Datsun Roadster Forum-311s.org

How much does the RX7 rear end need to be narrowed on each side?

Eric AZ wrote: Tue Jan 07, 2025 4:23 pm How much does the RX7 rear end need to be narrowed on each side?

Great how-to and info here from Spriso:
viewtopic.php?p=116659&hilit=spriso+mazda#p116659


Narrowing will depend on your suspension type and wheel fitment. I've seen 48" total or about 4-5" off each side.

Oh that might be perfect with the flares at stock length. Thank you

Eric AZ wrote: Tue Jan 07, 2025 7:29 pm Oh that might be perfect with the flares at stock length. Thank you

Please measure your own setup first!

Eric AZ wrote: Tue Jan 07, 2025 7:29 pm Oh that might be perfect with the flares at stock length. Thank you

I have a narrowed one installed in my car. I think it will need to be narrowed unless you are flaring the rear. I have flares that give a little extra room and work well with my wheels (Cosmics from the '70s or '80s, not sure on the offset) with a 205/50 15 tire. If there's some easy and useful place for me to measure without pulling the wheels off I'd be happy to check. I don't have the vented discs shown in the above pic... I think that's an upgrade or a different year. The RX7 rears are getting hard to find.

sort of off topic.........Greg, your aero is quite intentional, we need to be educated. Do you (looks like) block all the ducts to regulate specific flow to air-in-grill? Or/and, are you minimizing air moving under the car via the engine compartment to moving it around the car? I know you have a specific duct behind grill direct to the intake. Thanks for the help.
BTW, very nice 67.5 2L -----------------still being improved and driven.

drieseck wrote: Tue Jan 07, 2025 9:41 pm sort of off topic.........Greg, your aero is quite intentional, we need to be educated. Do you (looks like) block all the ducts to regulate specific flow to air-in-grill? Or/and, are you minimizing air moving under the car via the engine compartment to moving it around the car? I know you have a specific duct behind grill direct to the intake. Thanks for the help.
BTW, very nice 67.5 2L -----------------still being improved and driven.

Well... I wish I could say something like "Yes, its been extensively tested in a Boeing wind tunnel..." or some smart aleck response, but to be honest it's all just based on what I thought looked good ! The front dam is one of Dean's, slightly modified to attach how I wanted, then driving lights in the bumper bracket holes and gold colored mesh or plate in other spots... but no, I don't do anything special to route air, except to make sure the scoup for the rad is well fed. We definitely drive air bricks, but compared to the Z cars I've driven fast the Roadster felt less nose light vs the (stock) Z. The Roadster has always felt sort of planted to me, but I can't say I've driven the best Zs to compare.

success, it looks great, thanks