I’ve been fortunate to own FD RX7s off and on over 30 years, I’ve owned stock FDs since 1995, I’ve owned maxed out twin turbo cars since 1999, and now I’m enjoying high powered single turbos that have been built to be as reliable as possible by some of the best builders in the rotary world. I even have a Semi-Peripheral port Han RX7 that’s better than bridge port in every way possible and I’ll share the YouTube video that someone did that proves it.

Over the years I’ve had countless conversations one on one with rotary shop master technicians and owners, and it’s simply not possible for every rotary owner to gain this kind of access. Again I’ve been fortunate. Rather than hoard that information, I want to share it via simple blogs on this website and in a set of new YouTube videos in a way that’s informative and easy to understand. Mark S and I already did a local users group and engine build seminar at the FX JDM shop summer 2025 where we gave out tons of this type of information, and that’s kind of where the idea came from to start the blogs and YouTube videos.

This is a fairly long article that we will try to break up but here you go:

I’ve a seasoned turbo rotary owner (NA rotaries aren’t stressed as much and tend to last far longer between rebuilds). I’ve driven over 100k miles on FD turbo powered cars from 1995 to today (over 31 years of driving) and I’ve NEVER blown an Apex seal.

• A lot of that successful mileage came from from daily driving my first FD few FDS from 1995 to 2005 when the cars were newer, gas didn’t have any Ethanol content, and all the hoses / gaskets / O-rings were new and sealed well.

• 65k miles back in the day. Back then with a fresh 3 year I car and not knowing anything I barely changed the oil, never changed the coolant, didn’t even know that a rotary powered car was inherently different than a piston engine car (I turned the key and it started and got me where I pointed it), and I thought my FD was cool because I had a K&N air filter from Pep Boys and it was bone stock except for that. My car was fairly new, I drove it like a Honda Accord, I didn’t even know you could modify them (I couldn’t afford it anyways back then) , and it held up - never ever left me stranded.

• Next up was I traded that car out around 1999 for a 6 year old garage queen 8k mile same silver/black touring 5 speed build, and it had literally never been driven in the rain. The first owner sold it to help pay for his new pool. I promptly took it to Rotary Performance, and they built it out with Apexi power FC, Apexi FMIC, Apexi twin air intakes, down pipe, hi flow cat, Racing Beat twin outlet catback. The car was transformed from 220 WHP to 315 WHP. I even raced my 2001 911 Turbo and from a rolling start they were dead even from 20MPH to 85 MPH. Again never had an issue and I drove that semi-daily (had rain Honda Accord 4 cylinder) and had 10k trouble free miles still not doing any special for the car.

• Got the bug again in 2005 and added a rear seat for my young kiddos in case my wife couldn’t pick them up from day care and then went dormant on these as I played with Lambo, Ferrari, whatever.

• Around 2018, I got this garage setup and I bought a unicorn mint condition 29k mile red base no sunroof. It looked just as nice as my 8k mile car did in 1999. I expected it to be just as reliable as my earlier low mileage cars, but I did have a few problems with radiator caps leaking after I parked it on a hot day, idle hunting from the original paper gaskets (UIM, Throttle Body, LIM) that had NEVER been changed out since the car had never been apart. Nothing too major, but I started to learn that a 25 year old car even in mint always stored inside condition will have some issues. Chris at Rotary Performance gave me some tips and we addressed the minor issues that crept up.

• I ended up getting back into the community and bought 4-5 FDs and way too many MKIV Supras. I started selling the FDs to people I met and watched them start to have issues, plus I met other folks that had serious issues. I met some folks that really read up on the rotaries and learned a lot the last 7 years plus I’ve talked with master techs and rotary shop owners and learned a ton from them.

The only motor I’ve had to rebuild had 30 year old coolant seals and the prior owner drove it “sportingly” quite few times and overheated it too many times, so the coolant seals were COOKED. I mean they were burned into the metal to where I had to spend 4-6 hours per rotor housing removing hard baked in material. These were the worst cooked on coolant seals I’ve seen yet. HEAT KILLS ROTARIES. BOOST KILLS ROTARIES TOO. AND DETONATION KILLS ROTARIES (leaning them out under hard boost).

• Why the rotary engine has such a bad reputation and what can I do to prevent becoming another horror story?

• What fails on the rotary to need a rebuild, and what can I do to avoid being yet another rebuild story?

  • I’m writing this here right now because it’s the first thing I THINK every rotary engine owner should do (and I didn’t do this stuff back in 1995-2001 because I didn’t know and the cars were so new and the gas didn’t have any ehtanol content then that it didn’t matter as much back in the day)

    • Premix 1/2 ounce to each gallon, keep the OMP unless you’re a track car or you REALLY know what you’re doing,

    • Change the oil every 1k miles if it’s just a weekend play thing (I do know some people that daily drive their cars but I think 90% or more are second cars at this point)

    • Change the coolant every 2-3 years at the very least. I just dumped out 20 year old coolant - Gross!

    • Use a Power FC on EVERY twin turbo FD to turn the fans on before you’re melting your coolant seals down, keep fresh 93 octane in the tank,

    • Install a wideband (on every turbo powered rotary engine car) and watch the AFR and have someone tell you what’s a good AFR and what’s a bad too lean AFR for a rotary. A proper “good tune” should read around 10.8 AFR when in mid to high boost which is pig rich for a piston engine. All of my modified FDs run 10.8 AFR through the entire pull). If it’s running 12.5 or 13.5 idling, that’s fine you aren’t going to blow an apex seal idling or gently driving out of boost. They break under high boost when too lean. They can also break just from too much / too often prior abuse, but they are 2mm thick metal and they fail for a reason / they don’t just fall into pieces on their own.

    • Install a boost gauge and watch that your boost isn’t exceeding what your tuner built your car to handle. If you have a pump gas build that’s safe to 0.9 or 1.0 bar / 14.7 PSI, don’t let it run to 16, 17, 18, or Rob Dahm level 26 PSI of boost (Hats off to Rob Dahm and what he’s done for the Rotary Community. I think it’s safe to say most of his epic builds aren’t weekend driver street cars).

    • Know when to back off the throttle or blow your 4k mile crate motor because you over-boosted it by exceeding the tiny IWG of the stock twins even though the IWG was ported as much as possible but you didn’t have a wideband to watch it lean out just before you popped your apex seal from leaning it out. (and that car has been off the road for 3 years now, but is finally almost back on the road as we got it running again last year and it’s in for final fabrication and tuning).

      • If this car had a wideband and the person was glancing at it while doing a high RPM pull, the wideband would have been screaming “Danger Will Robinson” even without a boost gauge. The wideband is a catch all. It can catch overboosting, low fuel pressure, bad fuel pump, 30 year old injectors that are flowing 10% or 20% less than they would if they were flow tested and cleaned.

      • Any issue that starves the system of the fuel it’s supposed to have will be visible on your wideband with a higher AFR (LEAN) than we want to run on the rotary in boost. The wideband won’t say what the problem is, but it will say Houston, we’ve got a problem and you need to back off the throttle get it out of boost, figure out the issue now before you have to rebuild it.

      • If you’re lean, just keep it out of boost and you won’t blow an apex seal if it’s a bit lean. Do a bunch of high RPM high boost pulls while too lean and I guarantee you will blow an Apex seal and it’s Rebuilding time.

  • Apex seals break primarily from detonation which can happen when too lean under boost and can also happen with spark plug timing that’s too advanced (fire early and blow a dent in your rotor). A “good tune” should ensure your ignition timing is correct, so the main culprit is leaning out from “bad tune”.

    • What causes detonation and how do I avoid it? I will show you dents in the rotors caused by a “Bad Tune” That term gets tossed around all over social media and the older forums, and we’ll share what makes a “bad tune” versus the “good tune” you can get at Rotary Performance in Garland, TX.

    • There are of course many (these days maybe just a few) other excellent rotary shops, it’s just I’ve been going to Chris at RP since my first FD I purchased in 1995. That first 1993 Silver FD I bought while I was still in college was from an insurance auction and it was one of the original engine fire cars that caused Mazda to do a recall. I go that far back / as my friend who is even older than me told me, “Yeah you’re old as Sh*t”.

  • Coolant seals fail from the engine being overheated too many times (or simply from age). And sadly the original Mazde ECU programming turns the fans on way too late. You’ve already cooked part of your engine when the ECU kicks them on.

  • Pro-active rebuild: When I buy 30 year old garage queens that have never had a rebuild, these days I’m just rebuilding them before putting them back into service. It’s easy enough for me and low enough cost for me that I just man up and do it. A 30 year old coolant seal just isn’t the same as a 5 year old coolant seal. Unless your car has been rebuilt within the past 10-20 years, it could do for a preventative rebuild.

• I want to buy a car, what do I need to look out for? Even I’ve bought cars wrong and I have 30 years experience buying at least 20 FD RX7s. Here’s what to look out for to avoid being that guy that needs a rebuild on day 1 of ownership. we will move this to a separate page, but I feel this strongly about it that I’m going to go full stream of consciousness and data dump what I’d do to make an informed purchase:

  • At the very least do this: Drive the car after having driven a properly sorted out FD. The car you buy ought to at least feel as fast. If it doesn’t, run the other way unless you want a project and are getting a good deal.

  • One friend noticed during the test drive that the power was less than the last FD he’d been in. I got the car to perform some work, and the properly run compression test was around 92 PSI rear rotor (good not great), but front rotor was 72 PSI all around (it’s rebuild time). So we took it apart and found that the primary turb blades were bent (at a rock? did the previous builder let somethin in that caused FOD? Foreign Object Damage? Well they sure made a bunch of other mistakes - at least 5 hand tight bolts on has engine and/or driveline. Tore the engine down and found that the foreign object must have flown through the front turbo and ruined his nearly new replacement front turbo (no you can’t rebuild them / well you can, but you can’t get them balanced and they won’t make boost every again - For stock twins replacement call BNR Turbo), the rock, piece of metal / whatever got blown through the intercooler, just happened to end up in the front rotor, spun around a few times, took a 2mmx1mm chunk out of an Apex seal, gouged the front rotor housing to where I had to sell him one of my low mileage spares.

    All of that could have been avoided if he “ran the other way” when it didn’t feel as fast as he knew it should feel. On the plus side he has an FX JDM rebuild (Rotary Performance performed all the fabrication work) with all new rotor seals (apex seals, corner seals, side seals, all new springs, oil control rings), every engine gasket inside and out, all 15 new coolant hoses, etc. And his car should be as reliable as a 2-3 year FD was way back in the mid to later 90s.

  • Drive it to operating temperature - The coolant gauge needs to be at least 8 O’clock. If it gets to 9’ Olock, run the other way as the car has a coolant issue and likely needs a rebuild. Once you drive it for 10-15 minutes, shut it off. Pause 1 minute. Try to start it. Did it turn over slower, did it barely start? If so then run the other way unless you get it for a price that you’re cool with doing a rebuild. I can recommend JDM DRE in Florida that imports FDs from Japan and sold me the donor car that became my Han RX7. When it’s not practical to do a compression test, he at the very least does the procedure I just described.

    If I followed that procedure above I would have never ever bought one of my cars that I was lucky enough to get $4500 back from the Bring a Trailer seller because I got him to pay part of what a rebuild costs. Call a Rotary Shop - Get a rebuild quote. The labor to remove your engine, remove all the accessories, tear your motor apart, the rotor seals you have to buy, the internal O-Ring kit you have to buy, put all that back together, and if you’re doing it right like I do, replace EVERY SINGLE 30 year old coolant hose, O-ring, gasket that is in any way related to the engine. A real shop is going to charge $10-15k. So, why not buy one that you can enjoy and not immediately drop $10-15k on.

  • Check the car fax. If it drove 100 miles over the past 20 years, then expect a rebuild. Rotaries can sit for a year. Rotaries can sit for 2 years. Especially in my nice air conditioned / heated garage. I’ve proven that with before and after compression tests. Rotaries CANNOT sit for 20 years especially if they are started up periodically and not run to full operating temperature. I will show you documented proof of “carbon build-up” another issue I’d never seen until my most recent Bring a Trailer purchased 18k mile Silver with black interior where it was slow: this 5 speed 18k mile mint condition FD lost a race to my 12k mile automatic and that’s just sad. So I did my own compression test (seller had a Mazda dealer do it and it had supreme compression results 105-115 PSI all six points). My properly run compression test showed it in the low 80s which is meh and you are losing power in the low 80s. I knew it would need a rebuild sometime due to never having had a rebuild, but I sure didn’t expect I’d have to do it immediately upon purchase. Turns out since it hadn’t been brought up to redline or close to redline it really didn’t burn off the carbon and the rotors were hilariously carboned up (like the lunar surface). I had them vapor huned to brand new condition, I’m replacing all the rotor seals, and re-sealing the engine, and she’s going to be tip top (plus all the vacuum lines, all 15 coolant hoses, every external engine gasket, every external O-ring). When I’m done this 18k mile car will be about as reliable as an 1993 FD was when it was 2-3 years old. This is the same 18k mile silver FD that I saw Facebook Group posts about before I won it at auction where one person seriously thought it’s a great candidate to be LS Swapped (why why why do that to a survivor all original 18k mile car), and another person joked it would fall apart as soon as someone started to drive it (they weren’t wrong on that point).

• I want to import a car, how do I do that or are there any trusted FD JDM importers (YES! I bought the donor 1997 RHD black FD from a great shop in Florida and then I turned it into a Han RX7, and I’ll share his contact information with you and will try to get his permission to be a link on our website.)

• I just bought a rotary powered car (or maybe you’ve had it for a bit), what do I need to know to not be that guy that rebuilds it every other high RPM pull?

And then there’s power mods (this is where the real fun is at). We’ll be sharing success stories that we’ve had or our friends have had with these types of power builds. Here are some pretty common builds to consider:

• Maybe you want to go OEM+ with free flowing exhaust and some safety mods,

• Maybe you want maximum safe power that your stock twins are able to handle before spinning themselves into twisted metal from overboosting.

• Maybe you need to replace your fried stock twins with something comparable but Mazda stopped making them a couple years ago.

• Maybe you want to ditch the twins but want to have some more WHP than the stock twins are capable of (BNR, EFR 7670, HKS Special Setup, etc.)

• Maybe you want 400 WHP at safe boost levels for Pump gas 93 octane (HKS Special Setup GTIII-4r, EFR 8374, etc.)

• Maybe you want a build like my Han RX7 (550 WHP which is as much as the stock driveline can handle at high RPM. The stock 5 speed will break 3rd gear - just ask the guys that drag raced these cars in the late 90s.)

• Maybe you want to make Rob Dahm level power - 700 WHP 2 rotor at high boost levels that 93 pump gas can’t support safely

• Maybe you want to make a 4 rotor like Rob Dahm - What does this take and where do you start to get the parts?

Thinking about adding more power (Of course you are!)

First tip: Talk with one or more people or shops that have built a car this way, what went well, what didn’t go well, what did it cost, etc.

Second tip - Find your tuner, then find out what ECU platforms they support and see if they have a successful build sheet they can share with you (parts list and expected budget). I’m turning my old MKIV Coco Crisp early 2000s show car into an epic Brian Supra left hand drive, targa top, full film accurate interior, exterior, and full A/V equipment. The first thing I did was setup an appointment with a local tuning shop that tunes my high end Syvces ECU. We’re going to talk through what I want to do with my car, what my car already has on it, and we’ll come up with a build plan that sees how we can accomplish my goals and stay within my budget. I do this with people on the FD all the time and have sample build sheets with recent pricing and current parts to share. Will be working on getting all of this up here on the web page.