i have a 1987 firebird formula 5.0 TPI with ram air II ws6 sytle hood with special inuction and magnaflow exhaust and soon to be a set of headers while cutting out the cat.
im trying to decide on how to build my drivetrain to add on to this car
i was told that a 4.11 gears with a mild shift kit would wake the car up??
tell me what you think?
im looking for more low end and acceleration not top speed
i do not care about MPG this is my muscle car that eats gas and thats what they do and thats what you pay for owning them thats why they are special cars!!!

thanks to anyone who can give me a hand!!!
Devin

 

If you still have the long-runner TPI intake, as it appears, that's WAY too much gear. Especially with the super-lame cam that came in that engine.

You'll have one of those deals where the car will launch like a rocket but run out of breath by 10 mph... about like a 4x4 in 4-lo. At the strip, it will leave hard, stack-shift all the way to 4th, and drive down the last 800' of the track wound out as far as the motor will go (not far) without any further acceleration (mph & engine RPM in the ¼ will be the same as the mph & engine RPM in the ⅛).

Choose your gears with the engine's ACTUAL power band in mind. The gears should put the engine RPM into the range where it makes the most power with the greatest efficiency, as much of the time as possible. With TPI, that means peak torque at 3600 RPM and peak HP at around 4200. No hood is going to change that.

3.42 is about as high as you want to go with that setup.

Now if you had a short runner intake (favors high RPMs) with a big solid cam or something, i.e. a typical muscle car induction system instead of that stock low-RPM one with the less-than-RV cam, it'd be a different matter.

A good shift kit (not the B&M one) would be a good idea.

 

I totally agree. I just went from 2.77's to 3.45's and its a world of difference, but 1st gear is pretty short now. 4.11's is insane....

 

thanks for all the help

so going from a 2.73 to a 3.43 i would notice a big difference in the direction that i want?
that direction is accerlation and not top speed

 

does anyone have any links that i could find a good shift kit? i have a 4 speed with OD tranny

 

http://www.bulkpart.com/Merchant2/me...ode=4L60-700R4

 

do you suggest any of them shift kits
i want one that will just make it more aggresive and one that i will enjoy driving around on

also if there is a shift kit that a stall converter would help with im willing to spend any amount of money needed too