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The Autocross Information Thread

108K views 83 replies 57 participants last post by  4ceFed4 
#1 ·
It's about time this forum had a thread for common questions and answers. Feel free to add specific information or links on autocross or autocrossing VWs..

What is autocross?
Autocross, at its essence, is very simple. It's motorsports for the masses. Anyone can come out, with virtually any car, and test their driving skills in a safe, controlled manner. My favorite description of what exactly it is comes from Dennis Grant, one of the founders of the Street Modified class: "The basic concept is simple: take a large paved area. Describe, on it's surface, a race course, marked off with traffic cones and flour lines. Place a timer at the start and finish, and one car at a time, drive through as fast as you possibly can. Hit a cone, and get two seconds added to your time. The track is never the same twice from event to event. There are no practice runs. We run rain or shine. In Formula One terms, an autocross is like bringing your team to a track (which was completely torn down and rebuilt from the last time you were here); you get three qualifying laps, from standing starts (each one!) and on cold tires (no tire warmers allowed). The next day, you do the same thing, but in the opposite direction, and then the track owner rips up the track and starts building a new one. 6 runs total [generally 3 runs for one day events], best one each day counts. This all makes for a sport that is very different from any other style of motorsport. On the whole, it is less expensive and less dangerous than other forms, as there is very little chance of crashing into something hard, and speeds tend to be slower. On the other hand, it demands a very high level of aggressiveness and driver precision - you have to be instantly fast, and everything must go right right away. There is just no margin for error.
Races are won and lost by thousandths of a second, and the mental pressure can be enormous."

Is it dangerous?
Just like any other form of motorsports, Solo2 has some element of risk. However, the SCCA has specific rules defined to make an event as safe as possible and, in general, Solo2 is at least as safe as driving on the street. Usually, there are no more than 3 cars on a course at a given time, and that's only when the course allows sufficient separation. Workers are positioned around the course with fire extinguishers and red flags to inform cars when there's a problem. Courses are designed so that if a car does lose control, or spin, there's nothing even close to it that could be hit. Spectators are only allowed in certain areas around a course. Kids under 12 are not allowed in hot areas, which include grid, prestart, course and impound. Be aware that other organizations have differing rules, and many are not as safe as an SCCA event.

What is ProSolo?
ProSolo is a national series run by the SCCA. Where most Solo2 events run one car at a time, a ProSolo runs two cars head-to-head on mirror image courses with a drag strip start and a Christmas tree. Reaction times are part of the times. Each car gets 4 runs on each side and the best run on each side is totaled for their time. ProSolo also has a Super Challenge at the end of each event. Each car in the Challenge has a dial-in similar to bracket drag racing. In a given round, the two cars get a run on each side, whoever wins advances.
Example map: http://www.wincom.net/trog/new...e.JPG

Don't expect much in the beginning..
Out on the street, we all think we're the best drivers. And who wouldn't? There's no evidence to the contrary, so we get to think whatever we want. Often someone new checks out an autocross and just thinks it doesn't look like that big of a deal. Driving is a lot different than watching. Once you get to the start line, and there's a big sea of cones in front of you, things change. For those of you who may be nervous or a bit intimidated already (hopefully you're not!) the next couple sentences are not for you. For the street racer or canyon cruiser or spirited street driver, read on. Here's the first step. Check your ego in at the gate. Assume you can't drive, because chances are, compared to a seasoned autocrosser, you can't. This isn't a hit or a knock on your driving skills, because we all start out at this point. We all think we're the greatest, and then we get out there on course, see our times, and realize we're not. The best things you can do is listen to the experienced people around you, pay attention during the course walk, and take advice. Your goals for a first autocross should be to stay on course and, if you can do that, improve your time by the end of the day. At this point, the car you drive, or what modifications it has won't really matter. In fact, having a modified car will only hurt as it may mask things you may be doing slowly. The primary limiting factor will be the driver. As you get better, you will be able to truly take advantage of making the car better. A couple of mantras you will probably hear repeated in one form or another, but won't really "get" for awhile. "Slow down to go faster." The beginner usually tries to be too fast in the slow parts of a course, and too slow in the fast stuff. "In like a lamb, out like a lion." Generally, late apexing is the only answer.

Walking the course
Your goal when walking the course is twofold. To commit the entire course to memory so you can go through it in your head at "full speed", and to choose the line through the course that you think will be the fastest and be able to do it without thinking. So walk the course twice. Generally try to focus on what you're doing and have enough clear area ahead of you so that you can see what the course will look like when you drive it. Break the course up into sections and try to analyze the entire section as a whole to determine where you want the car to be at each turn. Memorize it, play it back through your head, and go!

SCCA Solo2 Classing Structure
Cars are classed in the SCCA first by modifications and second by the cars' set of traits and capabilities. Each ruleset is strict; in other words, if it doesn't say that you CAN do it, than you CAN NOT do it and remain legal for the class. The general progression of levels of modifications is as follows: Stock, Street Touring, Street Prepared, Street Modified, Prepared, Modified. Note that this is not a linear progression. Everything, for instance, that is legal for Street Prepared is not necessarily legal for Prepared. Once a car is placed in one of these categories, its placed in a specific class along with other cars that perform similarly. Example cars for each class are below.

Why the rules are the way they are; or why even adding 1psi of boost must be considered the same as adding 20 psi.
The ruleset is very stringent. To people new to autocross or motorsports in general this may seem antithetical. "Why does having a chip place me in Street Modified, its only a software map and I'm still underpowered!" or "I have a different transmission in my car, but it doesn't really help that much, so why am I placed in such a hard class?" are common questions. The ruleset for each class has to cover all cars. Further, the rules must be able to place cars properly based on the car's potential as it would be if it were modified TO THE LIMIT OF THE RULES. This is important. Changes in stock boost level, for example, are illegal in Stock, Street Touring, and Street Prepared. It would be an impossible task to set boost level maximums and actually be able to control or check levels at an event. The alternative is either allowing unlimited boost (which is what Street Modified does) or allowing no boost changes (SP and lower). Note that the below listings are not exhaustive. For complete rule details see the SCCA Rulebook. This is just a general guide.
Stock
Allowed Modifications:
Driver harness
Roll bar or roll cage (SCCA specs)
Shock absorbers with the same mounting type
Trailer hitch
Wheels with the same diameter and width as stock (i.e. a GTI 337/20th must use a 18x7.5", it cannot use a 17" from a GTI)
Front swaybar
Brake pads
Air filter (not intake)
Tires (anything D.O.T. legal including R compounds)
Cat-back exhaust
Classes and example/common cars for each class
Super Stock: Corvette Z06, Viper, 996 911, 93+ RX-7
A Stock: C4 Corvette, Mitsubishi Evolution, Subaru WRX STi, 00-04 Honda S2000, E46 BMW M3, Porsche Boxster S
B Stock: Mazda RX-8, Nissan 350Z, E36 BMW M3, MR2 Turbo, Porsche 968 M030
C Stock: Mazda Miata 1.8L, Toyota MR2 Spyder, Porsche 914
D Stock: Integra Type-R, Audi S4, VW GTI/Jetta 24v VR6, R32, Lexus IS300, BMW 325/328/330
E Stock: Toyota MR2 non-turbo, 90-97 Mazda Miata, Porsche 924
F Stock: Camaro V8, Mustang V8
G Stock: Celica GT, Mini Cooper S, VW Corrado VR6, GTI/Golf/Jetta 1.8T, 16v
H Stock: Mini Cooper, BMW 318

Street Touring
STS - four seat vehicles, maximum displacement of 3.1L NA and small displacement forced induction sedans
Allowed Modifications:
Shocks, springs, swaybars, strut bars/braces
Wheels up to 7.5" width
Tires up to 225 width
Street tires with at least 140 treadwear rating
Steering wheels
Short shift kits
Fully upholstered seats
Pedals
Body kits, spoilers, wings, removal of factory trim
Brake pads, rotors, lines
Intake, cat back exhaust, header
Emissions legal engine management
Underdrive pulleys
Relocation of battery
STX - 2WD vehicles may use any LSD, engines up to 5.1L NA, 2.0L forced induction.
Allowed Modifications:
STS modifications carry over
Any LSD for 2WD vehicles
Wheels up to 8" width
Tires up to 245 width
Example cars:
STS: Honda Civic, Dodge Neon, Toyota Celica, Mini Cooper, VW GTI/Golf/Jetta 1.8T, Jetta/GTI 16v, Corrado VR6, Audi A4 non-Quattro
STX: Honda Civic, Mini Cooper S, Subaru WRX, Integra Type R, E30 BMW M3

Street Prepared
Allowed Modifications:
The allowed modifications in SP are extensive, the following is a general summary.
Anything allowed in Stock
Update/Backdate rules for any cars on the same line in the rulebook
Any wheel and tire width
Shocks, springs, swaybars, strut bars/braces
Camber plates
Any fully padded seats, steering wheels, pedals, roll cages up to 8 points of attachment
Fuel cells allowed with certain qualifications
Suspension bushings
Limited Slip Differentials
Carburetion, fuel injection, intake manifolds, intake, exhaust manifolds, exhaust
Motor mounts
Clutch/flywheel
Overbore to .0472" with oversize pistons
Balancing
Port matching, milling
Pulleys
Ignition system
Classes and example/popular cars for each class:
ASP: C5 Corvette, Lotus Elan, 996 911, 93+ RX-7
BSP: C4 Corvette, E36 BMW M3
CSP: Honda CRX, Toyota MR2 Spyder, Mazda Miata, Mazda RX-3
DSP: E36 BMW 325/323/328, Lexus IS300, E46 BMW 330, Fiat X1/9, Acura Integra GS-R, Mini Cooper S
ESP: Camaro V8, Mustang V8, WRX, WRX STi, Mitsubishi Evo
FSP: Honda Civic 92+, VW Scirocco 8v, VW Rabbit/Jetta 75-84

Street Modified/2
Allowable Modifications:
Anything in Stock, Street Touring, or Street Prepared
Drivetrain is unlimited except: engine from same company as manufacturer (Honda/Acura, VW/Audi swaps are OK)
Max displacements:
FI: 3L OHC, 4L pushrod
NA: 6L
Rotary: 1.5L
Suspension is unlimited except: Must use original suspension attachment points
Brakes unlimited
Rear passenger seat can be removed
Hood/front fenders can be changed
Firewall, roof, doors, rear quarter panels, floor pans, trunk lid must be stock
Minimum weights:
SM:
FWD: 1800 lbs NA, 1900 lbs FI
RWD: 2200 lbs NA, 2400 lbs FI
AWD: 2400 lbs NA, 2600 lbs FI
SM2:
FWD: 1500 lbs NA, 1600 lbs FI
RWD: 1900 lbs NA, 2100 lbs FI
AWD: 2100 lbs NA, 2300 lbs FI
Common cars:
SM: Any sedan/coupe with four seats (not sports-car based) such as VW Scirocco, Golf, Jetta, Passat, Dodge Neon, Honda Civic, BMW 3 series (including M3), Supra, WRX, Mitsubishi Evo, Talon/Eclipse, etc, etc
SM2: All two seaters/sports cars such as Corvettes, MR2, 911, Z cars, Honda CRX, Miata, or an underweight or over displacement SM car. All Lotus are excluded.

Autocross specific wheel philosophy
The general, most common rule of thumb in autocross is get the most rubber possible down at all 4 corners. While there are some minor exceptions to this rule, it almost always holds true. Wheel size will help you do this. Lets start with diameter. On the street, we all run big wheels because it looks cool. Drag racers tends to run small, wide wheels and tires with lots of sidewall. Several factors play into choosing a wheel diameter: weight, gearing, and fitment. The smaller the wheel, obviously, the lighter it is. The less unsprung mass, the better, so this is a good thing, and favors a smaller diameter. The shorter the wheel/tire combo, the shorter your gearing will be as well. So if you have a low-powered car, or your gearing is already very tall, a smaller diameter wheel will help you get a better gear ratio. Suddenly, you might not have to be shifting to third in a short straight. On the flipside, if you have a car with very short gearing (the STi comes to mind), a taller wheel/tire combo could help you stretch that out. The last main factor is fitment and tire size. Make sure you have an appropriate tire size for that wheel, and make sure it will fit on your car, clear your brakes, and not cause any tremendous problems.
As two examples, there are the high powered ASP/BSP cars, and there are the low powered ASP/CSP/FSP cars. The Corvette's of ASP/BSP want as much rubber as possible under their high powered, relatively heavy cars. So they run 17x11s or 17x12s with 315 or 335 width tires. The ASP Corvettes may also run 18s up front, allowing even less sidewall for better turn-in. The BMW M3s of BSP and even the E36 DSP cars are moving to 18s with 285 series tires and very short sidewalls. The low-powered, smaller, more nimble cars of ASP/CSP/FSP have none of these weight or power problems. So they all run 13" wheels that give them the shortest gearing, and the least amount of weight. Chances are they couldn't heat up a 275+ width tire anyway, so the 225/235 R comounds that Hoosier and Kumho offer are just fine.
Now on to wheel width. Let's say we've decided we're going to run 13" wheels on our SP cars. We have tires available that give us an 8-9" recommended width. What do we do? Well, the common thing to do here is to move to the wider side of the spectrum. The more width the wheel has that the same tire is on, the more width of the tire will be put down, so the wider the contact patch, to a point.
Of course, in a stock class, your wheel choice is limited to what came with the car, in which case you simply go with the lightest thing you can find, and then stuff the widest tire you can on it. C Stock Miata's usually have 225s on their 5.5" wide wheels.

BFB info
http://forums.vwvortex.com/zerothread?id=1362998

Links:
http://www.scca.org
http://www.tirerack.com
http://solo.wdcr-scca.org
http://www.sfrscca.org/solo2/
http://www.autox4u.com
http://www.nedivsolo2.org
http://www.sedivsolo2.org
http://www.solo2.cendiv-scca.org/
http://www.solotime.com
http://www.solo2.com
http://www.solo2.org
http://www.soloperformance.com
http://www.sccaforums.com
http://www.autocross.com/evolution/
Add more good information!


Modified by Mhyrr at 6:30 PM 1-28-2005
 
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1
#5 ·
Re: The Autocross Information Thread (AutoXMan)

Also:
How do I class my car? (SCCA and clubs that use SCCA rules)
For starters, take a look at a worksheet like this one:
http://www.scca-milwaukee.org/...n.pdf
This will give you a basic idea of which class you go into: Stock, Street Touring, Street Prepared, Street Modified, Prepared, or Modified. The lists above are also good, but this chart will help quite a bit.
Then read the rules pertaining to that class. You can find the online rulebook here:
http://www.scca.com/_filelibra...s.pdf
You may find that there are other items you have that are illegal for that class - or you might get some ideas on what to optimized to better yourself in a given class. For instance - you put on a rear swaybar and that's all you did. That puts you in Street Touring or Street Prepared. Well, those classes also allow camber adjusters, coilovers, etc. So you can take advantages of the rules in that class instead of trying to bump down into stock.
Lastly, refer to Appendix A of the rulebook. Find the class you are in (say, Street Prepared) and then look for your car. If you have, say - an RX8 you will find it listed under 'Class B'. So you are competing in B, Street Prepared. Or BSP for short.
Note: Stock class is NOT SLOW. It is relatively cheap, but that plus R compound tires make the class extremely competitive. I daresay that Street Touring is a generally slower class. Some regions may offer 'Street Tire' classes. These will allow you to run stock class rules with street tires (or SP, SM rules). Check with your region to find out what they do.
 
#12 ·
Re: The Autocross Information Thread (Mhyrr)

Quote, originally posted by Mhyrr »

Wheels with the same diameter and width as stock (i.e. a GTI 337/20th must use a 18x7.5", it cannot use a 17" from a GTI)

I'm not questioning you at all, but I was under the impression that an option wheel (and size) could be used?
Example: I have a GTI that came with 16" wheels. I can race in Stock if I use either A) VW BBS 18x7.5, B) VW 17x7 Arietta, C) stock 16" wheel, or D) either of the mentioned sizes wheel in SSR Competition.
(Because the wheels were offered options to me) Confusing?



Modified by performula at 4:44 PM 1-17-2006
 
#14 ·
Re: The Autocross Information Thread (performula)

Quote, originally posted by performula »
I'm not questioning you at all, but I was under the impression that an option wheel (and size) could be used?
Example: I have a GTI that came with 16" wheels. I can race in Stock if I use either A) VW BBS 18x7.5, B) VW 17x7 Arietta, C) stock 16" wheel, or D) either of the mentioned sizes wheel in SSR Competition.
(Because the wheels were offered options to me) Confusing?

12.4 Standard Part
...could have been ordered with the car, installed on the factory production line...
Were they dealer optional, or could you choose the different wheels standard from the factory? That's the answer. Dealer option wheels are out unless you could get them installed at the factory, on the car as it were delivered.
 
#15 ·
Re: The Autocross Information Thread (towerymt)

Actually in this case, I believe the distinction is actually that a 337 or 20th is a package, so you could use the wheels, but you'd have to add the entire package.. including the seats, transmission and all other associated parts, etc, etc..
 
#16 ·
Re: The Autocross Information Thread (Mhyrr)

I have a 1989 GTI that was originally a 16v with 14" rims.
It now has a 2.8 12v vr6 and 15" rims and a Koni coilover suspension.
Other mods include:
Corrado Front seats
No Back seats
2.5" exhuast
poly bushings
11" brakes (stock are 9.4)
K&N panel filter
im sure there is more, someday soon it will be turbo'ed.
Would I be Streed Mod 2?
 
#17 ·
Re: The Autocross Information Thread (xpalendocious)

Quote, originally posted by xpalendocious »
I have a 1989 GTI that was originally a 16v with 14" rims.
It now has a 2.8 12v vr6 and 15" rims and a Koni coilover suspension.
Other mods include:
Corrado Front seats
No Back seats
2.5" exhuast
poly bushings
11" brakes (stock are 9.4)
K&N panel filter
im sure there is more, someday soon it will be turbo'ed.
Would I be Streed Mod 2?

SM, because it's a 4 seater and you're not over any displacement limits that would bump you to SM2.
in SM you *are* allowed to remove the rear seats.
 
#19 ·
Re: The Autocross Information Thread (exim@uu.pp121.biz)

I just looked at the 2006 rules, and see no mention of the new 2006/2007 GTI 2.0T FSI. What class would this be in? I have heard GS and thinking STX?
Has anyone tried these yet? How well did you do? I have DSG in mine, am thinking it should not do too bad.
 
#24 ·
Re: (turbosprentice)

Quote, originally posted by turbosprentice »
can somebody help me on my 1994 celica gt? i'm having problem finding it's rank, i know it's in g-stock but is that it? all i have on it is exhaust and 18x7.5 rims(i don't know if that makes a difference in my ranking), otherwise everything is stock.

If the exhaust is cat back you are fine; however, the 18" wheels were not available from the factory.
 
#26 ·
Re: (2.9litersofdeath)

there is no way to know if someone is honest about mods or not exept that anouther competitor can protest a part or potetially illegal mod and unless you can prove that the mods in question are legal for your class you will loose your trophy and have to pay far the dissasymly/reassymbly of your car.
as far as most local events they are just for fun and a simple protest to something obvious may mean that you have to run a class or two high than you thoght, but most small or insignificant mods will be overlooked unless you turn out to be a national level driver in wich case they might protest anyways to move you out of ther class.


Modified by meangreen18T at 10:42 AM 4-16-2007
 
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