C7 3:90 & 4:10 Gears
01-04-2019, 10:49 PM
#181
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A320Flyer (01-09-2019)
01-05-2019, 03:33 AM
#183
Drifting
Member Since: Oct 2013
Location: Fort McMurray Alberta
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2018 C7 of Year Finalist
Out of curiosity, will this change the trap speed of a car as well? It makes sense to me as you are in your power band much more, therefore making more power longer. But I am not very experienced with gear ratios.
From an online calculator, I put in at 7000rpm with a 4.10 ratio and 28.5” tire diameter, it came up with a top speed of 144mph. And currently on my set up I cross the line at ~141mph @6815rpms which is very close to my redline in 4th. Would I be better off doing a 3.90 ratio instead which gives me a top speed of 152mph in 4th? Assuming a 141 trap, I’d cross the line at ~6483rpm which is better than the 5700 I’m currently crossing at. Should note, my power begins to fall off at 6700.
From an online calculator, I put in at 7000rpm with a 4.10 ratio and 28.5” tire diameter, it came up with a top speed of 144mph. And currently on my set up I cross the line at ~141mph @6815rpms which is very close to my redline in 4th. Would I be better off doing a 3.90 ratio instead which gives me a top speed of 152mph in 4th? Assuming a 141 trap, I’d cross the line at ~6483rpm which is better than the 5700 I’m currently crossing at. Should note, my power begins to fall off at 6700.
Last edited by blue_bomber697; 01-05-2019 at 03:46 AM.
01-11-2019, 06:43 PM
#187
Safety Car
I got a different answer from other person at RPM. He said Motive Gear was the only source and it would be at minimum a year away. He sounded like he knew what he was talking about.
Wish I received better news...
would love to have 4.10s.
What a dream they were to drive in my stick shift C6.
.
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phantom1 (01-12-2019)
01-12-2019, 06:20 PM
#189
Burning Brakes
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01-13-2019, 04:23 PM
#190
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St. Jude Donor '05
know there is epa stds but holy cow what performance car comes with a 2. or low 3. anything? Girly!
01-13-2019, 05:28 PM
#192
Burning Brakes
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01-13-2019, 05:31 PM
#194
Burning Brakes
Thread Starter
01-14-2019, 11:44 AM
#197
Le Mans Master
Out of curiosity, will this change the trap speed of a car as well? It makes sense to me as you are in your power band much more, therefore making more power longer. But I am not very experienced with gear ratios.
From an online calculator, I put in at 7000rpm with a 4.10 ratio and 28.5” tire diameter, it came up with a top speed of 144mph. And currently on my set up I cross the line at ~141mph @6815rpms which is very close to my redline in 4th. Would I be better off doing a 3.90 ratio instead which gives me a top speed of 152mph in 4th? Assuming a 141 trap, I’d cross the line at ~6483rpm which is better than the 5700 I’m currently crossing at. Should note, my power begins to fall off at 6700.
From an online calculator, I put in at 7000rpm with a 4.10 ratio and 28.5” tire diameter, it came up with a top speed of 144mph. And currently on my set up I cross the line at ~141mph @6815rpms which is very close to my redline in 4th. Would I be better off doing a 3.90 ratio instead which gives me a top speed of 152mph in 4th? Assuming a 141 trap, I’d cross the line at ~6483rpm which is better than the 5700 I’m currently crossing at. Should note, my power begins to fall off at 6700.
An accurate dyno graph in several gears and some PUC calculations will get you even closer to the best shift points for et as well. I like to try and be very accurate and account for all parameters less obvious like tire growth, etc. But for most cases a good general educated estimate is fine.
01-15-2019, 07:46 AM
#198
Out of curiosity, will this change the trap speed of a car as well? It makes sense to me as you are in your power band much more, therefore making more power longer. But I am not very experienced with gear ratios.
From an online calculator, I put in at 7000rpm with a 4.10 ratio and 28.5” tire diameter, it came up with a top speed of 144mph. And currently on my set up I cross the line at ~141mph @6815rpms which is very close to my redline in 4th. Would I be better off doing a 3.90 ratio instead which gives me a top speed of 152mph in 4th? Assuming a 141 trap, I’d cross the line at ~6483rpm which is better than the 5700 I’m currently crossing at. Should note, my power begins to fall off at 6700.
From an online calculator, I put in at 7000rpm with a 4.10 ratio and 28.5” tire diameter, it came up with a top speed of 144mph. And currently on my set up I cross the line at ~141mph @6815rpms which is very close to my redline in 4th. Would I be better off doing a 3.90 ratio instead which gives me a top speed of 152mph in 4th? Assuming a 141 trap, I’d cross the line at ~6483rpm which is better than the 5700 I’m currently crossing at. Should note, my power begins to fall off at 6700.
01-16-2019, 01:08 PM
#199
Burning Brakes
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