try every combination imagineable tonight. I will get there when the gates open and won't leave until they throw me out, lol. :D