The SRT-4 and Autocrossing

[stowaway]

The possible classes for a SRT4 are:

Stock: GS
Street Touring: STU
Street Prepared: DSP
Street Modified: SM


Stock Rules (GS)

The following modifications are allowed in stock class:

- Port installed options: rear spoiler, diff protector, armrest extension (specifically allowed in February '03 FasTrack, the general rules allow factory options only).
- Appearance, comfort and convenience options, e. g. gauges, alarms, turbo timers, shift knobs.
- Removal of spare tire, tools and jack.
- Harness (seat belts cannot be removed).
- Any DOT approved tires (see rules for restrictions), including R-compounds, of any size (no modification of fender well).
- Wheels (stock size only, offset within 0.25" of stock).
- Wheel spacers (resulting offset within 0.25" of stock).
- Lug nuts.
- Brake pads, speed bleeders.
- Shocks that maintain stock ride height, can be adjustable. See rule book for details!
- Front sway bar.
- Different alignment using factory adjustments (no camber bolts).
- Spark plugs.
- Air filter element can be removed or replaced.
- Cat-back exhaust.

STU Rules

All modifications from the STX rules are allowed. In addition, the following modifications are allowed:

- Stock category allowances
- Pedal kits and other interior trim
- Front seats (15 pounds minimum weight each)
- Rub strips, emblems, and mud flaps removed
- Body kits, spoilers, and wings added
- Shocks/struts
- No wheel restrictions
- Tires for 2WD cars up to 275 mm wide (245 for AWD)
- Drilled/slotted rotors (standard size) and braided
- DOT brake lines
- Anti-roll bars, front and rear
- Lowered suspensions using standard-type springs
- Suspension bushings (non-metallic)
- Camber kits, plates, or bolts
- Traction bars, torque arms, panhard rods
- Strut bars, 2-point only
- Battery relocated
- Air filter systems up to throttle body or compressor inlet
- Headers, emissions compliant
- Engine computers (PCM/ECU) reprogrammed
- Shifter kits
- Accessory drive pulleys
- Motor mounts (non-metallic)
- Limited slip differentials allowed (including aftermarket) for 2WD cars
- High-flow “cat”
- Larger brake calipers and rotors


Street Prepared Rules (DSP)

In addition, the following modifications are allowed:

- Modification (e. g. rolling, cutting) of fenders for tire clearance. Adding of fender flares.
- Seat (fully upholstered seating surface).
- Remove seatbelt for replacement with harness that meets safety restrictions.
- Any steering wheel.
- Front spoiler.
- Rear spoiler.
- Removal of radio/stereo/AC.
- Any DOT approved tires (see rules for restrictions), including R-compounds, of any size.
- Wheels of any size and offset.
- Cross drilled and/or slotted brake rotors (ferrous, standard size, no two-piece).
- Brake cylinder.
- Fuel injectors and pump.
- Intercooler (including hoses).
- Intake water injection.
- Turbo-back exhaust (no cats required).
- Clutch (metal).
- Flywheel (metal).
- Shifter and shift linkage, e. g. short throw shifter.
- Transmission mounts (non-metallic).
- Differentials.
- Standalone engine management for non-turbo car.
- Port matching (see rule book).


Street Modified

Consult the rule book for details of the Street Modified rules. Street Modified inherits all allowances from Street Touring and Street Prepared. The following does not attempt to list all additional modifications that are legal in this class, it just lists a few popular mods that are common in Street Modified, but not allowed in Stock, Street Touring or Street Prepared:

- Certain replaced body parts: e. g. carbon fiber hood, fenders.
- Removed rear seats.
- Suspension control arms, lateral and trailing links.
- Metal bushings, subframe bushings.
- Different/updated turbo.
- Blow-off valve.
- Intercooler water spray.
- Any kind of boost control (MBC, EBC).
- Any other changes to boost control, like the popular resistor mod.
- Engine management systems that modify boost.
- Standalone engine management.
- Internal engine modifications..
- Different/updated transmission.
- Steering rack.


2009 SCCA Autocross Rulebook:

Consult this for further class questions and finer details of what is and isn't allowed:

http://cms.scca.com/documents/Solo_R...Solo_Rules.pdf


Not Allowed In Any Class

The following are not allowed in any class:

- Nitrous (NOTE: Bottles not allowed on event sites for safety reasons).


Uncertain Mods

No clear rules are currently available for the following popular mods:

- Ground wire/Electrical modifications.



Common Questions/Generic Information:

What Tire Pressure do you run at Autox Events?


- Get to the events early, and talk to the other drivers about common pressures.
- If you can't take/borrow a small air compressor, start with the pressures high (45-50 psi) and take a tire gauge and some sidewalk chalk. Mark a line in 3 or 4 places on each tire, from the last inch of the tread block down an inch on the side wall. After your first run, see how much chalk is gone and adjust accordingly: 1. Still some on the tread, lower the pressure. 2. If it's gone from part of the sidewall, increase the pressure/
- Tire pressure for autox - SRT Forums - SRT4, SRT6, SRT8, SRT10 & Dodge Forum
- Race rubber pressures? - SRT Forums - SRT4, SRT6, SRT8, SRT10 & Dodge Forum
What brand tires are good to Autocross in?

- Autocross tires?... - SRT Forums - SRT4, SRT6, SRT8, SRT10 & Dodge Forum
- Need new tires for autocross . . . - SRT Forums - SRT4, SRT6, SRT8, SRT10 & Dodge Forum

What should I set my alignment to, for autocross/daily driving?
- Alignemnt Settings - SRT Forums - SRT4, SRT6, SRT8, SRT10 & Dodge Forum
- Suspension and Alignment Suggestions for Autocross - SRT Forums - SRT4, SRT6, SRT8, SRT10 & Dodge Forum

Could I scuff or scratch up my paint if I hit a cone?
- It's very unlikely, usually a little scrubbing and/or polishing will take the mark right off the paint. Sometimes residue will be left behind, and rarely older rougher cones can hurt some body panels, ie: bust a foglight.

[Woon]

Great listing Stowaway. This is definitely great for people getting into auto-x and keeping current competitors up-to-date on classing rules and regulations. I did find a bit more clarification in certain areas that changed since I last looked at the regulations.

Here are some additional things (while I still had the patience to look) that I found to add/update to your list that may apply to many of us SRT-4 owners who have specific parts that they may need more direction on how to class their cars at a glance.

STU Rules

- Front seats (15 pounds minimum weight each) *25 lbs minimum including mounts
- Fenders may be rolled (cutting/flaring not allowed)
- Battery may be relocated but not into the passenger compartment
- Lateral locating links/arms may be modified or replaced.
- Traction bars, torque arms, panhard rods (solid axle suspension allowance only)
- Sub-frame connectors(h-braces) are not permitted
- Engine computers (PCM/ECU) reprogrammed (except that no changes to standard
boost levels, boost controls are permitted) (i.e. Mopar Stage 1 etc...)


Street Prepared Rules (DSP)

- Airbags may be electrically disabled but not removed. (i.e. Airbag delete tray)
- Wheel spacers are permitted.
- Wheel studs and knock-off wheel drive pegs may be changed in length and diameter.
- Wheel bolts may be replaced with studs and nuts.
- The use of ‘two-step’ rev limiters used when the car is stationary is permitted.
- Sub-frame connectors(h-braces) are permitted

OH and also in regards to ...

Uncertain Mods
No clear rules are currently available for the following popular mods:

- Ground wire/Electrical modifications.

This seems to apply starting at the STU classing level...

- Section 14.9 Sub-Section B
- The addition of electrical grounding cables and associated distribution blocks/terminals is permitted

Happy racing!
Woon

[Rouserman]

Left out prepared...granted not too many folks run their SRTs in prepared.

I always ran EP. Those of you who get crazy with the weight redux, or start stripping the front half of your interior can get bumped from SM.

Great write-up though, very informative. Will probably save someone's 'tech' guys some questions on sunday

[RumbleFish]

some regions, mine included, have created a street-mod street-tire class. rules may vary, but here its street mod with tires that have a treadware rating of 140 or higher. its become quite popular and is easily the largest class at any event in my region.

[05Blast]

I haven't been around for about a year... I see the SRT-4 did wind up getting moved from DS to GS. I guess I need to get a couple "G" magnets now :-)

[JmalB]

Quote: Originally Posted by RumbleFish

some regions, mine included, have created a street-mod street-tire class. rules may vary, but here its street mod with tires that have a treadware rating of 140 or higher. its become quite popular and is easily the largest class at any event in my region.

My region has a street tire class as well. Works like novice where you grouped with everyone else who is running in there standard Stock, Street Prepared, Modified, Prepared classes but just on street tires. Excludes anyone running in the ST classes.

[stowaway]

Quote: Originally Posted by JmalB

My region has a street tire class as well. Works like novice where you grouped with everyone else who is running in there standard Stock, Street Prepared, Modified, Prepared classes but just on street tires. Excludes anyone running in the ST classes.

same here, as well as a ladies class.

[JmalB]

Yeah. I don't race in the ladies class because that's just too many women to be out driven by...

[AQuimby]

How about some alignment recomendations for the car. I drive an SRT-4 ACR in GS. I have the camber mod and koni SAs. I usually run 0 toe in front and max neg toe in rear and 0 camber in back and -2.2 in front.

I used to drive a 1st gen Neon R/T in STS and my alingment was pretty much the same except for the toe settings. Less neg toe in rear and a little bit neg toe in front.

I was planning on going with a little more neg toe in front with my ACR.

[JmalB]

If that doesn't rotate enough for you, try dialing in a little more positive camber in back

[AQuimby]

Thanks for your response. I am more interested in toe settings for the front. I have heard many differents things and am wondering if anyone has a good amount of experiance with toe in the front and what works best.

Some say toe "in" to battle tourq steer and some even say that it lays down the power better in corner exit with toe "in". Which really doesn't make sence to me. With my expirience with autox in general would be to toe it out in the front about 1/8 of an inch.

[JmalB]

Search around this section. I thought there were some setups in here. And you can always check GRM's old articles.

[solort]

I just purchased an 05 ACR for GS. I have run many ACRs in DS and GS over the years and I have to agree with the rear camber suggestion. The car seems to work best with a little over -2 front camber and as close to 0 camber in rear. When Daddio tried to autocross an O4 SRT-4 in DS, the limited front camber forced him to push the rear camber as pos as possible.

I will set mine up initially with 0 camber and 0 toe in rear with appx 1/4 to 1/8 toe out in front. Then I will max stiffness in front with shocks and then rear and add toe out in rear if needed for sweeper balance. Then adjust rear pressure up to get final rotation.

On my HS Mazda3, I had to get konis valved for increased compression and rebound in front to get car to really work well. I went this route to use a smaller front bar to minimize wheel spin on corner exit. My car was the fastest Mazda3 at Nats this year (.1 out of first on the good course without the endless 180 deg corners).

Just some suggestions...