I have a 2000 SS and I'm picking up a spare rear end to build and put in with a new t56. But I don't know which gears to go with the car is goin to see some normal everyday driving between me and my gf but I want to get into autoXing . . . but what gears are best? 3.42, 3.73, 3.90 or 4.10's?? I'll either be running C5 z06 rims or zr1 rims. Thanks for your time

I've got a 396 LT1, but I'll help as much as I can. I know I've read on here that a lot of people like 3.42 or 3.73. I've got 4.10 and I love them for the road course. In this video I took last weekend, I'm in 4th and 5th gear the for the entire race track, except for Oak Tree (the turn before the long back stretch), which is 3rd. I don't shift very much at all. I can pull out of a turn at 45 MPH in 4th gear, yet still bast down the straight at 130+ MPH with only 1 gear change. But, I've got tons of low end torque.

On the street, I don't like the 4.10s. Too much shifting. I think for the street, 3.73 or even 3.42s would be perfect.

I hope this helps just a little.

Steve

http://www.youtube.com/watch?v=FjiA3lfgU10

Awesome thanks man! I've been leanin towards 3.42's and 3.73's and since my gf will drive it everynow and then the less shifting the better for her lol what track is that btw??

I also have a 2000 SS with a t56 and im running 3.89 in a 9" set up, in 6 gear i can cruise at 70 MPH at around 1900 rpm and still get great high way mpg, and for the last 4 years i was running 3.70 and i like the 3.89 a lot better.

What class are you planning on running? I think some of those gears won't be stock replacements, and therefore not legal in some of the classes the car is eligible in. That said, depending on your region, you'll probably want to be able to run about 70 in second, maybe 65 if your region uses shorter courses, and maybe 75 if your region is famous for fast courses. That's what I'd look at, and set the gear in the car to hit.

I auto-x'ed a stock LS1 with the stock 3.42 gears, and for auto-x, I wouldn't go any lower. I had enough trouble being smooth and putting down the power with 3.42's, I don't see how 3.73 or 4.10 will help that.

Thanks guys! My car is an auto so I'm thinking any one of those will be better than my 3.23's with a t56 lol I'll have to check with the autoX club and find out . . . thankfully I haven't bought gears yet lol

Make sure you factor in rear tire size. From stock SS size to C5 size I lost about 3% then from 3.42 to 3.73 it made it roughly 6% lower than stock as opposed to 9%the lower if I run stock tires.

3.73 here. I feel its perfect for variable speed road courses. Makes using 3rd gear out of some of the slower corners possible. I'll spin near 6500 on some of the longer straights at 130ish MPH. No need for 5th gear which is technically an overdrive. I had to shift to 2nd much more with the 3.42s. I can't imagine 4.10s working well unless it is a very low speed course.

3.73 with direct top 4 speed Muncie. OK for all UK tracks with the possible exception of Snetterton. Oh I have 18" rims and 275 x 35 tyres.

Did you see my video? 2nd post of this thread.

That's with 4.10's, shifting at 5500 ish, and using only 4th and 5th, except for 3rd at the turn leading onto the front stretch.

I willl admit though, withought the TQ of the 396, it'd be a different story.

Steve

Have not seen it. I wouldn't want to use 5th gear on a road course. Its an overdrive.

When I say autoX I mean a smaller course with cones, not the larger road course that you spend more than a minute running. When the engine is built then I'll try road courses before the car goes to car shows and doesn't race anymore

Take 5 minutes and watch it.

Unless it's a road course with no/very short straight, you won't have a choice.
3.42 gears with my stock LT1 require 5th gear at Mid-Ohio, or bounce the rev limiter for about 50ft. And I'm slow... a faster driver would need to upshift even sooner.

In my AX region, our courses are from 45 to 65 seconds max. I'm in 2nd gear in my 2001 M6-3.42. But I'd love more low end power to come out of slow corners. I usually never get all the way up to the top of 2nd gear so I think 3.73 would be ideal to get more power but still have some legs. But I can't remember if a 4th gen ever came with 3.73 gears, so you might not be in ESP.

IF you do the final drive math, 4.10s is almost like moving the gear selection up one gear when compared to 3.42s.
2nd with 4.10s is like 1st with 3.42s, 3rd is like 2nd, 4th is like 3rd ...

Being as a 4.10 pinion shaft is significantly smaller, I just don't see it as a reasonable, long-term, viable option.

YVMV ...



3.42, 3.23 and 2.73 only, IIRC ...

I wonder what a 2.73 and 1st gear would be like?

Yep that's why I'll just be sticking with 3.42's until I have more power to get me along

See above post cause I suck at using my itouch lol

I have a 9" with 4.30's. My car makes 446rwhp/394rwtq. At VIR I used 3rd 4th and 5th and it seems to work well. The car is capable of 7k rpm, but I never shift higher than about 6200 at the track. 3rd gear pulls fine out of the slower corners, but I do have to be gentle on the throttle coming off the corners to keep the rear from spinning. But I'm just an hpde'er on street tires, more experienced guys may have different opinions on a 4.30 gear. I do think for autocross it would be way too much, it'd be hard to keep rear grip.

Watched it. Still wouldn't want to use an overdrive on the track unless its on the longest of straights. None of the tracks in central California have straight aways long enough to exceed 130ish MPH which is do-able in 4th gear with 3.73s or below. Additionally, the 3-4 shift is generally much faster than a 4-5 shift (not that my driving yet warrents shaving off hundreths of a second per shift....yet).

I understand. As I said before, 4.10 on the street is just way too much shifting. 1st gear is unusable at anything more than about 1/2 throttle. Even 2nd is easy to light them up with throttle only. But like I said, using 4th and 5th on the track seems to work pretty well. Someday, I'd probably go to 3.73 and see how it is. I just hope that I don't end up between gears all the time. And, as you could see, I still have to be careful with the power, even at low RPM in 4th gear.

Steve

I use only 3rd and 4th at most of my local tracks. None of the straights are long enough to exceed 130mph which I can do in 4th gear. You should switch Its easier to make the 3-4 shits and there is less paracitic loss when you don;t lug the car in overdrive (5th gear). I'm still having a tough time visualizing a track where 4.10s would be superior......too much tire spin for the tight tracks, too short of gears for the long tracks.

"Use the torque, Luke"