SCCA Solo Street Modified (SM) Discussion

[piknockout]

Ah yes, the gearing. That too. More than likely I would probably go turbo if/when I do a build. Build the engine for higher revs, new final drive, do what I can to hit 75mph in 2nd.

Also curious, in my turbo research it seems as if 4th gear becomes a breaking point at 400+whp. Not that it's an issue in autocross, but wondering if 2nd gear could be a potential issue as well requiring perhaps a stronger transmission.

[whataboutbob]

Where are the rest of the boosted SCCA Solo2 twins?

[trippinbillies40]

If someone competent got in Hyman's GTR, pretty much everyone in SM should just pack up and stay home. I'm anxious to see what Ramsey's new build can do with Mayfield at the wheel.

[e1_griego]

Jason Merritt's SM 240 car beat the GTR at the packwood tour -- both drivers .

It's a similar recipe to PJ's car -- 315s at 450+whp with a nice ka-t powerband.

But the GTR is pretty much unstoppable, I agree. The car is so crazy to see in person. Big car doing small-car things.

[Locust]

Originally Posted by e1_griego

Jason Merritt's SM 240 car beat the GTR at the packwood tour -- both drivers .

It's a similar recipe to PJ's car -- 315s at 450+whp with a nice ka-t powerband.

But the GTR is pretty much unstoppable, I agree. The car is so crazy to see in person. Big car doing small-car things.

To be fair to Eric... Their GT-R was down for pretty much the entire season up until that point. That course also didn't have much room for throwing down high power.

[e1_griego]

Oh I know, I run in SM. I'm aware of the score.

The GTR is stupid fast, but there's some other fast folks running around, too.

Still, it's all too rich for my pocketbook.

[rx3]

Based on the adaptations which are apparently allowed in SM, SM appears to be almost similar to our E1-class but those are not street legal cars:
[ame="https://www.youtube.com/watch?v=zYfNOWEOMxE"]Pure Sounds of Opel Kadett - VW Golf GTI Time Attack Frauenfeld 2012 Schweizer Slalom Meisterschaft - YouTube[/ame]

How can you still get them to be road legal? Or are the SM-cars usually put on trailers?

[e1_griego]

Street mod is essentially no cross-chassis motor swaps (but you can add forced induction), require interior in the front of the cabin, can't move suspension pick-up points, can't strip the car besides the rear interior (have to run stockish lights, bumper supports, etc), can run aero but limited as to how much.

It's sort of a dumb class, but super awesome.

And yes, every successful SM car lives life on a trailer. There is not much 'street' in street mod.

[Locust]

Originally Posted by e1_griego

Street mod is essentially no cross-chassis motor swaps (but you can add forced induction), require interior in the front of the cabin, can't move suspension pick-up points, can't strip the car besides the rear interior (have to run stockish lights, bumper supports, etc), can run aero but limited as to how much.

It's sort of a dumb class, but super awesome.

And yes, every successful SM car lives life on a trailer. There is not much 'street' in street mod.

Technically in SM you can't strip any interior. Seat removal is the only exception but that just pertains to the seats and not any panels. If you remove your trunk liner, for example, you are out of SM and into Prepared classes.

[e1_griego]

You can strip the back seats out, is what I meant. 16.1.k.

Again (I think I keep telling you this) I've run SM for a handful of years now.

If someone is actually serious about SM they will familiarize themselves with Chapter 16 of the rulebook.

[ultra]

Hmm. SM is where stuff like the Mark Daddio Evo used to live, along with plenty of maxed out E36/E46 M3s, right?

If so then the formula would seem to be power increase + traction increase + dialed chassis + weight reduction + aero.

My dream build would be something like so...

Power:
- built bottom end
- TVS supercharger (for torque & response) with a smaller pulley + E85 or watermeth for a little extra power while retaining safety.
- clutch + axles

Traction:
- purple crack Hoosiers; 315 rear + 285 front (or maybe 315 square?) and some kind of body kit to hide it all.

Chassis:
- High end coilovers with relatively high spring rates
- Swaybars to complement coilovers
- Tons of tweaks such as bushings, control arms etc. - to keep the roll centers, alignment & scrub radius in check due to using huge, heavy rubber and presumably heavier, lower offset wheels to carry said rubber.

Weight reduction:
- The usual trunk junk
- Lightweight battery + relocation to trunk
- Washer bottle
- race seats
- sound deadening
- as much of the interior as you can chuck under the rules
- Trick lightweight wheels to offset mass gains from running huge rubber (as per above)

Aero:
- The FT86 Speedfactory front splitter + rear diffuser plus some kind of wing would seem to be a good place to start. Could then augment one end or the other to maintain balance. I've seen SM cars attempting to use flat bottoms and 'full skirt' aero though, so this could be a very dangerous area to mess with financially, although if dome well it could be hugely beneficial.

Cons:
- Gonna cost a ton of money...and even more time, setting it all up and balancing it all.
- if aiming to be co petit ice would probably take some time to re-optimize the chassis setup if coming from a lower class. Worst case - might have to spend tons 'starting over'.
- No longer so streetable.

Pros:
- Don't see why a well built SM Twin couldn't be competitive since M3s have also been, historically.
- SM cars could work nicely as dual role SM + Time Attack + DE cars, depending on your goals. So maybe a little extra utility to be had from the dollars being spent.
- Might still be streetable in a pinch.


Am curious if a less hardcore, less expensive build could be made to be SM competitive though.

For example a car with a more basic FI setup and, say, 285 square Hoosiers under the stock bodywork, with more focus on making up time using a killer chassis setup and weight reduction + aero?

[e1_griego]

You wouldn't want to stagger -- square 315 setup.

400whp is minimum.

Min weight for an FRS would be 2480 with >275s -- can subtract 200# for <275 tires.

There hasn't been a front-running bmw since Simanyi's car a few years back Recently the Panda (s14 240sx, 450whp, 315s) has dominated, and other front-runners are the evos and Stis, jason merrit's s13 (450whp, 315s, etc), the Hyman's GTR (~700?whp, 345 a7s, generally nuts), and then a few Evos and STIs that I'm sure are all ~500whp, 285s-315s, etc.

[xwd]

Ultra, some of that stuff isn't SM legal. You can't get rid of sound deadening, can't use rear diffusers or other trick underbody aero. You are limited to the big wings and front splitters, which can't extend back all that far.

Simanyi wasn't too far off winning in 2013, that's not that long ago.

The recipe for being competitive in a FR-S/BRZ isn't complicated since it's a very good starting point, someone just has to spend the money and drive it well.

[Locust]

Originally Posted by e1_griego

You wouldn't want to stagger -- square 315 setup.

400whp is minimum.

Min weight for an FRS would be 2480 with >275s -- can subtract 200# for <275 tires.

There hasn't been a front-running bmw since Simanyi's car a few years back Recently the Panda (s14 240sx, 450whp, 315s) has dominated, and other front-runners are the evos and Stis, jason merrit's s13 (450whp, 315s, etc), the Hyman's GTR (~700?whp, 345 a7s, generally nuts), and then a few Evos and STIs that I'm sure are all ~500whp, 285s-315s, etc.

Hyman GTR is like 740whp and 800 for pros I think.

I also think the OP checked out of this long ago and decided he hates autocross because it "isn't real racing".