View Full Version : amgarrety's 1990 Mazda RX-7

06-24-2012, 01:52 AM
Read the post below this one for technicalities

The day we got it:


Its current state:





In preparation for repaint

Completely torn apart


Gaskets replaced



None as of now

06-24-2012, 01:53 AM
Ok, the title is a little misleading. To start, the car is not technically mine. My name isn't on the title. It belongs to a friend of mine, but we are in the process of building to race as a team. So we both take theoretical ownership of the car even though it technically only belongs to him. We got the car for free, and that is probably why he shares ownership so easily. I am helping design the car to race AutoX, while he does a lot of the engine work. We've already pulled, rebuilt, and replaced the entire motor, and we are about to start work on the interior, which is my specialty. I thought I'd make a brief build thread so you guys can kind of see what I'm up to when I'm not working on my car.

Here she is, the day we took ownership.


For anyone who knows anything about the RX-7, this is a S5 convertible with a 13b rotary engine, which by production numbers makes this the second rarest RX-7 available (next to the '91 convertible). We received it with some engine trouble and an exhaust leak. We thought the engine trouble was due to an internal gasket, so we pulled the motor. Here is a timelapse of that event:


So we pulled the engine apart and realized it wasn't a gasket issue, but the water jacket wall had cracked. So we had to order a new rotor housing. We got that, replaced all gaskets, opened up the intake ports a little bit, and put the engine back together this past week.


It's important to note that this is completely a track car. Because of that, all emissions, A/C, and just about anything that sucks power has been removed (we elected to keep power steering though).

We had originally decided to place the S4 transmission on the engine because it featured a tighter shift pattern than the S5, so we placed the S4 transmission on and quickly realized we didn't have the correct crossmember to mount it to the car. So we had to replace it with the S5 transmission, and it was only after completely bolting it on that we realized we forgot to equip it with a throw out bearing. So we had to take it apart and put it back together again. Anyone who has ever put an engine and transmission together knows how much it sucks to do even once, let alone three times.


We dropped the motor back into the car without any major issues. We didn't get the driveshaft to line up with the transmission very easily. We had to end up unbolting the driveshaft from the rear differential, which involved cutting the rusted-to-hell exhaust off. That'll be fixed soon. Regardless, the engine is now bolted in and hooked up with the drive shaft and the rear wheels. As of this post, that is how the engine sits. A few of the wires have been plugged in, but it's not ready to turn over yet. We are hoping to get it running by next weekend.


06-24-2012, 01:53 AM
Our future plans, in general, are to AutoX. What that means is we have a lot of work ahead of us. With all of our emissions deleted, we cut some weight, but our goal is to cut about 800 lbs in total. That means we are going to strip a lot of the interior and put in some racing seats. We are replacing regular fans and pumps to be completely electronic. This allows us to wire everything up to in dash toggle switches to turn things on and off independently so we can reduce our power draw on the battery. While the car will be used primarily for racing purposes, we might drive it on the road from time to time, but very infrequently. Due to this, we are equipping the car with speakers and an amp, but we are designing it all with quick disconnect wires so everything can be removed quickly and easily before an AutoX event. We are going without a headunit, and instead using an iPod nano because it comes with a built in FM tuner, holds 8 gigs of music, and weighs ¾ of an ounce. And it's a clock. Really, it's probably a better choice than any headunit out there.

Aside from all of that weight reduction stuff, we plan on upgrading to a stiffer suspension, getting some nice white powdercoated Rota Grids, upgrading the tires to something a little more suitable for AutoX, and we are seeking an E85 tune for the engine.

As far as cosmetics go, the car will be getting two small rust spots repaired, it is getting a turbo hood, and it is getting completely repainted its stock red, all in the coming weeks (at least that is the plan now).

That is all we have for future plans at the moment. Keep an eye on the build thread though, things should move rather quickly.

06-24-2012, 11:43 AM

06-24-2012, 09:11 PM
Looks good!

I always wanted a Wankel to play with.

06-25-2012, 10:16 PM
It is a really fun engine to play with. It's surprisingly simple.

So, an update. We've been working on the car all day, and now we're on a dinner break. But the plan is to have the car running tonight. A little ahead of schedule is never a bad thing.

How the car sat as of an hour ago:




Then engine is all there. The only catch was we needed a new fuel line (we got a little out of hand and got a huge line that ended up leaking a little), it needed a new radiator hose, we needed to get a new clutch line, and we made a trip to the junk yard today to pick up an electric radiator fan. And as of now we have everything, so give it a few hours and maybe tomorrow I'll have a video to show you guys of it running.

That's all for now!

06-26-2012, 05:36 PM
Subscribed! I can't wait to see how this turns out!

06-26-2012, 06:32 PM
Im glad I'm not the only excited one!

So last night we got it all back together to the point where we were ready to start it up. We'll get into that after the daily dose of pictures.

There's a pretty big group of us helping build this thing, but the two guys on the right and I (behind the camera) are the main guys building it. The guy in the orange owns the car and is the primary driver. The guy in the light blue has an RX7, so he's pretty much there to help us when we get stuck and to make sure we don't screw anything up. And then I am helping build the motor, i'm doing a lot of the wiring, and I am a co-driver. Everyone else has no real connection to the car, but they help us out whenever they are free, and they bring beer, so that's one reason this build has been pretty consistent so far.


Hard to see, but baseball bat and emissions make a good pair.


The engine now, with electric fan (that huge radiator shroud is gone for good).


So what happened last night. We got everything back together, and we began the final step before turning it over; filling the radiator with coolant. We noticed a leak in one of the hoses, so we took the radiator out to fix that. We decided to try turning the motor over with the radiator out just because it is easier to troubleshoot problems without the radiator in the way. We disconnected all spark plugs and turned it over a few times to get fluids flowing. Unfortunately, that's where we ran into our current problem. We failed to get any oil pressure, and oil didn't even make it to the filter. The only path the oil takes to get to the filter is from the pan, through the pump, through the oil cooler, and then straight to the filter, so we figured the problem is in the pump.

So guess what we're about to go do? Yep, take the front cover off the engine and get that pump working. As soon as that pump is working and the radiator leak is fixed, we plan on starting it for real, but I'm not going to jinx it this time.

06-27-2012, 12:18 AM
She lives!


Let's not jump ahead though. This is a build thread.

So it seems that the lack of oil pressure was something really simple. The bolt that holds the oil pump on wasn't tight, so basically, that bolt was spinning, but it wasn't turning the pump with it. We tightened that bolt up, and like magic, we had oil pressure!


We fixed the leak in the radiator and got that hooked back up. We primed the system, got it to fire a few times, but nothing stable. It was mainly a throttle cable issue. We couldn't find a happy place. We took the cable off and throttled it by hand, which is where we got our first official engine start and idle. We fine tuned the throttle cable and got the engine running (idling) for the first time by itself since being rebuilt. Don't mind the smoke, it is just excess gasket sealer being burned away. After awhile the idle smoothed substantially to a near normal rate, and the smoke stopped. We ended up splitting an old oil line after about 10 minutes of idle, but that is getting fixed tonight. Tomorrow we let it idle for about two hours, then it goes out on the road to break the engine in a little bit.



06-28-2012, 12:39 PM
Wow. thats pretty cool. I cant wait to see this thing in action sometime

06-30-2012, 04:20 PM

07-11-2012, 03:32 PM
We took a week off, but we're back at it.

Monday, we installed a temporary exhaust to get it passed for inspection. It is the most ghetto thing you can imagine. We had to use some flex pipe to get the new exhaust to meet up to the old header, and it glows cherry red when we run it for awhile. Well.... it did get cherry red... It seems to be fine now, but regardless, it only lasts until Thursday or Friday when we get it inspected. Then, we'll take it to an exhaust shop and get a nice exhaust (possibly mandrel bent) put on it.

Anyway, last night, we started it up again. It runs a little rich though. How rich?


Don't worry, we'll be working out the timing over the next week, and a tune is somewhere in the future. The fact that is running makes us happy enough though. It runs so well that we finally took it out on its first drive since putting the motor back in. There were no issues in driving it. We took it on a few drives without it stalling or blowing up, so I consider that a win. Here is a video of it driving for proof. It's really not an interesting video, but I like to have proof.


After that video, I took it out for a drive myself, and it feels great. We replaced everything except the clutch (it was an Exedy and it was in pretty good shape). The car felt very smooth, and even reacted nicely when I got on it a little bit. We still don't have power steering in it yet, so it handles like an old race car, which is arguably much more fun. I think so anyway.

08-06-2012, 09:25 AM
So after all that time and effort we put into our beautiful NA motor turned out to be more or less just a waste of time. A fun waste of time, but a waste of time none the less. Don't get me wrong, the motor still runs, the car still drives, and everything is great, but we also had the fortune of a Turbo II motor falling into our laps. So, with that being said, all that turbo motor needs is a turbo with a waste gate, and it just happens that we have a Nissan Skyline turbo (internally waste gated) laying around. If at all possible, we are going to try to pull out the NA motor tonight and drop in the Turbo II motor. Talk about a marathon run.

I may or may not have pictures/proper documention of the swap. I've been working crazy hours lately, which is why not much progress has been made on the RX-7. If at all possible though, I'll try to make it over there to get this motor in and as hooked up as possible. My best guess would be that it should be running by tomorrow, if not, the end of the week for sure.

It's really a good thing that we got the Turbo II motor, aside from getting more power, because even though we rebuilt the NA motor, we think the apex seals are a little worn and are giving us low compression. Lets hope the Turbo II motor works fine. It was definitely running when it was pulled from the last car.

08-06-2012, 01:48 PM
Hey, atleast now you have a turbo motor!!! At the Creatures of the Night car show in York a week back, there was a toyota corolla with a 1st gen n/a rotary in it.

This is the video I took of when he fired it up:

08-06-2012, 03:06 PM
nice. What color are you going to paint it? a deep red would look balls.

08-06-2012, 03:15 PM
We haven't decided for sure yet. We were looking at going back to stock red to avoid paint door jams and hard to reach places. We are strongly considering offset racing stripes (such as the style on the Mustang below), except the car would be red and the stripes would be white. We'd use white powder-coated Rota Grids to pull it together.


08-22-2012, 12:01 PM
Hey, whats the lug pattern on that FC? And the wheels size? I might get a set of those for my Toyota truck. Not really digging the Skyline wheels I got...

08-22-2012, 12:44 PM


Those are the specs of those exact mesh BBS rims that are on it now, according to a quick google search.

08-24-2012, 09:37 PM
Quick update. I haven't had much hands on time with it lately due to work, but the good news is it is getting trailer'd up to college with us tomorrow, so it will be an ongoing project, even while we're at school.

The turbo motor is in, we are just waiting on certain things to arrive in the mail (namely the intercooler piping). So the way we have it setup now is everything is mounted (including the intercooler), but we are just running through the intake, through the turbo, past the blow-off valve, and into the throttle body. Doesn't sound very effective, and it's not. Well, we don't know if it is effective for sure or not. We haven't been able to get the engine to turn over reliably yet. It just falls flat on its face, every single time. We know it runs, we've seen it with our own eyes in another car, but it's just a matter of getting it to go now. But how you see it in the following pictures is how it is going to college with us on a trailer. And yes, we know, the engine compartment is a mess. It'll get cleaned up when we get things working correctly.






08-24-2012, 11:48 PM
nom nom nom nom....

08-25-2012, 01:46 PM

08-30-2012, 09:16 PM
Just letting you all know, the RX-7 is in a brand new home now. She's at college with us now, just waiting to make more progress. We've officially joined the local car club up here, so there is incentive/pressure to get moving.

We didn't get it up here without problems though. We decided to use a two wheel dolly, which was really just making our lives more complicated in hindsight.



And the damn thing didn't want to cooperate, resulting in some 'less than stylish' new body features.


Yeah, that's a nice deep gash from the fender of the dolly. Dented in the door and created a nice deep scratch. In doing that, the fender also bent, and upon hitting the highway, the tire started smoking from rubbing against the fender. We almost just left the car behind until realizing it was just the fender of the dolly. All is well now, we are just waiting for some parts to arrive so we can get started.



Money is tight, so this might be the last update for a few weeks. Sorry its not exciting. Here is something to hopefully make up for the lack of cool in this post.


08-30-2012, 10:37 PM
Just as I get start at PSU York, you all move up to main.....haha

08-30-2012, 10:47 PM
Haha you clearly need to come to UP.

08-31-2012, 02:40 AM
the convertibles are the only old rx7's i like lol. Glad to see someone building one! you had me subscribed at the FMIC!

03-13-2013, 11:31 PM
Have you guys made any progress on this since college started?

03-13-2013, 11:41 PM
Actually, yesterday was the first time we've touched it since the last update. The battery was dead (of course), and we had problems getting it to turn over before that. We really need to get it to turn over, then get the correct intercooler piping kit to get it working again. Our attention has sort of shifted to another project for the time being, since my roommate just picked up an internship in NY and needs a car ASAP. His other project is closer to completion so this one is on hold.

Plans are still to get it running and gut the interior.

03-14-2013, 12:24 AM
Get it going!!

03-14-2013, 12:26 AM

03-14-2013, 12:30 AM
If I had a car to drive right now I'd be down there to help!

03-14-2013, 06:36 AM
Nice build. I love the FCs. It's that whole 80's and 90's Japanese turbo car thing again.

03-15-2013, 07:45 PM
I once built an RX-7 convertible. In 1/24 scale.

04-09-2013, 01:38 PM
I guess I'll update this quickly. Let me begin with saying that State College weather sucks. Completely horrible. Because of that, we completely neglected working on the RX7 at all this winter.

However, weather has been getting warmer, and because of that, we started playing with it a bit again. So, since putting the Turbo motor in, we haven't gotten it to run, however, we had it running just days before dropping it in our car. Just to be sure, we did a compression test, which turned out fine. We checked to make sure the spark plugs were getting a spark, and they are. The only thing we can tell is that fuel isn't flowing. That is most likely due to us not having any ignition power. We, err, "misplaced" the keys for the car at some point in the last month, and because of that, we have a momentary switch to turn the motor over, but we don't have any way of getting ignition power to the rest of the car as of now. So without ignition power, we have no fuel pump.

We're not entirely sure that is the only problem though. We can't even get it to start with starter fluid. We put mystery oil in the rotor housings, and made sure all leading and trailing wires were going to the correct plugs. No luck though. We're going down the checklist of possible problem after possible problem, so we'll get to it eventually, but we only have limited time to work on it during the week.

We did take out a bunch of the pointless plastic trim yesterday (in the trunk and behind the seats), some carpeting, and the two convertible top motors. Only the plastic was thrown away. The other stuff will likely be sold.

No pictures because the car looks largely the same, but I'll post some more updates when something substantial happens. Hopefully that will be the motor running.

04-09-2013, 01:59 PM
In fact, we're at it again today.


04-09-2013, 10:30 PM
Ugh I hate u so much lol I love the fc rx7. So sleek and sexy. And the sound of a 13b singing in it ear is pure sex lol. I had a few opportunities to buy them but idk squat about a rotary but do know I'm incapable of working on them lol. Love it car. I'd like to see more updates soon :)

04-09-2013, 11:29 PM
Haha we didn't know anything about the rotary either until we tore it apart and rebuilt it ourselves.

We did get it started today. We removed the lock cylinder and ignition switch, and gained access to just the ignition switch itself, which we can turn with a screwdriver, aka we have ignition power again. And after messing with the timing a bit, paired with our excessive use of starting fluid, we got it running. Not reliably though. It seems that the gas we have in it isn't a high enough octane, but any time we spray starting fluid in, it runs fine. So that is a very big step forward, since we haven't had it running since we put it in the car. We'll put some better gas in it soon and see if we can get it running on its own.

We also gutted the entire interior today. Dash, seats, carpet.... all gone.


The seats will be going back in but the rest is now in the dumpster.

As you can see, it started getting dark, so that is where we ended for the night, but we plan on working on it more tomorrow.

Thank you nice weather!

04-09-2013, 11:40 PM
You gonna build a custom dash or something? Half-dash?

04-09-2013, 11:47 PM
We're going to mount just the necessities, so we're going to build a custom mount for the gauge cluster, and a panel for switches, but other wise it will stay bare. We want to race it, and we think the race ready look looks good.

We're also looking into a hydraulic brake to engage just the rear brakes.

We figure the car is near impossible to get back to stock, being a convertible (which aren't common), so we're going to build it.

04-10-2013, 12:46 AM
You gonna build a custom dash or something? Half-dash?itll be dash-ing if he does some custom work lol

Also amgarrety have u looked into some brake proportioning valves off some trucks? That'll be a good place to look into I think

04-10-2013, 09:41 AM
We actually haven't looked too much into how we are going to address the braking system yet, but that isn't a bad idea. We're trying not to replace the entire system, as that would cost more money, but as of now we haven't put any thought into it, so options are still open.