I just thought you guys might be interested in this. It's a project that myself and Redshft have been working on for a few months for local club racing.


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Redshft and I are in the process of re-building a 1986 GT2 RX7 for the 2007 road racing season. The car was built into a race car in 1992/93 I believe, and ran in the Moosehead Grand Prix in '93 & '94. It raced at Atlantic Motorsport Park (www.atlanticmotorsportpark.com) until 1996, and then was parked in a barn/carport for 10 years (started up yearly, and driven around the yard, always winterized), after which we found out who had it, bought it and brought it home.

The engine is a 13b rotary that is N/A with turbo internals. When it was built (on an engine dyno), it made 285hp at the flywheel. It runs on race gas mixed with 2-stroke oil. Has Weber 45DCOE sidedraft carb on a Racing Beat Intake Manifold, Racing beat header and sway bars, stainless brake lines, dual core rad, Pheonix Halon fire system...

The car basically needed a refreshing and some tender loving care. We got it in the late fall, and have been working on it ever since basically.

We have gotten a few sponsors. Mazdaspeed Motorsport Development Team Support, T. Bonin's Autobody, Cobbco Signs and Xtal Design Labs are a few that we have nailed down at the moment.

Here are some pictures of the project thus far.

When we first brought it home:










So this is after the interior was painted and the decals were stripped and the car was sanded.













...continued below....

 

In the paint booth:




Roll cage padding:




New paint:




Seat bracket:



Wing:




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nice.. looks like its gonna be a fun car :-D

 

At a car show in April:










Here is a list of what I can remember that we did:

Replaced the brakes with an upgraded stock Mazda option (4 piston alum. calipers in the front, vented rotors on the back) with Gran Sport GS3 racing pads
New rotors
New belts
New hoses
Dual belt Alternator pulley + new alternator
5-bolt hubs, and now sporting ARP studs and Volk Racing TE-37's with Goodyear R430 23x9x15 slicks
Fresh KYB AGX shocks/struts, Eibach Springs, Ground Control Coilover sleeves
Dual HKS exhaust
Momo Detachable steering wheel
Corbeau FX1 Fibreglass racing seat
New OMP 6-point camlock harness
Cleaned up the distributor to fix a spark problem
MSD Blaster 2 coils
Removed power steering pump assembly
Mallory 6al ignition box
Fresh paint and decals
Sunpro Super Tach II
Duck bill spoiler from "Sport" package
Cleaned and adjusted Weber carb, changed some jetting
New plug wires
Royal Purple tranny and diff fluid
Replaced anti-freeze with distilled water and water wetter
New Holley fuel regulator
New braided line with AN fittings from regulator to carb
Re-routed fire system to add 2 nozzles and run along the transmission tunnel
New roll bar padding
Added a Choke Cable

I'm probably forgetting some stuff.

Now, we have to put in:
-Holley Blue Electric fuel pump + in-line filter
-Flat Out Motorsports fibreglass splitter
-Custom gauge package from Xtal Design Labs (http://www.xdesignlabs.com)

And we're now running proper race fuel! Yippeeeeee!!!


Here are some pictures I took on the weekend. I'll try to get some updated underhood pics tonight.







Enjoy!

 

285hp?
How?


-Ted

 

A CRAZY bridgeporting job (like, it doesn't like to idle at all), and turbo rotors and carbon seals in a NA case, plus the carb and jetting. It was built on a dyno, so they tweaked as they went.

 

Good you got rid of that power steering you dont need that, it'll build some muscle and endurance. But for an S4 the car looks good. I like it, it looks as though time and money was spent on that car. I wish I had the time and money to finish mine but I just drove it cross country! Not too many FC's do that, and I race mine too lol

 

Turbo rotors? You mean the lower compression ones? That seems a bit odd to me because it's a total downgrade. There's no advantage to running turbo rotors in an NA and it's just costing power....Any idea why this was done? Is it a 4 port block?

Great work on the car so far!

 

^ i was thinking the same thing.. why lower the compression on a na?

 

Yeah, the turbo lower compression ones. I have no idea why they did it (the engine was built before our time -- 10 years ago), but it seems to work.

I'm inclined to think it runs on voodoo and black magic.

The guy who used to own the car gave the engine builder an NA engine, a Turbo engine and $9000 and told him to build something fast. haha The engine builder owns a shop specializing in rare and weird imports and he has been building race engines for like 25 years +

 

WoW, someone raped themselves...

 

Yep, he was a non-mechanically inclined doctor

 

isn't that the truth!

 

you know i love it Jenn

 

You should take it to a dyno, and then post up the sheet.

 

Very nice work! I'm glad you shared.

 

agreed

 

very nice car mine is on the way to looking like that, interior is already all gone lol

what does it weigh?

also, since its a race car that see's high rpm's, i'd say either get a serpentine belt setup, gilmer drive belt setup or go back to a single alt pulley and get a pineapple racing yoohoo belt. also, i've heard from a few people they've had bad luck with running water and water wetter with the water pump having issues and the coolant seals.

 

I want to see the 285hp dyno sheet. Do you have one? Otherwise I think whoever said it was just giving a very generous guess.

 

also, i'd hate to see the temps on the coolant when it was being raced, that fan has no shroud and its a stock radiator. when i raced on a track with stock radiator and fan i could only squeeze out 5-7 laps without getting too hot to come in on a S5 making ~210hp at the flywheel.

im also guessing that 285hp number is at the flywheel, but its possible its a whp number if its got a nice bridge port.

 

Well I was reading the part that aaron cake posted asking about the lower compression rotors in a track n/a 13b, and I also was wondering why someone would do this. Well I went and asked one of the technicians where I work that is fairly knowledgable about rotors and this is what he said.

It is possible to increase the hp of a rotary by changing the stock timing. So what I gathered after talking with him for a bit was that if you combine the combination of the lower compression rotors with the adjusted timing, and obviously the other mods in the car combined, you could have a rotary that would run more effectively than the normal approach of high compression.

I hope that this might answer some questions any one has. I also hope that I didnt mess anything up in the translation, if i did and you know for a fact what it is, please enlighten me.

btw he said that yes it also is possible that it is just running on black magic

 

know lower octane with the right timing will produce more HP than race gas ......but i cant see lower compression...but it may be equivilant i suppose if tuned right

 

Either way, that car is grade A sweet. S4 FTW!!!!!

 

Damn, nice car. S4 and N/A, hmmm my favorites!

 

very nice project! looks like a blast to drive on a track...

are you planning on buying swaybars? poly buschings? seems a nescessary addition to a track car.....