Converting to ITS, need info on RX7s

[jcocke]

Hi everyone,

The last two seasons I raced in Spec Miata with the NCRSCCA. My good friend runs an ITS 280Z, and now I'm thinking of building an ITS RX7. I want to build the car, b/c I have more time than money right now, and we're pretty capable with what we can do.

I don't know much about RX7s yet. I'm thinking the best donor would be a S5, 5 lug wheels with the big brakes, and preferably no sunroof (sounds like I need a GTUs). I've heard most guys run a 4.88 or 5.12 rear gear, but with which LSD...the Mazdacomp unit?

I will have a ton more questions in the months to come, but right now I'm focussed on finding the best of the cheap donor cars out there.

Any help is appreciated. I'm pretty excited about building the new car and racing with y'all!

-Jason

[tnord]

do you already have a miata?

[jcocke]

I "had" a SM, until about 3 months ago when I sold it. I have another Miata that I use as an instructor car for HPDEs.

[JeffYoung]

I think the best S RX7s are a mishmash of S4 and S5.

I think most folks start with an S4, and put the five lugs and brakes on, the 5th gear from the GTU, the aluminum hood and the 5.12 rear end (which I understand is hard to find now).

PM Steve Eckerich or Racing Ralph about this, or the Flatout guys up in the Northeast. THey know the cars inside and out (lots of others do as well, and I'm sure they will chime in).

Hi everyone,

The last two seasons I raced in Spec Miata with the NCRSCCA. My good friend runs an ITS 280Z, and now I'm thinking of building an ITS RX7. I want to build the car, b/c I have more time than money right now, and we're pretty capable with what we can do.

I don't know much about RX7s yet. I'm thinking the best donor would be a S5, 5 lug wheels with the big brakes, and preferably no sunroof (sounds like I need a GTUs). I've heard most guys run a 4.88 or 5.12 rear gear, but with which LSD...the Mazdacomp unit?

I will have a ton more questions in the months to come, but right now I'm focussed on finding the best of the cheap donor cars out there.

Any help is appreciated. I'm pretty excited about building the new car and racing with y'all!

-Jason

[ulfelder]

Mucho good stuff has been said already. My 2 cents:

• S4 or S5 will work.
• Starting with a 5-lug S5 makes life easy.
• Some folks think a sunroof car is a hair stiffer due to the additional structure up top. And no-sunroof cars are hard to find. I wouldn't worry about it either way.
• Yes on the 5:12, yes they are pricey.
• The S5 nose is slightly aero-superior.

Email my partner Nick Leverone for much, much more info - I just drive one, he builds 'em!

Steve Ulfelder
Flatout Motorsports
05 ITS
www.flatout-motorsports.com

[seckerich]

My .02 cents worth:

Start with the S5 if you are not good at swapping wiring harness. Be careful as many of the S5 cars have single piston front calipers and small brakes.
Start with 86 sport (Lightest ever and has 5 lug with good 4 piston calipers) if you are motivated to swap the harness.
Run the complete S5 motor setup (more torque) and seriously look at aftermarket injection computer for tuning.
5.12 is the best all around gear and they are now available again. I have 5 that are all spoken for but a new batch will be available in a few weeks. I prefer the factory clutch pack LS unit but many like the torsen. If you like to curb hop go with the LS.
Run the GTUS (legal) fifth gear. Comp has them but it is best to get someone who has the proper tools to do this for you. You will not find this gear in a junk trans.
Make sure the cage goes into the door cavity as all the later cars have very heavy window guts.
Aluminum hoods are usually found on the convertibles so go hunting. (I have about 10 so I can tell you that now)
Plan on running a very big oil cooler (Mike V at ISC Racing sells a really nice one)
Good luck if you decide to build one and I am sure many of the RX drivers will be glad to give you their pointers.
Add up the items I listed and your suspension parts alone and you will be better buying a wrecked/junker to steal expensive parts from.

[jcocke]

Thanks for the help guys. I'm still trying to learn all the differences between the models to make sure I get a good one to start with. I will most likely end up getting 2 cars as Steve E suggested. Let me know if you know of any good donors

One question I have...do all 5 lug cars have the 4 piston brakes? Or where all the S5 cars 5 lug? Are 4 piston brake setups east to find to swap with?

So if I understand this correctly, an S4 isn't bad, just gotta swap over to an S5 motor (for best results). 5.12 gear seems to be the consensus. Don't be scared of a sunroof car. I planned on nascar door bars in both doors. Find an aluminum hood.

I have some concerns about the rearends, b/c I ain't sure what was stock. Will either rearend (torsen or VSLD) accept the 5.12 gear? Is the VSLD something Mazdacomp sells, or is that stock?

I think thats it for now. I plan on being at VIR this month running in the ECR with my buddy's 280Z, so I might see some of you on the track. Not to mention, I will probably come visit you in the paddock and pick your brain a bit.

Thanks,
-Jason

[Tom Donnelly]

Found this on a link from the Atlanta Region site....

http://www.roadracecar.com/cgi-bin/s...proved_Touring

1990 ITS RX-7 only 2 years old - $7,000
1990 ITS RX7, 2yrs old - $7,000 -------------------------------------------------------------------------------- ITS Mazda RX7 for sale. 1990 S5 car. One pole, one third place finish. Consistant top 5 finisher in the very competative Northeast ITS field. This car has only been raced two years, it is very clean underneath and inside. Front Splitter. Underdrive pulleys. Adj. fuel pressuere regulator. Racing Beat header. Shift light. Longacre carbon fiber switch panel. Ultrasheild deluxe road racing seat. 2 nozzle fire system. Wired for radio system. Strut tower brace. Individual rear camber links. 4.88 Torsen. Howe aluminum radiator and front duct work. Aluminum hood New ISC exhaust with resonator. Remote filter. Magnacor wires. full gauges inc. A/F mix. Removeable steering wheel. Two sets of Kozei s wheels w/Hoosiers. 1 set of toyos rains Large inventory of spares including: Diff,Transmission doors, etc. Brakes, rotors You will not be disappointed in this car. $7,000 or BO. Car is located in central Florida. Call Wes @ 772-919-5996 or e-mail [email protected] for info or more pictures. - Florida_Region.
Phone 772-919-5996

[xr4racer]

Jason, where are you located, I assume near VIR. The early cars are called Series 4 and were 86-88, in these cars if you find a GXL you will get the 5 lug and big brakes with the clutch type LSD, unfortunately it will be a 4.10. The best ring and pinion off the shelf is the 4.33, the lower gears ( higher numerically) are only a bolt in after the 1st gen Rx-7 pinion is mated with a donor, apparently Steve Seckerich has a source.
If you find a 89 or newer, Series 5, 5 lug car many were not the 4 piston big brake caliper and vented rear rotor as they were in the S4 cars. The parts will easily bolt on though as long as you have everything. You do not want a VLSD, they are not the hot setup for racing. I can speak fo rthe earlier S4 cars that you will not have any problem getting to the 2680 weight (if you weigh under 250lbs) even without the aluminum hood, although your CG will be higher. Depending on where you plan on racing the 4.88 is cheaper than the 5.13, and can be semi competetive on the normal 225/45/15 tires.
Whatever you do spend the money on an excellent radiator and oil cooler and kepp your temps down or you will be buying engines. I fyou can keep the water below 200 and the oil around 230 you will have great reliability.

If you are looking for a roller, I have an 88 with the S5 front end, 4.88 LSD, 5 bolt big brakes etc. The car was just painted Subaru STI blue The car was prepped for the 24 hours of Nelson but not ran due to lack of entries and a flash of sanity.

matt
ITS #7

[benspeed]

Found this on a link from the Atlanta Region site....

http://www.roadracecar.com/cgi-bin/s...proved_Touring

1990 ITS RX-7 only 2 years old - $7,000
1990 ITS RX7, 2yrs old - $7,000 -------------------------------------------------------------------------------- ITS Mazda RX7 for sale. 1990 S5 car. One pole, one third place finish. Consistant top 5 finisher in the very competative Northeast ITS field. This car has only been raced two years, it is very clean underneath and inside. Front Splitter. Underdrive pulleys. Adj. fuel pressuere regulator. Racing Beat header. Shift light. Longacre carbon fiber switch panel. Ultrasheild deluxe road racing seat. 2 nozzle fire system. Wired for radio system. Strut tower brace. Individual rear camber links. 4.88 Torsen. Howe aluminum radiator and front duct work. Aluminum hood New ISC exhaust with resonator. Remote filter. Magnacor wires. full gauges inc. A/F mix. Removeable steering wheel. Two sets of Kozei s wheels w/Hoosiers. 1 set of toyos rains Large inventory of spares including: Diff,Transmission doors, etc. Brakes, rotors You will not be disappointed in this car. $7,000 or BO. Car is located in central Florida. Call Wes @ 772-919-5996 or e-mail [email protected] for info or more pictures. - Florida_Region.
Phone 772-919-5996


Too late - I bought that car as it was a fantastic value.