Hi. I currently have a stock series 5 RX7 (89-91) turbo on my mildly ported 13B-REW motor in my FD. I know it's not the ideal setup, but I bought the car with a dead motor and rebuilt it. The factory twins were dead, so using the turbo was a cheap and easy way of getting the car up and running. Of course, now I'm bored with it and its time for a turbo upgrade. I've got the ECU, fuel etc. sorted, but I'm not too sure about the turbo.

I was considering upgrading the compressor wheel, housing and backing plate, than than going the whole hog.

Obviously a some stage the factory series 5 RX7 exhaust wheel housing becomes a restriction, so my question is where that limit is? Going to a bigger exhaust half, new manifold and external wastgate is going to put a big dent in my bank account so i'd rather not unless I have to.

I mainly want the car setup for spirted driving through the twistys (not drags). So what are the biggest HP numbers have you guys seen for people with compressor upgrades? Thanks.

300rwhp-320rwhp is about the max you can get....

Go with a gt 35/40. Probably the best all-round turbo for the rx-7

jesus, christ, ihor. does anybody ever recommend anything other than the turbo they have? i recomend you go with the kia sante fe sport twins... nah, not really. ok, ok. you can upgrade the stiock twins and make nearly 400 rwhp on the edge or 365 or so witrh some reliability. just get the snails machined out and stick in garrett T25 compressors. -gonzo again

Thanks Vosko, that was a damn fast reply to my question.

Silver93tt, in regards to the GT35/40 I'd love one, but I doubt there would be another FD owner on this site trying to build their car on as tight a budget as I am.

Another option I was considering was to use two samller turbos non-sequenctially with one running off each port. I thought that pic of the 3 turbo 20B floating around here was pretty slick. Anyway, it makes a lot of sense by my logic. The mainifold is easy to build as it requires no blending of pipes together. Two reasonably sized internal wastegates should easily keep up and two smaller turbos should have less inertia (therefore less lag) than a big single which flows an equivalent amount. I can fabricate the manifolds myself, but now we are back to the which turbos question. I was thinking along the lines of two FC turbos. I would seem like a cheap way of getting around 400hp worth of turbo. The only down point is the twin entry exhaust housing wouldn't be the best. I had a look for some single entry housings (at the turbo rebuilders) which might be suitable, but couldn't find anything. Any ideas or would you just like to abuse me for being such a cheap bastard?

i had a t04B-H3 compressor upgrade on my 89 TII. i ran 13.7@100 mph with the stock catback and stock intercooler at 7psi.... so it will make pretty good power

wow, another person with an fcd? (fc turbo in an fd=fcd), my friend todd has an 87 turbo in his fd, and he has an upgraded 89 ready to go in. if you want cheap then upgrade the compressor, it has trouble making more than 7.5psi on todds car.

if you want twins, k2rd has you covered there

http://www.2751engineering.com/MVC-765X.JPG

http://www.2751engineering.com/MVC-758X.JPG

they are using gt2835's, but you could used 2 fc turbos, or t3's



mike

Yeah. The non-seq twins looks like me. Thanks for the info. A couple of T3s would be easy enough to find. Someone once told me that factory rotary turbos have a different shaped exhaust wheel than their piston counterparts. But I compared an FC exhaust wheel to a couple of different T3s and the trims looked almost identical . Does anyone know exactly what the differences are if any. The rotary is supposed to have an 'high impact' wheel whatever that is supposed to mean.

i dunno, there are no aftermarket "rotary turbos" if thats what your asking



mike

i might need one of those manifolds LOL