n20fed

Well I made it out to the 1/8th mile track last night. I've been running nitrous the past few weeks and decided to hold off until next season due to my vig 4000 slipping 22% at 6500 rpm. My setup consists of:
-Ported LE AFR 190 's
-Bauer Cam( fairly larger hydraulic roller)24x/24x
-Ported Lt4 intake
-38lb injectors
-58mm tb
-tci t400 w/ trasbrake
-vig 4000
-moser rear with 3:73
-prostar skinnies and 15 x 10 on the rear with M/T radials 275/50/15
-Hals all aroud
-BMR and Spohn suspension
The car put down 400rwhp @6600, and 335ftlb at 5600rpm
I'm not so sure how well the M/T radials hook. The best 60' I got last night was 1.70. That was with the fronts on the softest and the rears on the third softest. I had 13.5psi in the rears cold. I don't hink the track prep was the greatest, but I'm kind of dispointed in what it ran. It ended up going a best of 7.7(roughly 11.9 in the 1.4) @ 92.7 mph. My race weight is arounf 3450 with me in it. Any ideas where I can improve or what my problem is? Temp was around 70 degrees with low humindity. I race in Glenwood IA, about 1100 above sea level.
Chris

MeanGreen97Z

92.7 is a really nice mph for the 1/8th..... give us the rest of the numbers from the slip.... 330ft ect. 7.7 with a 1.7 60ft. seems odd. With 92.7mph trap speeds i'd expect 2-3 tenths better. You said the TC is slipping? Could be your issue right there.

n20fed

Its only slipping about 7.5% N/A. I will try to post the rest later, the slips are in my car. Wouldn't 93mph, be good for about 7.2-7.3 in the 1/8th?

n20fed

Ok, here is the rest of the slip
R/T .094
60' 1.704
330' 4.997
1/8 7.710
MPH 91.76

marshall93z

335 TQ??

Mike96z

I'm thinking wasup with the 335 Tq. With 400 Hp you should expect atleast 415 Tq on the dyno. That number is low and is probably due to that slip and plus you have gears so the Tq should be way higher. Do you have a dyno graph? Also if you are running slicks or DR's why run 13 PSI? Run 10 at the most and it should hook up great. I'd still check out the rest because of that low torque number.

n20fed

I was running radials at 13.5, I didn't go lower becasue my 60' time got worse. I have always dynoed low on torque because of the new winpep7 software on dynojets. Maybe Lloyd or Bret could chime in on the torque numbers. Bret had told me that the torque would be low N/A because the cam was designed for nitrous. For reference Bret/Lloyd my name is Chris Falcone.

NightTrain66

I would have guessed the RWHP and RWTQ #'s took a big hit with the TH 400, no lock up feature on the trans, 4000 stall and 12 bolt/9" Moser rear end.

I am guessing the tires are about 26" and the car would ET better in the 1/8 with more gear in not using the NOS. It is probably just about right for the 1/4 mile and NOS though.

If you could have ran the car in the 1/4 mile, you would have been happier since the car is really moving at the end of the 1/4 and that 60 ft time is killing you.

A 1.70 60 ft is OK for a street car but with youir trans, stall, etc, etc, you should get the thing in the 1.4X or better 60 fts. Alklk of the faste cars art4e getting a MUCH better 60 ft than you have.

Every tenth in the 60 ft will be worth 1.5 to 2 times that in the 1/8 or 1/4 mile. If you can get a 1.45 60 ft (2.5 tenths faster than your 1.70), you will see 3.75 to 5.00 tenths in the 1/4 mile just from the better 60 ft. This will turn your 7.70 into a 7.34 to 7.20.

Once you get the car to hook, play with the tune AT THE TRACK (not on a dyno). Add/subtract timing and fuel at high RPM and play with different curves to get the best ET and MPH. There is alot of gains to be had here.

A few months from now, with cooler weather, you will see even better track times with cooler air.

Just focus on the 60 ft times first and then go from there.

Lloyd

n20fed

Thanks LLoyd, anybody with these M/T radials have good insight on how to get these things to hook?

93redBirdMan

heat em up

n20fed

Lloyd, generally people multiply their 1/8 mile time time to get their 1/4 time, is that true in my case because of 60' right now or not?

n20fed

I did a comparison with the old dynojet software, and it showed about 50ftlbs more torque.

NightTrain66

What suspension stuff do you have (Tq arm, shocks, LSA, etc, etc)?

If they are 15" M/T drag radials, they should bite pretty good. Clint ran 9.80's on some 275/60/15 or 275/50/15 and 1.5X 60ft I believe. Heat em up and play with tire pressure. look at contact patch on the launch and see what it looks like. That will tell you more/less pressure. I have seen people run them at 18 PSI and at 10 PSI. Run em as high as you can and still hook.

Is it spinning or just nost launching hard?

You canm "usually" multiply the 1/8 ET by 1.5 and get the 1/4 ET. This will be pretty close. If the launch is not good and the car pulls hard on top, it will be different or if the car launches HARD but then runs out of gear, lays over, etc.

Only way to REALLY know is toi run it in the 1/4 but this should give you "some" idea. The crummy launch and GOOD MPH for your 1/8 results look like it should be faster than the average car running a 7.70 in the 1/8 that launched well and is trapping 88-89 MPH. Way too many variables.

Lloyd

n20fed

\
I have full suspension except rear sway bar( hals all 4 corners, spohn tq arm, bmr subframes, bmr panhard, bmr trailing arms) It is actually spinning. I did pull both wheels(barely 3-4 inches) on my 1.7 60'

MeanGreen97Z

Yup get that bad boy to hook up and you should see some 1.5x 60 foots... then your lower 7s will come. Drop the tires to 12psi or so psi and heat em up like crazy (John Force them is what I do) and you should get there.