Race Car Tech Discuss anything related to road racing and auto X.

Source for 4.88 or 5.12 rear for FC

Old 10-20-07, 12:28 PM
Spinning Dorito
Thread Starter
iTrader: (1)
Redshft's Avatar
Join Date: Aug 2006
Location: Halifax, NS, Canada
Posts: 551
Likes: 0
Received 0 Likes on 0 Posts
Source for 4.88 or 5.12 rear for FC

Hello. As per the subject, looking for a source for 4.88 or 5.12 rear for my S4 FC race car. The 4.10 gearing is all wrong and I need something lower.

Posting here as it's somewhat race-specific, and I need to get something strong enough to survive race conditions. I have seen some bad things about just getting any old machine shop to modify the pinion.

I had seen somebody on ImprovedTouring (I think) say they had just ordered a whole rear from SpeedSource, but that's a little out of my budget I think.

Anybody aware of a source for these things? For such a popular mod, you'd think it would be easier to find.

Redshft is offline  
Old 10-20-07, 01:38 PM
Lives on the Forum
10 Year Member
Black91n/a's Avatar
Join Date: Sep 2003
Location: BC, Canada
Posts: 5,707
Likes: 0
Received 1 Like on 1 Post

They've got a 5.12:1 in stock now apparently, $2450 US, but luckily for you the Canadian dollar's doing well against the US dollar at the moment.

Other 2nd gen race shops should be able to make one, such as AWR, Speedsource and whoever else does EP, ITS or other classes of FC's.

If you talk to Mazdaspeed I believe they'll give you the instructions on how to do the pinion modifications and you can try to get a local shop to do it for you.
Black91n/a is offline  
Old 10-21-07, 09:49 AM
iTrader: (3)
SCCAITS's Avatar
Join Date: Dec 2006
Location: Dallas
Posts: 1,080
Likes: 0
Received 0 Likes on 0 Posts
These are all but impossible to find. The only new one I have seen in the last year is the one at ISC for $2450 that is linked above. On the used market they only come from someone getting out of racing or an EP car going to a different tranny and back to 4.10 gears. Getting one made is very expensive and just as hard to find someone competent enough to do it right.

You may be in luck, there is a guy I talked to in FL 2 months ago, he had left racing 5 years ago after a big wreck and never cleaned out his stuff or put anything up for sale. I got a few parts from him, he did have a 5.12 and wanted a reasonable price IMO for it. I already had a 5.12 so I passed. PM me and I'll see if I can find his contact again.

BTW, get a 5.12 rather than 4.88 - all the top cars run seem to run the 5.12 over the 4.88 - also do the .756 5th gear and you are set.
SCCAITS is offline  
Old 10-23-07, 07:49 PM
iTrader: (3)
SCCAITS's Avatar
Join Date: Dec 2006
Location: Dallas
Posts: 1,080
Likes: 0
Received 0 Likes on 0 Posts
Rare find.... not one but (2) 4.88's just went up for sale

SCCAITS is offline  
Related Topics
Thread Starter
Last Post
08-25-15 02:46 PM
Marty RE
New Member RX-7 Technical
08-17-15 09:36 AM

Thread Tools
Search this Thread
Quick Reply: Source for 4.88 or 5.12 rear for FC

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
  • Ask a Question
    Get answers from community experts
Question Title:
Your question will be posted in: