Rupanrx

I was gonna go with the m400 from motech. I'm gonna be running a renesis engine in my 1987 mazda rx7 gxl. I will be using a custom tps(from second gen rx7) and a custom throttlebody(from 1st gen rx7) with a fly by wire cable throttle(so I don't have to convert to obdII). With the m400 can I just use stock engine, wiring, and intake manifold? Or is there another motech that would best suit my needs? I will also been running the stock 87 gxl tranny.

Rupanrx

no one knows anything about using motech in rx8s?

max5roadster

Not usre about the motech, but you may consider using a tII tranny.

MazsportScott

Check out the Interceptor-X for the RX-8 at Mazsport.net. It's plug and play and their are alot of people using it. Check out the Mazsport vendor forum on this board.Scott

Nemesis8

iTrader: (3)

That would be sweet, there are guys over at RX7Club that are thinking of dropping the Renesis in 1st gens. So the Interceptor becomes a full standalone. Pretty cool.

Hey Scott, check this one out: http://www.rx7club.com/showthread.php?t=496533

hondasr4kids

I will suggest to use an Intake manifold from RX-7. I think FD ones will fit from the picture I seen. Then use a conventional Throtle cable, not a "Fly by wire" one like the one we use. Then go from there. You may have to make your oun harness but is not difficult to match the 2 since you are planning on using a standalone.

Rupanrx

I think I might go with a Interceptor-X for mazsport.

TeamRX8

iTrader: (25)

you might want to learn how to operate a search engine before tackling a Motec

alnielsen

iTrader: (4)

I'm not sure that the throttlebody from a 1st gen RX7 would be optimum for the Renesis. I think it is too small and you wouldn't get the best out of the engine. A 2nd or 3rd gen throttlebody would be a better choice. I believe I read once that the TB was accually undersized for the 13B in the 84/85 RX7's (ref: How To Modify Your Mazda RX7 by Dave Emanuel, page 28)

Rupanrx

I was asking a specific question to the rx8club members that have motech or have used moteh in rotary applications.

Nemesis8

iTrader: (3)

Hymee is using a MoTeC in his supercharged RX8 down under

rotarygod

The 2nd gen tps sucks. It's not full range. Use a more generic tps such as a Ford unit. They are very common.

Custom throttlebody from a 1st gen? Which one? I have no clue how you are going to do this. All the 12A 1st gens had a Nikki carb and the 13B 1st gens had a 3 plate throttlebody that was very small. These were smaller than the throttlebodies from the 2nd gens.

How do you expect a 3 plate throttlebody from an RX-7 to bolt up to a single plate intake manifold from an RX-8? Even better still, how the heck do you plan on using a drive by wire with these? Wouldn't it just be easier to use the stock RX-8 throttlebody with the stock drive by wire on the stock manifold? That makes far more sense.

I don't want to sound like a ***** but you haven't really thought this out have you? It sounds like you just listed a bunch of random parts and are hoping they'll work together.

rotarygod

The intake runner configurations are VERY different from any 13B. It would be very difficult to adapt any RX-7 manifold to a Renesis although not impossible. The Renesis manifold is a much nicer unit anyways.

He's still got to worry about a host of other things such as motor mounts. That also will require some very custom work including welding new motor mounts to the frame rails.

Rupanrx

The mounts are no problem.

here is a pic of the special throttle body I was gonna make

hondasr4kids

You know what? I even forgot that FD's are 4 port not six.

rotarygod

That's a pic from Paul Yaw's website. He didn't use a 1st gen throttlebody. That is an RX-8 throttlebody that he modified. He used a part of the throttle shaft from a 1st gen throttlebody which he welded carefully onto the RX-8 throttlebody after he removed the drive by wire motor. He did this so he could get a cable pulled throttlebody. That one is not still drive by wire. The Motec has the ability to control the factory drive by wire which means you don't have to use a cable pulled throttlebody. Paul built that engine about the time that the RX-8 was first coming out. At that time the Motec could not control drive by wire nor could it read the factory ignition trigger wheel like it can now. You can take a stock Renesis and control a Motec with it now. You don't need to do anything except fab up motor mounts.

If you really want to get easy, use the Turbo II transmission. The stock T-II clutch assembly is compatible with the Renesis. Otherwise you'll need to use an aftermarket flywheel and clutch intended for a nonturbo RX-7 along with an RX-8 counterweight.

Rupanrx

Thank you, I tried to ask paul for info about it but they said they were to busy this summer. I was thinking about using the t2, I guess it is a better idea. Thanks for teh help.