[christisnt]

I had my 2019 Camaro SS with the A10 dyno’d
It made 554 at 5800 rpm on 6 psi.
My question is regarding the gear that the test was done in.
It was done in third gear, all of the tests. 3rd gear is a 2.15:1.
I have seen that the best gear to dyno in with my car with the 10 speed is 7th gear because the ratio is 1:1.
Can anyone tell me what the difference in tests would be? Based on an educated guess.

[Msquared]

Yes, 7th gear is the 1:1 ration for this transmission. It's a direct drive with no gear reduction, so it would provide a bit less mechanical drag than the other rations. Also, because the engine is spinning a lot less quickly for a given wheel speed, it accelerates less quickly in 7th. So you remove a lot of inertial resistance from the rotating mass upstream of the transmission's input shaft, including the torque converter, and this also frees up a little power to the dyno roller.

On an old-school 4-speed automatic, such as a 4th-gen Camaro's, 3rd gear actually would be the direct-drive ratio. But in your car, the wheel speeds would be so low in 3rd, and the traction on the roller so poor, that I'm surprised nobody at the shop noticed. That would be enough to make me question if they know what they are doing in setting up and operating a dyno.

[christisnt]

So my tuner doesn’t usually dyno. he is more of a street tuner. so him and my mechanic were asking each other if they knew what gear to run it in and they both just decided with what they usually do which is third. the tune turned out great, especially knowing that it might have a little more power than what was recorded, not to mention it was only on 66% ethanol. How much more power do you think it would have in 7th gear? as and educated guess

[KingLT1]

3rd gear pull is skewing your power numbers a bit and its not putting enough load on the engine.

Most shops will dyno the A8 in 5th and A10 in 6th gear which is 1 gear below the 1:1 because they will exceed the dyno's MPH limit if not. That normally results in power reading 20whp low but very seldom will anybody actually use 1:1 on these cars unless they are running a Mile event.

Has the fuel system been upgraded?

[christisnt]

Originally Posted by KingLT1

3rd gear pull is skewing your power numbers a bit and its not putting enough load on the engine.

Most shops will dyno the A8 in 5th and A10 in 6th gear which is 1 gear below the 1:1 because they will exceed the dyno's MPH limit if not. That normally results in power reading 20whp low but very seldom will anybody actually use 1:1 on these cars unless they are running a Mile event.

Has the fuel system been upgraded?

yes, fore innovations low side dual pump, new fuel lines, and lt4 high side and lt4 injectors

[KingLT1]

Originally Posted by christisnt

yes, fore innovations low side dual pump, new fuel lines, and lt4 high side and lt4 injectors

Nice. I would get it back on the dyno or atleast do a street/track pull up into 6th gear and log some data.