Pdaddy43

iTrader: (3)

Hey guys i just recently baught a 94 RX7 with 81,000 miles on it. im just wondering what i should do in the future to make it more reliable. im thinking of going to a single turbo but which is more reliable and better for the car single turbo or stock twins?

Turblown

iTrader: (12)

Single is more reliable if done correctly.

djseven

iTrader: (56)

I dont honestly believe one is more reliable than the other. The tune and the maintenance items are what control your reliability. Yes the single kit will likely help with under hood temps and with intake temps(nothing that cant be combated with a cheap AI setup) but there are a lot of other variables that come along with a single kit. It is all in what you want out of the car.

gracer7-rx7

iTrader: (16)

What he said.

I've had my current FD running sequentially w/o issue for the last 4 years. Car starts every time, makes the correct boost and is well tuned for that boost. I haven't had any reliability problems that couldn't have been avoided with maintenance appropriate to a 15 year old car.

Coolant, air and oil temps are well controlled thanks to my V-mount intercooler and radiator setup (although a SMIC will also work well but the V-mount provides much lower underhood temps).

If you want it to be reliable.

A. Do all the maintenance appropriate for a 15 year old car. This includes:
A1. wiring harness,
A2: solenoids,
A3: replacement of rubber components such as vac lines and coolant hoses

B. Mod safely
B1. meaning don't do a midpipe on twins w/o a boost controller. Even w/ a boost controller you will probably boost creep in colder weather so I'd advise a high flow cat over a midpipe on a car with twins.
B2. Appropriate fuel upgrades to match air flow upgrades

C. Good tuning - I've seen too many cars on this forum with lots of parts thrown at them (including single turbos) yet they don't make good power b/c the tuning sucks or the turbo system sucks.

D. KNOWLEDGE - This really should have been the first item on my list but you need to research the mods before you do them and really understand the pros/cons of each and plan your upgrade path appropriately.

I could go on but you can learn more about this by searching and reading old posts on the topic or just go to the FAQ thread stickied in this forum and READ IT. Also read the threads in the Archives. A single is easier in many ways b/c there are fewer moving parts to worry about. You just need to make sure you have the correct supporting parts along with the turbo (fuel, tuning, wiring, boost control etc).

ZumSpeedRX-7

iTrader: (12)

very good points posted up here.

i would first do the reliability mods as gracer7-rx7 put up, and then decide what you want to do with the car. Daily driving, weekend warrior, autocross, track, or drag or any combo of all. What you want to do with the car will call for separate builds; but the common denominator of all is reliability.

you can build a great twin turbo car that you can reliably use, have fun with, and make good power out of. you can also find a great single turbo set up to meet your needs. again, find out what your needs are and go from there.

there a lot of great resources on this website, so take advantage of it. check the FAQs Sticky on the 3rd Gen section and you should be able to find what you need.

Good luck with your build and have fun with it.



Gordon, i always find it funny to see new owners take their new cars, single turbo it without adding any reliability or supporting mods, up the boost, blow the motor, and come back wondering why they blew their motor. these are often the same people complaining about how unreliable the rotary motor is and that's why they're going to throw a LS motor in.

Fact: Rotary motors don't kill rotary motors; ignorant owners kill rotary motors.

Turblown

iTrader: (12)

Apples to apples for mods a good single turbo will yield lower exhaust manifold back-pressure over the stock twins. That will put less stress on the engine.

Pdaddy43

iTrader: (3)

okay sounds good thanks alot

ProjectD_

iTrader: (1)

Wouldn't it depend on how you drive it too?

I mean, heating issue comes up with the twins because there are 2 turbos right? But if you keep the RPMs below 3500(?) doesn't only the primary one fire up, and the secondary one does nothing except spool up? So if you're not doing much racing, and only occasionally redline it, would single or twin make that much of a difference?

Not that I'm an expert or anything, I too am curious.

Prometheus

iTrader: (2)

It's more the manifold and it's solid construction rather than the turbos themselves.

karl0003

iTrader: (7)

i would check out howard colemans threads and decide for yourslef. he makes some very good points about single vs. twin. check it out. https://www.rx7club.com/3rd-generation-specific-1993-2002-16/making-case-rotary-powered-fd-fix-806104/