1985 GSL AutoX and HPDE Build
 

Hey guys, here's my new (to me) car! It's a 1985 Rx7 GSL with the 12a. I'm trying to turn it into a nice handling machine and just get familiar with working on rotaries. My progress will probably be pretty slow, I'm a student and have only 1 or 2 days a week to work on it. Let me know what you guys think as the build progresses, should be fun!
Current mods so far are...
Mostly stripped interior
Procar by Scat race seats
Overkill aluminum radiator

I'm doing the same type of build with a little rallycross mixed in.
I've stripped almost everything out so far except for the sound deadening which I'm working on now. If you have any questions let me know. Looking forward to your build.

Thanks, how do you plan on stripping the sound deadening? I've been using a wire brush grinder, but that takes 20 minutes to do one square foot of floor.

If you look online you'll find a video where dry ice is used to make it brittle so that it just pops right off. I found that as long as it's about 30 degrees or so in my garage, I can make it come off with a rubber mallet and a metal paint scraper. Dry ice appears to be the easiest tho...

I'm using the dry ice method. Smash it into a bunch of small pieces then just crush it into the deadener. You have to hammer and chisel it out. I still haven't come up with a good way to get the vertical parts like the trans tunnel but it will come off in larger chunks for the most part. Still very time consuming.

Attachment 753199
Attachment 753200

This is where I'm at right now. Got about 4-5 hours in it.

More Pictures
 

Here's some more detailed pictures of the interior, seat, and header. And a good shot of the engine bay and new radiator.

I forgot to mention, I removed the driver side fender which was badly damaged and I'm installing a new one off an 85 sitting in the liberty u-pull.

Hey, no bin rust. That's a major plus. :icon_tup:

I always have to stare at my '84s rear wheel wells when I have it in the air. NO RUST :D Then I cry for my SA's with horrid rust.


What kind of carb are you going to run? Webber or stick with the nikki?

I would like to buy the weber, but my wallet says no. So probably a holley off craigslist.

I'm also trying to eliminate all unnecessary wiring, including all the emissions junk running to the stock nikki.

So I got most of the dash out, but wiring does not come easy to me. Any good tips on how to simplify the harness down to the bare bones? I'm already removing the emissions control unit.

I would suggest just leaving the wiring if it's a matter of weight savings. I have the entire wiring harness for my parts car in a box and it probably weighs less than 15 pounds. Biggest weight savings will be removing speakers and radio.

If it's a matter of decluttering, it might be best to zip-tie unused wires together out of the way. That way if you discover you need something that you unplugged, it's still there.

If you want to autocross that, avoid the Holley.

Its garbage.

Youll waste all of your money tuning it and modifying it and itll still cut out in corners. Do not buy into the turds here on the forums who claim they run "perfect".

The wiring harness behind the dash, inside the car and under the hood came out to damn near 30 lbs, I don't know if it's worth it to you because I don't how extreme you're going with weight reduction.

Pretty extreme, I'm trying to remove everything that isn't necessary to make it run, just ignition, lights, wipers, fuel, fan, and starter.

What would you recommend instead? Webers? (Please don't say EFI)

I also bought some 13b housings, rx-8 internals. For when I get bored with the 12a.

Nikki.


I have an Edelbrock on my gold 79 (which is a cousin to the Holley), and it isn't worth a damn in the corners. Strait line and pig rich... rock on! but as soon as you turn the wheel its either gonna lean out or choke up with fuel slosh. The Nikki doesn't do this, and I don't think the 2 barrel side drafters do either. So your options are Nikki, side draft, or some kind of fuel injection.


Don't get me wrong. If you wanna go strait and have a relatively maintenance free carb that will start and run every day, the Eddy or the Holly is a nice carb, but for rotary performance in cornering its not gonna happen.

So the nikki is good, are there any ways to make it better? Remove the choke maybe?

Knock the venturies out and make them a little larger. Then tune it with a wide band. ;)

A wide band O2 only costs about $100. Knocking the venturies out and cutting them doesn't cost much more than a $20 HF dremel. Tuning it will only set you back $10 for some micro drill bits and a vise. Little bit less costly than a Solex, Mickuni, or webber.


After I finish doing some stuff to my bike I'm gonna jump on my resto mod white 79'. That'll get a slightly ported 12A with the long primary exhaust and a hogged out Nikki. Just about as good as it gets streetable wise.

you should go and have a look at a rule book for the class you're interested in running, the SCCA has a strange rule set.

b, holleys are junk. either stick with the nikki, or run a weber

Sorry I haven't updated this in a while, my winter has been crazy. I haven't been able to get much done. I machined an adapter for the stock intake (home ported) and threw my old motorcraft carb on top. I'm still working out the throttle linkage though. I bolted the header up and made some exhaust hangers. Got most the dash out, drilled holes in some sheet aluminum to make my new dashboard. Wiring is not my strong suit however and I could use some advice. Also got the quick release steering wheel on the column.

I got a racing beat pre silencer and welded it onto the header. Seat brackets are welded in, it's really close to running and driving. I'm trying to have it running for driver's school in a week and a half. That might not happen though.

With respect to wiring, I have found that it is best to either leave the stock harness alone and disconnect the items you don't need OR start over from scratch. I have seen stock harnesses picked through for racecars and it can be allot of work for not much weight savings. Also, you have not indicated how much of the harness you need to retain - such as do you need to drive this car to and from events or is it a trailer queen.
The Mazda wiring is very good. My 83 was road raced for 14yrs with the stock harness with no issues. When I rebuilt the car for a different class that has more liberal rules, I started from scratch which turned out to be a pretty long process.

Regarding carbs....Niki carbs work well as long as you maintain the proper fuel pressure and float levels. Race prepped versions come up for sale from time to time and can be worth it in a class with limited performance allowances.
That said, I have yet to see a racer use a Niki instead of an IDA given a choice between the two.

I am using an EMPI version of the Weber IDA on my car now. It is a Chinese knock off of the Weber but uses all of the Weber parts and has good castings. They are cheap - I paid $350 for my 51mm version from a VW Bug parts supplier.


I am local to you so if you want to look at my car and discuss your build, shoot me a PM. Also, this part of the world offers a wealth of RX7 race and street car experience and information. There's Charlie Clark at KC Raceware, David Long at Santa Fe Garage and last but not least - Jesse Prather at Jesse Prather Motorsports. All of these guys have built and campaigned very fast FBs in SCCA Club Racing. We also have a quick F Prepared solo car that comes out to our local events.

Put the dry ice in a pillow case, crush it up as small as possible, then pour isopropyl alcohol on it. You can drape the bag anywhere you need to, and by soaking the pillow case with alcohol it will transfer the cold from the dry ice very well. It’s still a pain, but worth it in the end.


Attachment 613177