Going for my 13th RX-7? S4 TurboII probably, help out...
 

Ok, here's my situation, I've been through a ton of RX-7's, from a '90 TurboII with a J-Spec I dropped in that had some sort of magic on it or something because it ran 13.75 @ 104.8 in the 1/4 mile at 5.5 lbs boost on the stock turbo, with a turbo-back custom ghetto exhaust. I miss that car...

Anyhow, I've had race FB's, built a few FC's, and owned one FD (well, bought it to sell it, turned out good).

So, my situation is as follows. Right now we're down to 1 car, a Honda Odyssey (we've got 3 kids), but I need something to drive around from time to time, or daily, whenever my wife needs the car.

Also the Odyssey gets horrid gas mileage (like 23-25 is ALL highway, stopping on the turnpike, filling up, and driving till empty, then filling up again). I know FC's don't get great mileage either, but they'll do better in the city than the Odyssey anyhow.

I've found an '87 TurboII with fairly low miles (on the original motor I think), and I may pick it up. But I've been out of the RX-7 scene for a few years, so I'm wondering a few things:

1) S4 TurboII's, I've had one I think before, didn't quite like the feel as much as the S5 for some reason, not sure why. But I understand 10 psi with an rtek 1.8 and 720/720 injectors is possible?

2) Since I'm going with this partially to get decent gas mileage (I had another S5 T2 with a standalone that got like 8 mpg, ouch), what effect does the rtek 1.8 have on mileage?

Basically if I can put down 200-220 to the ground, and keep 95% of the stock fuel economy, I'd be happy. Any suggestions or new info?

From what people have posted, and what Rtek's website lists, you can run 12 PSI with an rtek 1.7, 550/720s and a bigger fuel pump. So running bigger primaries would be even more on the safe side.

I can't say what mileage you'll get running that ecu/injector combo, but don't expect to get 20+ mpg city from any RX7.

I think you're forgetting that the gas mileage sucked in the first place. I think it was Motor Trend in their review of the 10AE that said they got 13mpg in the city unless they were very careful to stay out of boost.

You will also need premium gas unless the vehicle is absolutely 100% stock. they are rated at like 16 or 17 in the city and that is what you will get. Don't expect better than 18 combined. Even your average Rx-8 driver doesn't get much better than 18-19. Once you get into boost gas mileage goes to shit, especially when you start modding the thing. Now the Rtek will help if you upgrade injectors so you don't burn quite so much gas when you boost it, but the factory gas mileage wasn't that great anyway.

get a tercel if you want gas milage

I dont see why the RX7 cant hit 25+ highway on a lean tune map. Maybe you guys just dont get a good enough tune?

RB exhaust, better intake, working needed emissions, awesome running motor (preferably rebuilt), Routine matenence and tune ups completed, gutted interior, S5 or vert wheels (deffinatly lighter than S4s), Rtek 2.1 leaned out and tuned. Im confident you will see awesome gas milage in a FC, and still see roughly 170-190whp