Darren P

iTrader: (1)

am I going to be better off with 3.70 or a 3.50 gear in turbo car with 6 speed tranny
my car is a 2002 Z-28 with a PTK air to air kit with a T67 turbo for now running 7 PSI but it will be more soon enough

BrandonDrecksage

iTrader: (1)

what are you doing? street driving? drag racing? road racing, auto x?

Darren P

iTrader: (1)

most of the time street but it will be on the dragstrip some with slicks or mickey thompson DRs

BAD ASS TA WS6

iTrader: (5)

I say 3.70 out of the two you listed.

I'm going to do a 3.90 in a 9", but that will be with a turbocharged 408.

Darren P

iTrader: (1)

well I was wondering if a 3.50 would allow it to build boost faster because it loads the engine more

JZ 97 SS 1500

iTrader: (2)

Go 3.50, you want load. Steep gears are not needed on a turbo car unless you have no cubes.

Zombie

iTrader: (2)

Another vote fore 3.50, it's what I have in my car. Worked good as a 6spd and I'm keeping them for the a3 setup.

Slow Z28

iTrader: (19)

what size TIRE? I guess that could be a consideration for everyone. 3.50 at 26" tire is similar to 3.70 at 28" tire, or atleast SOMEWHAT close

Mike 01WS6

I'd go for 3.50. I have stock 3.42's in mine and there's plenty of load. I like the long hard pulls too. When you're making that kinda power and torque, time spent in gear is much more beneficial then time spent out.

Slowhawk

iTrader: (12)

A Turbo system has a ton of midrange which is why you want a nice low gear to drive the torque. We are running 370's on the T88/408 combo from the old setup and might switch to a 3.40-3.50 gear.

sr71

iTrader: (17)

I have 3.50's and 31" tires. works great for me.

y2khawk

iTrader: (5)

I had 3.70's originally, and swapped to a 3.60. Both on a 28" 10.5W

I swapped more for extra MPH than load however

When I had the 6 speed, I tried various gears. 3.42, 3.55 and 3.73. 3.55 was the best match of RPM range, MPH, and ET.

Ryan K

iTrader: (11)

3.50's but thats to let me hit 140 in third...

67Firebird455

iTrader: (27)

I am also running 7psi in my stock-cube LS1 and a 6 speed, but running 4.10s, and I don't even get 7psi until the top of 3rd and into 4th, only 3-4 in 1st and 2nd, HUGE waste. I am also running a MP T70 T4 turbo rear-mount and 255/50/16 MT ET Street DR's. I wish I could go back to my 3.42's I originally had in the car! If I would've only known I was going to go FI I wouldnt've spent the $ getting the 4.10s! Just my .02, another vote for 3.50's on a 26" tire, or 3.70's on a 28".

cablebandit

iTrader: (37)

i vote 3.50ish on either tire. I did a 3.73 to 3.23 swap in one weekend and compared times during that same weekend...results were 3.73=10.16............3.23=10.12........I stayed with the 3.23 cause i didnt have to wind the motor up so high at the end of the track

WicketMike

iTrader: (13)

are 4.10's not even an option for a turbo?

I have 4.10's now with a 4400 stall, should i get rid of the gears? and what about the converter?

Pro Stock John

iTrader: (34)

I'm not 6mt, but I went 144mph with 3.50 and 28x10.5 tire. Not turbo either.

longrange4u

iTrader: (2)

Another vote for 3.50 Thats what I got in my STS M6

Frost

iTrader: (45)

You MUST mean 4th....

ABeasst

iTrader: (5)

no 3rd....auto