SCCA Solo Street Modified (SM) Discussion

[itzmik3]

Originally Posted by dwx

My old GC was around 2690 with a 6 speed transmission, my 2002 WRX was 2830. I was thinking you could get the twins in the high 2400s or low 2500s fully prepped. Once you add things like aero, big wheels/tires, and FI it starts to get a little more difficult though.

I do expect it to be an extremely popular car in the future for SM though along with the RX8. Not sure why no one has built an RX8 yet since you can pick them up for dirt cheap now.

well minimum weight w/ forced induction is 2480 so we aren't that far off the pace right now. granted we still have aero to add to the car.

there is definitely some more weight to be dropped out of the car

[mav1178]

Red v Red:

[Laloosh]

Fender flares allowed? Imo you guys are going to need a 315 on all 4 and about 400 to the wheels. My bank called as I typed this and told me I'm locked out as a precaution.

[whataboutbob]

Originally Posted by vroom4

So whats the big part of the build? Do you feel limited on power/weight or suspension?


I think Id probably do a bare bones type build with my STX build+supercharger, wheels/tires obviously, and axles. Is that about where you are bob?

You need power and grip IMO. I've done quite a bit of suspension work and added aero, the car is really panted at the moment. I also recently went to a 69mm pulley and the Delicious E85FF kit which is definitely helping. In the Pro Solo competitions it is really hard to keep up with AWD on the launch. I'm also in an auto so my launches aren't all that spectacular anyway. One day I'll have a Hollenger sequential and a Motec 150 ECU to solve that problem.

[whataboutbob]

Originally Posted by dwx

I have a pretty well prepped STX car but I do plan on going to SM eventually, maybe next year.

It takes money and some engineering know-how. I had a 2.5L WRX I built back in 2004 and raced in SM and later put all of it into a 98 RS Coupe body.

There is a SM BRZ thread on NASIOC I've kind of kept updated over time and I did mention your car in that one after the Tour results.

I have one of the TRD superchargers which was produced, and should be good for roughly 400WHP on E85 with the right pulley. The Harrop S/C coming out is basically the same thing, TVS1320. I have a set of built heads I picked up for a good price and should be able to rev to 8500RPM without too many issues. I'm lacking a built block right now but will keep the 12.5:1 CR. I want to keep my stock engine intact, so I'm basically building a second engine. I decided to go S/C rather than turbo but I believe you could use either. An EFR setup with a 6257/6758 would likely work well.

How light have you guys gotten your cars? My old WRX and the GC I built after it had pretty much everything stripped out of it to the limit of the rules. A/C, all radio stuff, seat belts, etc. I'm not ready to do that with my BRZ. I have seats leftover from my old build but they aren't tremendously lighter than the stock seats and certainly much less comfortable.

2775ish, not much weight reduction.

[whataboutbob]

This is a shot from the 2015 SD tour, I'm about to shift from 2nd to 3rd. The RS-R CR coilovers are doing good work here keeping the car planted.

[vroom4]

My god you would've done pretty darn good with a manual transmission and some weight reduction.

[FastWhite]

With you running in SM, with the stickier tires and all, have you changed your sway bars from what you were running in STX? Just curious.


Sent from my iPhone using Tapatalk

[whataboutbob]

Originally Posted by FastWhite

With you running in SM, with the stickier tires and all, have you changed your sway bars from what you were running in STX? Just curious.


Sent from my iPhone using Tapatalk

No, just the settings. I have changed the coils to the RS-R Club Racers.

[FastWhite]

I'm still running STX, with Tein SRC coils. Love them. Initially I went with the recommended stock rear bar and a 20 mm front bar. I found just a bit too much under steer for MY liking. So I put the 18mm rear bar back on. Now on slower course's it feels neutral and on the higher speed I had a touch of oversteer.
I liked it better this way. Still teaching myself this suspension magic. If I get time I will put full stock back on just to compare.
I can't see myself going to SM, way to many mods for a DD. Into SP is where I will end up. Intake stuff, E85FF. But then again ANY trany mods, valve body, clutch packs etc. is a straight SM move. 4.56 gears or higher could get you better launches.
BUT say never and that's where you up.


Sent from my iPhone using Tapatalk

[ksconekiller]

What size wheels & tires are you all able to fit on the car?

[piknockout]

As has been said, I think the magic numbers are 315 and 400. I like to use Panda as the standard for the direction the FRZ's should be going. Gotta fit the 315's and need at least 400whp. Of course the 315's will require someone to be willing to do some cutting and the reliable 400whp will likely require some decent engine work. Oh yeah, and axles. Gotta have axles.

I have a lot of evil thoughts that have been going on in my head as well. Aaron Shoe in his SM Evo is a really good friend of mine and we've discussed how to do it. I've seen the work that goes into that car (which can win Nationals) and it's not cheap. A lot of custom work and working through issues constantly. It's not cheap to run at the front, although Panda might be the exception. It helps to have a co-driver who is as dedicated to the build as the car owner and willing to put in a good chunk of funds to offset costs. And sponsors.

[whataboutbob]

I'm at 275/35 and an estimated 300WHP on a dynojet. I haven't dynoed the car since the smaller pulley and the Delicious FF kit. I also have 450cc injectors that need to go onto the car.

[xwd]

Originally Posted by piknockout

As has been said, I think the magic numbers are 315 and 400. I like to use Panda as the standard for the direction the FRZ's should be going. Gotta fit the 315's and need at least 400whp. Of course the 315's will require someone to be willing to do some cutting and the reliable 400whp will likely require some decent engine work. Oh yeah, and axles. Gotta have axles.

I have a lot of evil thoughts that have been going on in my head as well. Aaron Shoe in his SM Evo is a really good friend of mine and we've discussed how to do it. I've seen the work that goes into that car (which can win Nationals) and it's not cheap. A lot of custom work and working through issues constantly. It's not cheap to run at the front, although Panda might be the exception. It helps to have a co-driver who is as dedicated to the build as the car owner and willing to put in a good chunk of funds to offset costs. And sponsors.

I've posted a bunch of stuff in the BRZ SM thread Steve Garnjobst started on NASIOC awhile ago.

I think the newer group of TVS1320 superchargers coming out will be able to do 400WHP with a very good torque curve on E85. I have one of the original TRD superchargers using the same blower. KSR was able to get a little over 350WHP out of it running on 98 octane on a 9.5:1 CR engine. They built the car for road racing and had to use that fuel in the series. It's not going to be a torque monster but will still be good for ~300ft-lbs across a wide RPM range with pretty much instant response >3000 RPM.

There are always EFR turbos as well but I like the idea of running the S/C.

I'll do a build but not for a little bit yet. The main part I'm missing is a short block if anyone wants to donate one. I'm trying to build a complete second engine so I can keep my stock one intact. I've got a set of heads and most of the ancillary engine parts, but no block.

The cheapest wide wheels are probably the Forgestar F14s although I don't like the look of them. The key is going to be going as wide as possible with keeping the car as narrow as possible. Kits like the Rocket Bunny and other crap are not only expensive but they widen the car waaaaay too much for autox. I don't think the car needs all that much to run 315s, 275s already fit without doing anything really.


Running a 3.91 final drive may be the best option for a manual car. Revving the motor to like 8200+ RPM even with built heads may not be great since the rockers can be a weak point and shifting 3-4 times on a faster course sucks. You can pick up a complete IS250 3.91 rear diff for like $150, there are a ton of them out there.