RX-7 Rear Suspension Project

[Alvin]

I wouldn't do anything until you have driven a roadster with stock suspension, then comp suspension, for thousands of miles on street, track, freeway, etc.

I appreciate that advice, but I'm trying to do this right from the beginning.
I don't know what "right" is, but this setup is not "right". There is nothing "wrong" with leaf springs.
I've been looking to do the Spriso solution or a Ford 8", but I love the four-link. You've been holding out on me when I keep asking rearend questions. Lol. You have exactly what I've been looking to do. I should have known.
You can ask me about my rear end anytime :PI am happy with the link'd setup. It is far from bolt-on though. In the time it took to complete, many other options became available, so I would be hesitant to recommend to others especially with proven, bolt-in solutions are out there like the Spriso RX-7 rear end and the Kevin Desirello 8". These use factory leafs prings/pickup points and are truly bolt-in. You also need to consider your power goals and driving style. I'd recommend the 8" for >300whp and hard abuse.
So help me out, is it worth it? Also, does your ebrake work?
I don't have an e-brake. I have a line-lock. A real e-brake can be added and it's on my to-do list. One more reason to go with the Spriso setup!

[Alvin]

another link'd setup on a race car:

appears to be triangulated, not parallel and base on stock housing?

[fj20spl311]

Don't forget the composite and mono leaf rear spring set-ups have come along.
Also 3 link and torque



I think both the Mazda RX7 and Ford 8" have the e-brakes worked out.

[Alvin]

Don't forget the composite and mono leaf rear spring set-ups have come along.

this is true! and from what i've read great improvements over the NISMO comp leafs...run these with the RX-7 or Ford housing

[Alvin]

5+year update!
Over 22,471 miles logged and no problems at all with the 4-link/RX-7 rear axle setup.
Mixed driving with 2-3 open track days/yr, drag strip launches, highway and spirited/casual driving.
A few burnouts too

[youtube][/youtube]


I had hopes of pulling everything to get it powdercoated but I guess driving always comes first Also on my wishlist is an e-brake, something that in the last 5 years has been perfected and sorted for this application!

So, I would still recommend the RX-7 axle whether it be mounted via OEM leaf springs or other setups. Standard vented disc brakes and LSD are totally worth it, especially with today's pricing imho.

[Alvin]

For the curious, a stock 14" roadster wheel fits perfectly over the RX-7 disc/caliper

[Gregs672000]

The only thing I have not been able to get to work right yet is my ebrake despite adjustments... Not sure what I'm doing wrong... Need to talk to John.

[Alvin]

6+year update!


LSD still works
[youtube][/youtube]

[redroadster]

Whats the size of the mazda ring gear, pretty sure they are smaller / high speed rear end. Better for the highway, RX7s
Were such a dog off the line ( just driving normally) I remember guys blowing the rear end or trans by reving it and dumping the clutch

[silvertiger]

Thanks Alvins for the great info.

I already bought my Rx-7 rear end and removed all the old mounts. My plans is to all do the same set with the 4 bar and Qa-1 shocks. Yours works really great so why not follow a proven method.

How much power can the Rx-7 rear end handle?

The rear end gearing I was just talking with a friend about. The stock 3.90 seams a bit tall. How difficult was it to switch to 4.11? what would be the cost Ball park idea. I know it will depend on the area of the country one might live. As I'm just south of you it would be great.

[spriso]

The stock RX-7 gearing is a 4.10:1 so you are good to go Silvertiger...

[fj20spl311]

The stock RX-7 gearing is a 4.10:1 so you are good to go Silvertiger...

I hear they make a nice 4.78:1

[Alvin]

The stock R&P ratio is 4.076
https://www.mazdatrix.com/faq/ratios.htm

You can get several different ratios from Mazdatrix, ie 4.444 and 4.778:
https://www.mazdatrix.com/g6.htm

[fj20spl311]

Like We said 4.10 and 4.78.......some people like Pi = 3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679

but I use 3.14.......LOL

[Alvin]

Like We said 4.10 and 4.78.......some people like Pi = 3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679

but I use 3.14.......LOL

Phil, looks like you round to the hundredth.
So using your logic, 4.076 = 4.08

How is that 4.10, using your Pi example?