RX8 is screwed in Street Prepared...

 

Yep, but some people think the Mazda's chassis/suspension advantage will help overcome that.

Stuff that might help the RX-8 in SP:

Series 2 diff via UD/BD.
Fender cutting/flaring to fit much wider wheels/tires (obviously a tradeoff with width).
I imagine the cat elimination might open up more engine tuning flexibility b/c EGT will be less of a concern...??
Flywheel/clutch can be lighter/smaller.
Seats don't need to hit a minimum weight.
You could also UD/BD the smaller brakes from the auto model, but I don't know if they're lighter than the other stuff that you can use in STX.

 

I don't think so. Marc (Zelse)'s car is very quick. Maybe next year he will spend less time at hard-parking photo shoots and more time at national-caliber autocross events

At the end of the day, top drivers will do well no matter what car you put them in. I think a fully-developed RX-8 will be close enough that it will come down to who is behind the wheel.

 

more to it than most people realize


Street Prepared allowances above Street Touring:


Remove A/C components (interior & exterior but heater system must not be modified)

Cut or flair fenders (for 295+ tires)

Any high-back seat (no minimum weight limit)

Any steering wheel (no air bag requirement)

front splitter & rear spoiler aero is allowed, but no aftermarket rear wings (there is an SP aero proposal out in the latest FastTrack to delete or modify the rule)

Stereo/speakers/amps can be removed (wiring must remain, any resulting holes must be covered)

Any single brake master cylinder or brake booster.

A single bolt-on master cylinder brace is allowed.

A brake proportioning valve is allowed.

No limit on rotor cross-drilling surface area

Brake backing plates can be modified or removed. Brake air ducts are allowed as long as the body/structure is not modified

Steering rack bushings can be changed as long as the metal content is equal or less than OEM

Any ignition system or component is allowed

Any oil pan, oil pump, or oil pump pickup is allowed, including an Accu-sump

Fuel injection and intake manifold are unrestricted, including injectors, rails, throttle body, linkage, pressure regulator, etc.

All emission control devices may be modified or removed

Intake water injection is allowed

Any fuel pump(s) is(are) allowed, any fuel line is permitted up to 1/2" ID with one supply line, one return line, and an added fitting is allowed at the top of the fuel tank (allows converting the RX8 non-return system to an external return system with a second pump in the RH saddle to eliminate the siphon pickup configuration)

Any gasoline fuel is permitted (E85 is already allowed)

Any radiator is allowed as long as it uses the OE mounts and is equal or larger in size, fluid capacity, and dry weight than OE (may serve no other purpose such as allow a cold air intake passage, etc.)

Any radiator fan & shroud is permitted (except flex-fans, not applicable)

Any clutch & flywheel is permitted, an alternate slave cylinder/device is permitted (allows conversion from slave/mechanical actuator to full hydraulic direct actuator)

Engine & drivetrain components may be balanced

Intake and exhaust port matching is permitted within 1" of the interface joint

Any aftermarket engine computer is allowed (MoTeC, etc.)

Update/backdate between 2004-2008 and 2009-2011 vehicle components assuming they are listed on the same classing line


.

 

^I swear this guy likes me

Thanks Mark!

With that said, If you were going to choose a turbo to run in SM, which set up would it be? A good friend is trying to convince me to do it.

 

You will want to convert to a 13B REW engine configuration. From there I would approximate Carter Thompsons setup.

 

but with the right tuning this would probably suffice to start:

https://www.rx8club.com/rx-8-parts-s...bo-kit-236923/

then upgrade the turbo as you progress

 

This is tempting..

 

it's too high, make him a more reasonable offer

rolling the rear fender lips this Saturday for big tire clearance

 

WTB: 18x10.5 SSR Type-C's

(40% serious / 60% kidding... I think)

 

recent BSP results. Unfortunately there was only one car that was registered under DSP this past weekend which was a MS3 (hopefully more DSP show up next year). My local competition isn't that bad aside from the fact that I suck and my numbers are terrible compared to my STX and B Stock bretheren

 

just rolled my rear fender lip for clearance with 295s on them last weekend ...

have a set of 18 x 10 CCWs that I'm looking for wider outer halves to punch out to 11"

just playing for now, no definite plans

 

Sounds like fun... I'm still trying to sell my car, but so far there's been very little (zero) interest. I'm half tempted to move to DSP just to give Zelse some local competition. It's a big financial jump, though. Of course, so are the other options I'm considering for next year.

Decisions, decisions...

 

Glad to see this finally went through. I had sent in a number of letters over the years about this.

Looks like not much has changed since I was last on here about 9 months ago.

Still on a sabbatical from autocrossing. Crushing it on the tennis courts. Just one level below a semi-pro now...

 

unfortunately stuff like a balanced & blueprinted engine, 5.5" clutch/flywheel, etc. aren't cheap

taking up something else is starting to make more sense

 

Mark is thinking about being a semi-pro tennis player too?

Nice!!

 

An NA 3 rotor would put you at a 2732 weight limit vs a 2701 weight limit for a turbo 13b. Should be able to get similar power levels and you wouldn't have to deal with boost.

 

Ok let me go find 20K laying around real quick!

 

I thought about going FI on my r3 and then I realized that for the same cost I could just pick up a c6 z06 and up with a faster car that got better mileage, didn't rust, and had more trunk space.

 

I'd be even more clumsy with a tennis racket than a steering wheel and some pedals ...

an R3 (or any S2) would be a terrible place to start to begin with. An FI 2-rotor engine will cost less and provide great low end power with more than adequate high end power. The only pro for a 3-rotor NA engine is durability. Making sound without killing power is going to be a real struggle too.


.

 

It'd be a bad place to start if the end goal is to dominate ssm. It'd be a great place to start if the end goal was to make a quick car a bit quicker. I feel like that goes for any rx8 though.

As far as the NA 3 rotor goes - I think you could have it built and installed for 10k in parts. I don't know that a properly set up rew is going to be any cheaper initially. Peak power wouldn't be as high, but I think that not having to deal with boost lag would make up for it.

Don't know who I'm trying to convince here. It's just something that seems pretty rad to me and I'd love to see it done.

 

So here's my list

Lightweight Flywheel
17x10 wheels with some 275/35/17's
Replace the cat with another resonator
Aftermarket steering wheel?
Some new pullies.

That's about what i'm looking at doing IF I decide to do a DSP build..

As far as an OS giken goes...I have not looked into it yet.

 

You really have no idea what you're talking about. A 20B Na engine is great at the track because you can always keep it wound up and in the narrow powerband. In an autox scenario you will either chug out of a corner and then be hitting your brakes just when the power is finally starting to climb or to avoid it you'll need a sequential trans and a really short rear gear which by itself will cost more than $10k and row gears like crazy.

Does this look like boost lag to you? Autox FD Dyno - RX7Club.com

Stop being silly. If you want to pursue an SM thread then go start one and demonstrate your expertise there. This is a DSP thread.

 

I've seen that fd, but I didn't realize it was making that much power. Street ported 20b would leave you down 50hp or so and with a narrower power band. Sorry to hijack the thread!

 

well sorry for having been so blunt about it, but you aren't even in the ball park. It is a custom job beyond the engine itself. You will need an aftermarket racing ECU and everything that goes with it including grafting it with the rest of the chassis electronics. You will need to mate it to the drivetrain/PPF, custom header/exhaust, etc., etc.. The list just goes on and on. $10k is a pipe dream and then you will be lucky to get anywhere close to the power goal you stated for that price even if you do everything yourself, not to mention it will be a ton of work requiring a lot of fabrication equipment

20b Engine Build and Conversion Pricing from Vendors - RX7Club.com

20B NA update - dyno results (LONG) - RX7Club.com

I had this idea several years ago and after researching it out the it was quickly scrapped. No way will it compare in price, effort, and end result over a proper 13B single turbo setup.