Some questions about modifications in Stock Class

[ilarson007]

Ok, here's quoted text from the "Quick Reference Guide"

Stock
This category includes mass-produced, common vehicles that may be “daily drivers” (cars used for normal, everyday driving). Stock Category cars compete in their “factory” configuration with a minimal number of allowances (not requirements) such as:

Removal of spare tire and tools
Front anti-roll bar(s)
Suspension/wheel alignment using standard adjustments
High-performance DOT tires (including competition R-compounds)
Shock absorbers/struts (2 external adjustments maximum)
Competition-type seat belts (no shoulder belts in open cars)
Brake linings (pads/shoes)
Air filter element (the “throw-away” part)
“Cat”-back exhaust systems
Wheels of standard size (diameter, width, and offset within ¼”)
Roll bar/cage
Gauges, indicator lights, etc.
Please refer to the SCCA® National Solo® Rules for more details and specifics.

Ok, so firstly, does this mean that removing the upper intake resonator is not allowed? Second, are any catback systems allowed (i.e. any diameter, metal, etc)? Third, could one get away with switching to S/R components and claiming it as stock?

Thanks

[STS-ZX2SR]

Ok, here's quoted text from the "Quick Reference Guide"



Ok, so firstly, does this mean that removing the upper intake resonator is not allowed? Second, are any catback systems allowed (i.e. any diameter, metal, etc)? Third, could one get away with switching to S/R components and claiming it as stock?

Thanks


Removing the resonator will put you in (at least) STS.
Any catback will be allowed in stock.
If your car was a 1999 or a 2000, and you switched all S/R components except for Borla and struts (i.e. PCM, Clutch, STS, brakes, IM Intake, Eibach Springs, seats)--including making sure you have AC and foglights (both STD. on S/R), then you could switch from HS to GS.

[ilarson007]

Bleh... my car is a '98. And why is it not allowed to use the Borla and struts, but everything else is?

My other question that I forgot is, could I switch up to the 15" wheel size (because aftermarket wheel are allowed as long as they are the same width and diameter and offset within +/- .25)? Because 14's are really small.

[STS-ZX2SR]

It is allowed to use the Borla and the S/R struts---but you can use any other struts or cat back as well.

You can run the OE size 15's--they were availible on all 98 ZX2s as I recall; must be OE size +/- .25" offset. To make it easy, just get some Escort/Tracer wheels out of a yard...

[zxtwou2]

i'd stick with the 14's and run a really short tire with a stiff sidewall. in stock class, you can go with race rubber too. in fact, if there's no open street tire category where you race, you'll have a severe disadvantage. if there's an open street tire category, though...you'll race against every other car with street tires (except street touring) and your time will be indexed. as long as you are only running at local races, you should be able to get away with your resonator replacement, so long as you don't tell anyone it's not stock. it's when you get to regional and national level that your car must be every nut and bolt to the books. heck, even in a large 170-racer-per-meet region like chicago, i'm running without a cat in STS.

[ilarson007]

It is allowed to use the Borla and the S/R struts---but you can use any other struts or cat back as well.

Okay, that's cool. But my car would have to be a '99 or '00?

You can run the OE size 15's--they were availible on all 98 ZX2s as I recall; must be OE size +/- .25" offset. To make it easy, just get some Escort/Tracer wheels out of a yard...

But I was asking about the wheels though to see if I could get aftermarket 15's? From what I read, any aftermarket wheel of stock diameter and width and offset within +/- .25" so is that true? Any aftermarket wheels that meet that requirement? Or just the OE wheels?

Thanks again, hopefully I might start running auto-x's next summer.

[ilarson007]

i'd stick with the 14's and run a really short tire with a stiff sidewall. in stock class, you can go with race rubber too. in fact, if there's no open street tire category where you race, you'll have a severe disadvantage. if there's an open street tire category, though...you'll race against every other car with street tires (except street touring) and your time will be indexed. as long as you are only running at local races, you should be able to get away with your resonator replacement, so long as you don't tell anyone it's not stock. it's when you get to regional and national level that your car must be every nut and bolt to the books. heck, even in a large 170-racer-per-meet region like chicago, i'm running without a cat in STS.

Open street tire category? Please explain... I'm trying to learn all about this solo scene... Also, at least for now, I will only be running regional solo events (the ones that are in town and in this region; duh... lol). So street tires would be... any tires that are DOT approved? What is an indexed time? A cat back exhaust would replace the resonator; so why then do you have to run a stock resonator with your exhaust? And I never actually saw this rule; I did see where you have to keep the exhaust stock from the mani to the cat.

[STS-ZX2SR]

Okay, that's cool. But my car would have to be a '99 or '00?



But I was asking about the wheels though to see if I could get aftermarket 15's? From what I read, any aftermarket wheel of stock diameter and width and offset within +/- .25" so is that true? Any aftermarket wheels that meet that requirement? Or just the OE wheels?



Good luck finding an aftermarket wheel in 15x6...

If your region has a 'street tire class', running some 195/60-14 Falkens would be a decent way to get your feet wet.


Yes, a cat back would replace the resonator--its legal. ANY catback is legal in stock so long as it meets the sound requirements--and with a functioning cat it should.

All classes have an "index" which is a multiplier fraction. Your car is in HS. It has an index of .792. Take your raw time and multiply it by .792. I run in STS with and index of .816. If I run 60.00 second on course, my indexed time is 60.00*.816 or 48.96. If you run a 61.80, your indexed time is 48.95...and you beat me. Google "RTP index" and you can see the list for all classes. Most regions have street tire classes, and the results are deterimed by using the index system. If you run in 'actual' HS, you'd want to be on DOT race tires (eg Hoosier A6) in oreder to be competetive. Learing autocross is lomething that takes a few years--only seat time makes you better. It is adventageous to learn on street tires--they amplify mistakes, whereas race tires will mask them.

[zxtwou2]

Open street tire category? Please explain... I'm trying to learn all about this solo scene... So street tires would be... any tires that are DOT approved? What is an indexed time?

basically there are two types of tires you can use in autoX. DOT approved R-compound race tires, and street tires. street tires are any DOT approved tire with a treadwear rating of 140 or higher. there are a few tires that are blackballed from the list of approvals, but most of your tires on the market will work....and that's a whole other conversation there on tire choice.

what chicago does, and some other large regions, is take all of the classes, and group them together into one large group (if the cars are on street tires.) for instance, you take a zx2, and a corvette c5. both run in seperate stock categories. the zx2 would be in HS, corvette in AS. both would run in those seperate categories with race rubber. if they were to both race with street tires, they'd be thrown into an "open street tire category". in this group, you are running against every other car with street tires. obviously, your raw time will be much higher than that of the 'vette (given the skill of the drivers are about the same). so what happens is all the cars are given a multiplier (see PAX index) to make all cars of different classes competative against each other. if the 'vette runs 60.000 seconds with a PAX (made up in my head, not the real number) of 0.980, his indexed time would be 58.8. now if you got 63.000 and your PAX was 0.920...your indexed time would be 57.96...and you'd have beat the corvette.

not all regions have this category. chicago gets about 40 people per event that run in this category...but they usually have 170 people racing total. so for a smaller region with say 40-50 people racing, they might not make that category.

A cat back exhaust would replace the resonator; so why then do you have to run a stock resonator with your exhaust? And I never actually saw this rule; I did see where you have to keep the exhaust stock from the mani to the cat.

when i said the resonator, i meant the upper resonator you did on your intake...i.e. the keman mod. any modification to your intake other than the air filter, would put you in STS, which is a class where you run street tires, bolt ons, and just about full suspension. you can have any exhaust...heck, you can have nothing from the cat back if it weren't too loud. they usually have (at least in the SCCA events) a decible limit from a certain distance from the car. but i've heard some real screamers out there...and i don't think you'll have a problem as long as you have a few feet of pipe in there to take it behind the driver seat.

[ilarson007]

Maybe I'd be better off running a different class then, because I want to get wheels, but I don't want to mess with changing the speedometer calibrations every time I go to an auto-x. Besides, it costs me money everytime I need the speedometer calibrated.


Oh, and that's funny about the sound requirements... I'm pretty sure there were plenty of cars without any muffler of any kind, because there was this one Civic and a Miata that were loud as hell...

[zxtwou2]

i just saw erik edited his post to say what i was saying :p

[ilarson007]

basically there are two types of tires you can use in autoX. DOT approved R-compound race tires, and street tires. street tires are any DOT approved tire with a treadwear rating of 140 or higher. there are a few tires that are blackballed from the list of approvals, but most of your tires on the market will work....and that's a whole other conversation there on tire choice.

what chicago does, and some other large regions, is take all of the classes, and group them together into one large group (if the cars are on street tires.) for instance, you take a zx2, and a corvette c5. both run in seperate stock categories. the zx2 would be in HS, corvette in AS. both would run in those seperate categories with race rubber. if they were to both race with street tires, they'd be thrown into an "open street tire category". in this group, you are running against every other car with street tires. obviously, your raw time will be much higher than that of the 'vette (given the skill of the drivers are about the same). so what happens is all the cars are given a multiplier (see PAX index) to make all cars of different classes competative against each other. if the 'vette runs 60.000 seconds with a PAX (made up in my head, not the real number) of 0.980, his indexed time would be 58.8. now if you got 63.000 and your PAX was 0.920...your indexed time would be 57.96...and you'd have beat the corvette.

not all regions have this category. chicago gets about 40 people per event that run in this category...but they usually have 170 people racing total. so for a smaller region with say 40-50 people racing, they might not make that category.



when i said the resonator, i meant the upper resonator you did on your intake...i.e. the keman mod. any modification to your intake other than the air filter, would put you in STS, which is a class where you run street tires, bolt ons, and just about full suspension. you can have any exhaust...heck, you can have nothing from the cat back if it weren't too loud. they usually have (at least in the SCCA events) a decible limit from a certain distance from the car. but i've heard some real screamers out there...and i don't think you'll have a problem as long as you have a few feet of pipe in there to take it behind the driver seat.

Ok, that explains it better. I would have to check to see if my region runs a open street tire. It sounds like I may be better off to run in STS (so I can do the S/R Tokicos with a 1.5 to 2" drop). Looks like you can do quite a bit with STS. May be better to run in than stock.


And just wondering... how would they be able to tell if you have an LSD in your car or not?? Because isn't that kind of ... inside the transmission (for FWD at least)?

[STS-ZX2SR]

The ZX2 fits nicely into STS; see the link to my thread about WAI #6.

In STS, you can run any struts, springs and swaybars, and poly bushings, camber plates...any cat back, any intake up to the TB, a chip, a UDP, shifter, 7.5" wide wheels of any diameter, and up to 225 wide tires with treadware of 140 or more.

A nice and 'simple' setup is to get the SR struts and run GC coilovers with about 300F/200R springs. Get a EGT/Wagon RSB and do poly bushings on as much of the suspension that you can. Use some camber bolts and dail in as much negative camber that you can. Do the Keman intake, get a SPT chip and a UDP. Get a nice catback. Get some nice light, "inexpensive" 15x7 or 7.5 wheels (eg Rotas) and some decent tires and go.

You'll have a car that can do well at any event that you go to...once you hone your driving skills.


If you want the LSD, simply take the above and run in STX...because, yes...we (eventually) can tell.

[zxtwou2]

you can have the LSD and run in FSP, also. this year it'd DSP, but we got it changed to FSP for next year, so we'd be more competative. in the SP categotires, you can have everything you can in STS (except a body kit) and run an LSD, catless header, and race rubber.

STX is a fun alternative, and it allows you an LSD and to relocate your cat up to 6" from it's original location.

if you get contested at a higher level competition (like regionals and up) they can check for an LSD pretty easily by jacking up the front and checking wheel rotation.

STS is fun, though...i'm having a blast. i can't wait to get a CARB legal header and high flow cat...and put some peices back in the car...to be fully STS legal and see how i do then.

[STS-ZX2SR]

STS is fun, though...i'm having a blast. i can't wait to get a CARB legal header and high flow cat...and put some peices back in the car...to be fully STS legal and see how i do then.

The rule is 'emissions legal'; CARB is a California thing...not applicable. Anyhow, I would not read to much into that--if the cat is legal, that is the main thing. We just put on a Pacesetter about a month ago. Its low-test quality wise, but way cheaper than the JBA, and we dont DD the car, either...its also actually a better design with the primaries. Its a bit lighter than the OE log--that was the main reason for us. We also put in a WalMart lawn tractor battery. 350CA/275CCA...10 pounds and $25. Saved about 35 pounds with both items.

[zxtwou2]

i've been thinking of going the route of using a focus shorty header. right now i have the hotshot 4-2-1 full length header...but i need a cat in there. i've also been playing with the idea of starting over on a fresh car, swapping my performance parts over, and going in FSP. i might wait a couple years on that jump, however. STS is giving me quite a fun time, and really letting me keep track of where i need to improve.

[ilarson007]

The ZX2 fits nicely into STS; see the link to my thread about WAI #6.

In STS, you can run any struts, springs and swaybars, and poly bushings, camber plates...any cat back, any intake up to the TB, a chip, a UDP, shifter, 7.5" wide wheels of any diameter, and up to 225 wide tires with treadware of 140 or more.

A nice and 'simple' setup is to get the SR struts and run GC coilovers with about 300F/200R springs. Get a EGT/Wagon RSB and do poly bushings on as much of the suspension that you can. Use some camber bolts and dail in as much negative camber that you can. Do the Keman intake, get a SPT chip and a UDP. Get a nice catback. Get some nice light, "inexpensive" 15x7 or 7.5 wheels (eg Rotas) and some decent tires and go.

You'll have a car that can do well at any event that you go to...once you hone your driving skills.


If you want the LSD, simply take the above and run in STX...because, yes...we (eventually) can tell.

Where is said link? I clicked on the link in your sig and (unrelated) I browsed to the classifications page and it says that the ZX2 is not eligible for STS... What up w/that?

[STS-ZX2SR]

Where is said link? I clicked on the link in your sig and (unrelated) I browsed to the classifications page and it says that the ZX2 is not eligible for STS... What up w/that?


http://www.teamzx2.com/showthread.php?t=5680


I just emailed Jeff Cashmore--we'll get the chart fixed.