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Mazda RX-7 GSL-SE Rear End Swap -- Spriso Motorsports
Posted: Tue Mar 24, 2009 11:18 pm
by spriso
Deleted
Re: Mazda RX-7 GSL-SE Rear End Swap -- Spriso Motorsports
Posted: Wed Mar 25, 2009 1:39 am
by Daryl Smith
Very nice! I have an RX7 assembly here waiting.
Are you going to offer this as a service to the roadster community?
You have everything set up.....Would you take a few orders? Time permitting?
And of course the bottom line....What would it cost?
I was thinking of just the cutting welding and axles.........But maybe the whole works......
Re: Mazda RX-7 GSL-SE Rear End Swap -- Spriso Motorsports
Posted: Wed Mar 25, 2009 7:55 am
by spriso
Daryl wrote:
Are you going to offer this as a service to the roadster community?
Yes, this will be a service that
Spriso Motosports can provide. I would like to get an installation done in one of the drivers first though just to make sure everything is 100%.
We have done 5 axle housings at this point, the race will be to see who gets theirs in their car first!
More soon,
Michael
Re: Mazda RX-7 GSL-SE Rear End Swap -- Spriso Motorsports
Posted: Wed Mar 25, 2009 10:49 am
by Alvin
oh so pretty....great work Michael.
Re: Mazda RX-7 GSL-SE Rear End Swap -- Spriso Motorsports
Posted: Wed Mar 25, 2009 11:35 am
by caraddict
Drool.....
Better be careful or you're gonna end up spending all of your time building really cool rear ends instead of building really cool roadsters.
Nicely done
Jon
Re: Mazda RX-7 GSL-SE Rear End Swap -- Spriso Motorsports
Posted: Wed Mar 25, 2009 2:25 pm
by ppeters914
Beautiful work as always.
spriso wrote:So, the SR swap is done, the car is running great, is a hoot to drive, but the lack of a limited slip differential is frustrating,
Can you elaborate?
Re: Mazda RX-7 GSL-SE Rear End Swap -- Spriso Motorsports
Posted: Wed Mar 25, 2009 3:28 pm
by xeddex
Damn, I guess I know what my next modification will be. Time to start saving the pennies again.
Michael: With the
rear disc brake setup, how's the f/r bias? Any use of a proportioning valve , etc? The OS Giken unit intrigued me back when it was talked about in Oct '08, but your conversion, once again, looks very professional.
Awesome product!
-Eddie Wu
Re: Mazda RX-7 GSL-SE Rear End Swap -- Spriso Motorsports
Posted: Wed Mar 25, 2009 4:11 pm
by spriso
We install adjustable brake bias valves on all of our cars when we build them. All of our cars already use a 7/8" master cylinder so we should be pretty close for fluid capacity with the big front brakes and and the
rear disk brakes.
None of the RX-7
rear axles have been installed in running/driving cars yet. Eric's is bolted into his chassis, but I don't think that I am going to put mine in before the trek down to Solvang. I really want to change my ring and pinion to the 3.9:1 ratio and use the Miata Torsen LSD instead of the RX-7 clutch unit. This all takes time to do it right and we have 2 cars to finish for Solvang which is the priority right now.
As for why a LSD, there is nothing more frustrating that accelerating out of a corner and having a single tire haze away instead of putting the power to the ground. This will fix that problem!
Michael
Re: Mazda RX-7 GSL-SE Rear End Swap -- Spriso Motorsports
Posted: Wed Mar 25, 2009 6:08 pm
by Datrock
Hi Michael, WOW, that is impressive. I do have a question as to what type of E-brake set up are you planning on using? Do keep us updated... Bill
Re: Mazda RX-7 GSL-SE Rear End Swap -- Spriso Motorsports
Posted: Wed Mar 25, 2009 6:20 pm
by S Allen
That is one classy looking rear end swap. Very nice job indeed.
Steve
Re: Mazda RX-7 GSL-SE Rear End Swap -- Spriso Motorsports
Posted: Wed Mar 25, 2009 8:36 pm
by FoxyRoadster
I was looking at redoing the brakes and bearings on my rear end, any guess at when these will be available? I am thinking this might be worth it since I'm going to be doing rear axle work..
Re: Mazda RX-7 GSL-SE Rear End Swap -- Spriso Motorsports
Posted: Thu Mar 26, 2009 9:42 am
by Skyman
Very nice work indeed. To a Datsun neophyte it could almost look stock. So, Michael, what's next on your plate? Air Bags?
I think I'll look around and pick up one of those
rear ends for when I'm ready to build another car.
Kyle
Re: Mazda RX-7 GSL-SE Rear End Swap -- Spriso Motorsports
Posted: Thu Mar 26, 2009 10:11 am
by spriso
Bill wrote:
I do have a question as to what type of E-brake set up are you planning on using? Do keep us updated...
Great question Bill! That is one of the details that we will get sorted out before we start building these for customers.
The RX-7
rear caliper uses a cable linkage to actuate it, and I envision that we can tie the cable linkage to the stock roadster e-brake cable assembly which is mounted to the floor under the passenger seat. But we need to get the cable lengths, etc. sorted out in a car with the body actually on it.
An emergency brake is a "must have" for me. Not just for me, but because I have several drivers who regularly drive my roadster and will expect that it is operational.
One of the conversions that we are working on is using the 300ZX
rear 2-piston calipers, but they don't have an e-brake assembly built into them (as they used a built-in
rear drum on the inside of the
rear disk) so either a mechanical parking brake caliper (like the one sold by Wilwood) or another arrangement will be used on that car.
Of course, I will keep this thread updated with photos and info as we go along with this project.
If you are interested in doing this conversion to your roadster, start searching for a 1984-1985 Mazda RX-7 GSL-SE (NOT a GSL, not any other RX-7 version, it MUST be the GSL-SE!) They can be hard to find, so start searching now!
Michael
Re: Mazda RX-7 GSL-SE Rear End Swap -- Spriso Motorsports
Posted: Thu Mar 26, 2009 10:55 am
by dieter ka24de
When we put the 85 300zx brakes on the back of my car we used a Lokar universal e-brake kit.
I don't know if this will help.
Re: Mazda RX-7 GSL-SE Rear End Swap -- Spriso Motorsports
Posted: Thu Mar 26, 2009 4:05 pm
by ppeters914
spriso wrote:If you are interested in doing this conversion to your roadster, start searching for a 1984-1985 Mazda RX-7 GSL-SE (NOT a GSL, not any other RX-7 version, it MUST be the GSL-SE!) They can be hard to find, so start searching now!

Just did a quick search on Google and evilBay. Appears the only way to get this
rear end is to buy a whole car....and they're asking $2k and up.
