RallyCross idears

Been itchin' for a while to fab and strap back in the seat, ain't gettin' no younger. If I could do 1 or 2 races/ month just to knock the cobwebs out that'd be a win. A $10K dirt street stock is a back marker around here. Can't get my mind around Auto-X like you guys. An old D/SR or F1000 like the Lola that lurked around here was callin' my name, good regional car but still a lotta time w/ my schedule. Historics, maybe one or two events/ year. Hello RallyCross, not very popular around here but a big maybe. OVR has 7 events/ year but at a 4 hour tow, eh. Looks like a blast.

So, idear. There's a fresh 0.030 over 4.3L Chevy in the basement and a 700R lurkin' in the garage, they will fit in a Miata. Paco lift and suspension redo, wheels n tires. Maybe a T5, dunno. Never been a real fan of Miata like yunz guys but a good lightweight platform for hoonery on dirt. Under $5K I'd plan, eh prolly not.

Search says: https://grassrootsmotorsports.com/forum/build-projects-and-project-cars/90-mazdaspeed-miata-rallycross-project/43300/page1/

Quick look at SCCA class rules, this build oughta fit in somewhere. Not lookin' at National competition, just fun for now. Miata would actually fit in the garage and Duramax Canyon would tow no problem.

Good idea, bad idea? Different car? This build would definitely be centered around the 4.3 tho. Enabling is expected. TIA

Don't lift it too much or roll!

Worst thing they could do in our classing is bump you up a class. I am not sure of the SCCA classing but I think you would be in MR.

Autoboxes work surprisingly well in rally-X for getting off the corners. Torque multiplication is a wonderful thing.

NGTD wrote: Don't lift it too much or roll!

Quoted for truth.

Miatas with nearly stock ride height, rally tires, and superchargers win in Modified Rear. A V8 with torque could work very well. Low and stiff seems to be the ticket for using ruts as "train tracks" to steer without flipping.

Engines are unlimited in MR so the V8 swap would be kosher.

I wouldn't lift it, stock ride height is fine. Our courses aren't extremely rough.

Kylini wrote: Miatas with nearly stock ride height, rally tires, and superchargers win in Modified Rear.

Miatas with turbochargers can win too.

In reply to EvanB:

Do you have any info on that Vic?

EvanB wrote:

Kylini wrote: Miatas with nearly stock ride height, rally tires, and superchargers win in Modified Rear.

Miatas with turbochargers can win too.

I hear that things that spin tend to not do well. I think that applies more to the driver than the turbo though.

The_Jed wrote: In reply to EvanB: Do you have any info on that Vic?

Not really. They just said they got it cheap to run the Detroit gambler, lifted it and put on big tires.

The_Jed wrote: In reply to EvanB: Do you have any info on that Vic?

I was doing tech and the event chair and I had a thorough look at it. Pure stock cop-car interior, and some interesting stuff done with the chassis. Radiator was lifted and angled to change car's angle of approach, they had two spare tires mounted in a rack in the trunk (which you opened by reaching inside and pulling on the emergency release), they had spares bags and tools and stuff extremely well secured in the trunk with numerous D-rings and ratchet straps, well organized too.

They said they were havin' fun They loved it when I pointed out they were lifting a tire coming over that crest under power.

So a hardtop Miata sounds promising. Like aftermarket parts availability too but nix the Paco idea. Can't think of any other car that can be done cheaply and the 4.3L V6 is a documented swap.

Is there a preferred Miata model/ year for rallycross?

The 4.3 has flat tops, 270HR Comp Cam, Performer intake w/ 390 or 500 Holley and would get headers. It will absolutely sound like E36 M3 and prolly won't see over 200 hp.... but it's paid for.

Now the big IF. OVR is 4 hrs. There's a little interest in SW PA area but no rally sites. Two sites have tried but are no more. Heard a region guy say they're looking into a local site.... 15 miles from me. Hope that pans out. May be time to get involved w/ the region again to get this done. Off-road is popular though w/ ATVs, side X sides, Jeeps and tube buggies. Maybe oughta talk to them about a site.

Damn, I wanna build somethin'.

If you're engine-swapping, the 1990 was the lightest and is usually used for CSP autocross abominations (that class allows update-backdate parts so the competitive cars use as many light 1990 parts as possible with more modern engine goodies). 1990-1991 are also the cheapest (1.6 L engine that no one wants).

1994-1997s are "in demand" and command premium prices. 1999-2000 are the lightest of the stiffer NBs. The 1999 sport package is in demand for autocross, but the 2000 is "just another Miata" and is likely your cheapest NB option (especially for motor swap). VVT on the later NBs is nice if you were keeping the motor.

Remove your plastic fender liners (allowed for tire clearance), find some 185/65-15 rally tires (like the Indy Sport BR or SG, the Maxxis gravel tire, or if you're feeling super fancy, order some Federally G11s from England [14 in but good outer diameter]), and go to town.

Low to stock height is good. Very slight raise is probably fine but not advised. Normalish sway bars recommended (disconnecting the rear is an option for some courses). 550 lb/in : 375 lb/in front:rear is a decent spring rate to start with (slightly stiff in the rear to help rotate). 700/400 blows shocks in my experience. You can gain a lot tweaking the suspension, but having a running car is step one!

fasted58 wrote: So a hardtop Miata sounds promising. Like aftermarket parts availability too but nix the Paco idea. Can't think of any other car that can be done cheaply and the 4.3L V6 is a documented swap. Is there a preferred Miata model/ year for rallycross? The 4.3 has flat tops, 270HR Comp Cam, Performer intake w/ 390 or 500 Holley and would get headers. It will absolutely sound like E36 M3 and prolly won't see over 200 hp.... but it's paid for. Now the big IF. OVR is 4 hrs. There's a little interest in SW PA area but no rally sites. Two sites have tried but are no more. Heard a region guy say they're looking into a local site.... 15 miles from me. Hope that pans out. May be time to get involved w/ the region again to get this done. Off-road is popular though w/ ATVs, side X sides, Jeeps and tube buggies. Maybe oughta talk to them about a site. Damn, I wanna build somethin'.

What's wrong with the Mazda engine? It's more than enough to have a lot of fun with and stock is more reliable.

Was noodling this out with Adam (Brock, just competed in his first stage rally last weekend) while working corners. Rallycross courses are supposed to be built/constructed so that completely stock cars may navigate them without damage. Modified allows you to reinforce the heck out of anything and everything and you can also remove a lot of weight. Yet people drive the Stock cars to and from events, people (mostly) trailer Modifieds, yet the Modified cars are the ones that tend to have breakage issues, and Stock is often about as fast on course as Modified. You would think the heavier/weaker cars would live on trailers and fail to finish events, and the tough Mod cars would shrug everything off... no?

Only conclusion I can come to, is most people who modify their cars do so very, very badly, and create negative gains.

I'll say what I say to everyone: Do a few events first, then think honestly about where you want to go from there.