Turbos and New Gearing Affects? - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

HOJO · 05-10-2021, 02:38 PM

I have a question for the Camaro family, especially those with gearing experience in performance.

Last fall I installed a new cam and a set of AGP twin turbos on my 1LE and it is just stupid fun and fast to say the least, for my older age anyway. So here is my question; I am changing the rear cradle & diff assembly for a ZL1 drop out I picked up. The ZL1 diff is from a manual so the gears are 373.

From my research I find that the ZL1 and 1LE transmissions have identical gearing in gears 1-4. 5th and 6th gear are different as the ZL1 are a little shorter. This means my final drive ratio will be going from 2.89 to 2.76 in 5th and 1.96 to 1.86 in 6th.I am just wondering how my 5th gear performance will be with the drop in gearing. Not really worried about 6th gear.

TIA for your knowledge, experience and input.

HOJO

dreksnot · 05-10-2021, 03:35 PM

Being one who's tried 3.25 through 3.73, and from SS to ZL1/1LE tranny gearing, you will notice the difference. I presume you want to know what going from a 3.91 to 3.73 will be like? It's not going to be huge but you will notice you'll need just a little more clutch to start out.

HOJO · 05-10-2021, 06:19 PM

Thanks Drek, hoping you would chime in as I know you’ve been down this path in various ways. Not to worried about 1-4 just wonder if 5th gear will be very useful. I know turbos like to be loaded and that gear will do it, just not sure that’s the load they like. Lol

dreksnot · 05-10-2021, 07:38 PM

Quote:

Originally Posted by HOJO

Thanks Drek, hoping you would chime in as I know you’ve been down this path in various ways. Not to worried about 1-4 just wonder if 5th gear will be very useful. I know turbos like to be loaded and that gear will do it, just not sure that’s the load they like. Lol

What is your concern - not pulling in 5th gear?

I'm running a similar gearing but 0.76 versus 0.74 5th gear drive. Running my 3.25 rear in 5th is no problem at 55mph (~1,600rpm) but I don't want to try and accelerate uphill; it's good for flat or small hilly cruise.

HOJO · 05-10-2021, 09:14 PM

Yeah, actually more concerned with how it would pull in 5th under hard acceleration if needed. Never know who may roll up on ya. Not that it’s my plan to run it out that far but it could happen. I figured it would be good on the road with a little lower rpm but as you stated nothing to hilly without a down shift I’m sure. Hoping to do the install in a couple weeks, still waiting on the driveshaft.

dreksnot · 05-10-2021, 10:34 PM

I shift into 5th gear at 163mph: 2018 Colorado Mile

That was with my SS tranny gearing and 3.25 rears. See how close the 1LE and 3.73 overall ratio is in 5th gear. Had about 745rwhp on this run.

HOJO · 05-11-2021, 01:56 PM

Thanks Drek, that helps give me a better perspective on what to expect with the new unit. Those numbers look good. I bet yours pulls like a freight train. Hopefully the driveshaft will be here in the next week or two and I can get this in and going.

dreksnot · 05-11-2021, 08:31 PM

Quote:

Originally Posted by HOJO

Thanks Drek, that helps give me a better perspective on what to expect with the new unit. Those numbers look good. I bet yours pulls like a freight train. Hopefully the driveshaft will be here in the next week or two and I can get this in and going.

I thought that could help. I'm glad. That mile run was with my old SBE LS3 and AGP base kit. I'm sure it would be a totally different story with the new LSX427 and bigger twins, and next level power. Too bad they stopped doing the Colorado Mile (wasn't economically feasible anymore). Guess I have to pack up and go to Texas!

*SSE 4 2SS* · 05-12-2021, 10:44 PM

I’m not sure the power you are making but bare in mind that loading a bunch of power on stock trans gears at speed is rough on them.... 1-4 shouldn’t be an issue, and depending on your power level and traction.....

In my case, 1-5 are all billet gears with billet shafts.

I run a 3.07 rear gear with the ZR1 gear ratio in my trans....

I keep in mind that shifting to 6th under power is a quick recipe for needing a new transmission....

Usually not an issue, but high gear hard pulls are rough.... especially in these heavy cars.... but with the 3.73 you should pull 5th really well...

HOJO · 05-13-2021, 01:53 PM

Quote:

Originally Posted by SSE 4 2SS

I’m not sure the power you are making but bare in mind that loading a bunch of power on stock trans gears at speed is rough on them.... 1-4 shouldn’t be an issue, and depending on your power level and traction.....

In my case, 1-5 are all billet gears with billet shafts.

I run a 3.07 rear gear with the ZR1 gear ratio in my trans....

I keep in mind that shifting to 6th under power is a quick recipe for needing a new transmission....

Usually not an issue, but high gear hard pulls are rough.... especially in these heavy cars.... but with the 3.73 you should pull 5th really well...

Thanks for the insight SSE. I'm Currently at 650 rwhp and 619 torque and running at 8 psi. Plan is to up the boost to 12 psi when I have a few more miles on the car....it's a 2014 and I have roughly 6400 miles on it and 400 since the install. I never really considered how hard it would be on the tranny up in 5th gear with a load, something I will need to watch I'm sure.

Thanks again gentlemen I greatly appreciate your input.

Rem0v3r · 05-21-2021, 07:11 PM

I went from the 3.23 to 3.73.. car feels faster although I kinda miss how my old gear loaded my turbos.

05-10-2021, 02:38 PM	#1
HOJO Drives: 2014 Camaro SS/RS 1LE 1967 Camaro Join Date: Oct 2013 Location: Fort Wayne, IN Posts: 887	Turbos and New Gearing Affects? I have a question for the Camaro family, especially those with gearing experience in performance. Last fall I installed a new cam and a set of AGP twin turbos on my 1LE and it is just stupid fun and fast to say the least, for my older age anyway. So here is my question; I am changing the rear cradle & diff assembly for a ZL1 drop out I picked up. The ZL1 diff is from a manual so the gears are 373. From my research I find that the ZL1 and 1LE transmissions have identical gearing in gears 1-4. 5th and 6th gear are different as the ZL1 are a little shorter. This means my final drive ratio will be going from 2.89 to 2.76 in 5th and 1.96 to 1.86 in 6th.I am just wondering how my 5th gear performance will be with the drop in gearing. Not really worried about 6th gear. TIA for your knowledge, experience and input. HOJO

05-10-2021, 03:35 PM	#2
dreksnot Served USN - Atomic Chimp Drives: 2021 Camaro ZL1 1LE A10 (stock) Join Date: Jul 2012 Location: Fort Collins, CO Posts: 1,709 View My Garage	Being one who's tried 3.25 through 3.73, and from SS to ZL1/1LE tranny gearing, you will notice the difference. I presume you want to know what going from a 3.91 to 3.73 will be like? It's not going to be huge but you will notice you'll need just a little more clutch to start out. Attached Images __________________ > > 2021 Camaro ZL1 1LE A10 > > Past Builds: 2013 Twin-Turbo LSX434 M6 - 1,359rwhp daily

05-10-2021, 10:34 PM	#6
dreksnot Served USN - Atomic Chimp Drives: 2021 Camaro ZL1 1LE A10 (stock) Join Date: Jul 2012 Location: Fort Collins, CO Posts: 1,709 View My Garage	I shift into 5th gear at 163mph: 2018 Colorado Mile That was with my SS tranny gearing and 3.25 rears. See how close the 1LE and 3.73 overall ratio is in 5th gear. Had about 745rwhp on this run. Attached Images __________________ > > 2021 Camaro ZL1 1LE A10 > > Past Builds: 2013 Twin-Turbo LSX434 M6 - 1,359rwhp daily

05-12-2021, 10:44 PM	#9
SSE 4 2SS Boosted Moderator Drives: Bone Stock LS3 Join Date: Sep 2009 Location: Marion Tx Posts: 15,799	I’m not sure the power you are making but bare in mind that loading a bunch of power on stock trans gears at speed is rough on them.... 1-4 shouldn’t be an issue, and depending on your power level and traction..... In my case, 1-5 are all billet gears with billet shafts. I run a 3.07 rear gear with the ZR1 gear ratio in my trans.... I keep in mind that shifting to 6th under power is a quick recipe for needing a new transmission.... Usually not an issue, but high gear hard pulls are rough.... especially in these heavy cars.... but with the 3.73 you should pull 5th really well... __________________ If the car feels like it is on rails, you are probably driving too slow. -Ross Bentley Horsepower is how fast you hit the wall. Torque is how far you take the wall with you. “If everything seems under control, you're just not going fast enough.” Mario Andretti If you can turn, you ain't going fast enough...

05-10-2021, 06:19 PM	#3
HOJO Drives: 2014 Camaro SS/RS 1LE 1967 Camaro Join Date: Oct 2013 Location: Fort Wayne, IN Posts: 887	Thanks Drek, hoping you would chime in as I know you’ve been down this path in various ways. Not to worried about 1-4 just wonder if 5th gear will be very useful. I know turbos like to be loaded and that gear will do it, just not sure that’s the load they like. Lol

05-10-2021, 09:14 PM	#5
HOJO Drives: 2014 Camaro SS/RS 1LE 1967 Camaro Join Date: Oct 2013 Location: Fort Wayne, IN Posts: 887	Yeah, actually more concerned with how it would pull in 5th under hard acceleration if needed. Never know who may roll up on ya. Not that it’s my plan to run it out that far but it could happen. I figured it would be good on the road with a little lower rpm but as you stated nothing to hilly without a down shift I’m sure. Hoping to do the install in a couple weeks, still waiting on the driveshaft.

05-11-2021, 01:56 PM	#7
HOJO Drives: 2014 Camaro SS/RS 1LE 1967 Camaro Join Date: Oct 2013 Location: Fort Wayne, IN Posts: 887	Thanks Drek, that helps give me a better perspective on what to expect with the new unit. Those numbers look good. I bet yours pulls like a freight train. Hopefully the driveshaft will be here in the next week or two and I can get this in and going.

05-21-2021, 07:11 PM	#11
Rem0v3r Drives: 2013 ss2 vert l99 Join Date: Apr 2017 Location: South florida Posts: 151	I went from the 3.23 to 3.73.. car feels faster although I kinda miss how my old gear loaded my turbos.