recian

I'm curious if there's any real difference between the NA and TII versions of the engine aside from lower compression rotors. Also what's the main tranny difference? I intend to swap to a TII but I'll end up going into the engine before I do it. Most swaps are 75-90psi compression anyway and places sell them as "GOOD" If that's the case I can get a n/a engine and build that then add the turbo parts to it. There's a car at a local yard that's a TII. Really it's the ONLY FC in a yard within 100 miles. I can get my hands on the smaller parts before they crush it. It's been there over 6mo and the engine is untouched besides the intercooler and hood are gone. If i get the manifolds and turbo, wiring and ecu, maf and boost sensor then build up an engine. Main reason is idk if i'll have $300 (ontop of the fact theyre only open 8-11:30 on weekends) for an engine/trans before they crush it.

rx_214

Entire drivetrain is bigger and more durable to handle abuse from high horsepower. Turbos have LSD, bigger sway bars, front and rear brake calipers are different, and the voltage meter is now the boost meter.

recian

well i've got all that being a GXL. I plan to do a JDM TII swap. Seems i'll need the trans from a TII. What about the engine? Are the rotor housings the same? I was gona turn my NA engine into a backup TII by changing out the rotors to either TII or FD rotors, putting better apex seals and stationaries as a backup slow build til my JDM stock TII swap goes

rx_214

The engine internals are pretty much identical from what I know, so it's safe to do have the NA as backup.

FD rotor is lighter from what I know though, best to confirm that before getting the rotors.

recian

but the FD rotor will still work in the 13b housing right? I want lighter for faster revs

rx_214

It will, but it doesn't necessary make the rev go faster.

You should get a aluminum flywheel to get the faster rpm, aluminum driveshaft, bigger diameter exhaust pipe for high flow (3" to 3.5").

Lighter rotor means you will have to adjust the timing, TPS, and also some mapping with the ECU. If you know what you're doing then go right ahead, but I suggest do more research on this.

recian

Sounds like that wont be worth it til im ready to make big power later on. Ive considered the 3 things u mentioned since they can all be used on the turbo model. Does this engine need backpressure? Thats y im procrastinating getting a nice exhaust system with cat and egr delete. Ontop of the $650 price tag lol anything else we can do for a faster rev? 2nd gear taking a minute to redline with the pedal floored is pathetic

Baldy

Just put in a lightweight flywheel, and it'll rev much more faster.

1988RedT2

Even an n/a RX-7 isn't THAT slow. Is everything else up to snuff? Before I started a bunch of go-fast mods, I'd be sure that what I had was tuned up and in good condition.

rx_214

Just go with what you have on the exhaust system for now, it's better if you save up the money and get a complete good system (whether pieced together or custom made).

Flywheel and driveshaft is model specific, so get the turbo one since that's what you're going with.

Also, you can get a closer ratio transmission gears, one popular mod is using the miata tranny. Aside from that, change the final gear ratio to 4:30, that will also assist in faster rev. However, horsepower will suffer a bit.

2nd gear taking a minute to redline sounds ridiculous.... stock one doesn't take that long, so something must either be loose or worn out. Also, if you're talking about going from stop-to-redline with 2nd gear, then it does take quite an effort for the engine to rev up at the lower rpm range.