OK heres the story.

Last April, April 00 actually, I ran 14.9@93mph. That was with the following mods:

Flowmaster catback w/gutted cat
160 stat
quarter in fuel pressure regulator (worth 5 psi)
ported plenum

so last night I go to the track and run a 15.2@89, with the following additional mods

rebuilt 700R4
Trans Go shiftkit
2000 stall converter
Catco high flow cat
ported intake base

I have lost 4 mph and .3. My 60 foot time was the same as it was on the 14.9 run, a 2.3. Is my car just out of tune? The plugs and wires, and cap and rotor have about 12k on them, that isn't much. I did however remove the quarter from the fuel pressure regulator, I wonder if my engine had been using that extra fuel that the quarter was giving it? Or is this just a case of an engine that is too choked up to see the benefit of the mods? I am running the stock exhaust manifolds and y-pipe, both of which are very small, the same size as what is on the TBI cars.

The weather conditions were the same both times, around 60 degrees.

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91 Trans Am WS6
Bright White
5.0 TPI auto
Flowmaster 3" 2 chamber catback
Trans Go shiftkit
2000 stall converter
ported TPI setup

Built on Wednesday

[This message has been edited by MrJ (edited August 25, 2001).]

 

Maybe the higher stall converter could have hurt your time? You may want to match it to a new cam, that should definately improve your times. That quarter in the regulator could have helped, if you read the front page you will see that raising fuel pressure can raise power substantially.

I know that you know that you need headers.

 

You might want to get a fuel pressure gage and check to see what your pressure is. A little drop of 10 pounds could explain the time increase.

 

I know the feeling! I ran a 14.6 @ 94 then I ran consistant 15.0's @ 92! My knock sensor is freaking out because of my valvetrain noise, and I'm sure it's pulling a ton of timing. Also, my 60' s sucks *** because my posi is taking a dump. It's also 100% humidity and 95 degrees every damned day here in FL. I ran the 14.6 in the dry, cold MD winter. I hope that hlpes any man..heh.I know how it feels to pay money to go alot slower..

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• Red '88 IROC 305 TPI T-5 w/3.08
• Accel 300+ Ignition
• Accel 300+ Pro Sleeve Plug Wires
• AC Delco Rapid Fire Plugs
• Dual Friction Stage III Centerforce Clutch
• Energy Suspension Transmission Mount
• Flowmaster Force II 3 Chamber Cat Back Exhaust
• Gutted Airboxes
• Hypertech Stage II PROM
• Hypertech Airfoil
• Throttle Body Coolant Bypass
• Best Maryland (40 degrees) E/T 14.686, 60' 2.205, 1/8th mile 9.461, 1/4 mile MPH 93.91
• Best Florida (80 degrees) E/T 14.88, 60' 2.163, 1/8th mile 9.540, 1/4 mile MPH 92.74
• Best 60' 2.163(Florida)
• TPiS AFPR set to 42psi using Accel Fuel Pressure Gauge (Installed after Maryland run)
• Aluminum Driveshaft (Installed after Maryland run)

I am looking to buy Edelbrock T.E.S. headers with the y-pipe. I am also looking for a 3.42 - 3.55 posi disc rear. cheesy@fred.net is my e-mail, send a letter if you can help!

 

Why did you remove the quarter from the FPR?

------------------
Ray87Z
-Vortec headed 350.
86 IROC w/ a cammed 305 TPI.
Formerly Ray86IROC.
www.inter-scape.com/Ray

 

Ray, I removed the shim because I had been talking to Glenn91L98GTA, from what I've gathered from him and from others on the PROM board, the stock PROM tends to make things overly rich.. and bumping up the FP only makes things worse. I think I may put the quarter back in there, I'd rather run a little rich than run slow.