FINALLY - C7 3.90 and 4.10 Differential Gear Sets
#22
Drifting
#23
Race Director
,
The point being competition gear sets are not recommended for street use, and visa versa, So again what grade of steel are these made of and for what venue were they designed? Street or true competition? And as a side note these are gears for the rear differential, not the transmission as some are assuming.
The point being competition gear sets are not recommended for street use, and visa versa, So again what grade of steel are these made of and for what venue were they designed? Street or true competition? And as a side note these are gears for the rear differential, not the transmission as some are assuming.
#24
Burning Brakes
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Gear ratios are pre-programmed into the engine and transmission calibrations and the gear position indicator is set and can be learned with a GM tool (but isn't needed).
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phantom1 (02-17-2019)
#28
Drifting
#29
Drifting
i think you are confusing these with drag only gear sets which are made if a softer alloy which makes them less brittle and allows the gears to absorb the shock of a launch. The downside of these gears is that they wear quicker. These gears don’t appear to be drag only gears.
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#33
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2018 C7 of Year Finalist
Out of curiosity, Lets say I am trapping 140-141 consistently in the 1/4 with my M7 Stingray. Is there any kind of guess what this would raise my trap speed to with a 4.10 set? Purely speculative, not looking for an exact scientific number. Just trying to gauge the expected performance gain from going to these gears.
And any estimate on labour time? My car is going into a shop for a month and will already be on a lift with the motor out....
And any estimate on labour time? My car is going into a shop for a month and will already be on a lift with the motor out....
#34
Le Mans Master
Out of curiosity, Lets say I am trapping 140-141 consistently in the 1/4 with my M7 Stingray. Is there any kind of guess what this would raise my trap speed to with a 4.10 set? Purely speculative, not looking for an exact scientific number. Just trying to gauge the expected performance gain from going to these gears.
And any estimate on labour time? My car is going into a shop for a month and will already be on a lift with the motor out....
And any estimate on labour time? My car is going into a shop for a month and will already be on a lift with the motor out....
So, you can do a comparison with your current gears vs. 4.10 gears on a spreadsheet based off the data from a dyno graph to see which one will work better.
#35
Drifting
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It all depends on setup and power curve. With most cars you want to shift several hundred rpm above peak hp and go through traps above as well. This will yield the best et and mph provided traction and that your car can handle it and run stable at those rpms.
So, you can do a comparison with your current gears vs. 4.10 gears on a spreadsheet based off the data from a dyno graph to see which one will work better.
So, you can do a comparison with your current gears vs. 4.10 gears on a spreadsheet based off the data from a dyno graph to see which one will work better.
#36
Drifting
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Talked with RPM today and they said Trap speed shouldn't change too much, might pick up in the 1/8th but lose on the back half for instance, but we really won't know till some cars get out there and try them out. But the gear sets are $850 and about 15 hours of labor to install for all of you interested.
#37
Burning Brakes
Modern vehicles use wheel speed sensors. The only thing that will change your speedometer is tire height. Since the C5 for sure, not sure about the C4.
Gear ratios are pre-programmed into the engine and transmission calibrations and the gear position indicator is set and can be learned with a GM tool (but isn't needed).
Gear ratios are pre-programmed into the engine and transmission calibrations and the gear position indicator is set and can be learned with a GM tool (but isn't needed).
Last edited by phantom1; 03-14-2019 at 05:47 PM.
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Rpinaiii (09-28-2020)
#38
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no there should be no learning needed. unless something changed with the C7, I don't think anyone has been swapping gears in manuals until now.....maybe I am wrong about it.
#39
Burning Brakes
Thanks
Last edited by phantom1; 03-14-2019 at 08:14 PM.
#40
Drifting
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Should look into getting a Dragy, or borrowing a Dragy/Vbox from someone else who has one. That will tell you for sure and then you can also compare performance data.