So I have jsut switched over from my Vortech that I was running the 3.9 FD with to a Greddy TT kit. I have been trying to trade out my 3.9 FD pumpkin for a 3.5 one. Ive had a lot of interest but I recently was wondering....I am on a stock block with the GReddy kit, and running 9psi max on the car. Will a 3.9 FD really be that bad for the car? And should I really switch out to a 3.5 and that low boost level?

BTW this is my brothers name, forgot he was logged in.

 

I would switch back to the 3.5... The RPMs will shoot up really fast with the 3.9. I dont think you will enjoy it. Thats ofcourse just IMO

 

il trade ya. im planning on draggin my car in the future. so single turbo and some 3.9s are in my vew.

 

Trade someone with an auto and go with the 3.3 FD. I did that back when I was stock blocked and loved it, and now that I am built, I think it may have been one of the best mods to date!!!

 

3.9 isn't 'bad' for the car, but not ideal for your setup. 3.3 or 3.5 will be much better.

 

With that gearing you will need to shift so fast and so soon that you will probably bounce off the rev limiter all the time.Go and get a 3.3 or a 3.5 and call it a day.

 

if you are staying at 10 lbs or under, just get the 3.5. The 3.3 will feel a little bit boggy unless you get near 500. At 500 or more the 3.3 is exactly what the doctor ordered.

 

+1

 

If traction is possible and all things being equal the 3.9 would be faster. Chances are on street tires the 3.9fd will be too much.

+1 on Zivs advice. 3.3fd is for 500+whp cars.

 

Don't mean to thread jack, but i was wondering about doing a 3.9 gears on my car. My turbos don't fully spool until around 4200 rpm so i was thinking the gears would help the car get into boost a little faster (relatively speaking ). Any thoughts on this?

 

Don't do it...

Turbos are not RPM based. They are load based. shorter gears would take some load off the motor and may actually hurt spool times

 

Didn't think about that, thanks for the insight!


Maybe i should just put a fat chick in my hatch

 

Or another angry person

 

ZING!!!!!!