ChampCar Tech Desk

The tech desk is used to ask technical questions and is not to be used as a post race tech line or to phish for how others built their cars.
Please reference the BCCR as most questions submitted to the TechDesk can be answered by reading the BCCR.
You can download the BCCR here:

2020-01-10 - Miata rear differential gear ratios

I want to confirm I am reading this rule correctly.

4.7.8. Rear-end gear-ratios are open to all OEM differentials available for that year, make, and model or chassis generation (excluding specialty high-performance models not listed on the VPI table).

Does this allow us to run a 4.3 ratio in a 1997 Torsen differential since the NA generation had both a 4.1 and 4.3 ratio?
We are running a 97 driveshaft, stub shafts and half shafts.

I believe the 4.30 ratio was only available in the 1.6 NA and the 1.8 had 4.10 with the Torsen from 95 to 97. 
So you can run it.

Article Details

Article ID:
Date added:
2020-01-10 20:56:55
Rating (Votes):

© 2009-2023 ChumpCar International Inc., All rights reserved.
ChampCar Endurance Series ® is a Registered Trademark of ChumpCar International Inc.. ChampCar, CCES, and ChampCar.Live,
are trademarks and /or service marks of ChumpCar International Inc..
The ChampCar Endurance Series Logo and the ChumpCar Logo is a service mark of ChumpCar International Inc. and is fully protected.