Hi Guys,

was chattin to the guys of at www.mazdarotayclub.com and asked this same question.
there was one young lad inthe midst of this but he stoped posting about 4 months ago.

has anyone done or know of someone that has put an RX8 rennesis engine in an RX7?

the guy back here in (Sunny) England picked an engine up for £1k including a 6-speed box (not bad considering a rebuild is £2k) and was waiting on and ECU to tune the engine. and mounted it in his FC3S.

sounds like a good and almost straight forward conversion.
any thoughts?

 

The ECU will probably be the hardest part, since the RX-8 ECU is tied into such things as the wheel speed sensors, so you may well need a standalone to be able to do it.

 

Some Japanese guy did it to a first generation car a few years back.

He used the RX-8 computer, and dashboard and HVAC hardware, since everything is tied into everything else.

For a while, it would keep getting reposted in the 1st Generation Section about every week.

 

with some of the newer software type stuff they have for the rx8, is possible that maybe you dont need all the stuff that is normally linked to the ecu, which would be really nice

 

You don't need to use an RX-8 ecu. Just use a mechanical throttlebody and a standalone ecu.

 

There's a guy in the 2nd gen section doing it right now.

 

you should start seeing it more, as these engines become available more cheaply.

when i looked into it, engine was $2600 from mazda, intake manifolds and stuff was like $4000...

so i'm doing a PP 12A instead.

power between the two is about the same, but in that config the renny passes smog, and isn't louder than a rock concert.

the PP can pass smog, but hp goes out the window, like 20%

 

OMG no wai pp can only idel at 4000 and it dont make powar till 8500 i no cus peopel told me so on teh club lol

 

I don't see any way a PP can pass smog. Here in Texas your car has to idle under 1000 rpm on the test. If it can't, it won't pass. While I don't doubt that a good PP could be made to idle that low, I do doubt that you could make it clean enough at that rpm to pass smog. I don't see how it's even remotely possible.

 

I am sure j9fd3s will correct me if I'm wrong (since he gave me this info ) but the factory spec idle for the MFR P-ports was 1000rpm.

Mine would idle down that low, the only problem (with my setup) was that manifold vacuum was insufficient for good throttle response. OTOH I also had major plug fouling problems probably stemming from the same source (extremely restrictive exhaust) and I do know from my earlier carb installation that the idle gets better when the exhaust is free flowing.

As it was, it never brapped with EFI. Just a kind of sandpaper-edged purr. (Video: http://www.youtube.com/watch?v=Tr7vU...eature=channel Note that my tach does read 10% high) With air injection, I don't see why it couldn't pass an idle or a roller test. Actually, given the way the roller test works, a PP probably would pass no trouble, just some auxiliary air and a converter like any other rotary.

 

its been done

we used to have that stationary test here in CA, the no load idle is the hardest one for a rotary, the dyno test is easier, by a LOT

so the 1000rpm thing doesnt matter for me, but i did notice that the #7 daytona SA mazda has idles quite nicely at 900 rpm. its just the second loudest noise i've ever heard

 

JUst stuff as much stainless wool up the exhaust as you can so it barely runs but idles low. We did that to my mates rx3 13B PP and it passed a Warrant Of Fitness. Had to pretty much tow it to the workshop though....

 

We're concerned with the chemicals in the exhaust, not the sound

I remember when I had my carb setup, when it was idling around 1200-1300, it had a restrictive baffle type muffler (a "Turbo Muffler") and the carb needed the idle screws about six turns out, basically wide-open, and it ran terrible. Cut the muffler off, slid a Dynomax Ultraflo on, the noise was the same, but it idled a lot nicer and only needed the screws 2 turns out... made about 2" more vacuum too as I remember it.

 

the car in question is the scoot 4 rotor FD, its smog legal.

 

OH my bad