i was just curious. all the big nitrous guys i see have 3.73's or 4.11's. this car is an ms3 with 28" tall qtp's AND an m6, i was thinking 4.30's would be the optimal gear, and i know it will be N/A, but how will 150 - 175 shot be?

 

Run as much gear as you can for the MPH you want - that's the conventional wisdom anyway. The big dogs run numerically lower gears because they need them for the mph. Some M6 guys like the numerically lower gears so they have a little more time before they're shifting, and to make it easier for the tires to handle the hit.

 

ok. well that makes more sense. mph calculator dumdumdum. thanks.

 

I am switching to 4.10s the 4.30's might be too much rpm to pull through the traps. They were for my old setup.

 

cool. thanks guys.

 

Cam only and 150 shot with a th350 and a 4.30 gear i was on the limiter going through the traps at 7200. Trap speed was 137. Might want to go with a 4.10 or 3.73.

 

i would stick with a 4.10.

 

With no converter slip you might be able to get away with 4.30's, depends too on how much those tires grow and how high you're willing to spin the motor.

Calculate it out with the tires at 29 inches in diameter (roughly an inch of groth) and see what that gives you for available mph at your max rpm... if it's not enough then 4.10 the car.

If 4.30 is optimal for n/a use chances are it's not gonna be enough gear when you're spraying the car. Figure that a 150 shoht should add about 15 to 17 mph to the trap speeds from what the car runs n/a

 

I had 4.57's and a 28" tall tire and would run out of gear about 133-134 at 7400. No experiance with 4.30's but I think they will get you in the ~145 range with a 28" tall tire.

 

what size tire was that with?

 

local ls1 this weekend just went 140 mph on the 7000 rpm limitor at the traps with a 28" et drag and 4.10 gear.

depends on where you want to be mph and rpm wise.

 

Also, take into account your 60ft times... A car that spins off the line is going to theoretically run out of gear faster then a car that dead hooks. That is a lot of the variation you see from car to car, atleast from my experience.

 

that also makes ALOT of sense. and we're planning on DEAD hooking. another factor is RPM's. think 4.30's will be the perfect gear for this car. and if not a 29" tire will be enough to correct that.

not only that, but say eventually the car were to have a motor that loves rev's, like 7500+, the gear will also fit in there.

 

Sounds like your mind is made up.