East Tennessee Region SCCA

Ok so I'm brand new to all of this. I'm thinking about heading up to Bristol for the autocross event. But I dont know how or where to class my car. It's a 2015 impreza STI. I've got a cold air intake, cobb downpipe, Tomei catback exhaust, cobb AP tuner, boomba BPV, cobb short shifter with bushings, RCE yellow lowering springs, whiteline sway bars with endlinks, and I'm on factory rims with michelin tires. I've read so much that I'm confused on what class to be in. Help

Basically the BPV bumps you way up in class, I believe either SM (street mod) or at the least ASP (A- Street Prepared). I used to have an aftermarket valve on my STi and i remember it caused me to be way outclassed.

As long as the tires are 200TW or higher you can run in either STM or XSA ( I think XSA is the right one for the STI ).

STM is a heads up, run what you brung , class on street tires that the region uses for a catch all for cars that might be over modified for certain classes.

SM ( Street Mod ) is a class that would normally have people running on race tires ( under 200TW ) so, especially for new people so they don't get discouraged against highly prepped cars, they made the STM ( Street Tire Modifeid ) so everyone plays on an even level.
Additionally, since you're new, you're also going to be in the "N" Novice index class.

Hope that helps a little. It's really confusing at 1st and for new people that have cars they modified for either street fun, drag racing or track use, the ruleset might not make sense and seem stupid, but it's a pretty well thought out set of standards.

If you get hooked on solo, you might end up altering your car to better suit a specific class, or change cars.

Hope you have fun and remember 2 things... tell them you're a 1st timer so they can make sure you get help and 2) ask questions.

DBOWMANEOD wrote: ↑Wed Jun 09, 2021 1:24 pm Ok so I'm brand new to all of this. I'm thinking about heading up to Bristol for the autocross event. But I dont know how or where to class my car. It's a 2015 impreza STI. I've got a cold air intake, cobb downpipe, Tomei catback exhaust, cobb AP tuner, boomba BPV, cobb short shifter with bushings, RCE yellow lowering springs, whiteline sway bars with endlinks, and I'm on factory rims with michelin tires. I've read so much that I'm confused on what class to be in. Help

Put the stock BPV back on and come run in STU with me!

Buck05Sti wrote: ↑Thu Jun 10, 2021 1:33 pm

DBOWMANEOD wrote: ↑Wed Jun 09, 2021 1:24 pm Ok so I'm brand new to all of this. I'm thinking about heading up to Bristol for the autocross event. But I dont know how or where to class my car. It's a 2015 impreza STI. I've got a cold air intake, cobb downpipe, Tomei catback exhaust, cobb AP tuner, boomba BPV, cobb short shifter with bushings, RCE yellow lowering springs, whiteline sway bars with endlinks, and I'm on factory rims with michelin tires. I've read so much that I'm confused on what class to be in. Help

Put the stock BPV back on and come run in STU with me!

Wouldn't the stock bpv mess up my tune?

DBOWMANEOD wrote: ↑Thu Jun 10, 2021 3:48 pm

Buck05Sti wrote: ↑Thu Jun 10, 2021 1:33 pm

DBOWMANEOD wrote: ↑Wed Jun 09, 2021 1:24 pm Ok so I'm brand new to all of this. I'm thinking about heading up to Bristol for the autocross event. But I dont know how or where to class my car. It's a 2015 impreza STI. I've got a cold air intake, cobb downpipe, Tomei catback exhaust, cobb AP tuner, boomba BPV, cobb short shifter with bushings, RCE yellow lowering springs, whiteline sway bars with endlinks, and I'm on factory rims with michelin tires. I've read so much that I'm confused on what class to be in. Help

Put the stock BPV back on and come run in STU with me!

Wouldn't the stock bpv mess up my tune?

Depends on the tune. Is it Speed density? I used to have a 50/50 valve on my car that wasnt tuned for, so when i would shift after a hard acceleration, i'd get a loud pop/backfire. Is your valve VTA or a 50/50?

It's a boomba BPV. I got my tune at fast tech. It pops a little now after hard acceleration but not much

Is the BPV a full recirculating valve or one that vents to the atmosphere?

Full recirculating.

DBOWMANEOD wrote: ↑Sun Jun 13, 2021 6:11 pm Full recirculating.

If that's the case, youre most likely fine running a stock BPV, unless you're running a crazy amount of boost and NEED an aftermarket bpv

In sport sharp max boost is 21 lbs. So not an insane amount at all.

DBOWMANEOD wrote: ↑Tue Jun 22, 2021 6:51 pm In sport sharp max boost is 21 lbs. So not an insane amount at all.

You should be fine with a stock valve. I run about 19PSI on my stock BPV. And still get all the fun noises with the intake