At his local Rotary Anonymous meeting:
madhat: Hi. My name is madhat... and I have a problem. I'd been clean for years, but back in 2019 I let myself hear a rotary drive, so I bought an FD. Work and home obligations keep it from taking over my life, but it's still sneaking my money. It's starting to figure out how to take bigger chucks despite my attempts at boundaries.
Everyone else: Hi madhat!

I first technically learned about Rx-7s when the first F&F furious came out in high school. I was into muscle cars at the time (66 GTO was my high school car, followed by a 93 5.0 Mustang, and an 86 Buick GN), and had no interest in the import scene. A few years later (2005ish) my new wife's family had a non-running "Mazda Eclipse" or something. Turned out to be a 79 SA22 with a crappy spray can sunset paint job and late 70s Firebird side vents and rear duck tail spoiler. The engine was shot, but we dragged it home and I found a replacement engine. I'd dubbed it Project Falcon and planned to make use of its worn aesthetic and go crazy...a double knife switch for the ignition, etc... well, it was in worse shape than I thought. Ended up meeting another Rx-7 guy in college who sold me a mostly repaired 82 Fb with an SA22 front (he'd ran up a bridge column avoiding a family that cut him off). The block was cracked, but I still had that engine! Got the junk of junk running, and enjoyed my first beater! Painted it baby poop green with flat black hood, which resulted in fun...




I eventually painted purple hot rod flames on the right side. Worried that people would think i thought it looked cool, I did pink hearts decreasing in size (channeling the flames on the other side). Saw an FD ad and wanted to trade my GN for it, but the owner assured me I was not the right buyer because he couldn't in good faith sell a "poor" college kid with a toddler an FD as a daily car.
Life happened, got divorced, became a primary custody single father for the next 13 years, and became a mechanical (HVAC) engineer intern. During this time, the Rx-7 became a play car as I kept my newly ex wife's 2007 True Red Mazda3 (got rid of the GN for her).
Eventually got bored and had a spray party where I handed everyone a white can of spray paint! Eventually put red flames on it, and way later gave it to someone if they came with a trailer (it had no title; I just did a 30 day list time and then drove it). That car taught me my love of the rotary sound (and the concept of a rev buzzer).
Bought a house and a salvage title 95 Miata. Looked ok, but had been not so well repaired in the front after a front collision. I didn't want to spend $10k on a toy when I was going to spend a bunch of money installing a supercharger (for the sound mostly). It was Tom's Fast-forward Superchargers kit with a cold side twin screw and extra injectors post charger in the intake manifold (like constant alky injection). My $15k $3k Miata caused a lot of heart ache, but I did eventually have fun with it. I used it as justification not to buy an FD (my obtainable dream... my out of reach was a supercharged Aston DB9). Just couldn't see enough smiles-per-gallon jump to justify it. So, I swore of anything rotary (even video clips) to protect myself.
Not sure why my Miata pics come in this way... they're the HEIC pics at the end of the post.

The FD journey started in 2019. I'll get to that post soon... hopefully tomorrow. I've got a bunch of chores today plus I'm removing the urethane R side skirts...

 

FD time!

Winter 2019 I was looking on BaT at an FD. It had a driving video. I figured it wouldn't hurt to hear... wrong. Rotoritis was immediately contracted, and I knew I needed to get one while I could still afford one.
Started keeping my eyes out, and even started bidding on a few. I still was a bit miserly, and even bid on a flood damaged red one in Austin (I think). COVID hit, I threw some money into the market figuring i could make a few more bucks to put towards one (i wanted to pay cash). August came around and I saw a nice 30-40k mile red one at Duncan Imports for a palletable amount. Called saying I was looking for the nicest one I could buy. The salesman immediately said "did you look at the white one?" I had, just didn't like the price. Said I'd think on it... and a few minutes later called back saying I'd like to get an inspection done on the white one. This thing was perfect...20k km (equivalent to about 12k miles) and not a rock chip or crease in the leather! They linked me up with a transporter, and I got my Hagerty insurance going. About a week later it showed up at work. The driver was really wondering about it because people were taking pictures of it, etc the whole way. 🤣





I was so freaking excited! And nervous! I'd never even sat in a RHD car. It took me no time at all to adapt, and I'd totally do another RHD as a play car. It's so natural to me i get more confused getting back into a LHD car.

Very quickly, though, I decided it was too quiet! Since I was buying an exhaust and intake, i figured i better add a boost gauge and Profec boost controller. Wanting it to stay looking stock, i swapped out the oil pressure gauge for a Speedhut boost gauge. And yes, I did acquire a battery box cover!

Auto Exe Intake

SpeedHut gauge

Tanabe Medallion exhaust


I decided i wanted to switch wheels within months and ordered a set of the staggered 17" 5 spokes (17x8, 17x8.5). My now wife came into the picture right after getting these, so they didn't get mounted for another year and a half!

BTW, I knew she was a keeper (for a bunch of reasons), but mostly because the first time i took her out in it she said "Wow! That was fun! Can we go to a track?... I'll wear a bikini!!"

Ok. That's enough for today. Not the most exciting build thread so far, but I'm getting to talking about what I'm dreaming up now... next time i promise.

 

Wow, incredible buy, that car is SUPER clean.

 

White FD with no sunroof. Nice one!

 

Thanks! It's definitely a nice one! Also worth noting, it's a 94 Type-R that was speced with leather seats, Bose Acoustic Wave, and "cold region specification".

In the past 5 years, unfortunately, I've put no more than 5000 miles on it. Wish I could drive it more, but life gets in the way. Since moving from TX to AZ in 2022, I've done some maintenance type stuff like replacing the starter, battery, boost solenoid, added the Dale Clark check valves, changed diff/trans fluid for Amsoil. As is the way, once you start touching stuff it never acts right! I started having transition issues (slow to transition back to single turbo after a down shift), and I haven't gotten it sorted yet. I've checked all the actuators and they seemed to be operating OK. Also having some boost creep issues (which is odd since only major mods are intake/cat back!).Our first place in AZ had an awesome garage, so we installed a 2 post lift. Man... everything is better with a lift! Also finally got the 17" wheels painted black and installed with Conti ECS02. Never liked the R spoiler, so removed it and covered the holes with white tape temporarily until i could get the whale tail from the 96-98 models installed. It's definitely my favorite option for the FD... which has taken 2.5 years! 🤪




After a year to the day, we said goodbye to the less than desirable town and the wonderful garage and moved up into Gilbert. Now we've got a smaller 3 car with an 8ft ceiling...my Rivian R1T barely fits! I've got one of the Bendpak 7000lb portable lifts now, so not as awesome as before we're making do while still having a lift.

Finally started the process of filling the front license plate holes, rear wiper and sprayer, as well as the R spoiler holes.


Also, many months ago I ordered the SakeBomb MS02 wheels in gold!

And a scoot style hood from Seibon

 

What's the plan from here? I'm going to wrap it, probably in white, until I decide to do a nice paint job. The paint work I'm doing is good enough to wrap, but the color match isn't perfect.
oh yeah, since we're doing that (my wife always helps), we decided to rip off the side skirts that I've never felt like that good.




BTW, the 3M strip wheel is a great way to remove adhesive without damaging your paint (assuming it's adhered well of course).

Oh! Almost forgot i installed a PFC intercooler and did the homemade projector headlights. No Pic... I'll add that next time

Ok, but what are your plans for the engine? Oh boy. So you're probably thinking I'll just get a PFC or Haltec and call it a day... nope. But that's a story for next update.

 

Looking good. Looks like you have my twin. I definitely understand about the garage. I looked to add a 4 post to my current house and I'm about 4" too short to make it work. Had an engineer look at raising the ceiling in the garage and its a no go unless I want to pull the entire roof off the house and create an addition.

 

Thanks! I saw your build thread, especially when you added the intake, and thought the same!
Looked at raising the ceiling as well, but unfortunately it's an pretty complex mess of trusses up there with two hips for the garage roof plus the vaulted ceiling main house roof structure all occurring overhead. Man...why couldn't they have carried the vaulted construction into the garage as well??

So, regarding the engine changes. I loved my first gen because it was all rotary, and in the past I've loved turbos. But, I'm over the whole turbo thing...I have decided to ditch the turbos and go NA. I want to HEAR the rotary, not the turbo system bleeding off pressure under 4500rpm nor the sound of the turbo that hides the intake noise. My goal is a streetable 200-230whp from a 9000 (or maybe a higher ) naturally aspirated set up. I've always drooled over the high rpm first gen builds that hit 11k! I don't plan on that because it would be a straight up race car engine and wouldn't be fun on the street. I considered going 3 rotor, but I don't really want to go down a $30k+ engine build route. The FD stock is already at the upper limit of fast but still able to enjoy it on the street, so if I don't get more than 200whp I'm ok with that. I'd rather be a bit slower having fun in a beautiful body than so fast I can't enjoy it for more than 3 seconds at a time. My Rivian has already rewritten what quick acceleration feels like to the point I could never realistically make the FD feel faster.

I'm still in the research phase and am happy to have any advice yall have! Basic data I've collected so far - hopefully I'm headed down the right path! I probably will need to find an engine builder to help me figure out all the details.
-Balanced E-shaft and rotors
-Lighter flywheel, but not too light to cause drivability issues
-2nd gen rotors
-Upgraded oiling
-Single larger throttle body - ITBs seem to be more finicky and prone to bucking at light throttle
-Intake runner length - seems like longer is better (very simplified here - I understand there's a lot of optimization to be done)
-Thinking I'll duct the intake to the front hood scoop
-Fuel injection, Haltech
-Exhaust header
-I'd like to keep the cat to keep the smells and sound volume down
-Goal for the power is to have enough down low that I don't have to take off at 4k rpm just to keep it from stalling, but I'm ok with it not having torque peak until the top half of the revs.
-I am planning to put a 4.77 rear (should I go further?) in so that I can keep it feeling responsive and keep the shift points at lower speeds so that I can enjoy shifting gears. Stock transmission will likely stay, but I wish I could have some lower ratios in the lower gears - I would prefer the top of second to be ~60mph or less like my old Miata.
-I really want high reving, but am I making my life more miserable by not building it for an 8k redline considering my relatively mild power goals?

 

Hi Madhat.
If you do decide to do go in this direction, I honestly wouldn't bother with the 9.7 compression ratio rotors from the NA series 5 cars unless you can get them cheap enough and sell your old ones. The gains would be minimal. (I think J9fd3s or someone posted some info from an SAE paper in a thread somewhere showing that the 9.0 and 9.7 rotors are very close.)
If you're inclined, I would look at a series 2 RX-8 transmission as the closer ratios would probably be better suited for something like this. You could probably forego the balancing if you keep the OE rotating assembly and stock seals and aren't planning on running it near redline all day long. Same deal with increasing the oil pressure. The OE pressure regulator should be sufficient. You won't need additional injector capacity for this so your stock ones will be sufficient if yours are in good condition and you want to keep them.
As a general rule, a longer intake tract will shift your torque curve to the left. Here's some info on exhaust manifold length: Rotary Tech Tips: Exhaust System Configurations
As to the final drive, I think you can even go as high as 5.10 with an aftermarket one? I think it's from Australia and costs a lot, but it does exist.

Hope that helps. NA power can get really expensive to build really quickly, but there's a lot of stuff that you could retain that would probably get you the same experience and enjoyment out if it.

 

Awesome. Thanks for the tips! Did a bit of a search about the rotors: SAE Paper 890331 (titled "The New Mazda 13B Rotary Engine for 1989")

Since I'm going stock power or less, I think the Rx-8 transmission would be a good call...I'd leaned away from it since it's a weaker trans. But, that trans with a 4.77 and FD tires (~25" rather than ~26" for Rx-8) would get me to the top of second right around 60mph.

I'll do some digging based off your comments here to try to see what might work. I would love it if I can keep the engine build under $15k. I know it's less return for dollars, but I think I'll be happier with the result.

 

You shouldn't have much trouble achieving your power goals and staying under budget for the engine. I think if you do it right, it'll make about the same or a little more power than the stock turbo setup and you can use 87 octane fuel instead of 93 which is nice.
If it's of any help as a data point, I have a peripheral port 20b going together, and I'll be using injector dynamics 1050x, one for each rotor housing. If it didn't require a new fuel rail to be designed and the stock injectors that came with the engine checked out good, I'd have no problem using them.
Looking forward to seeing how it goes! It's always neat to see a na third gen since I think it is a closer ideal of what the original RX-7 was trying to achieve.

 

thanks! That's encouraging to hear.
I'm surprised you feel like I can get that much power that easily; is modern ECU tuning the difference? Do you think a street port is sufficient? I definitely need to spend some time finding more modern information on NA builds - most of the info I've seen seemed to indicate over 200hp would be much harder to achieve.

I don't want to pester you into a full build list (unless you want to deep dive), but I appreciate you taking time to point me in a good direction.

I agree on NA FDs; I think turbocharging was just an easier way to keep up with the power buyers were expecting.

 

I haven't seen numbers for a non-turbo rotary, but most other non-turbo engines gain a few percent torque at all RPM by switching to E85 fuel so that might be worth a try. There are downsides, it needs the right premix and it will cause fuel system problems if it sits for weeks at a time without running. But if you need a bit more power for race days, it might make sense for you.

 

Ahh...good to know about E85. I had looked at it but decided against it due to the hassle of pump availability. This car would definitely sit dormant for periods; guess I'd have to drain the fuel for just stick with non E85!

 

Take a look at post #31 in this thread 13b-rew n/a set-up help (racing) - Page 2 - RX7Club.com - Mazda RX7 Forum. They've got a new stock port 13b and have added a new upper intake and exhaust manifold, and to my knowledge all of the fuel system components are stock too. They claim to be making in the neighborhood of 235 at the wheels at 9000 rpm.

 

I too like the idea of a N/A 13b FD. I always thought that would be a good recipe for a reliable track car. Considering how long all the N/A stuff lasts it should go forever too. It's not like a stock-ish turbo 13b is fast by todays standards anyways.

 

That is what they claimed but I really doubt they achieved that. Doesn't make sense that you remove turbos on an otherwise stock engine and gain power...


OP said he was fine with 200 and that is potentially achievable NA with a healthy street port.

You'll totally kill the resale value but could be a fun car.

 

thankfully it's RHD and no plans to sell, so I'm not too worried about resale. It's definitely more about my personal enjoyment. (And my wife is OK if it's slower🤣 )

 

Been busy with life, but we finally finished installing the MaxJax portable lift in the garage! Spent an hour and a half Saturday afternoon going to hardware stores looking for an M16x2.00 100mm bolt and nut because the one that came with the lift (used to hammer the concrete anchors in) bit the dust as the threads got damaged halfway through. Seems to be a somewhat common issue, so i guys i should have been proactive and had a back up ready!
Forgot to take pics, but it's nice to have a lift again, even if it's not a permanent fixture and only able to life the car 4ft.

Since the lift was up, finally got my Sakebomb wheels installed!



I just might have a thing for gold wheels.

While out on a drive, we discussed FD interior plastics. Got back, and it started make some gurgling noise. About 2 minutes later, my AST started spraying coolant out of its side seam... maybe don't talk about plastics next time?

 

It can be a pain trying to track down metric hardware at times, especially something that size. Wheels look great with the white. May want to think about converting to Evan's coolant so you can run pressure less and never have to worry about old plastic in your cooling system like that any more. Not to mention you never have to replace it and not worry about rusting out your Irons anymore too. I'm interested to know how you like the lift. I'll be on the search for some type of lift because my ceiling is just a couple inches too short for a 4 post but I'm tired of the dance of jacking and jackstands at my age.

 

Took a bit to get back to this!

I have a new raw aluminum Pettit AST, and will get it installed at some point... It's Phoenix, so not heavy driving season admittedly.
The new wheels make me feel like stock height is a bit high now...that's a down the road problem for sure.

@boostin13b my concern with Evan's is the lower heat transfer living in Phoenix. I concede I probably won't be driving it when it's 115F out, but converting to a high revving NA engine I do have concerns about heat removal with Evans. I like the idea of no pressure and no rusting though! Did you overbuild your cooling system for it?
I like the lift. I prefer two posts because you can do suspension/wheel work much easier. Four posts are more for storage in my eyes, and the quickjacks seem like they would make doing trans work etc no fun (and they don't go as high). I miss being able to raise it up to where I can walk under the car, but being able to lift it up to 4ft in my low ceiling garage is as much as I can hope for. Be aware that there's solutions for permanent installs, but the nice thing about this unit is that I can unbolt it and store it in a corner. It takes a bit to set up because I have to roll the heavy posts into place, install the arms, and quick connect the hydraulics. It can be done fairly quickly (I'd probably plan on 15 min). We don't have space for a fixed lift, so this is the best compromise in my opinion. It is capped at 7000lbs, so I wouldn't be using it to lift my Rivian for anything other than quick tire rotations. It's got all the same safety features of a standard lift, minus the posts being tied together at the top. Overall, I think it's worth it if you can't have a permanent lift and don't mind the set up. I won't be pulling it out for less than a tire rotation or major work, though.

 

I've never had an issue with Evan's and extreme heat conditions. You are also in a dry climate and don't have to worry about the humidity with that heat. I used t live in Denver where it would get to be 105-110 and it wasn't an issue. If you run a decent radiator like the Koyo NFlo, its overbuild for the system. I had the Fluidyne when I lived there and moved to florida which is the size of the stock radiator and it performed great. I've been driving around here with the Koyo NFlo in the mid 90's and had a dyno session on Friday where it was 100 degrees in the shop and we beat on the car pretty bad trying to get the intercooler hot and the cooling system was more than enough with less than ideal air flow on the dyno. I've also never had an issue with the S14, we've had Evan's in there for 20+ years and it stays cool in the heat of summer with A/C running and autoX. The cooling capacity between Evan's and water based is minimal so I've never had an issue. I've even run it in stock cooling systems without issue.

 

Not my thread, but I think ya'll have talked me into Evan's. Can't hurt to give it a shot and it seems like a fresh rebuild is the best time to try it since there's obviously no water in the system.

 

Hmm. Worth considering! I planned to upgrade the radiator from the original anyway... with the AST going i suspect the radiator might not be far behind.

 

The koyo NFlo is really overkill for these but a good reason to run Evan's because of the added capacity. I'm 100% fine with overbuilding the cooling system even if it adds extra weight. I ended up making my own brackets for a cleaner install and better fitment than what we've been doing the past 20 years with these radiators. I used to run Fluidyne but they don't make them any longer.