I'm thinking about getting an Injen cold air intake (or some other brand) for autocrossing this summer. I don't think that intake modifications will bump you out of the GS class in Sports Car Club of America Solo II.

Anyway, my question is whether an after-market intake is worth $200.00 + for application in autocrossing. I've heard that cold air intakes reduce low-end torque, and it seems like you would want plenty of torque for your typical squirt-out-of-a-90-degree-corner-in-second-gear autocross antics. Does anyone have any thoughts?

 

Intake does take you out of stock class in the SCCA autox's. Take off your resonator to remain in stock class. You get bumped to street prepared where you'd might as well add more to your car.

 

what class would i end up in with intake, exhaust, coilovers, strut bar, and lighter wheels

 

Are you sure about this? I was under the impression that intake modifications were ok. What is a source where I can look this up?

As far as removing the resonator goes, how does that affect performance relative to a cold air intake? Also, does it make the car sound ghetto?

 

Makes the car sound simliar to a SRI just not nearly as loud, at least to me

 

Aftermarket intakes like AEM, Injen, K&N will bump you out of Stock classes. In Stock classes, you're allowed to change the air filter element ONLY. Removing the resonator is also considered as illegal in Stock. Here is the rule regarding intake.

The last sentence basically says you can't remove the resonator since it is part of the induction system.

 

Street Touring S, or STS for short if your wheels are 7.5" or narrower and your tires are 225 or narrower.

Street Touring X, or STX if your wheels are up to 8" wide, and your tires are up to 245 wide.

 

Stock

As a rough guide, if your car has modifications beyond this list it is not eligible for Stock Category:
Anything available on the exact model and year of your car as standard or optional equipment, as installed on the factory assembly line (nothing available only dealer-installed is allowed), plus
Standard OEM identical replacement parts
Accessories, gauges, appearance, comfort, and convenience items (not replacement driver's seat, though) that basically don't help
Added roll bar or roll cage to spec (not required, though)
Driver harness (no cutting seats to install, though)
Trailer hitch and/or tow bar mountings
Any wheel of diameter and width identical to a stock or factory optional wheel, offset within +- 0.25 inch
Most street legal tires that will fit the mounted wheels and stock bodywork
Any shock absorber of the same type and mounting as original; no change to standard spring mountings is allowed; suspension geometry may not be altered; gas or hydraulic shocks are permitted
Any brake linings; pre-1992 cars may use solid/braided metal brake lines.
Any front anti-roll bar (no change to stock/optional rear anti-roll bar, if present)
Manufacturer specified ignition settings only
Any replacement air filter element (or removal of air filter element); no plumbing changes, however
Engine bored no more than .020"; no balancing or porting/polishing of head
Replacement of any part of the exhaust system past the catalytic converter (if quiet)
Any oil filter
Added clutch scattershield


Street Touring - S

If your car is a normally aspirated sedan (four seats, four factory seatbelts, not sports-car derived) of 3.1 Liters or less, or one of a few small turbocharged cars specified in the rules, and perhaps prepared further than allowed in Stock Category, it may be eligible for one of the Street Touring Classes. Street Touring - S is an SCCA National class, but Street Touring-R is an optional Regional only class. Street Touring allows anything allowed in Stock, plus (roughly) these modifications:
Any shocks, struts, and springs, using original attachment points
Any sway bars
Any wheels up to 7.5" in width that fit over stock brakes
Tires up to and including a width of 225, with a treadwear rating of 140 or greater.
Strut bars/braces as allowed in Street Prepared.
Exhaust system downstream of catalytic converter(s)
Short throw shift kits
Spoilers, body kits, rear wings, etc.
Pedal kits and other interior cosmetic accessories
Alternate brakes pads and linings
Any fully padded and upholstered front seats with reclining seat backs
Removal of factory trim (rub strips, emblems)
Alternate steering wheels of any diameter, otherwise meeting Stock rules
Cross drilled and/or slotted brake rotors
Alternate air cleaner enclosures
No limited slip differentials except factory viscous coupler type units
Stock brake calipers/drums
Fenders may not be cut or flared (but specific modifications for tires OK)
Emission-legal headers
Emission legal modifications to Engine management system, either electronic or mehanical, but not both.
Engine and transmission must remain unmodified, including emissions equipment


Street Touring - 2

This is a regional class implemented in San Francisco and other places, not a National class. Same limitations as Street Touring - S, but generally allows 2-seater sports cars cars and 2 + 2 sports-car derivatives.


Street Touring - X

Same limitations as Street Touring - S, but generally allows cars up to 5 liters or 2 liters turbo- or supercharged, with Limited Slip Differential, and certain other extensions.


Street Touring - U

Same limitations as Street Touring - X, but generally allows cars of unlimited displacement , or up to 3.1 liters turbo- or supercharged, with unrestricted wheel width, tire width up to 275 (RWD) or 245 (AWD), .


Street Modified

Street Modified is a pretty free-for-all class that is a full National class since 2002. For streetable sedans, expands eligible vehicles and modifications above Street Touring, above Steet Prepared, and perhaps even above Prepared category.
All Street Prepared modifications are allowed, plus
Unrestricted modification of engine, drive train, and suspension, and some other modifications, as long as the car uses highway fuels.


Street Modified 2

Street Modified 2 is a new optional Regional class beginning in 2002. It has similar rules to SM, but allows 2-seater cars, and cars too light or small to qualify for SM.


Street Prepared and Beyond...

More vehicles and different changes are allowed in Street Prepared, but major modification will put you in the Prepared or even a Modified category; consult the rules for details

 

A.K.A. Get your ass kicked if you bring a TSX.

 

http://www.scca.org/_filelibrary/File/2005SoloRules.pdf

Go there for the official rules.

I guess with my SS, intake, and debadging I'll run in the STS. It'll put you at a disadvantage though. But as long as you do well for your car in the autoX that's all that matters.

 

My best time was 60.28 on the course I ran with just an Intake, for some reason I couldn't break that time.

The times most cars were running was around 55-58 so I was still behind a bit. There were two guys though, running a z06 and some car that looked like a little F1 that ran 53's and 46's respectively.

I beat a Evo, 911 4S, and a Elise that were running in the mid 60's that day but the Evo was a first timer, the guy in the 911 had one leg, and the Elise.. well he was old and scared to push his car (though it was probably the fastest out there).

 

Well, in that case, then get ready to have your ass kicked if you run a TSX in either GS, STS, or STX.

Hmm...I'm wondering what SP class the TSX will fall into. The 2005 rule book doesn't list the TSX at all in any SP classes. I'm thinking it would fall into DSP, which you'll also get your ass kicked by those BMW's running on 285/30/18 Kumho 710.

Well, to sum it up, you'll get your ass kicked in any class if you bring a TSX.

 

So long as you're having fun, that's all that matters. Auto-X a great way to improve your driving skill.

 

100%

 

I would think GS is a tougher class than STS. Mini Cooper S' on r-compounds I run middle of the pack STS, but I think that comes from having a whole lot of crappier drivers than me. I'm hoping to beat some of the better drivers in STS, but here in DC I'd say we have a pretty weak class overall.

 

Yeah, I just checked out the cars in GS class, and it's a pretty tough class. On the other hand, the TSX seems comparable to (or faster than) a lot of the cars in the class.

Why is the Mini Cooper S in the GS class, though? They must totally dominate.

 

its all about power to weight ratio, yes the TSX probably has the most HP of a car in GS, but its also considerably heavier than everything else.

 

you dont need the back seat passenger seat or the spare tire come on now

 

Spare tire usually comes out no matter what class you're in. But if you start removing the back seat, you're now in Street Mod. And if you continue on and remove the passenger seat, you're now in Prepared. In these 2 classes, you'd better get ready to be "murdered" if you're running the TSX.

 

its all about the fun so who cares and taking out seats is to much work

 

That's just sad to hear, is there any car out there that we can "murder"?

 

Jr. Karts?