Vito95

Hello Rotorheads!

My name is Pål from Norway, and I'm really excited to finally join this forum.
I've had an obsession with RX7's and Rotary engines since I was very young, and it seems like I will finally have the opportunity of buying one in the coming year.

We have an import rule here in Norway allowing any car 30 years or older to be imported at a much cheaper rate than any other car. This means I will import a car from 1986 or older in 2016. I have long considered obtaining either an FB or FC as my first Rotary car, but what held me back was my research on the reliability of the RX7 (especially the FD). I was told by many people that Rotary engines are some of the most unreliable engines out there. Lately though I have heard many people saying they can be as reliable as any other engine, as long as they are well looked after. This of course sparked my interest for my dream car again, and I'm looking to learn as much as possible to make either an FB or an FC my (somewhat) reliable daily driver. Naturally I have some questions for you guys, at the best RX7 forum there is! I have a lot of questions on my mind, but I will try to write down the most important ones.

First off all, which RX7 would you recommend as an all round daily driver? (FB or FC) It will be driven hard but also long distances, and I will do my best to give it the proper maintenance.
Overall I'm leaning towards the FC at the moment, simply because it's a newer and more refined car. Independent rear suspension, newer 13b engine, more parts available, better ride quality, these are some of the reasons for my FC preference.

Also, Turbo or NA? Power isn't as important to me as having a car that I can enjoy for a long time to come, so I'm currently thinking NA.

I have considered several other 80's classics like the Nissan 300zx z31, Toyota Supra and the Porsche 944, but they don't seem to have a big advantage over the RX7, reliability or otherwise. And of course my dream car has always been the RX7, to me nothing beats the sound of a Rotary engine!

I will be using the car to travel a bit throughout Europe, and therefore need sufficient cooling and not to much boost. Luckily I heard that Rotary engines enjoy long trips, when it comes to the difference between the 12 and 13b though, I'm not sure which one performs better in this aspect.

With regards to upgrade potential, I might end up swapping out the engine for an NA 3 Rotor some time in the future if the circumstances are right, which chassis would be the best to do this on?

Thank you for your time, and I'm looking forward to learning more about this unique car!

Kind Regards,
Pål K S

Evil Aviator

The rotary engine is very reliable, and because of that Mazda is the only Japanese auto manufacturer to win the 24 Hours of Le Mans.

The FD is the least reliable of the RX-7 models due to things other than the engine, and most problems are due to the negligence of the owner.

I recommend the FC for the reasons that you mentioned, plus it is more comfortable on long trips and it has a bigger luggage space.

Both are good. In your case I don't think it makes much difference, although the turbo would be better if you are driving at high altitude.

Just so you understand, a 3-rotor engine is more expensive when converted to NA than it is with the original turbos and there is no significant reliability difference between the two configurations. I assume that labor is cheaper in your area, but in the USA a 3-rotor conversion costs about $35,000 USD. Due to the stronger drivetrain I would recommend the FC Turbo or FD chassis for any engine that produces over about 200-250hp, depending on how the car is driven. The non-turbo RX-7 drivetrains are not as suitable for this.

misterstyx69

iTrader: (142)

Small story,with a lot of insight here for ya.

I bought an N/A.
Went crazy,modified the living hell out of it(357 hp on a TII engine) and spent a butt load of cash.
Hardly drove it but when I did I enjoyed it...Then I said enough,too many little quirks and annoyances.Parted it.

NOW,since I had nothing to do(or work on..lol!),I got an N/A.
Put some odd stuff on it,like wheels,nice spoiler,seats,Kick *** Stereo.
THIS CAR is Better than the Turbo car I had!
I have had ZERO problems with turning the key and going for a drive.
I have enjoyed the car all summer and frankly it has been driven more hours than the Turbobeast that I had.

SO,moral of the story is:..N/A FC..reliable,less headache,more cash in your pocket,Your friends see you more often.

RotaryEvolution

iTrader: (30)

meh, i had a guy come in with a 10th AE that had nearly 500k miles on it.

Evil Aviator

Fixed

misterstyx69

iTrader: (142)

/\..finally someone "gets me",,heh!

Vito95

I most likely will not swap it for a 3 Rotor after hearing the price tag, not in the near future anyway. Do you know if they are more reliable than the 2 Rotors though?

So what you are saying is that Turbo or NA, as long as it's been taken care of and not tuned, Turbo will last as long as NA?

Evil Aviator

There is no significant difference in inherent reliability based solely on the number of rotors. The winning 24 Hours of Le Mans car had 4 rotors, and it obviously worked just fine. However, there are more rotors to rebuild periodically, and some of the 3-rotor-specific engine parts are expensive to replace. For example, a 2-rotor eccentric shaft sells for about $400-500 USD, while a 3-rotor eccentric shaft sells for over $3,700 USD.

Well, it depends what "tuned" means. If it is tuned by a professional then it will last longer than if it is tuned by a novice. Also, an engine tuned for racing performance will not usually last as long as one that is tuned for reliability, and that is simply due to the physics of heat, metal fatigue, and wear.

There is a difference between 'reliability' and 'endurance'. Reliability means the quality of not breaking unexpectedly. Endurance means the interval of time or distance between servicing. A well-maintained stock 13B and 13BT have about the same reliability with respect to the odds of whether the engine is going to break down or not. I guess you could consider the 13BT less reliable because it has more parts that could potentially fail, but when you are talking about maybe 99.98% reliability vs. 99.99% reliability I think it is an insignificant difference. However, with respect to endurance, the 13BT needs the oil changed more often, the 13BT has a slightly higher fuel consumption rate, the 13BT typically needs a rebuild around 100,000 miles vs. about 150,000 miles for a 13B, and the 13BT has a turbocharger to rebuild while the 13B does not. For comparison to engines that are modified, a typical high-boost turbo 13BT or high-boost 13B-REW street engine usually lasts about 60,000 miles, and a bridgeported NA 13B engine can last as little as 3,000 miles.

RotaryEvolution

iTrader: (30)

where do these myths about bridgeports lasting so short a period come from? perhaps a J-port or improperly built bridge may last such a short span with carbon seals.

one customer ran one of my bridges for 50k miles with a turbo full bridge @450whp and there was no significant wear and he flogged the crap out of that car.

Evil Aviator

^ This, and unfortunately it is not myth, lol.

Fortunately, 3,000 miles = 12,000 drag races, which isn't too bad.

Vito95

Ok, so you recommend keeping it 100% stock only doing maintenance, for reliability and endurance? An upgraded cooling system and a more free flowing exhaust should help it breathe more freely, and therefore last longer right?
Also, I don't know much about porting engines. Let's say I did a street port, what would be the HP increase on a series 4 NA and Turbo engine? And would it be as reliable as a stock one?

Akagis_white_comet

iTrader: (4)

As far as cooling is concerned, the go-to radiator is a Koyo all-aluminum one. Mazdatrix has them for a nice price. Don't bother trying to 'upgrade' the FC's oil cooler, it does a fantastic job even with very modified RX7s. When it comes to exhaust I have only two words: Racing Beat

If done correctly, Street Porting will not affect reliability. In the grand scheme of things, it is a rather mild internal modification but would require adjustment of fuel by means of a piggyback (Apex'i S'AFC or similar) to account for the extra airflow.

In terms of power, a 13B putting out 500hp is under a certain amount of stress. A 20B at 500hp is under considerably less stress as it has more displacement to create 500hp with. But, the downside of a 20B is that almost everything has to be reworked or re-packaged to accommodate the ~8" of extra engine. Full standalone EMS (Haltech PS2K in my case), six ignition coils, aftermarket 13B flywheel and clutch suitable to hold the torque being produced. I'm currently using an ACT Heavy Duty Street/Strip clutch (Part# Z65-HDSS) and it BARELY holds the torque out of boost. When the car goes into boost, I'm sure the twin turbos would quickly overwhelm the clutch's 330ft.lb torque rating. Mazda originally claimed the 20B-REW put out 300ft.lbs but there seems to be some disparity about if that is at the flywheel or the rear tires. But what I do know is that 10psi of boost at 1800rpm can be hard to 'clutch'.

Beyond that, clutch options get heavier, more expensive and less suitable for daily drivers. Oh, and you'd have quite the treat trying to package enough cooling capability in the nose too. Mine was quite the feat to make work

Vito95

So a 1986 Series 4 NA FC will be a good daily, as long as it's well maintained? The one I'm looking at has 88000 km on the clock.

DC5Daniel

iTrader: (10)

A Honda Civic would be a GOOD daily

An s4 NA would be just as fine as any other year, taken into account it's a 30 year old rotary. What I mean by that is it's not going to have the refinement and fuel efficiency that is usually associated with a "daily driver". As long as the car is well sorted and you stay on top of maintenance, you shouldn't have much issue though.

Casual_John

iTrader: (8)

Sounds good to me. Low KMs, cheap and simple to work on and repair. When you are bored of it and want more power, sell it and buy a Tii car, instead. If the engine blows, rebuild it with stock ports, to keep the low end torque. The bigger the porting, you will gain high end performance but lose on the low end. For racing you want high rev performance, but for daily driving, you want to try and keep it quiet and smooth while crusing.