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sangell · 02-26-2017, 06:19 PM

ChuckLee,
Something is wrong there, 1.60 is not what is in there. I'm not saying that's not what you came up with but your method is flawed.

There are a number of RPM calculators in the web that will allow you to determine the rpm at any speed you want. You will need to know your tire height in inches and your 6th gear ratio which in an F Body t-56 should be a .50. Things to watch for are driveshaft rpm as they get out of hand quick with these double OD transmissions. If your tire is 27-28" a 3.73 or 4.10, if it 28-29" then 4.10-4.56 works well. Like I said watch that driveshaft rpm and it's speed is simply the given rpm of the motor divided by .50 in your case so you can just double the engine rpm. You will end up around 3700-4200 depending on your new gear ratio and not just any shaft will handle that speed.

02-26-2017, 06:19 PM	#64
sangell Registered User Join Date: Jun 2015 Location: Overland Park KS Posts: 173	Re: My LQ4/T56 build thread ChuckLee, Something is wrong there, 1.60 is not what is in there. I'm not saying that's not what you came up with but your method is flawed. There are a number of RPM calculators in the web that will allow you to determine the rpm at any speed you want. You will need to know your tire height in inches and your 6th gear ratio which in an F Body t-56 should be a .50. Things to watch for are driveshaft rpm as they get out of hand quick with these double OD transmissions. If your tire is 27-28" a 3.73 or 4.10, if it 28-29" then 4.10-4.56 works well. Like I said watch that driveshaft rpm and it's speed is simply the given rpm of the motor divided by .50 in your case so you can just double the engine rpm. You will end up around 3700-4200 depending on your new gear ratio and not just any shaft will handle that speed.