Best rear end gear ratio for all around performance?

[2SSHADOWLSX]

Okay, so I have the stock 3.45 rear end gears in my 2SS. I plan to install a whipple 2.9L supercharger that will ultimately give me around 825 at the flywheel, or 700 and change at the wheels. Would my car perform better on the street, strip and track with the 3.45 gears at around 700< wheel, or would it be better to change them out for 3.73/3.91 gears for all around performance? I roll race, drag race, and take the car to the track, but most of the time I drive it on the street. I'm concerned for top end speed as well as acceleration, but I'm not sure what would be all around faster. I don't believe I will run into any issues where I am going so fast my car can't rev any higher without over revving, but I'm not sure what would give me the best speed in general. If I had 3.73 gears would I be slower at higher speeds north of 130 verses my 3.45 gears, or would I be faster in general with just a lower top speed number with the 3.73s?

[Vegas Bound]

Depending on transmission, your best gear ratio would be around 3.50. The SS diff and axles won't last long with that power. As you have 3.45, you are manual trans.
The ZL1 3.73 are awesome, I run them, but low end traction is an issue on poorly prepped tracks. I wish someone made a 3.50 for the ZL1 case.
3.23 will give you better trap speeds than 3.73, but 3.73 will give better 60'.
There is more to consider than just gear ratio. Add a trans swap and everything starts over.

[Vegas Bound]

You could run the 3.73 and use the MT ET Street R 315/50x17 and that would be the same ratio as a 3.50 with 305/45x17.

[Vegas Bound]

With a stick, you should be running slicks at the drag strip anyway.

[POWERFREAK]

With a whipple, traction is going to be a big issue...and you're going to have to shift quickly...I'd leave the stock ratio in there for now and see how you like it once you've added the power.

[fz4k98]

I have a 2.9l whipple on my ls3 ss. When it came to replace the rears end, people I talked to said I should stay with the 3.45s since I'm struggling to get it to hook off the line even with slicks,

Higher gears numbers equal higher torque to the tires at launch which can make it worse if there is trouble already.

Be prepared to replace a lot of driveline and rear suspension stuff. That kind of power is addictive.

[TommyC]

Agreed with all posts. You only want higher numerical ratios on n/a builds. Especially positive displacement blowers, the longer the first gear, the better. You’ll have so much low end torque compared to a big cammed n/a setup

[Greenhornet2]

I'm on stock drivetrain and don't plan to change the gears. I'm on road course tires and 1st gear is basically useless. 2nd holds on good roads. I have slicks for the track on 17" welds but haven't run it at the track, i think i'll hook in 1st at the track but clutch is stock and i'm not ready to do the trans work. On the street i'm not breaking anything

[fz4k98]

Originally Posted by Greenhornet2

I'm on stock drivetrain and don't plan to change the gears. I'm on road course tires and 1st gear is basically useless. 2nd holds on good roads. I have slicks for the track on 17" welds but haven't run it at the track, i think i'll hook in 1st at the track but clutch is stock and i'm not ready to do the trans work. On the street i'm not breaking anything

The stock drivetrain works as long as you don't hook up the tires on hard launches with slicks etc. I drove mine for 1 year and half on stock drivetrain and after 3 runs with slick destroyed a lot of parts. I hammered the rear cradle up and twisted it right, cracked 2nd gear in the trans, created a vibration in the driveshaft and twisted the trailing arms etc. About 3k later the posi was burned up.

Still smiling though, it's addicting.

[2SSHADOWLSX]

When I said "Track", I wasn't referring to a drag strip, I was talking about a track with turns and laps, trying go figure out what would give me the best lap times. As far as the street is concerned it seems I might be better off with the stock rear based off of the advice I'm being given in this forum. If I brace my car to prevent wheel hop I might be fine.

[10 Bumblebee]

I would gear a track car to be at the top of fourth gear (1:1) at the end of the longest straight.