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STF (Street Touring FWD) STS Rules Summary

Old 01-21-2004, 06:05 PM
DancesWithCones is offline
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[edited 20 Feb 04 to match 2004 Rules]

The following is a summation and interpretation of the rules for SCCA Street Touring Street Tire (STS). Complete rules are best viewed by purchasing the rule book from the SCCA. While you're there, get a membership because it's the most fun you can have legally while the car is moving. For an overview of STS, see the STS FAQ. Visit the STS How To FAQ for tweaking of set-up, etc. This thread will be updated when the 2004 rule book is in my hands.

An unoffical version of the rules can be found on this STS Site. Be aware that the rules are constantly updated via the FasTrack insert of SportsCar magazine, the official magazine of the SCCA. FasTrack is also available online at although 2003 has strangely disappeared from their pages. If you follow this link you'll see them all. Also check this forum for additional changes and comments.

Since you're visiting the North American Motoring website devoted to Minis, I'll skip all the details about eligible vehicles. The Mini Cooper is legal for STS. The Mini Cooper S is not, but can run in STX. For more details on STX, see the FAQ, etc. in the STX forum.

14.1 Modifications:

A. This section says you may only perform the modifications that are specifically allowed under the Stock rules and whatever is in section 14 of the rules. In Stock, you're allowed to replace all "wear" parts like brake pads, shocks/struts, fluids, etc. plus some hard parts like spark plug wires, exhaust from the last catalytic convertor back, and front anti-sway bar. You need to read the complete rules to ensure you understand what is allowed. It's not a lot but it is important.

[2004 Rules: update/backdate has been deleted.]

B. You can remove the air conditioning but not the complete heater set-up. This is essentially saying that anything that's in the engine compartment that's related to providing cool comfort to the passengers may be 86'd. Since the engine accessories are all run off of one belt, a shorter replacement would have to be found. It would be possible to switch belts on race day to remove parasitic drag. Complete removal could take ~20 lbs (complete guess) off of the nose. Check the How To FAQ to see if a replacement belt has been found.

14.2 Body Work:

A. Addition of cosmetic accessories. This is here because of the limitations in Stock which prevents such additions. Be aware that the intent is to allow customization not weight shaving. Challenges are possible and you could be found guilty of not following the spirit of the rule.

B. Replacement front seats. This is where some weight can be removed from the car but if this is your daily driver, may certain you can live with your seats. The replacements must be upholstered on the seating surface, the seat must extend up to the center of the helmet, and it must weigh 15 lbs, not including the mounting hardware. Note that the seat does not have to recline. Nor does it have to have upholstery on the back. This means you can now use a shell-style seat (obviously this is different from previous rules.)

c. Removal of factory trim. Again, this isn't meant to help remove weight. It's intended to allow customization.

D. Alternate steering wheels. This will allow you to switch from the Mini 2-spoke to a 3-spoke, or from one without radio controls to one with. But for the most part, it's not relevant since you can't go from to one without an airbag.

E. Fender mods. This may be important if you're looking to fit a set of 225 tires (see 14.3). You can roll the fender lip but you can't cut anything away. It really comes down to what constitutes the "lip." There have been a couple of How-To's written about rolling the lip. Links are in the STS How-To FAQ. Note that the fender well must be retained intact.

F. Spoilers, body kits, rear wings, etc. This is a very open ended rule but again the intent is to allow for customization.

14.3 Tires:

The rules for tires is simple: upto 225 in width with a minimum tread wear rating of 140. [2004 Rules: width was changed to just a number indicating some people actually measured.] There are many to choose from and everyone has their favorites. The best way to see what works is to see which brands were used to trophy at Nationals and the ProSolo Finale. Serious people put lots of thought into their tires.

14.4 Wheels:

Wheels are even simpler then tires: Any wheels up to 7.5" in width. The catch here is that everyone tends to interpret this to mean they can go to 17 or 18 inch wheels. And you can but that does not mean their faster. The rule also states that they must fit over stock brakes. The original concern is people going down to 13 inch or below. See the STS How-To FAQ on wheel and tire testing and results.

14.5 Shock Absorbers:

A. Bump stops may be altered or removed. This is really something that should be done only if the situation warrants. Plan on keeping them (in some capacity) until you can't. Again, the STS How-To FAQ should address some of the whys and whatfores.

B. Any shock/strut that fits the original design. There are additional rules prohibiting alterations but section 14.8 provides greater insight into permitted configurations.

14.6 Brakes:

A. Cross drilled and/or slotted brake rotors are permitted. To understand if this is a benefit, you have to understand the environment of a rotor during an autocross. That is again left to the STS How-To FAQ.

B. Alternate DOT brake lines. This is one area that most don't fully explore. Most stock rubber brake lines bulge under the pressure of high effort braking. Aftermarket lines don't bulge, thus providing greater feedback and control. You'll understand why that's important once you've gone around a course a couple of times.

C. Air ducts may be fitted. This is another mod that can wait to see if you need to do it. Generally speaking, a Mini should never need them. To understand why you might, see the STS How-To FAQ.

14.7 Anti-Sway Bars:

Any anti-sway bar is permitted [2004 Rules: or removal added]. Like the shocks there are other restrictions and they must fit the original design. The interesting thing is that bushing material, method of attachment and locating points are unrestricted. Which means that all compliance within the anti-sway bars may be eliminated.

14.8 Suspension:

A. Ride height may only be altered by suspension adjustments. This means that coil-overs are allowed and that the perch may be adjustable.

B. Suspension bushing may be any non-metalic material. The benefits of urethane bushings on some cars is remarkable. The benefits in a Mini are yet to be proved. Installation is difficult for most locations and should be taken into account prior to the undertaking. Check with the How-To FAQ for potential real world reports.

C. Camber plates permitted with slotted [2004 Rules: insert "original" here] mounting holes. Original rules didn't permit slotting of holes or of the center hole. This severly limited the potential of a camber plate. Minis benefit greatly from this addition.

D. Camber bolts may be used. For the Mini, this isn't really necessary unless you don't wish to use camber plates. There are some draw backs to bolts and plates but that discussion is in the How-To FAQ.

E. Addition of suspension stabilizers. This doesn't apply to Minis.

F. Camber kits may be applied to non-strut suspensions. This allows the replacement of the rear locator arms in the rear trailing arm suspension of the Mini.

G. Alignment changes resulting from allowable modifications are permitted. IOW, if they've given you the ability to change the alignment, you can take advantage of that.

H. Strut bars are permitted. Transverse bolt-on bracing may be added to upper and lower suspension mounting points to stiffen the subframes. [2004 Rules: Interior panels may be modified to accomidate installation.]

14.9 Electrical System:

Any 12V battery may be used and it may be relocated. This is very important for the Mini Cooper. Very small batteries (including motorcycle batteries) that can be installed at the event will decrease the vehicle weight while redistributing it, preferably to the passenger-side rear.

14.10 Engine:

A. Engine and trans must remain unmodified unless otherwise noted. This rule is redundent.

B. Alternate air cleaner enclosures up to throttlebody. Some cars possess elaborate resonators in the fender. The MC is very simple in comparison. But becareful what you select. Autocross is a slow speed event and sucking hot air from the engine compartment into the engine could rob you of power.

C. Header. As of this writing, all available headers for the MC replace the catalytic converter which is forbidden. There may be alternatives but that will take some experimentation or time.

D. Engine Mangement: Reprogrammed ECU, "piggyback" ECU, fuel pressure regulator (if fuel not controlled by ECU), ignition timing (at distributor), valve timing controller. Out of these mods, only playing with the ECU would be possible but may be difficult to justify considering the limited power gains that can be made. Check with the How-To FAQ to see if there are any developments.

E. [2004 Rules: Changed to "Any mechanical shift linkage..."] This is really more cosmetic since a proper autox course doesn't have any shifting required except for a single first to second upshift, and most likely you're losing far more time elsewhere. Go for it if you want but don't install it for on-track performance. [2004 Rules: This could present some interesting interpretations. Cables shifts could be replaced with rod and hiem joints, etc. Still doesn't matter much if you're only shifting once.]

F. Accessory pulleys and belts. You can replace the pulleys on the alternator, water pump, power steering, A/C and the crank to reduce the parasitic drag. This could be benefital but you don't want to create situation where those services are lost when they're needed, like electical power while idling. If you replace the pulleys, add gauges to monitor those systems.

G. Engine mounts may be replaced. This could prove important in reaction to throttle inputs. But it may make the everyday use too rough as more noise is transmitted throughout the car. [2004 Rules: Second paragraph added] Rear engine locators may be replaced as long as they are of the same type (i.e. gas / hydraulic).

John Stuart

Moderator: SCCA STS Forum

[email protected]
Old 06-12-2005, 09:59 AM
DancesWithCones is offline
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2005 Rules Online

The SCCA rulebook has been posted online. It use to be $15 for the print version but this make it much easier to know what can and can't be done. Remember, the rules are evolving and each month can bring new rules for the membership to consider for the next season, new rules that are effective upon publication, and re-wording of existing rules for clarification. These are part of the Fastrack News and are part of the Sports Car magazine. As an SCCA member, the magazine is free and these updates would be delivered to your door.

The following link is to the 13MB rulebook PDF. I suggest you right-click and save to your desktop. Street Touring is chapter 14.

2005 SCCA Solo II Rulebook

Enjoy and hope to see you out there.
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