i have a 91 240 HB w/ rb25det S1, 3" downpipe and exhaust and a cone filter, stock SMIC, 10psi, exedy hyper single, z32 vlsd, tien HEs, bfg 205/50/15 drag radials. i went to the track wed. night just to give it one more go before parking it for winter and doing a bunch of stuff under the hood. i just wanted to see if anyone could look at my time slip and give me any advice and also any sugestions for setting up my suspension since i haven't messed with it this year and what size tires i should be getting for next year. i plan on making around 400whp.

best time was:60'...1.921330...5.5261/8...8.507mph...82.601000..11.0711/4...13.209mph...104.87

no full throttle shifting and taking it kinda easy into 4th, it grinds a little on a hard shift. i can post more slips if it would help. as far as tire sugestions, i usually run different street and track tires on stock size wheels. ideally i would like to run slicks at the track and drag radials on the street.

just seems you need to get the launch down a lil more. even a nice 1.8 60' would get you into the 12's

tryout the 235/60/15 bfg's or MT's. they hold my 500hp at the track, not really on the street tho

thanks for the reply. i was wondering what you are running for a diff. and axles. any advice for my coilover settings or any things i should look into upgrading to help deal with the power?and your car kicks ***.

You want a nice soft spring rate in the back for weight transfer. Stock springs actually launch quite well as an example. What PSI are you running in your tires? Try lowering it a few lbs, I believe aslong as you stay over 25psi they'll stay on the rim. This will help with the sidewall give. Limping into 4th hurts, are your syncs going bad?

Bigger tires then 205's will also help quite a bit on the launch. I know the RB25 has decent lowend torque that is probably giving some decent tire slippage. I used to launch my Skyline at 5500-6000, but I had the RB20, so nowhere near the lowend torque curve.

WD

my best launches were with 20 psi in the tires, a good 2nd gear burnout in the bleach box, and dropping the clutch at 4300. the 205 bfgs are dead and since i was too close to redline in 4th i know i'll need taller tires for next year. my trans has shifted hard into every gear when the trans is cold since i got the motor in. 3rd and 4th are hard to hit even after i've been driving for while and have everything good and warm. i have valvoline in the tranny right now but bought some ams oil to try. hopefully that will help a litttle bit.also, does anyone know where i can get a pair of 15x8 wheels for the stock 4 bolt for cheap?thanks

Redline Heavy Wt oil is what I always found to work the best. Best of luck with the cheap rims...all the cheap ones are like 6.5 and 7 inches wide. I looked myself. The 300ZX rims are decent, but they are 16".

*edit* you said 4 lug, so nm the 300ZX rims