ToSi

re: street - lets allow changing springs & +1" wheel width too. (eliminate ST to keep the total # of classes reasonable )

Leave stock as-is w/ 140 tires though.


Q for the SCCA guys: Did anyone survey RT competitors or ask various local region street-tire stock class guys if they had problems w/ tire wear?

abqautoxer

Yes.


Also, the 200tw is because an anonymous tire company said it would be easy to make a track day type tire and get up to a 180tw stamp on it. So 180 or 200tw was believed to be the magic number, and 200 was chosen for now.

Remember it doesn't take a very large bar to begin to damage OEM mounts on cars such as Miatas and BMWs even with just one bar limiting the size escalation. Allow just even a slightly bigger bar at the opposite end would allow that bar to get even larger putting even more cars at risk long before the car would like it had two additional leaf springs.

ToSi

Really?

'Evil Mini' @ 7500mi / ~90runs on Star Specs (owner can remain anonymous if he wishes )


My Boxster @ 10k mi / ~80runs on RE-01's - in the interest of full disclosure, these were flipped @ ~50runs. Difficult to see but the majority of wear is 1/3 in from edge, right where shear stresses are highest, i.e. textbook wear.




Sounds like hearsay - Would a 200TW stamp really be that difficult? On the other hand, 140TW was convenient because it happened to be the lowest wear rating of commonly used OEM, performance-oriented but clearly not cheater tires at the time (Bridgestone RE050).

I think you just made the case for allowing *zero* swaybar changes in stock!

abqautoxer

Yes really... Not sure why you would question that. There are several RT guys on the SEB and SAC... I happen to be one of them. I worked with several others and have talked to more than I can count. We've had the equivalent of RT since 2006 in my region.

Not sure what point you are trying to make about the tire wear picture?

Not hearsay - fact. That's two doubts in your post, do you want the facts or would you rather I didn't provide what I know to be accurate to add to the conversation to hopefully reduce some speculation. I don't know everything and will gladly admit what I don't know as fact.

Both OEM sway bar points have been made, personally I would not like it. Several cars I've owned benefited quite nicely from the front bar allowance. I think the rear now gives people options for those that perceive it to be better.

ToSi

My point was to address the concern that camber allowances are required to improve tire life.

Basing a rule off of what someone 'heard' seems silly, no?

I don't mean to come across as attacking you (& will be more careful w/ my tone, after re-reading my previous posts). I'm just disappointed w/ the misguided vision behind this latest proposal.

sjfehr

I notice a huge difference in handling even between two adjacent settings on my gt3 front swaybar; I can't imagine the misery if I tried to go monster stiff on it! One of the SEB guys let slip an implication that they've decided to withdraw the 2-swaybar allowance. We won't know for sure until it shows up in fastrack, but I think everyone sees that 2 swaybars is not a good thing for stock/street class. That single monster swaybars aren't a problem now in stock is a pretty good indication they won't be a problem in street, either.

How much camber can I get from slotting the top mount of my strut? That (and 200TW) are the changes I'm most excited about.

abqautoxer

I never said they were...

What part of the tire company told us DIRECTLY. No hearsay 2nd hand stuff, Tire company was present in person...

I have no problem with that, I didn't write the proposal, didn't see it until a day before it was released and disagree with several of it's points. I'm on the Stock Advisory Committee, not the SEB. I get to deal with the aftermath of it, but I certainly didn't have anything to do with what went out in Fastrack.

Audii-Dudii

I find the same to be true: The very furthest hole is a bit too soft, the next furthest hole is a bit too stiff, and I can't imagine the Stock-class setup that lets people successfully use the middle hole, as it seemed like my car would hardly turn when I tried using this setting...

Personally, while I would like to add a second a/r bar, I'll still compete in the Street Class even if the final version of the rules doesn't allow it. For me, the two Street Class "must-haves" are: 1) the allowance to increase static negative camber and 2) the +/- 1" wheel diameter adjustment ... without those, I won't be able to use any of the new generation of street tires without also using the narrower, non-optional 18" wheels, and this limits the performance of my car enough that I would probably quit attending SCCA events and do my autocrossing with the PCA and other clubs.

The slots will need to be lengthed approx. 10mm to gain approx. one additional degree of static negative camber. Lengthen them a little bit further, however, and the top of the strut (or in the case of my PASM-equipped car, the wire coming out of the strut) will make contact with the edge of the center clearance hole, so the upper limit without camber plates will fall between 2 and 2.2 degrees for most cars.

Personally, I'll be using camber plates, as much because I don't think I can bring myself to permanently modify the chassis of my car as the potential improvement in performance that will result from replacing a rubber bushing with a spherical bearing. The $450 cost of the camber plates is unfortunate, of course, but it's not high enough to be an insurmountable obstacle...

sjfehr

I was also worried about the bushing getting to the curved portion of the shock tower; didn't know what we could get in practice. If I can get 2 degrees for "free", I'd be absolutely thrilled; will kick the *** of the half degree I have now.

Audii-Dudii

Yeah, I should have mentioned that the strut mount will need to be trimmed as well, for exactly the reason you mentioned ... not a big deal, though. Another alternative is to leave the slots alone, push out the studs in the strut mount, redrill the holes, put in new studs, and trim the pointy end for clearance. This is what Mantis Sport does with the modified strut mounts they sell.

Oh, and I should also have mentioned that my experience with this is with the 987 chassis, so while the process should be fundamentally the same, your results may vary somewhat, as most non-PASM 987 chassis are able to get a few tenths more negative camber than your half degree ... still, what I've described should get you at least another degree, if not a bit more.

sjfehr

If all goes well, I'll in a 987.2S before this rule goes into effect. Might just pony up for camber plates; will have to look & see and make a judgement call, I suppose.

panzrwagn

I am totally looking forward to the new classing. Having competed with a fully prepped D/SP BMW 325 for several years, I specifically went to a 986 Boxster S to run in an indexed street tire class for more competition and to get away from R-Comp issues.

As for camber - the existing slots are good for about -1 degree, which makes a huge difference in front grip without being tail-happy. The slots could easily be extended for at least one more degree, but I'd put some big washers under the nuts to spread the load. At that point you'd want to add some rear camber by rotating the adjusters on the rear suspension, and then have a pro set your toe front and rear, or you will be eating tires and the car will get squirrely.

As for suspension, I have a ROW M030 kit in transit. And if that's not enough I can have the original shocks revalved as well.

I have run a couple local events with the camber added and Yoko Advan 024s and the car is more than competitive with the local S2000s, which was the goal. Given a little more time and the M030 springs/shocks/bars I'm really looking forward to this season, and the rule changes next.

sjfehr

ROW M030 isn't SCCA stock class legal because it wasn't offered as an option in the US; it bumps you into ASP. You need US M030 springs & rear sway to stay BS, which unfortunately costs twice as much because it's all special order and isn't as good. You can use GT3 sway in the front which works well.

Arominus

The SCCA needs to do this, I've brought 4 of my friends into auto-x with me and we all hide in the local street tire class, along with many others. At every event I attend during the summer SCCA season the local indexed street tire class (RTR) is larger than any of the stock classes. I say this as a guy who ran from Stock to RTR after my first season. I've been hiding there for the last 3 years so I can have fun on the Direzzas I DD on. Same with my friends.

Restricting stock to street tires would be far cheaper than the 2 sets of R-comps the of the "stock" guys around here burn every season. As a beginner E-Stock driver I found this cost retarded. I showed up on Direzzas and had everyone that ran stock look over my car, chuckle and tell me I bought the wrong tires for stock. Like a $900 set of R-comps was a requirement. I thought to myself, this is no fun, I came to run these sticky street tires and I find out I'm screwed if I don't cough up some significant money and commit to bringing a floor jack, tires, and everything else to the event in my 944. I never had a chance of coming in anything but last. Period. It was a huge turn off and I almost quit, RTR kept me from bailing.

This has huge potential for getting younger car guys hooked. Seriously. Make your lower classes more accessible so those of us without tow vehicles can come, have fun and be something besides dead last purely because of tires. Having this be a national class would be even better, RTR is a dead end as a regional class. I'd like to think that if I got the car set up right I could still make a low budget assault on a national event someday if my driving skills were good enough.

burglar

That's part of the thing - SCCA has to balance the desires of the top level diehard National competitors while keeping things accessible and understandable for the casual local guy.

At the top level there's still going to be street class cars showing up on trailers with three sets of tires, shocks that cost more than the car, and alignments that could not be used on the highway. You can't stop that.

However, I agree, the cost and hassle of R-comps was a pretty serious barrier to many. Of course, now you have to buy the hottest street tire, but at least they're cheaper and last longer - for now.