CT5-V ZL1 1LE transmission in 5BW? Or, how the 5BW is a 7-speed missing 6th gear.

[thefleshrocket]

The wild drop in RPM between 5th and 6th gear is irritating. Redline in 5th gear is ~162mph; upshifting to 6th drops the RPM to around 4500 and completely kills acceleration. The drop in RPM from 5th to 6th is so huge, the transmission feels like a 7-speed, where 6th gear is missing. To be fair, I also don't like the stupid-tall 6th gear during normal street driving, either. There are numerous times where if I upshift to 6th gear, the engine almost feels like it's lugging, but if I downshift to 5th, the RPM feels too high.

From what I understand, the ZL1 1LE transmission's 6th gear is appropriately short. Has anyone considered swapping a 1LE transmission into a 5BW? Or, if possible, changing the ratio of 6th gear to something shorter?

This is mostly a theoretical conversation, as I'm sure any real fix will be cost / time / warranty prohibitive but.. I'm still wondering.

EDIT - I just discovered there's a thread with the same topic in the Blackwing mods section.. which is where I should have posted this to start with. Mods, you won't hurt my feelings if you move or delete this thread. Sorry.

 

[sps4runner]

Here is a perfect example of what he's talking about.

 

[BW56M]

Here is a perfect example of what he's talking about.

And another.

 

[CaddyTrack]

Here is a perfect example of what he's talking about.

ugh, to take it to 196, but not push it to 200+.....why just why. Set some goals

 

[RobC7]

ugh, to take it to 196, but not push it to 200+.....why just why. Set some goals

It takes a lot of power to cut through the air at that speed + you are gaining ground so quickly you end up running out of space.

 

[CBH]

I knew it would have lots of room left after redlining 5th, but how much faster can it go with the loss in momentum after the shift into 6th ?

I haven't had room to test it myself.

 

[Slick Blackwings]

I’m wondering if the claimed 200 MPH is done with automatic!

 

[RDATLTE]

I’m wondering if the claimed 200 MPH is done with automatic!

Or, without the top end robbing downforce of the carbon packages.

 

[Slick Blackwings]

Or, without the top end robbing downforce of the carbon packages.

Nope that’s not it, look up Recoil Racing YouTube videos, auto no carbon stock 196 MPH. Still pretty good

 

[Champale]

OP - I understand exactly what you are saying. Since the TR6060 transmission has been around for many years, I am sure there are revised ratios available. How much is a ZL-LE transmission brand new from Chevrolet?

 

[Slick Blackwings]

OP - I understand exactly what you are saying. Since the TR6060 transmission has been around for many years, I am sure there are revised ratios available. How much is a ZL-LE transmission brand new from Chevrolet?

I understand the cost as far as I could tell anywhere from $3000/4500, but the splines on shaft, is it the same as the Cadillac and the Camaro?

 

[Kevin0311]

Tremec TR-6060 transmission - Wikipedia

en.wikipedia.org

says torque ratings based on gearing, shows the different gearing ratios

 

[Champale]

TR6060 Gears - Texas Drivetrain Performance

At Texas Drivetrain Performance, we are proud to offer auto enthusiasts the parts they need to unlock the full potential of their vehicles. If you're looking to elevate your car's performance and precision, our TR6060 gears are the answer you've been searching for. We take pride in offering a...

www.txdrivetrain.com

 

[SS_Shooter]

The current gear ratios make the car very useable in every gear. For most highway driving, having that big 6th gear overdrive helps keep rpms low BUT is still very useable to get through traffic.

The issue is at that momentum is hard to gain after the 165 mph mark, but realistically, how often are you at that speed? Even on the track, you won't be running out of 5th gear anywhere this side of the Mulsanne straight....

 

[Exia]

This might matter on the autobahn but we don't get that here...

GM still tries to make its performance cars have some kind of fuel economy and I can say that putting the Blackwing in 6th still returns a good amount of torque that I never need to downshift on the highway unless I hit a traffic jam, same for the Camaro.

The ratios are designed for a number of reasons and the miniscule amount of owners who can take it to V max on a public road are not part of GMs calculations.

 

[bloominguez]

Thinking about 6th gear again, searched and found this thread. I don't even know whether we need 6th in this car for street driving the way it's geared. On the highway I'm at maybe 3200 rpm in 5th at 80, which drops to maybe 2100 rpm in 6th. If there are some uphill grades, and I'm working around traffic (most of the time around Atlanta), I just leave it in 5th. Yeah, 2100 is not too bad, but it's happier at 3000+ for this driving, and I don't notice a significant drop in mileage. Just feels strange to NOT automatically go to the highest gear when on the highway, this is a first for cars I've owned. I don't mind the way 6th is geared, if I'm cruising on a flat highway. I just don't use it very often with this car.

 

[565565]

Thinking about 6th gear again, searched and found this thread. I don't even know whether we need 6th in this car for street driving the way it's geared. On the highway I'm at maybe 3200 rpm in 5th at 80, which drops to maybe 2100 rpm in 6th. If there are some uphill grades, and I'm working around traffic (most of the time around Atlanta), I just leave it in 5th. Yeah, 2100 is not too bad, but it's happier at 3000+ for this driving, and I don't notice a significant drop in mileage. Just feels strange to NOT automatically go to the highest gear when on the highway, this is a first for cars I've owned. I don't mind the way 6th is geared, if I'm cruising on a flat highway. I just don't use it very often with this car.

Dude I'm in 6th by 55mph.

 

[hawk02]

I traded a standard M6 ZL1 (not a ZL1 1LE) for my 2023 5BW. The sixth gear in the standard ZL1 was strictly an overdrive gear. It had almost no power. Engine rpm was just under 2000 at 80 mph. To pass anyone at highway speeds required downshifting into 5th gear. My 5BW has a lot more juice in 6th than the ZL1. I rarely feel the need to downshift to pass at highway speeds unless I am going up a fairly steep hill.

 

[coffee_time]

Dude I'm in 6th by 55mph.

Similar here. If I'm on the highway I'll shift to 6th around 60.

I traded a standard M6 ZL1 (not a ZL1 1LE) for my 2023 5BW. The sixth gear in the standard ZL1 was strictly an overdrive gear. It had almost no power. Engine rpm was just under 2000 at 80 mph. To pass anyone at highway speeds required downshifting into 5th gear. My 5BW has a lot more juice in 6th than the ZL1. I rarely feel the need to downshift to pass at highway speeds unless I am going up a fairly steep hill.

Yeah you can still pass traffic EASILY in 6th on the highway.

 

[vagabond]

5th gear should be slightly shorter for track use, then perfect in every way.