i have a 91 firebird with a 3.1/auto. It has 129,000 miles and is in really good condition, i have the following mods

-dynomax superturbo catback
-dynomax high flow cat
-custom cai/ k&n filter
-jet 180 t-stat
-accel 8.8 wires
-accel dist cap/rotor
-accel super coil

what should i run in the quarter mile and 0-60 times?

 

16's

0-60 7 secs

Guesses...

Your only probably pushing around 150 HP at the flywheel...

 

16.7 @ 80mph.

 

16.67@81.2 with a 2.30 sixty foot!

 

if im only running 16.7 now what mods can i do to run 15.9?
(no 3.4, no turbo, no nitrous)

 

Headers, Cam, Port and Polished heads, roller rockers, underdrive pulleys, port and polished intake manifold...That shoudl do it...I think!

 

how much would 3.73 gears and a shift kit take of my quarter mile times from 16.7 to what and what will i run 0-60 with these to mods including the ones i got

 

There are a lot of variables that play into this. I can't say "do this mod and it will equal that."

In my experience taking a stock car and knocking a couple tenths off with a good tune up and some bolt ons isn't hard. But taking the next few tenths off are harder.

Plus, altitude of the track, temparature and humidity at the time of the run can make a huge difference as well.

One of the biggest corks on these 3.1's is the factory "T" connection where the exhaust joins two to one. Replacing your manifolds with headers and a "Y" pipe will help a lot.

But will it get you from 16.7 to 15.9? You have to run the thing to find out. And it seems to me you haven't run it yet. So again, it's bench racin'.

Run the car, and get back with us!

(I'm not being negative, I'm and old dude who's been around awhile and done that)

 

my best is 16.2 @ 83 with a 3.4, 1.52 roller rockers, underdrive pulley, MSD coil, 8.5mm wires, dynomax catback, highflow cat, open airbox, 180 t-stat, AIR pump delete, suspension mods, and some weight reduction. it takes quite a bit to reach 15s. and ive been told i can drive a manual quite well. im hoping to hit 15s this spring w/ some other mods ive done, including headers. good luck.

 

Back in the day, I hit 15.6s-15.7s with my 2.8L. I did nothing to the internals of the 2.8L. It was all intake, exhaust (including headers), suspension and drivetrain.

 

Yep, I am also doing high 15's and low 16's on a fairly stock auto 2.8 based on gear ratios. The motor has the best of everything stock and has 1.52 rollertip rocker, power pulley, fully built ignition, and 2.5" highflow cat and rear exhaust. A few tweaked goodies here and there but for the most part its stock. My success is a very expensive and lightweight and perfortmance built drivetrain from the convertor back to the wheel assembies.

 

huh....i need to work on my 60s and get traction. I was traping at 82 and running a high 16. shows i can improve alot. i was also shifting poorly.

 

Headers/Y pipe/Catback for the single biggest gains

 

high flow cat

 

Any new catalytic convertor is basically nowadays a "highflow" cat. Just as long as you dont have that dinosaur 80's cat on there. Any aftermarket brand is good and will flow great on a 2.8-3.4liter car- the same singles are used on V8's. I have the same Gibson Cats on both my truck (5.7 V8) as my Camaro (2.8 V6). The truck puts out over 300 HP and runs no different whether the single cat is on it or off.