Mazdaspeed 4.66/4.99 final drive
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From: Fremont California
Mazdaspeed 4.66/4.99 final drive
Ive been doing some research but cant seem to find any info on this. I just got a Diff for my second gen rx7 and it came with a 1.5 kaaz and rear gear set says 4.99 or 4.66 I have to double check. Can upload pics later but can anyone confirm existence of any of it? Guy says it came from mazdaspeed. Or is there any way to check.
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Joined: Sep 2020
Posts: 15
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From: Fremont California
After doing the marking and spinning. Its Def a 4.3 I was just thrown away by the markings on the gear set that says 4.99 and also 4.66
If the FC is running the stock diff, the only factory alternate ratio available was the 4.30. The FC uses a long pinion diff unique to it... It's actually more similar to the R200 diff used on the early Z cars than to anything else Mazda ever made. Pretty much every other rwd Mazda has a short pinion rear.
Some shops offered other ratios for FCs by taking short pinion alternate ratio gears and grafting the short pinion with the long pinion from the FC. For FC NAs, they generally used the 7" R&Ps from an FB, 94 on Miata or early rwd mazda (other than the REPU which has an 8" rear). For the TIIs, 8" R&Ps could be sourced from the FD, 929, MPV or RX8....
I know Mazdatrix offered this service for a while, then stopped as the machinist they used retired, and they were having failures at the joint from everyone else they tried.... From what I remember hearing, the old-timer who retired used some sort of splining process to join the shafts, then welded the joint, then machined it back to spec.... These gearsets were not cheap, as you needed to first buy a set of factory gears, then add on the cost of the machining to transform them to long pinion....
Some shops offered other ratios for FCs by taking short pinion alternate ratio gears and grafting the short pinion with the long pinion from the FC. For FC NAs, they generally used the 7" R&Ps from an FB, 94 on Miata or early rwd mazda (other than the REPU which has an 8" rear). For the TIIs, 8" R&Ps could be sourced from the FD, 929, MPV or RX8....
I know Mazdatrix offered this service for a while, then stopped as the machinist they used retired, and they were having failures at the joint from everyone else they tried.... From what I remember hearing, the old-timer who retired used some sort of splining process to join the shafts, then welded the joint, then machined it back to spec.... These gearsets were not cheap, as you needed to first buy a set of factory gears, then add on the cost of the machining to transform them to long pinion....
PhoenixFc3s,I sent you a DM.
If the FC is running the stock diff, the only factory alternate ratio available was the 4.30. The FC uses a long pinion diff unique to it... It's actually more similar to the R200 diff used on the early Z cars than to anything else Mazda ever made. Pretty much every other rwd Mazda has a short pinion rear.
Some shops offered other ratios for FCs by taking short pinion alternate ratio gears and grafting the short pinion with the long pinion from the FC. For FC NAs, they generally used the 7" R&Ps from an FB, 94 on Miata or early rwd mazda (other than the REPU which has an 8" rear). For the TIIs, 8" R&Ps could be sourced from the FD, 929, MPV or RX8....
I know Mazdatrix offered this service for a while, then stopped as the machinist they used retired, and they were having failures at the joint from everyone else they tried.... From what I remember hearing, the old-timer who retired used some sort of splining process to join the shafts, then welded the joint, then machined it back to spec.... These gearsets were not cheap, as you needed to first buy a set of factory gears, then add on the cost of the machining to transform them to long pinion....
Some shops offered other ratios for FCs by taking short pinion alternate ratio gears and grafting the short pinion with the long pinion from the FC. For FC NAs, they generally used the 7" R&Ps from an FB, 94 on Miata or early rwd mazda (other than the REPU which has an 8" rear). For the TIIs, 8" R&Ps could be sourced from the FD, 929, MPV or RX8....
I know Mazdatrix offered this service for a while, then stopped as the machinist they used retired, and they were having failures at the joint from everyone else they tried.... From what I remember hearing, the old-timer who retired used some sort of splining process to join the shafts, then welded the joint, then machined it back to spec.... These gearsets were not cheap, as you needed to first buy a set of factory gears, then add on the cost of the machining to transform them to long pinion....
Mazdatrix sure did, I know the name of the shop that did the work for them, I don't know if I can recommend it on here so feel free to PM me.
https://www.stampcometal.com/
The e-mail you need is: seckerich@stampcometal.com
This company will machine the gear set for $500 and they often help build pinions for many racecar teams. This also may be the company that did work for a different company for years.
FWIW: Not to hijack. I've been hoarding 4.77 r&p and going to send out a couple at a time to be done. Might be just 2-3 a year, but it seems like I get questions about it all the time.
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Joined: Jun 2019
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From: Los Angeles
Hello! And thank you for that great information!
Mazdatrix sure did, I know the name of the shop that did the work for them, I don't know if I can recommend it on here so feel free to PM me.
https://www.stampcometal.com/
The e-mail you need is: seckerich@stampcometal.com
This company will machine the gear set for $500 and they often help build pinions for many racecar teams. This also may be the company that did work for a different company for years.
FWIW: Not to hijack. I've been hoarding 4.77 r&p and going to send out a couple at a time to be done. Might be just 2-3 a year, but it seems like I get questions about it all the time.
Mazdatrix sure did, I know the name of the shop that did the work for them, I don't know if I can recommend it on here so feel free to PM me.
https://www.stampcometal.com/
The e-mail you need is: seckerich@stampcometal.com
This company will machine the gear set for $500 and they often help build pinions for many racecar teams. This also may be the company that did work for a different company for years.
FWIW: Not to hijack. I've been hoarding 4.77 r&p and going to send out a couple at a time to be done. Might be just 2-3 a year, but it seems like I get questions about it all the time.
How much would you happen to sell a modified 4.77 r&p for? Im very interested.
would recommend you send him a private message instead through his forum social profile.
https://www.rx7club.com/private.php?do=newpm&u=53861
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https://www.rx7club.com/private.php?do=newpm&u=53861
.
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