SCCA Auto-x Stock Class Rules Question
09-26-2013, 10:46 PM
#1
Safety Car
Thread Starter
SCCA Auto-x Stock Class Rules Question
Not sure how many here participate in SCCA auto-x but I'll try anyhow.
As many of you know next year the SCCA is changing the stock classes to Street classes and running (you guessed it) street tires instead of R-comps. I am considering prepping my C4 for B Street next year but I need to do some needed maintenance on the rear diff. That being said, the rear diff bushings are old and cracked. I should replace them, however, stock replacements are NOT available. Are poly bushings acceptable in this instance?
Used and good shape controls arms and the like are difficult to find but not too hard. Some like the trailing links are available in new rubber. So not too worried about this at least in the short term.
Also, anyone who has ever ran a LT1 C4 hard knows the stock power steering line suck, and quickly leak from o-ring or flare failures. I went thru 2 in a month and then got a Doug Rippie Motorsports braided stainless steel unit and its been fine ever since. Due to this being a safety issue (at least in my book) is this acceptable under stock class rules?
Those should be the ONLY deviations I might have to worry about with the stock class rules. I'm fine otherwise, as long as I follow the rule book.
Thanks in advance and none of this will matter if I can get the C4 thrown in STU with the C5 and other RWD cars they want to get into STU. Hell, they want the Mercedes Benz CLK430 in STU as well. I don't see that even catching a C4 much less the boost buggies, IMHO.
As many of you know next year the SCCA is changing the stock classes to Street classes and running (you guessed it) street tires instead of R-comps. I am considering prepping my C4 for B Street next year but I need to do some needed maintenance on the rear diff. That being said, the rear diff bushings are old and cracked. I should replace them, however, stock replacements are NOT available. Are poly bushings acceptable in this instance?
Used and good shape controls arms and the like are difficult to find but not too hard. Some like the trailing links are available in new rubber. So not too worried about this at least in the short term.
Also, anyone who has ever ran a LT1 C4 hard knows the stock power steering line suck, and quickly leak from o-ring or flare failures. I went thru 2 in a month and then got a Doug Rippie Motorsports braided stainless steel unit and its been fine ever since. Due to this being a safety issue (at least in my book) is this acceptable under stock class rules?
Those should be the ONLY deviations I might have to worry about with the stock class rules. I'm fine otherwise, as long as I follow the rule book.
Thanks in advance and none of this will matter if I can get the C4 thrown in STU with the C5 and other RWD cars they want to get into STU. Hell, they want the Mercedes Benz CLK430 in STU as well. I don't see that even catching a C4 much less the boost buggies, IMHO.
09-26-2013, 11:12 PM
#2
Safety Car
I haven't been autoxing for over 10-12 years, but in those days neither of those changes were allowable.
You will need to have bushings from a Z07 (that is allowable) or stock C4 in the control arms. I ran a 94 Z07 Coupe in SS in those years.
The power steering pump heat problem is huge in autox because there is a lot more steering input than in road racing. RRing the problem is keeping the belt on the pulley. Autox the problem is keeping the fluid cool as there is zero heat transfer from the ugly little plastic boxes GM uses.
You may (and should) run red line PS fluid. It is synthetic and will help a lot. The other thing you (and most others on the grid) will do is pull the cap from the PS reservoir and try and let a little cool air in there. I was able to get away with that without boiling fluid but have been close to using a turkey baster to pull out hot fluid and replace with cooler fluid between runs.
Have fun. What else is in BStock next year? I am guessing some of the Mazda's that gave us a lot of trouble when we all ran SS together in the 90's. Thinking back on it, that was about the only trouble we had was the Mazda drivers and some were excellent. We had both Martin and Marinus (Shauna who ran WC for a while after that) running with us in SS regularly in the late 90's so they were a handful as well as the normal C4 SS hotshoes from N California. We always had a lot of the Blue National Championship jackets walking around on the early course walks in N Cal Region.
But that gave us a great opportunity to learn how to drive. Enjoy.
You will need to have bushings from a Z07 (that is allowable) or stock C4 in the control arms. I ran a 94 Z07 Coupe in SS in those years.
The power steering pump heat problem is huge in autox because there is a lot more steering input than in road racing. RRing the problem is keeping the belt on the pulley. Autox the problem is keeping the fluid cool as there is zero heat transfer from the ugly little plastic boxes GM uses.
You may (and should) run red line PS fluid. It is synthetic and will help a lot. The other thing you (and most others on the grid) will do is pull the cap from the PS reservoir and try and let a little cool air in there. I was able to get away with that without boiling fluid but have been close to using a turkey baster to pull out hot fluid and replace with cooler fluid between runs.
Have fun. What else is in BStock next year? I am guessing some of the Mazda's that gave us a lot of trouble when we all ran SS together in the 90's. Thinking back on it, that was about the only trouble we had was the Mazda drivers and some were excellent. We had both Martin and Marinus (Shauna who ran WC for a while after that) running with us in SS regularly in the late 90's so they were a handful as well as the normal C4 SS hotshoes from N California. We always had a lot of the Blue National Championship jackets walking around on the early course walks in N Cal Region.
But that gave us a great opportunity to learn how to drive. Enjoy.
09-27-2013, 06:18 AM
#3
No, neither is legal in stock/street. A few notes,
1) Street hasn't been approved by the BOD yet (they meet in October I think), so don't invest too much money there yet
2) I think only the base C5 is proposed to go to STU currently.
3) The RX7 is in A-street in the latest proposed Appendix A for Street. B-street has the C4's, base C5, and non-CR S2k's. Here's the FT with the Street Appendix A,
http://scca.cdn.racersites.com/prod/...strack-aug.pdf
Dave G.
1) Street hasn't been approved by the BOD yet (they meet in October I think), so don't invest too much money there yet
2) I think only the base C5 is proposed to go to STU currently.
3) The RX7 is in A-street in the latest proposed Appendix A for Street. B-street has the C4's, base C5, and non-CR S2k's. Here's the FT with the Street Appendix A,
http://scca.cdn.racersites.com/prod/...strack-aug.pdf
Dave G.
09-27-2013, 11:22 AM
#4
Changing the bushings and hose are not allowed. If you win at nationals, this will be a problem.
If you are finishing mid pack locally, and are up front about what you have done, I dont think anyone would care. This sport is self policed. The only cars that get much scrutiny are top finishing cars at nationals. The only exceptions are obvious things like wheel size, missing parts, carbon fiber where there shouldn't be carbon fiber, etc. Your SS PS hose will likely be noticed at some point.
I was in a similar situation running in a '94 FS camaro with 150,000 miles that broke frequently. I ran mid pack, and never ran national events. My diff went, and I wanted to replace it with a later year torsen (still FS class) diff because it would last longer. I told my competitors, they didn't care, since it isn't a performance advantage, so I did it. I wouldn't (and didn't) run national events with that car. Locally it comes down to your relationship with your competitors.
YMMV
If you are finishing mid pack locally, and are up front about what you have done, I dont think anyone would care. This sport is self policed. The only cars that get much scrutiny are top finishing cars at nationals. The only exceptions are obvious things like wheel size, missing parts, carbon fiber where there shouldn't be carbon fiber, etc. Your SS PS hose will likely be noticed at some point.
I was in a similar situation running in a '94 FS camaro with 150,000 miles that broke frequently. I ran mid pack, and never ran national events. My diff went, and I wanted to replace it with a later year torsen (still FS class) diff because it would last longer. I told my competitors, they didn't care, since it isn't a performance advantage, so I did it. I wouldn't (and didn't) run national events with that car. Locally it comes down to your relationship with your competitors.
YMMV
09-27-2013, 10:00 PM
#5
Safety Car
Thread Starter
Interesting....so basically because I have a on older car with worn parts and NO factory or aftermarket that are OEM style I get punished.
Nice.
The PS line is a load of BS, so apparently, the SCCA wants me to leak PS fluid all over the place with the stock line. I'll keep that in mind, when it leaks and they are cleaning it up. Even though it is NO advantage, other than not leaking, what so ever. KNOWN issue with these cars.
Oh, well...
I wrote the SEB about the STU classing thing so it the C4 MIGHT make it in. I DO NOT want to run the car in BSP, too $$$ to make the car competitive.
@pkincy, I am running RL PS Fluid, good stuff.
Truth be told, I want to play by the rules and that is what I'm trying to do. At the local level its not a huge deal, however, I.....DID......want to try a couple national events just for fun. Maybe not, and the SCCA wonders why the numbers are down.....well, stop punishing people for running older cars that don't have parts available.
A lot of the SCCA rules don't make sense. IF you cannot get OEM style parts, for a car that is STILL eligible for stock class, WTF are you supposed to do?
Nice.
The PS line is a load of BS, so apparently, the SCCA wants me to leak PS fluid all over the place with the stock line. I'll keep that in mind, when it leaks and they are cleaning it up. Even though it is NO advantage, other than not leaking, what so ever. KNOWN issue with these cars.
Oh, well...
I wrote the SEB about the STU classing thing so it the C4 MIGHT make it in. I DO NOT want to run the car in BSP, too $$$ to make the car competitive.
@pkincy, I am running RL PS Fluid, good stuff.
Truth be told, I want to play by the rules and that is what I'm trying to do. At the local level its not a huge deal, however, I.....DID......want to try a couple national events just for fun. Maybe not, and the SCCA wonders why the numbers are down.....well, stop punishing people for running older cars that don't have parts available.
A lot of the SCCA rules don't make sense. IF you cannot get OEM style parts, for a car that is STILL eligible for stock class, WTF are you supposed to do?
09-27-2013, 10:41 PM
#6
Melting Slicks
In May of 92 we tested at Kinross and I blew a PS line just above the pump, the metal line cracked just above the flare. JAC has organized the session and he went back and reported the failure to the Corvette guys, and I blew the replacement hose in pretty short order too. GM did some testing on their autocross course at Black Lake. They were able to repeat the failure consistently and then found a fix and came out with a revised part. Shortly after that there was a replacement hose that was released and after that, from mid-92 until 2001 when I stopped running my C4 I never blew another one.
I had thought that they had solved this problem and wasn't aware that these were still failing.
The problem was found to be a resonance in the PS line, and it was worst at high RPM. The failure was related to time at speed and how hard the PS pump was working.
The PS hose could be "detuned" by clamping it to the engine so that it can't vibrate sufficiently to cause the problem, or you could make a hose that had a lot shorter metal section and more rubber length, or maybe all rubber and that would likely work too and not be so horribly obvious that people will be writing paper on it. You don't need a braided metal hose to be reliable. Aftermarket hoses are braided steel for the "wow" factor and because they are easy to buy from a supplier and aren't much more expensive than rubber.
What I would do is run the hose as it is. What will happen is one of two things. First someone will complain and tell you not to bring it back that way but won't protest you. The worst case is that they will protest you. Since it isn't a performance advantage, the protest would likely stand, but they most likely won't dq you, they will just say don't bring it back that way again and give you a slap on the wrist.
The rear bushings need to be rubber. I'd be looking for a decent set. A bit of cracking isn't horrible, but if they are getting loose you need to find some better used ones.
I had thought that they had solved this problem and wasn't aware that these were still failing.
The problem was found to be a resonance in the PS line, and it was worst at high RPM. The failure was related to time at speed and how hard the PS pump was working.
The PS hose could be "detuned" by clamping it to the engine so that it can't vibrate sufficiently to cause the problem, or you could make a hose that had a lot shorter metal section and more rubber length, or maybe all rubber and that would likely work too and not be so horribly obvious that people will be writing paper on it. You don't need a braided metal hose to be reliable. Aftermarket hoses are braided steel for the "wow" factor and because they are easy to buy from a supplier and aren't much more expensive than rubber.
What I would do is run the hose as it is. What will happen is one of two things. First someone will complain and tell you not to bring it back that way but won't protest you. The worst case is that they will protest you. Since it isn't a performance advantage, the protest would likely stand, but they most likely won't dq you, they will just say don't bring it back that way again and give you a slap on the wrist.
The rear bushings need to be rubber. I'd be looking for a decent set. A bit of cracking isn't horrible, but if they are getting loose you need to find some better used ones.
09-28-2013, 10:09 PM
#7
Safety Car
Thread Starter
Thanks for the confirmation of what I expected on this guys.
It'll cost me more to run Stock class than some other class. Used rubber bushings, etc...are more then NEW poly components and so forth. Not to mention the fact one CANNOT find used C4 rear diff. mount bushings. I would have to buy an entire batwing assembly.
Cost=too much.
BSP or maybe STU if the SEB agreed with my letter. I really hope they re-class the C4 into STU. The C5 is in, and they added a heavier and underpowered (compared to the C4) Mercedes Benz CLK430, so no reason not to.
@Solofast, IDK, maybe like MOST of available parts from AcDelco for the C4, they went off shore and the quality went down hill. I had two failures in a month, that was enough of the BS for me. The OEM from 93 lasted for a year or so of hard use, then bad. All OEM replacements failed on me.
FYI, thanks for all your help with things for car setup advice. I've had a really good auto-x season. Running near the top of all smaller region events, even bigger regions like Steel Cities I do well, one of the more quicker guys anyhow. Not where I want to be but on my way. Car is a lot of fun, especially on a course that favors HP and TQ.
I did confirm one thing, I am WAY WAY under-tired. I make those Dunlap Dizerra ZII in 255/40/17 work, but when a Mazdaspeed 3 has the same size at all fours just like me.......
. I might be significantly faster, but I need more tire. Some C5 18X9.5 "wagon" wheels shod with ZII's in 275/35/18 might do the trick. 
It'll cost me more to run Stock class than some other class. Used rubber bushings, etc...are more then NEW poly components and so forth. Not to mention the fact one CANNOT find used C4 rear diff. mount bushings. I would have to buy an entire batwing assembly.
Cost=too much. BSP or maybe STU if the SEB agreed with my letter. I really hope they re-class the C4 into STU. The C5 is in, and they added a heavier and underpowered (compared to the C4) Mercedes Benz CLK430, so no reason not to.
@Solofast, IDK, maybe like MOST of available parts from AcDelco for the C4, they went off shore and the quality went down hill. I had two failures in a month, that was enough of the BS for me. The OEM from 93 lasted for a year or so of hard use, then bad. All OEM replacements failed on me.
FYI, thanks for all your help with things for car setup advice. I've had a really good auto-x season. Running near the top of all smaller region events, even bigger regions like Steel Cities I do well, one of the more quicker guys anyhow. Not where I want to be but on my way. Car is a lot of fun, especially on a course that favors HP and TQ.
I did confirm one thing, I am WAY WAY under-tired. I make those Dunlap Dizerra ZII in 255/40/17 work, but when a Mazdaspeed 3 has the same size at all fours just like me.......
. I might be significantly faster, but I need more tire. Some C5 18X9.5 "wagon" wheels shod with ZII's in 275/35/18 might do the trick.
09-29-2013, 01:50 PM
#8
Melting Slicks
When I was talking with one of the engineers who was doing the C5 suspension tuning at the time I asked him what size tires the car was going to have. He responded that the fronts would be 255's and we had a bit of disagreement as to whether that was enough tire. The told me they had tested and "benchmarked" against the competition and that was "enough" tire"... I told him that the car really needed enough wheel to be able to mount a 275 up front, even if that wasn't what the car was delivered with. A couple of years later, when they came up with the C5Z, he came up and said, "you were right, we found we needed enough wheel to mount a 275 to make it work".
That's been pretty much the story for years, but newer tires are better and I see plenty of BMW's running very quickly on tires that are smaller than a 275's, and they don't weigh any less than a Corvette, and there were some guys in DSP in a 325 a few years ago that were flat flying on a lot less tire than we had on our BSP car and they were almost as fast as us..
I'd be cautious about using a 255, but it's not out of the question that you could get it to hook up. I'd look for what seems to be the best tire and then try to get them in a size combo that works. Hopefully there will be a package out there that fits and works, but there is going to require some serious testing to get it figured out. Lots of folks are saying the Rival's will be the hot ticket for 200 utog tires, so a 275/18 sounds like the right move.
That's been pretty much the story for years, but newer tires are better and I see plenty of BMW's running very quickly on tires that are smaller than a 275's, and they don't weigh any less than a Corvette, and there were some guys in DSP in a 325 a few years ago that were flat flying on a lot less tire than we had on our BSP car and they were almost as fast as us..
I'd be cautious about using a 255, but it's not out of the question that you could get it to hook up. I'd look for what seems to be the best tire and then try to get them in a size combo that works. Hopefully there will be a package out there that fits and works, but there is going to require some serious testing to get it figured out. Lots of folks are saying the Rival's will be the hot ticket for 200 utog tires, so a 275/18 sounds like the right move.