Help me understand SCCA classing

I've never built a car to a class before.

I am considering modifying my Miata, and trying to figure out where to put it. I think I am looking at Emod, but not sure.

Here's where it will be at when I am finished:

• Original engine, with a turbo added. Aftermarket electronic engine management. Modified fuel and ignition systems. Fuel cell.

• Original transmission, but a swapped rear end with LSD and different gear ratios.

• Completely modified suspension, but factory geometry, and pickup points. Struts, springs, anti-roll, perches, camber adjusters, suspension bushings, etc.

• Race rubber. I've been running non-DOT legal road racing Hoosiers, but could switch this if I needed to for classing.

• Completely stripped interior. Race seat.

• Roll bar.

• Significant aero- most body panels modified or replaced with fiberglass panels (with different appearance). Some of the body modifications will be for aero, some for cooling.

• Windshield removed.

• Undercarriage aero (flat bottom plus skirts and diffuser)

• Wing.

• Very significant weight reduction.

• Considering active aero, but not sure if that is legal in any class. Might just be something I play with.

What else do you need to know? What should I change in my plan to keep things competitive?

My reading of your list looks like E Mod to me as well. That said, I'm a bit rusty on the current classing since I haven't looked at the rulebook in a while. I'm sure there are plenty of EMod miata folk on here that can give you a definitive answer though.

In the meantime, perhaps this handy diagram will help. I think it's the SCCA official classing rules.

In reply to irish44j:

I don't think your evil classing rules flowchart is welcome here.

Anything above street mod or anything related to club racing, I staple the rules up on the wall, get drunk, and grab a handful of darts. If one sticks, you're done. If two: take the average. If three, you should drink more until it all makes sense.

Everything looks good for Emod except the wing, no wings in EM, just spoilers. Amod would allow pretty much all of it except the active aero.

X prepared. If you still had your interior you could run in the RWD mod class. I think XP will be a little bit friendlier to a car that is not prepared to the Nth degree.

Xp at the national level pits you against a carbon fiber bodied lotus Elise.... Just saying.

Pick up the most recent copy of the scca magazine, it should have all the results from nationals in it. Looking at the times between classes is very helpful in picking a class you may want to run in or benchmarking yourself against other top drivers in other classes.

My impression is that the slicks you want for Mod classes are Avons, but I've never used them myself.

SCCA rules

In reply to MrJoshua:

I know where to find the SCCA rules. I also have a printed copy.

It's over 300 pages long.

I was asking for a little help classing the car, not a link to the indecipherable blah blah blah.

SVreX wrote: In reply to MrJoshua: I know where to find the SCCA rules. I also have a printed copy. It's over 300 pages long. I was asking for a little help classing the car, not a link to the indecipherable blah blah blah.

The first sentence of your post was I've never built a car to a class before..

If finding a competitive place in SCCA autocross is the goal, then a bunch of pages of "indecipherable blah blah blah" is where you need to start... Unfortunately.

""

In reply to SVreX:

300 pages? Do you read the dictionary from the beginning when looking up a word? Youre gonna have to read after you get all those great suggestions. Now you have a link ya grump.

That's Senior Grump to you, Little Grumpito.

Actually, seriously have you ever tried to weed through that? It's quite a useless bit of drivel without an SCCA Sherpa.

In reply to SVreX:

I read emod before i posted the link. It looks pretty good except for the ducktail instead of the wing and you are going to have to do some minimum weight calcs.

In reply to MrJoshua:

OK, but that's not classing. That's pre-assuming a class, then reading the rules for it.

Minimum weights are just an opportunity to put the weight in the right place.

Well, you could always just rallycross it ;) There are only three RWD classes (stock, prepared, modified) and Miatas are locally and nationally competitive in all three classes (I think they actually won all three at nationals last year). And the rallycross rulebook section on car classing is a whopping 9 pages long ;)

If you're going to autocross with SCCA, and want to built a competitive car at either the local or national level, you'd better get well-acquainted with the rulebook - because all of your competitors have probably spent hundreds of hours reading and re-reading it looking for every possible allowance and loophole.

OTOH, if you just want to do it for fun, just build the car however you want and just run in XP. You didn't really say if you want/plan to be high-level competitive or not. That makes a big difference.

I think XP or SSM would be easier than EMod. I competed in EM and am currently building an EM MGB, it's a tough, tough, tough class. check out my build and you will have an idea of what is required: https://grassrootsmotorsports.com/forum/grm/scca-emod-mgb-gt-v12-build/26822/page1/

Yes, as long as you're not tied to the underbody aero (it'll be a bitch to make and won't work right, it's not worth it), XP or SSM is where you want to go.

In reply to drdisque:

It wasn't that hard to make.

Sounds like a SSM car that through virtue of removing the interior & windshield, became an e-mod car if you remove the active aero, otherwise go straight to X-prepared, do not pass go, do not collect $200.

FWIW, I've been DQ'd on autox runs under the "active aero" clause for not latching the 318ti's hatch.....oddly enough, that car IS faster with the hatch in the air.

Your car can make E-mod, but you have to go without the significant aero, including the bodywork that adds aero. You should also switch to DOT legal Hoosiers to avoid having to use a driveshaft loop, kill switch, and scattershield. The front splitter and the rear wing are good.

Edit: Also like MrJoshua mentioned, you will need to start reading the rulebook yourself to be sure that you're in compliance. If someone in your class is competitive and you don't meet regulations, they can complain and have you move to XP.

I was building an MGA, blithely going along thinking that I had it all in hand until I got to the fiberglass rocker panel part . . . now I'm back to square one and wondering out loud.

Where are people getting the idea that I don't know how to read the rulebook? I have read it dozens of times.

I didn't ask what the Emod rules were. I asked where a car with significant aero fits in. The reason I asked is BECAUSE I HAVE read the rules, and it doesn't appear to fit.

Is there a reason I should build an Emod car?

I am telling you the type of car I am interested in building, and asking where it may fit in, so I can build to the limit of that class. What I am hearing is, "Don't build THAT car, build an Emod car. And while you are at it, read the rules!".

Meanwhile, some of you are saying, "OMG, you might get bumped to XP", while others are saying, "XP would be easier than Emod".

Some of you say, "No wing in Emod", while others say, "The rear wing is good in Emod".

C'mon, guys.

I think I am going to have to eliminate the advice of half of the people in this thread, because it is obvious you have not read the rules.

Let's make it easy and read the rulebook - Per rulebook, for DM and EM, 18-F-1:

F. Aerodynamic Aids 1. These classes are restricted downforce classes. No aerodynamic tunnels, wings, or sealing skirts may be added. No bargeboards, ramps, vanes, wickerbills, or other aerodynamic devices are allowed except as specified herein or as part of an SCCA®-approved GT-1 bodywork package for the specific make and model.

So no wings in EM.

Build the car how you want, put it where it fits best and enjoy.