4.10 or 3.90 gears
10-03-2006, 02:34 PM
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4.10 or 3.90 gears
I know the RX7's ran a 4.10 in manual and 3.90 in auto. What would be the ideal gear for the RX8 with turbo instead of these dreaded 4.44?
10-03-2006, 03:22 PM
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I've seen many people fight over the differance of a taller/shorter for along time. Some will say its better to just wind up as fast as you can and other tend to think the longer your in gear the more you can ride the boost.
With our motor in the higher compression area, meaning it can pull its self easy w/o the turbo. I'm guessing the taller gear would win out performance wise in a drag race.
This would all depend on where the boost came in and where it died out also.
This cames from years of people fighting over a LS tranny is better then a GSR for boost.
I was also told in the past by a guy that really knew his **** that it would be better to just ride under boost then going in and out of the turbo's range.
With our motor in the higher compression area, meaning it can pull its self easy w/o the turbo. I'm guessing the taller gear would win out performance wise in a drag race.
This would all depend on where the boost came in and where it died out also.
This cames from years of people fighting over a LS tranny is better then a GSR for boost.
I was also told in the past by a guy that really knew his **** that it would be better to just ride under boost then going in and out of the turbo's range.
10-03-2006, 04:34 PM
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Mazda gearing sixth as they did is using mechanical leverage to compensate for torque. Once you introduce boost, the torque is substantially increased and the downshift to pass situation is eliminated. 
However I would personally prefer a longer sixth gear in both N/A and boosted applications. JMO
However I would personally prefer a longer sixth gear in both N/A and boosted applications. JMO
10-03-2006, 05:22 PM
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At Mazsport we build performance packages to suit the intended use/application. Since the gearing is a very important part of the package it really depends on the power level and how the car is going to be used. Given those two choices I would in almost all cases go with the 4.10.
My FD RX-7- 4.33
My FC Turbo 2- 4.10
Keep in mind both of these cars are five speeds not six speeds.
My FD RX-7- 4.33
My FC Turbo 2- 4.10
Keep in mind both of these cars are five speeds not six speeds.
10-03-2006, 06:17 PM
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Well I may be waiting on your setup. So I guess your recomending 4.10 for your setup also. I may actually get some decent fuel mileage on hwy now.
Does anyone know how to correct speedo on these cars? Maybe Rgonza will respond since he has a 3.90.
Does anyone know how to correct speedo on these cars? Maybe Rgonza will respond since he has a 3.90.
10-04-2006, 01:21 PM
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Bummed, but bring on OU!
Originally Posted by rob3379
Still trying to find info on correcting speedo but no luck yet!
http://www.ricks2k.com/products/yellowbox.php
10-05-2006, 07:14 PM
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I will be ordering the 4.10 soon. I'll let you know. I think our gears are to short now. I think a 4.77 is overkill, not much range in those or drivabilty. I promise you can kiss fuel mileage away with those 4.77 and some tought fuel was bad with 4.44. I know with the 4.10 I will be able to hold 1st gear a little longer which is a good thing.
I took a ride in a FD 2 days ago that was stock with 3.90 and first gear was great. So I'm assuming RX8 w/turbo and 4.10 and being a little heavier will be very driveable with 4.10.
If you could get car to bite hard with 4.44 and not break anything w/turbo it would be interesting to see what it runs. I think Rgonza gave up with 10" slicks and 4.44. I believe this was with 13b also.
I'm still debating though on 4.10 or 3.90 b/c I don't want to pull rear down more than once. I'm so indecisive!
I took a ride in a FD 2 days ago that was stock with 3.90 and first gear was great. So I'm assuming RX8 w/turbo and 4.10 and being a little heavier will be very driveable with 4.10.
If you could get car to bite hard with 4.44 and not break anything w/turbo it would be interesting to see what it runs. I think Rgonza gave up with 10" slicks and 4.44. I believe this was with 13b also.
I'm still debating though on 4.10 or 3.90 b/c I don't want to pull rear down more than once. I'm so indecisive!
10-07-2006, 09:16 AM
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I use a 4.10 and rgonza use a 3.90, our cars really needed once we put the 20B engines.
rgonza have a better mpg than me. But I never drived a Rx8 with the Renesis and with a 4.10
manuel
rgonza have a better mpg than me. But I never drived a Rx8 with the Renesis and with a 4.10
manuel
10-07-2006, 01:15 PM
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The higher power and more torque you have, you are probably going to want taller gearing. Right now with a 4.44 final, going to a 4.1 will make a good difference. I think 4.7 would be too short for just about anything. The -8 already has very short gearing (it tops out in all gears at 9K where cars that I've driven top out around ~6K), so if you are boosted, get a 4.1.