Hiyo,

New to the forum and all that it brings. I'm also new to rotary engines. I've done several build-ups on both NA and turbo blocks for Ford, Toyota, and Subaru motors, so I know how to use a wrench.

Alright, now down to business. I'm looking to do a project car for SCCA and drift. I'm currently looking to swap in a rotary into my 1993 mustang hatchback.

Now before I get any one telling me that it's a stupid idea and to just go get an RX-7 or build up the 5.0, I'm looking to make a super light agile care. My goal is around 400-500 hp and a weight of just under 2000 pounds. Not really achievable with the 5.0L, unless I pay around 3k for a aluminum block from dart performance. Money that could be better spent else where.

I've a lift, a decent welder, and ton of tools. I'm also planning on making a bunch of carbon fiber body pieces and such.

Here's where the forum comes in. I'm looking on advice for the best setup to run. You know, most bang for your buck. I'm planning on buying two motors, one as a spare. This will be MOSTLY a track day car, but I would like to be able to do road race events. I'm even planning on entering Lap Around America. So road and track worthy. Anything you have please throw at me.

Thanks,

Cid

P.S. Flame the Ford boys, not me.

 

I don't have a lot of advice for you, but you might want to look at Petit Racing in West Palm, they have the experience in building the rotaries.

I'd also be interested in how you come out in the SCCA events...I am hoping to be getting involved soon once my 93 is finished.

 

Well thanks for the interest, and the name of a shop I can contact.

 

WARNING WARNING WARNING! THIS IS NOT A BASH AGAINST PETIT! DO NOT TAKE THIS IN ANY WAY TO SAY THAT I AM SOMEHOW SAYING PETIT IS A BAD SHOP, DOESN'T DO GOOD WORK OR IS IN ANY WAY A "RIP OFF".

First, I love your idea. For a while now I've had the sick fantasy to buy a fox body Mustang, 20B it up for 800HP or so, build an independent suspension and then take to the track. Even more fun would be the local car shows where I would thoroughly enjoy pissing off all the Mustang owners...I mean I already do with my RX-7 that makes more power then 98% of the Mustangs at the show, but I'd rather do it with a Mazda powered Mustang...

Now, about Petit. They may not represent the "best bang for the buck" you mentioned. They do top notch work and you pay for it. They have a very impressive facility with a lot of talented people. It is not necessary to use a specialty builder to make a 400HP rotary if you are handy and informed.

One concern: You know that the suspension setup for SCCA and drift are at polar opposites, right? A car set up to handle probably won't be a good drift car, and a car set up to drift will suck in all circumstances.

There is a big difference between 400HP and 500HP in the rotary world. You need to choose your power level.

After you've made you decision, head over to the Single Turbo forum and take a look at the sticky threads which describe other setups. It's a great place to get used to what people are doing at the power levels you want.

 

Cool thanks for the insight and the name drop for a shop. I'm glad that I'm not the only person to have thought up this crazy idea.

I thought that drift and SCCA are both accomplishable in the same car with the right suspension of course. Coil-overs with adjustable shocks and an IRS in the back really help with the switching of setups. Frame stiffing is going to happen either way, as the unibody is "flexible" at best.

I noticed you said build an independant suspension. You don't really have to build anything for an IRS in a fox body. Get the rear end out of cobra and it bolts into place. It's amazing what happens when engineers are told not to change any of the rear suspension mounting points, but fit an IRS in there any way. Cobra rear ends are expensive, cheapest going for about 1k. I'm going for with all the components out of a Mark VIII, which I picked up for close to nothing, mounted into a cobra IRS cradle. Just some food for thought if you plan on doing something like my project. Nice thing about the cobra setup is being able to adjust rear toe and camber.

Any way, I'm going to post pictures and video's when I start to build.

Thanks again for the response and directions to turbo build ups.

Cid

 

Well really I have three main questions.

First of which to go with. 13b turbo II or the 13b-rew? Is there a big difference in the setups? I am planning on running a single turbo and I would like to get 500 whp. I know thats a big number to shoot for.

Next, is there any weak links in the drive tran. Gears, sychnros, anything that is common to break in these setups?

Lastly, how much does a rotary engine weight with all accesories? Everyone says their light weight, but numbers seem to vary person to person.

 

turbo turbo turbo!!!! and make sure u have enough fuel

 

The 2nd gen S4, 87-88, TII is the easiest to work with. For your application, a standalone ecu is a must. As far as weak links, the 2nd gen TII drivetrain is near bullet proof overall. 3rd gen guys even use the TII tranny and diff gearset in some high hp builds. Weakest link is the TII diff mount, which can be modded/beefed up.

I say go for it and sow the stang owners what a ratay can do. You may wish to post this in the 'Other Rotary' forum also.
.
.
.
.
.
.

 

Good idea. Thanks for the information. The rear end is going to be a ford 8.8 IRS, so it's bullet proof to begin with.

What do you mean by stand alone ECU? Like aftermarket?

Whats the big difference between S4 and S5?

Thanks Again for helping a complete rotary noob

 

Yes, aftermarket. The S4 TII is easier to mount in some bodies if you need to use front engine mounts like the 1st gens have. If you can use the stock center mounts, either Series is fine. If either Series will work, go for the S5. If your goal hp is near or above 250-275, a standalone is really the only way to go. Read through the Engine Management forum for info on ecu options.

Stock, the S5 produces 20 more hp, has a lighter rotating assembly. It also has an electronic Metering Oil Pump which can be problematic and expensive to replace, (1300+ new). If it fails, the stock ecu goes into limp mode. The S4, and all earlier MOPs are mechanical.

 

Cool I'll check it out.

I think I will go with the S5 than. If it's lighter and stronger than it's what I want.

I have to make custom motor mounts any way, but that shouldn't be a big deal. The way the mustang engine mounts is by the front K-member. I'm going to pick up a tubular front K-member, cut off the stock mounts and weld up the rotary mounts. Simple...in theory.

 

For 500hp, look into auxiliary injection.

The 13B-REW drivetrain is not much different than the 13B T2 except for these things:
- the REW has a twin turbo manifold and twin turbos that you won't be using
- the REW has double-cone synchros in 2nd and 3rd where the T2 does not
- the REW trans has different mounting points. The REW is used with a direct brace between the trans and diff called the PowerPlant Frame (PPF).

I'm not an engine builder who can comment on which setup produces more hp or whatever. I'm just repeating a few things I've heard enough to trust.

 

I'd suggest going with the REW block instead of the S5. Some of the S5 blocks still have weak dowel castings, while all of the REW blocks are improved in many ways.

 

I'll look more into both motors. I did find two rx-7 first gens in the local junkyard. Complete motors too.

Wants 200 for the complete motor. Wondering if anyone would be interested in them.

 

Maybe it's FL, I don't know, but unless the engines run and the compression tests are good, pay no more than 100, if that, for each engine.

 

I wasn't interested at all for myself. Gen 1 motors have carbs, and not the type in beer (mmmm, beer). Any way, if anyone is looking for 1st gen parts I've got two complete setups locally.

 

Has anyone had any luck with getting the J-spec engines off ebay? I've never bought anything off ebay for more than $100 bucks, but it seems there is a shortage of engines and transmissions in southwest Florida. Any one have a good place to go pick up a 13b-rew or a 13b-t s5? Ebay has the s5 for 1200 and the rew for 1800? I've got that saved up just want to research some more.

Oh and I'm starting a website with everything I have done to the car, with photo's and video's. I'll post a link when it's up.

 

J-Spec engines are just junkyard engines. In most cases the sellers have no way to confirm the mileage and treatment they claim. There are J-spec dealers on this forum which are probably better to deal with.

It's great that you are making a website. You're going to get so much hate mail.

 

For the HP numbers you want, I would recomend the three rotor 20b. The way I see it, for the 3k budget, you'll likely be better off withan aluminum piston engine.

You could sink 3k in a 13b and get the power, or the 20b and get the same power,, but with the potential of much higher numbers, if you decided, later down the road.

One of the questions you asked was what is the weight advantage. I may not have the figures, but I had a friend that swapped a LS1 in his 3rd gen, and the aluminum block v-8 was 10 lbs. lighter.

The advantage is not so much overall weight, but rather where it is in the car. The rootory engine is so much smaller, it can sit farther back and lower than any v-8. The only downside, is becausethe eccentric shaft is in the middle, the transmission sits higher. The piston engine, of course, has the crankshaft at the bottom.

I do applaude the project, I'm biulding a '88 GXL for both auto-x and drift.

 

exactly what I was thinking... well put!

 

Bah humbug. While the 7 is a great handling car, the rotary engine is it's heart and soul. Mustangs are a a dime a dozen, everybody and his brother have one. If you want to stay near the 2000 lb weight mark, start with a 1st gen. With your experience and tools, it's a doable project with tenacious info searching and parts purchases. In all honesty, a 350 hp 2100 lb 1st gen is a beast. That should get you in the low 12s to high 11s in the 1/4 mile. Besides, it's so much more fun to show up those Mustang owners with a 24-30 year old car that has only 80 cu in.