[Crusher Camaro]

Originally Posted by Camfab

I think you may be under the impression that the ZLE is a wide ratio trans. It’s the opposite. 1st gear is far taller than a standard ZL1. It has a specific close ratio box for road racing. Gears are tightened up including both overdrive gears (5th and 6th). Coming out of a wide ratio trans, I absolutely love this box. I’ve never had a manual trans that works as good as the ZLE box and the gearing is awesome. I do understand the grass is always greener on the other side. I was on the other side for twenty years, lol. Perfect trans inmho.

pretty sure the zl1 and the zl1 1le share the same gears 1-5, 6th is the only change.

Edited:
they are close, found the old chart.

[Camfab]

Originally Posted by Crusher Camaro

pretty sure the zl1 and the zl1 1le share the same gears 1-5, 6th is the only change.

Edited:
they are close, found the old chart.

Yeah, it appears I am WRONG! However that chart is incorrect as well.
Crusher I found two other sources on the net that appear to be wrong as well. I went to the tremec site and found the applications specifically for the Zl1 and then the ZL1 1LE which shows both transmissions have the exact same gearing other than 6th. I have a Chevrolet factory publication that stated otherwise but it seems it may be wrong. I’m not sure what to believe at this point….

[Camfab]

So there’s this…..
https://static.nhtsa.gov/odi/tsbs/20...26120-9999.pdf

Then there’s this….
https://www.tremec.com/anexos/Product.Sheet_TR-6060.pdf

Is any of this correct?

[Camfab]

Back on point SoCal, sorry for the deviation. I think a slightly taller tire as mentioned above may be your only reasonable cost choice at this juncture. It will like change the handling characteristics slightly.

[2SS Capt]

The ZLE gearbox was built for one thing, racing, not cruising... It is a compromise you have to make for the performance...

[Gunkk]

Originally Posted by Camfab

a slightly taller tire as mentioned above may be your only reasonable cost choice

Not sure I would recommend this approach. Any tire that's tall enough to make a butt-dyno difference will probably also throw a stabilitrak code if it doesn't also rub the harness.

[Camfab]

You guys would know best, but I’m thinking one size bigger will help knock a few rpm off the cruising speeds. I went with a larger size on my old car just to pick up a couple mile an hour through the traps in the qtr as I was on the limiter. It’s a relatively simple change if the correct size is available, and yes if you needed to move or secure a harness, well that’s something you have to take care of. Throwing codes, well that’s certainly a pain. I don’t care for the over sensitivity these cars have, however it’s hard to argue with the out of the box performance package.

[Kamero6]

Originally Posted by Camfab

You guys would know best, but I’m thinking one size bigger will help knock a few rpm off the cruising speeds. I went with a larger size on my old car just to pick up a couple mile an hour through the traps in the qtr as I was on the limiter. It’s a relatively simple change if the correct size is available, and yes if you needed to move or secure a harness, well that’s something you have to take care of. Throwing codes, well that’s certainly a pain. I don’t care for the over sensitivity these cars have, however it’s hard to argue with the out of the box performance package.

The cost of the wheels/tires doesn't justify the almost insignificant increase in MPG.

I've seen people chase MPG in 60's cars and after changing diff ratios, tires and spent a buch of money they got 0.5mpg. Not worth it.

[Kamero6]

This guy installed a 2.85 in his M6 ZL1. It's very long geared...

[SOCAL.M6.ZLE]

Damn, that's exactly what I was looking for... just not as low of a gear as that.

Nice to know it works, would be curious to see what the RPM's were at 80mph unless I missed that detail. Would cool to feel my car with those gears for a day

[Kamero6]

Originally Posted by SOCAL.M6.ZLE

Damn, that's exactly what I was looking for... just not as low of a gear as that.

Nice to know it works, would be curious to see what the RPM's were at 80mph unless I missed that detail. Would cool to feel my car with those gears for a day

I really appreciate this guy doing this, to see the results, and sharing with the community.

But in my personal opinion, I think he just made a mistake. (a fun one though )

Speed @6500
1 --> 82 mph
2 --> 117 mph
3 --> 155 mph
4 --> 188 mph
5 --> 229 mph
6 --> 276 mph


If you want try it, Skip 1st altogether, move the car in 2nd gear only, then shift to 4th and then 6th.

He turned a 6 speed into 3 speed transmission . With 3 overdrives.
He might also have cut off max speed.
Even with over a 1000hp, to drop 5th you need to be over 170mph, unless you race nascar I don't see that happening.