First track night in years: Trapping in 4th looking for advice


Jun 6, 2007
Hi fellas I am not a guru and am looking for some advice. I got the car with the trans and converter already setup and have not been able to track the car in 6-7 years since i own it.

I made some passes but I feel like maybe something is off in the setup. I was trapping the 1/4 in 4th gear and am looking for advice on what to look for.

Best time:
r/t 2.140
60' 1.941
330 4.928
1/8 7.398
mph 99.00

1/4 11.383
mph 123.19


stock block n rods w TRW pistons
flat tapped 206 208
iron 8445s that have been ported (no flow numbers)
stock cleaned up intake
precision plenum w 1" spacer
v series nice size front mount w 3" pipes
tial 44 mm ext gate dumping to atmosphere
sd chip w 21 setting
dual walbros
120# injectors

old t70 w garrett 82 housing
TH dp
pushing through the full atr pitbull dual 2.5" exhaust
boost was at bouncing from 26-28 psi on the gauge ( have found map on pl reads 1-2 psi differently)

Transmission was done by local Tranny Tech
Convert is a Art Carr 3500-3600 stall non lockup
Running on tired street drags 275 40 17
launching with O boost

I am attaching a couple run files that will show the shifts and drop of rpm. Max duty cycle is about 80% on the injectors.

I feel like i should really be running faster and the trans setup maybe hurting me and i dont know what to attribute to it. trapping in 4th well into 4th actually

are the rims just too small? is the converter too loose? trans setup bad internally?

after 6-7 years with this thing i was happy w these numbers :) but the person i got this shortblock from years ago was running 10.70s w a similar setup


  • track1.26psi.dat
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  • track3.28psi.dat
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The tire you are using is too short at 26". Get a 28.5" tall tire and manually shift it. If you are stuck on that tire, install a 3.23 gear and manually shift it. Not the best option though. A converter change will help, but you still need a taller tire. The art carr is very loose but many go real fast with them. My NL 3021 would work nice in this setup. Contact me for more info
Looking at your 60' a good boost controller would probably benefit you more than anything. Even with a low profile tire you should be .3-.4 faster in the 60' consistently.
These cars love a taller tire,put a 28/29 inch tire on the car with a 15 rim leave on boost and hit that sidewall hard and hang on.
My experience...I went from a 25" tire to a 28" tire and switched from a Pat's 2800 to Dave's 3250 LU and gained 7 tenths and 10 mph. None of it in the 60ft.
.................launching with O boost................................................ the person i got this shortblock from years ago was running 10.70s w a similar setup

It makes no sense to me to go to the track and launch a build like yours at 0 boost, and wonder why your results are not up to your expectations? :confused:

Your 123 MPH indicates the HP is there to run a 10.70 like the "person" said, but 0 boost kills your ET.

Your chassis set up and springs, and the car being lowered are all factors in killing traction especially at the track.

A stock GN suspension set up will launch better than what you have, as I have seen many local guys with dropped spindles or springs get their ass kicked off the line by stock suspension GN's with less HP!
Thanks all for the input. Mods im sorry for the duplication. I came up w an action plan. 1. Try and see if a 28 " tire will fit while lowered without rubbing and try to manually shift. 2. If i cannot fit taller tire ill re evaluate the options. The car will see the track maybe 3-4 times a year so im not sure i want to either 323 gears b. Drop trans as Bison suggested and change parts for longer 1st etc coupled w a tighter converter. Atleast i was able to confirm the car should be able to hit 10s. In reference to the boost controller, is it possible to add a rjc type into the mix w an external turbonetic knob style controller?
Running on tired street drags 275 40 17

How about updating these if you can't get a 275/60 in there? I would also look at a better converter.
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I meant a 15" (275/60/15) not 17", sorry. With it lowered, the options for taller tires are restricted. If he can't work the tire then he might have go back to the 17s and go for a different rear end ratio.
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You think those monsters will fit he he (; working on testing some 15 w 28inch tire . I wish mt made some additional sizes in 17 inch rims
I put a set of tires in the trunk when I go to the track . Takes about 20 min and I work slow . 28X9-15 Hooser slick on a AERO 8 wheel, fear price
I got a converter from Dave heusek he's the man and knows all about it... Customer service is amazing too