[lt4camaro]

Anyone know the rear axle ratio on the 2020 LT1 with a 10 speed auto? any optional gear ratios?. I would like to create a 3.27 or a 3.42 rear gear car with the 10 speed auto and with a GM performance torque converter. Even a 3.73 gear to have a 1/4 mile killer combo

[RyanR623]

Originally Posted by lt4camaro

Anyone know the rear axle ratio on the 2020 LT1 with a 10 speed auto? any optional gear ratios?. I would like to create a 3.27 or a 3.42 rear gear car with the 10 speed auto and with a GM performance torque converter. Even a 3.73 gear to have a 1/4 mile killer combo

3.27

[lt4camaro]

Originally Posted by RyanR623

3.27

So Ryan, the 10 speed auto SS or LT1 (v8 cars) have a 3.27 rear ? I thought they were like a 2.78 .
I know the manual V6 cars and I believe the 4 banger turbo manual cars got 3.27 posi rears.

[Bumbleboy92]

A8 - 2.77
M6 LT - 3.27
M6 SS - 3.73

The only rear diff without LSD are LT’s with A8

This is what I got from searching, not sure if same applies to LT1 or not. Someone chime in if I’m wrong. I also wanna say that the LT1 probably used the diff from LT’s so it could be missing coolers but I’m not sure 100% on that

Edit: I believe I’m right, here’s from Chevy

[lt4camaro]

Originally Posted by Bumbleboy92

A8 - 2.77
M6 LT - 3.27
M6 SS - 3.73

The only rear diff without LSD are LT’s with A8

This is what I got from searching, not sure if same applies to LT1 or not. Someone chime in if I’m wrong. I also wanna say that the LT1 probably used the diff from LT’s so it could be missing coolers but I’m not sure 100% on that

Edit: I believe I’m right, here’s from Chevy

So the A8 behind the LT1 V8 in the SS or the LT1 is a 2.77 ratio ring and pinion posi rear. Thats what I thought. Those cars need the 3.27 gear or a 3.42 gear to liven the car up. That and one of GM's performance torque converters or aftermarket converter. Thank you for the info.

[95 imp]

The 2020 LT1 M6 has a 3.73. What ever the SSA10 rear gear is will be the same in the LT1. From what everyone is saying, you can't change gear sets.

For the auto guys, you can slip the 3.73 diff in the A10 car.

[Ron2ss]

Originally Posted by lt4camaro

So Ryan, the 10 speed auto SS or LT1 (v8 cars) have a 3.27 rear ? I thought they were like a 2.78 .
I know the manual V6 cars and I believe the 4 banger turbo manual cars got 3.27 posi rears.

Just for reference: My A10 SS build sheet lists the axle ratio being 2.77.

[wnta1ss]

You cannot tune the transmission/torque converter on the 2020 A10 at this time. So, your differential swap and converter swap ideas will not work.

Side note, while the differential is a 2.77, the A10 has a 4.70 ratio for first gear. So the 2.77 is not as big of a deal as you think, your overall ratio launching is a 13.019, compare that to 9.9218 for the M6 car that has a 3.73 differential.

[Msquared]

Originally Posted by wnta1ss

Side note, while the differential is a 2.77, the A10 has a 4.70 ratio for first gear. So the 2.77 is not as big of a deal as you think, your overall ratio launching is a 13.019, compare that to 9.9218 for the M6 car that has a 3.73 differential.

This is an important point. The full ratio list for the A10 with V8 is:

1. 4.70
2. 2.98
3. 2.15
4. 1.77
5. 1.52
6. 1.27
7. 1.00
8. 0.85
9. 0.69
10. 0.64

That means that whereas the M6 and most traditional setups reach 1:1 in 4th gear, this A10 isn't there until 7th gear. I don't think changing to a 3:73 would be the way to go, even if it were easy to do. 1st gear would be so steep that it would just spin the tires, unless maybe one were on true drag slicks. The A8 is kind of similar, to the A10 in this way, not reaching 1:1 until 6th gear.

[lt4camaro]

Originally Posted by Msquared

This is an important point. The full ratio list for the A10 with V8 is:

1. 4.70
2. 2.98
3. 2.15
4. 1.77
5. 1.52
6. 1.27
7. 1.00
8. 0.85
9. 0.69
10. 0.64

That means that whereas the M6 and most traditional setups reach 1:1 in 4th gear, this A10 isn't there until 7th gear. I don't think changing to a 3:73 would be the way to go, even if it were easy to do. 1st gear would be so steep that it would just spin the tires, unless maybe one were on true drag slicks. The A8 is kind of similar, to the A10 in this way, not reaching 1:1 until 6th gear.

A 3.73 gear may be a bit much for the low rpm LT1 engine, but imo a gear ratio of at least 3.20 would liven up the A8 or the A10 camaro performance noticeably. Thank you for your input, appreciate it bud.

[lt4camaro]

Originally Posted by wnta1ss

You cannot tune the transmission/torque converter on the 2020 A10 at this time. So, your differential swap and converter swap ideas will not work.

Side note, while the differential is a 2.77, the A10 has a 4.70 ratio for first gear. So the 2.77 is not as big of a deal as you think, your overall ratio launching is a 13.019, compare that to 9.9218 for the M6 car that has a 3.73 differential.

The A10 and the A8 LT1 camaros could use a rear gear ratio better than 2.77 imo, a 3.20 would be a definite boost in performance. GM sells a drag package for the NA V8 cars that includes a converter, the cars must be tuneable I would think. If was was to gear any car and or do a much better torque converter, I would tire the car accordingly to make the better launch characteristics work. Thank you for you input, I truly appreciate it.

[KingLT1]

Originally Posted by lt4camaro

The A10 and the A8 LT1 camaros could use a rear gear ratio better than 2.77 imo, a 3.20 would be a definite boost in performance. GM sells a drag package for the NA V8 cars that includes a converter, the cars must be tuneable I would think. If was was to gear any car and or do a much better torque converter, I would tire the car accordingly to make the better launch characteristics work. Thank you for you input, I truly appreciate it.

It depends on what you are doing. For 1/4 mile racing It has been proven the A8 cars don't gain much from a gear swap. In stock or light bolt-on form you might gain a little from a 3.27 but once you start to add significant power, 1st gear becomes too short. For roll racing the steeper gear would definitely help the 4-5 on the A8.

And no the 2020 SS A10 transmissions can not be tuned at this point since GM switched the TCM controller to the T93. So the Only A10 cars that have tuning support are the 2017-2019 10L90 and 2019 10L80. The GM drag pack was introduced long before the A10 came around and that is really irrelevant anyway. You can run a drag pack on anything long as the tire height is close to the stock specs. Even if it isn't it will only skew the speedo reading.

[lt4camaro]

Originally Posted by KingLT1

It depends on what you are doing. For 1/4 mile racing It has been proven the A8 cars don't gain much from a gear swap. In stock or light bolt-on form you might gain a little from a 3.27 but once you start to add significant power, 1st gear becomes too short. For roll racing the steeper gear would definitely help the 4-5 on the A8.

And no the 2020 SS A10 transmissions can not be tuned at this point since GM switched the TCM controller to the T93. So the Only A10 cars that have tuning support are the 2017-2019 10L90 and 2019 10L80. The GM drag pack was introduced long before the A10 came around and that is really irrelevant anyway. You can run a drag pack on anything long as the tire height is close to the stock specs. Even if it isn't it will only skew the speedo reading.

I am interested in 1/4 mile ET and 60ft times only . I would like to assume a gear change or a converter change , a tune for performance and torgue management along with a sticky tire I could achieve at least a .5 ET reduction and be looking for more. Can the 2020 A10 be tuned at all ? like wot shift points? especially in 1, 2 and 3 upshifts. They all seen to shift early in the lower gears at wot.

[KingLT1]

Originally Posted by lt4camaro

I am interested in 1/4 mile ET and 60ft times only . I would like to assume a gear change or a converter change , a tune for performance and torgue management along with a sticky tire I could achieve at least a .5 ET reduction and be looking for more. Can the 2020 A10 be tuned at all ? like wot shift points? especially in 1, 2 and 3 upshifts. They all seen to shift early in the lower gears at wot.

I dropped .5 alone with a tire change. I gained more from that mod then all of the others combined in the 1/4 mile when I was NA.

Mods were: Pray ported IM/TB, CA cat deletes, Rotofab dry, flex sensor. Best street run bone stock was a 12.4. Then dropped to a 12.0 with mods above still on stock run flats. Switched to 305/35/20 555r DR's and went 11.5... and it would do it all day. Gear and converter are the last mods I would do unless its a Head/Cam car with a Ported MSD or Hiram.

Nope...all transmission parameters are located in the TCM which is currently untouchable for 2020+ and HPtuners has said they have no plans to support it.