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the car is a full weight 99 Trans Am 402 ci. RPM stage 5 4L60E, Moser 12 bolt 3.73 gears, 3500 stall. car dyno'd 473 rwhp on a mustang dyno. M/T 255 street radials were used in place of eagle F1s. this is the first time i've ever made a pass with a decent tire. made a very stupid mistake on the first pass, tire pressure was too high and i didnt do much of a burnout, ended up kissing the wall (no damage to the car.) i got a lot of help from a couple guys on this site (i'm horrible with names and already forgot.) i'm not sure whats going on with the mph being low. another tune has been suggested. here are 3 of the passes. the highest i was able to stall was just over 2500 rpm any more and the car would start moving forward.

60 1.672
330 4.787
1/8 7.426@92.08
1000 9.711
1/4 11.636@117.11

60 1.898
330 5.144
1/8 7.810@92.42
1000 10.105
1/4 12.056@114.88

60 1.719
330 4.810
1/8 7.439@93.31
1000 9.712
1/4 11.625@117.84

results on street tires are here
https://ls1tech.com/forums/drag-racing-results/920342-first-time-track-year.html

i'm not too happy with the trap speeds, weather permitting i'll give it another shot next tuesday.

NOSJNKY

iTrader: (1)

Sounds like the converter may be a little tight(looking at your 60's). My 408 made the same power(474RWHP on Dynojet 248) through a TH400 and 9", 3820lb race weight and ran 10.72@123mph on motor with a 3.70 gear. My converter will flash to 3800. At what RPM is the car shifting?

shortdog

iTrader: (1)

Jesus, how much does your car with you weigh, 4000+ lbs?? You should be running 10s at around 125 mph with a 402.

theblur98ss

iTrader: (71)

I would agree that something doesn't seem right. What are your shift points? The dyno numbers don't look bad. Where did the power peak at on the dyno? Your short time could be a bit better but I'd think your mph should be in the 125 range. I'm sure a little more seat time will help also.

ads_99ta

sorry it took me so long to get back. it's shifting at i'd say around 6500 rpm. peak power came at 6600 rpm on the dyno. the part that had me guessing is that the car was trapping about 3-4 mph higher on street tires than it was on M/T street radials with a .4 difference in the 60' ft times. as far as the weight of the car i'm not exactly sure because i've never had it weighed. it is basically a full weight car minus the jack and spire tire with no miscallenous (probably screwed up that spelling) **** inside. the only thing i can think of is that it needs a tune bad. it hasnt been tuned since switching from 2.73s to 3.73s. oh yeah and on street tires the speedometer reads about 140 when i cross the line when it really trapped about 120.

MT RADIALS
1.898 5.144 7.81 92.42 10.105 12.056 114.88
1.719 4.81 7.439 93.31 9.712 11.625 117.84
1.672 4.787 7.426 92.08 9.711 11.636 117.11

AVG 1.763 4.91 7.558 92.6 9.843 11.772 116.58

EAGLE F1S
2.178 5.514 8.161 93.43 10.413 12.293 120.12
2.115 5.437 8.085 93.45 10.338 12.221 119.95
2.134 5.457 8.103 93.4 10.357 12.24 119.97

AVG 2.142 5.469 8.116 93.43 10.369 12.251 120.01

DIFFERENCE ON RADIALS 0.379 0.559 0.558 .83 MPH 0.526 0.479 3.43 MPH

venom ws7

iTrader: (13)

Why are you shifting ar 6500rpm if the peak power came at 6600rpm???

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its an auto, so i dont shift it. i think the tune is off

ndfrsd6

iTrader: (5)

im a 6spd guy but my friends with autos shift theres manually to get the most out of them

DrkPhx

iTrader: (15)

You need to set the shift points higher to maximize the power. Your 60-ft needs work as well. Consider switching converters. I run the same tire but with a PT4000 converter (recently switched to a Circle D 5C/5000). It would cut 1.52 60-fts no problem and pulled a best 1.48 60-ft on a well prepped track.

MARKSZ71

iTrader: (3)

your mph seems about 5 mph off and work on that 60ft times u need a 1.5 to be flying

1QuickT-A

iTrader: (12)

if your friends are shifting electrically controlled transmissions "manually" then your friends are ****** idiots..

1QuickT-A

iTrader: (12)

Definitely a problem somewhere.. Those times are **** poor for a 402.. You should be in the 6.90-7.20 range with out a doubt. My street car full weight with my fat *** in it will go 7.00's with a 402/4LshittyE/stock rearend/stock gears/completely factory suspension.

FASTFATBOY

iTrader: (23)

Does seem like something is amiss.

It should be a good bit quicker. Your 60ft should AT LEAST be in the low 1.60 range.

Your MPh sould AT LEAST be in the low 120's 1/4 and high 90's 1/8 mile.

My 3700lb 383 LT1 with 23* heads runs 7.0's and 11.0's on pumpgas with a 4L60E. All motor.

Has it been tuned on a chassis dyno? Post a dyno sheet if possible and lets see it.If that car made 473 RWHP on a MUSTANG dyno, thigs are WAAAYYYYYY off.

Mine made 441 rwhp on a dynojet unlocked, 463 locked.


David

Villain281H

iTrader: (5)

Get it tuned before doing anything else including getting the shift points set in the correct place (you want to shift about 400-600 rpm past the power peak). Don't shift it manually, have the shift points set correctly and leave it in Drive or OD. With that amount of power and speed you should be in the low 11s with traction.

Also, try launching it a bit lower on rpm (try around 1700-2000).

Good luck!

Derek

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well those dyno numbers came at EPP in june of 2007 and that was through the stock drivetrain and 2.73 gears. i'm sure they're a little lower now going through a 12 bolt. i'll be getting another tune on the car in a month or so, i won't have a chance to run it again until september. but i'll be sure to post the results. thanks for your help guys.

transam69230

iTrader: (49)

I was waiting for someone to mention launching it lower. If you launch it between 1500,-2200 rpms i think your 60s will go down if the car hooks well. You need to flash the converter to get full effect, and best 60fts possible. My 346 with a 3600 stall cuts 1.6x 60s all day long at the track.

Fred O'Bannion

iTrader: (-1)

yeah there's no shifting a 4l60E manually.

Pro Stock John

iTrader: (34)

Honestly that's not a bad start, 11.6@117 on a 1.71 short time.

I think you went bigger mph on the street tires because you got up in your power band faster.

Suggested changes:
-First off if you have an iron block, you are like 3800 raceweight (I assume no cage). That's pretty heavy.
-If you want to run better you need to look at your power curve, and see how much more converter you should run. A 4000-4200 stall would help a lot better and probably get you down to the 11.3-11.4.
-If you want a 10 second pass you need alot more converter, and you'd have to be cool with how the car will drive. A 4500-4800 stall would be going in the right direction.

ads_99ta

its an aluminum block and it doesn't have a cage. i'm going to see how it performs after it gets another tune and then go from there. if i'm still not happy with the results then i'll switch the converter. thanks for the advice.

BADSZ28

iTrader: (39)

Did you ever tune it after the 402 went in? your whole time slip is strange to me. Seams the car nozes off at the end of the track. 93-94mph in the 1/8 is good for 119 in the 1/4 I would think. But 119 is still slow if you ask me. How tall were the tires? PSJ is right though, a looser verter will really wake that thing up out the hole. As others stated, that shift point needs to be higher. I would say about 6800.

On a side note, that set-up would LOVE the juice.