SCCA Solo C Street Discussion

[SeanRTR]

I'm at 43k miles already, took delivery on 2/13, not driven in snow, as I keep the autoX tires on all year long. I too will making a run at the Pro Solo series this year in CS. See you guys out there.

[jdrxb9]

Originally Posted by DylanFRS

How do you decide what to tell them for the "custom" valving?

Like I mentioned above, I don't have the experitise to specify particular curves. So, you provide your application data (weights, springs, etc) and your expectations (high low speed values with as much digression as possible to keep high speed tolerable) and then trust in their experience and expertise. If you don't like it, send them back with notes and pay for another try.

For some cars, there is 'established' valving that you can copy, but that doesn't exist for the twins that I know of.

[renfield90]

Originally Posted by DylanFRS

How do you decide what to tell them for the "custom" valving?

http://farnorthracing.com/autocross_secrets19.html

Even includes a bit on stock class setup.

[jdrxb9]

Originally Posted by renfield90

http://farnorthracing.com/autocross_secrets19.html

Even includes a bit on stock class setup.

Yes, good reading along with other info at DG's site, e.g. http://farnorthracing.com/autocross_secrets18.html and the links within e.g. the Penske Technical Manual

I don't disagree with any of it and suggestions like "If you are knocking on 200% critical though, you almost certainly have way too much rebound" can be passed on as useful guidance. However, it's still not enough to actually specify curves, IMO, since unless you are a Koni builder, you don't know how much pressure to "dare", how that is going to effect the suspension frequencies, and how much additional damping to add as a consequence.

Presumably, one benefit of going with Koni's is that they have done this for lots of other cars in the past and have already looked at the twins when they developed our sport/yellows. So, adding in just a bit of compensation for the ~85% stiffer front bar, they should be able to make a really good guess at the valving.

However, since I don't plan on taking any detailed before/after measurements to check them, it will be impossible for me to quantify any difference. Any perceived differences could be 'placebo effects' or due to other factors - tires will definitely be different next year, for starters. The $0 option continues to be quite temping

[renfield90]

Originally Posted by jdrxb9

I don't disagree with any of it and suggestions like "If you are knocking on 200% critical though, you almost certainly have way too much rebound" can be passed on as useful guidance. However, it's still not enough to actually specify curves, IMO, since unless you are a Koni builder, you don't know how much pressure to "dare", how that is going to effect the suspension frequencies, and how much additional damping to add as a consequence.

I think Dennis mentions elsewhere on the site that overpressurized Konis are known to explode. If you revalve, be careful what you ask for!

Pro Parts USA comes highly recommended by a national champ in my region (among many others) as a company that understands Konis and understands autocross. If you have a general idea of what you're looking for they can probably help fill in the gaps - I hear they're very friendly and willing to talk shop over the phone without charging you.

[bslate3]

I'll be joining the CS crew next year with my 15 BRZ. Can't wait!

I plan to make the college station champ tour and mineral wells pro solo.

It seems a lot of people use different size tires 235/40 seems popular while some are still using 215/45. What are people running in the the Texas area?

[G_Ride]

Originally Posted by bslate3

I'll be joining the CS crew next year with my 15 BRZ. Can't wait!

I plan to make the college station champ tour and mineral wells pro solo.

It seems a lot of people use different size tires 235/40 seems popular while some are still using 215/45. What are people running in the the Texas area?

Congrats! You should be having some fun in 2015 I know there's people running 245/40 as well.

[7thgear]

noob question


is ballast allowed in stock class?

[AustinTX]

Not technically - 'if the rules don't say you can, you can't'.

[7thgear]

Originally Posted by AustinTX

Not technically - 'if the rules don't say you can, you can't'.

well, I'm allowed to take out my spare, just as much as I'm allowed to keep it. But who says I have to keep it in the trunk? Same goes for tools.

but please don't think I'm trying to be sneaky!

reason I ask is that right now we're going throw cold weather/snow/rain season in Canada and I've put about 100 pounds worth of gym weights underneath/behind my driver and passenger seats.


I'd like to think that there's no placebo involved... and say that I can feel the difference. My spine feels like the threshold for the rear coming around went up and I feel more confidence overall o ut in the near freezing rain and snow.


Not sure how that would translate to dry weather, but I wouldn't mind experimenting. After all, you can only drive as fast as you're comfortable!

[chriskory]

Weighing your car down to go faster?

I will say, if the weight isn't secured (and by secured I mean bolted into place), then you have loose items in the car and should fail any tech inspection.

[OkieSnuffBox]

Originally Posted by chriskory

Weighing your car down to go faster?

I will say, if the weight isn't secured (and by secured I mean bolted into place), then you have loose items in the car and should fail any tech inspection.

This

[7thgear]

Originally Posted by chriskory

Weighing your car down to go faster?

perception vs reality


the car may be slower from an absolute sense, but if I feel more confident driving it, then I will make it go faster

no different tuning f/r balance with swaybars. Some people prefer loose cars and like to catch them. I don't.


same thing for people who slam their cars, they become responsive and lack roll, which translates into confidence, which translates into going faster than they would in a stock car even though the limit is actually lower.

Originally Posted by chriskory

I will say, if the weight isn't secured (and by secured I mean bolted into place), then you have loose items in the car and should fail any tech inspection.

no man, I'm just gonna put a 25 pound weight on my dash and fucking go at it.


for arguments sake lets say it is secured.

[bimmer635csi]

An easy way to ballast is to run with different levels of fuel, and even washer fluid to a bit of weight change.

Can also try moving the passenger seat around.

But to adjust handling and run light weight, you should look at changing tire pressures.