Where did you post it?

I don't know that the "frame" rail reinforcements are necessary, but they serve two purposes: distributing the dynamic load (which is now going into the floor) from the gearbox in absence of the PPF and facilitating the addition of fasteners. I could have used rivnuts in the rails, but it would sure suck to have those mount locations tear out. They also don't weigh much and so it seemed like a bit of a no-brainer.

 

Looks like the Keisler mount straddles the frame rail and goes into the floor directly?

 

LIkely that the actual mount can be skipped and you will instead need to adapt something else more specific to the engine/trans combo being used.

 

That didn't exist when I built my car, but it's interesting nonetheless.

 

You're also putting down way more power/torque than the LFA and through a more severe transmission.

 

It's not intended to state anything. Several years ago it wasn't easy to put either a Nissan CD009 or BMW DCT transmission in an RX8 either.

And no, not necessarily. A modified LFX is capable of 450+hp, 400+ lb-ft.
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Oh yeah, not LFA . Have they done much forced induction? Most of their documentation is focused on the NA version.

 

the chassis mounts are the most critical pieces to have or make, putting whatever is required between them is not a big deal when operating at this level of chassis/drivetrain mods

It's not working in a vacuum either, the engine mounts will also contribute to carrying the torque and moment loads.

 

I just knocked my outers off. The first one took me 45 minutes of tapping, hitting, pulling, and smashing. I ended up putting an aluminum pickle fork to it and hitting it over and over and over with the mini sledge and it finally came off. The second one popped off on the second hit. I need a bigger vice like yours.

 

be sure to put anti-seize on them and it will be much easier in the future.
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I did my first trackcross this past weekend. Super fun.

Car continues to be a blast to drive, perfectly reliable and quick.

 

That looks like a ton of fun, certainly looks like a test of suspension stability with all of the on/off track maneuvers. Well done!

 

I just noticed that you have the coolant reservoir in the stock location up front, but the height is way below your front to back crossover pipe. Do you just unbolt and raise up the reservoir to fill the system, and then once bled, seal it up and lower it back down?

 

I was late getting to the Nationals results, but congrats to John V for becoming the 2024 SCCA Street Mod National Champion in his piston-ized RX8. This thread needs to be bumped more often.



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And he won King of the Mountain this year, too. He's running a 6R80 torque converter automatic from an EcoBoost Mustang which has apparently been a boon for reliability and not shattering drivetrain parts.

By whom? John left this forum for very specific reasons and isn't likely to come back.

 

anybody … possibly yourself , or me , or even him.

Been a while, but he occasionally pops in.
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Thanks, Mark and Mikael! No issue with this forum other than life getting in the way.

Hey Mikael, to answer your question, I ended up relocating my coolant reservoir adjacent to the passenger side shock tower. It's still below the height of the black pipe that returns coolant from the cylinder head, but I've never had any issues filling the system.

Lots and lots of changes to the car since 2021 when I last updated this thread. I ended up building a new engine in 2022 after I had a piston fail in my 2.5L. As best I can tell, I yanked the wrist pin out of the #4 piston which windowed the block and destroyed the turbo. The combination is now a 2.5L block (89mm bore) with a 2.3 DISI forged crank (94mm stroke) making 2,340 cc. Same EFR7163 turbo as before, same cams. Lots more boost than before, around 22psi at full song which is right at 500whp.

I ended up going to an electric brake booster from an Accord to gain some room for a better intake manifold, and used a Tesla Model Y brake master cylinder to make that happen. Still running the stock non-DSC ABS unit. It works awesome.

I went to an inverted rear shock setup to be able to run a high-rate rear tender spring to try to keep the inside rear down on the ground in corners. That helped put power down quite a bit better than the previous non-inverted setup.

I spent most of 2023 destroying stuff. Ripped the rear diff mounts out of the subframe, ripped the control arm mounts out of the V8Roadsters front subframe. Broke two axles I think due to shock loading from the rigid clutch.

I decided to reboot in 2024 and make the car more reliable. I reinforced the diff mounts on a replacement rear subframe and went back to a factory NC Miata front subframe. Swapped the GForce 4-speed for a Ford 6R80 automatic, and spent most of the season dialing that in. Ended up changing rear end ratio to 3.55, with the goal of making the car quicker out of slow corners. It took three iterations of custom torque converters to make it work but it's where I want it now. The big downside is the car gained 115 pounds with the automatic swap. Not much I can do about that unfortunately. It's right at 2800lbs with 3-4 gallons of fuel. I think it's worth the tradeoff.

Overall it's much faster yet easier to drive. I won the Seneca tour a few weeks prior to KOTM and that helped my confidence a bunch. I actually think my runs at Seneca were better than I put together at KOTM or Nationals.

 

glad to see all your efforts and passion come to fruition John
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Thank you, my friend! It was a long and at times frustrating road

 

Cleaned things up in the engine bay a bit.



Working on a conversion to MK60 ABS as well, because, why not?

 

NICE. I've looked at doing that for my M3 but never pulled the trigger. Can you keep the factory wheel speed sensors?

 

Yes*

* The factory VR sensors are incompatible with all MK60 units. However - there is a conversion box made by Happy Cactus Garage which converts VR sensor inputs to the active sensor square-wave that the MK60E1 and E5 units need. My understanding is it only works with those two units.

If you want to run one of the other flavors of MK60 you'll need to convert wheel speed sensors somehow.

 

Congrats on the championship John! I love that your chose to keep the swap in the mazda family and I'm still super digging your setup. My Mazdaspeed3 seriously hauls (at one time with BNRs4, fbo, etuned @350whp, now back to k04 with etune @270whp) and I bet the 8 is a literal rocket ship.

Do you every hang around the mazdaspeed forum? Any plans to increase the rev limit or anything like that? Most of most guys are into drag and / or freeway racing but I could see the benefit of the extra rpm's on a track car. There's a member currently building an engine for 8k+ rpm looking to push 30+ psi, etc but I don't remember what power figures he's hoping to achieve. If interested, I'll see if I can dig up the thread.

 

I turn it to 8,000 on occasion now that it's a 94mm stroke engine. Typical redline is 7800.

It's so much fun. Long time getting here for sure, though.

 

Wow 8k is awesome and I bet there's a very generous powerband to work with. Wish I had that kind of headroom with my Speed (6700 rpm womp womp).