hey guys, i will be running the mods in my sig. i just bought a strange 12 bolt with eberything but gears. it had a set of 4:11's but i know there no good for FI cars. befroe the 12 bolt i had stock rear end with 3:42's. should i stick with 3:42's or go to 3:73 or 3:90? its a street car but i dont car much about highway use to much seeing as its a 6 speed. thanks

 

What are you using the car for? What kind of tires?

For the track, rear axle ratio is determined by trap speed, engine redline, tire diameter and peak HP RPM. For the street its more an issue of what kind of traction can you get with the particular tires you are running.

 

well the car is a street car. it will see the track a few times for fun of course. but really i want it for light to light. i should be getting my hands on a set of c6 rims 18x10.5 rears with 295/?/18 drag radials. hope this helps. thanks

 

3.73:1 is a good street gear for a FI car. I think 4.10:1 is to much for FI on the street. Possibly you also have the choice of 3.90:1 with the Strange R_end. I almost went there. B.

 

so you are running 3:73 in a FI car? i know 4:10 is to high. i just want to get what will give me the best light to light/1/4 mile performance. thanks

 

You need to provide the info Fred asked for to get a more precise answer, but it is probably going to end up with 3.42's as the best choice unless you are running a tall tire.

Rich

 

The guys I know running FI lean towards 3.73's, but they may have a higher redline or taller tires than your set up. I agree, give Fred (Injuneer) the info and see what he comes up with.

 

Yes, running a Moser 12 with 3.73:1 gear with a TruTrac diff. (97ss 383 - D1 M6). Sorry, I'm not set-up for drag racing. More street-road/ cornering. 4.10:1 caused alot of wheel spin (old 7 1/2" 410 geared rear) even with a decent tire (315-35-17 bfg-kd) upgrade. Almost went 3.90:1. I had a 3.89:1 gear in my old boss 351 and liked it. With a T56, there are two overdrive gears, so, a cruz with 390 gear should be OK. B.