An RX-8 is just a long Miata. (RX-8 Turbo MZR Autocross car)

I've always wanted to see an RX8 with another engine from the Mazda family.  Your car is much more than I was expecting!  Nice work.

I'm pretty sure me cutting a piece of flat stock and drilling some holes in to it to run E46 seats in my E30 can be considered no fabrication skills.

What you created requires some fabrication skills 

I appreciate the kind words. I learned a lot putting this thing together and I will certainly learn a lot more.

SVreX said:

For a guy with no fab skills,you sure have pretty berkeleying good fab skills!

yes, my thoughts exactly

Amazing work. Well done!

Do you have any performance metrics on it (0-60, 1/4 mile), or did I just overlook them?

In reply to johnvitamvas :

What front subframe did you use?

Did you need to cut or clearance the firewall?

Thanks

Amazing. Carry on.

Brett_Murphy said:

Amazing work. Well done!

Do you have any performance metrics on it (0-60, 1/4 mile), or did I just overlook them?

 

 

 

Not really, but I do plan to take it to the strip at some point. It's more built to turn.

It's nutty fast for sure

In reply to amg_rx7 :

Firewall is stock. I used the V8Roadsters MZR subframe. In retrospect I should have just used the NC subframe. The V8R part had some quality issues.

New stuff this weekend.

Cut a hole in the transmission tunnel to accommodate the shifter housing and enable the driveline angles to work out correctly. I'll fill this in later.

Made a new crossmember for the gearbox.

Modified the driver's side engine mount. I had originally tilted the motor a little bit to the passenger's side to clear the steering rack. I fixed that issue so I wanted to level the engine so the gearbox was level. It also gave me a little more clearance between the top of the gearbox and the tunnel. I just sliced the bottom off of the mount, then cut a couple new pieces of metal to fill in what was missing. This mount also was always a little close to the oil cooler lines coming off of the engine, and I had notched it in a really ugly way. So I cleaned that up and made it look nicer.

Tell me more about the terblo setup.. are you able to share dyno plots, too?

Which transmission are you using?

Gearbox originally was an FD RX-7 box. For 2020 I have changed over to an ex-NASCAR G Force GSR (dog box).

Turbo is a BW EFR7163. Dyno chart below, around 400hp at 14psi boost. We had some ignition breakup when I first put the thing together so we were limited to around 6,000 RPM before it went wacky. Need to get back to the dyno this winter to break in the new motor. Should make an easy 450 with a bit more boost, the turbo is certainly good for it.

Very cool!

i have always loved those rx8’s.  

Off topic question: do you still have that charcoal canister you removed??  I’m looking for something exactly like that

jfryjfry said:

Very cool!

i have always loved those rx8’s.  

Off topic question: do you still have that charcoal canister you removed??  I’m looking for something exactly like that

Sorry I don't, I threw that stuff away long ago.

1. I Love this thread!

2. Every time I read its title, I mentally jump to one of those "prove me wrong" memes.

Carry on.

so wait, is that 400hp at the wheels? not terribly surprised at the ring lands if so, hah!  Do you have a plot w/ RPM on it?  If you'd rather not post on a public forum, would you mind sending a private email? my main is josh.sennett from the servers of google.

I have a 2.5 swapped B2300 that's getting forced induction this year, and I'm trying to decide on a realistic power goal without having to make changes to the short block.

Thanks! love the build!

In reply to bluej :

Yes, 400 at the wheels (dynojet). That's not what caused the ring lands to fail. There are several NC Miatas running around at that power level on the stock pistons. E85 or race gas. If you keep it around 350 at the wheels it should last a good long while on 93 octane.

I don't have any of the dyno plots, I could get them from Peter but  I never bothered because I'm going down there again relatively soon to run in the new motor and work a little more on the tune. So I'll have a new plot eventually.

Gotcha. Thanks, and good luck.

In reply to bluej :

Thanks!

It's gonna be fun to bang through the gears in this :)

Love it!

I relocated the ABS module to behind the driver's seat. It interfered with the intake manifold plenum when the engine was tilted over, and now that the engine is straight up there was no room for it. It will definitely make working on the engine a lot easier, but it was a pain in the ass. I ended up using -3AN PTFE hose and fittings for everything. I had enough leftover wire from the Haltech install that extending the wiring to the ABS was pretty straightforward.

Location before:

Location now:

Wow! And thanks, John, for sharing your latest project with us. It's perfect for this crew. 

Holy smokes!