SCCA Solo C Street Discussion

[ryan t]

in my last 2 events ive had a rider with me and noticed my faster times were with the rider as opposed to just i. ive not yet corner balanced my car to see if the weight evens it out or what. any opinions from those that have run back to back with a rider.

[justinco]

Originally Posted by ryan t

in my last 2 events ive had a rider with me and noticed my faster times were with the rider as opposed to just i. ive not yet corner balanced my car to see if the weight evens it out or what. any opinions from those that have run back to back with a rider.

Always slower with a passenger, especially in light weight, low power cars like these.

[DocWalt]

A passenger costs me ~3 tenths on a 50 second course in my GTI which runs about the same sort of times as my local hotshoes in C Street, fairly consistently. I'm not a very consistent driver, but it's pretty clear that a passenger adds quite a bit of dead weight that might balance the car (I doubt it) but certainly hurts overall performance.

FWIW on a road course a passenger made a VERY noticeable difference in acceleration when I was following another 86. The other 86 would pull on me a little down low even with his stock header/tune while I have a JDL UEL/tuned.

[Locust]

Originally Posted by ryan t

in my last 2 events ive had a rider with me and noticed my faster times were with the rider as opposed to just i. ive not yet corner balanced my car to see if the weight evens it out or what. any opinions from those that have run back to back with a rider.

Passenger = 2-4 tenths depending on course and acceleration points. If your passenger is a good instructor they can save you some time, though, if they're calling out braking points, etc. (if that's what you need, at least). Every pound you bring into one of these cars in C-Street form is a killer.

[strat61caster]

Passenger could also have a psychological effect. I know I picked up some time when my gf rode along because I focused on being smooth.

[ryan t]

i know lighter is better, the only thing it might be was the cold. these last 2 were 30-40 degrees. the last being the coldest, and i noticed the majority of cars had a rider with them. i would say 1/4 were driver only. there was even a bmw with a 3rd sitting in middle of back seat. could the extra ballast help in the cold/slick?

[ryan t]

Originally Posted by strat61caster

Passenger could also have a psychological effect. I know I picked up some time when my gf rode along because I focused on being smooth.

if its not the cold than you may be the correct one. lol

[DylanFRS]

Psychological. The car without a passenger is going to be faster if driven consistently. I almost always drive my fastest runs with a passengers but that is because I am still super inconsistent and not using 100% of the performance the car has to offer. Hence why I don't have a National trophy yet.

[DylanFRS]

So anyone see the 2016 PAX?

http://solotime.info/pax/rtp2016.html

Looks like CS took a pretty decent hit, even relative to everyone else>

I don't really understand since the top CS finisher at Nationals was 134th in the PAX standings.

[Biggins]

My theory is that too many of us did well locally and upset people who run in a PAX class?

I can't believe BS and GS stayed the same and FS didn't take as much of a hit... oh well.

[renfield90]

I discovered my front left left hub hasn't been securely mounted to the control arm for about a year. 2x top index like that. Don't tell Rick Ruth or he'll fix the index even more!

We were a little soft this year I thought. It's only a 3 tenths bump. Most street classes took a hit due to the Bridgestone/BFG effect.

What I'm unhappy with is SS unchanged, might as well call it Super Soft. There is a C7 Z06 locally that has been destroying us on anything but a tight twisty course. Sure, it's well driven, but it's also on the factory run flats.

[simpleisbest]

Well....here is the proof. The Koni full strut replacements appear to be illegal for Street Class.

The Koni strut's upper mounting holes are both symmetrical in size at roughly 16.3mm, OEM has 14mm on brake hose bracket side and 16.3mm on the other. This +2mm difference in diameter of the one hole gives the mounting bolt another millimeter or so of allowance, THUS the additional negative camber claimed by many on this forum.

If you examine the picture of the OEM 14mm crash bolt, you can easily imagine how the extra 2mm in diameter would help get more camber!

Luckily, with a simple machined spacer it should be easy to bring in these shocks back to legal compliance without much headache or costs.

Unfortunately, the measurements done by members in the past on this forum did not measure BOTH upper mounting holes. If they did, the difference would have been pretty obvious. I think as the Koni used the same size holes on both sides, it might have been mistakenly thought that OEM was similarly so.

[swarb]

here is some more info on the koni http://www.apexjunky.com/2015/12/kon...9ZA0I.facebook

[Jawnathin]

Thanks for sharing your findings Sean. As many predicted here, something was out of spec with the strut which gave the suspension some additional camber. Just didn't make sense that a car can get more negative camber with just a shock replacement if everything the same as OEM.

Just to be sure the bases are covered before we call them illegal, are there tolerances defined by OEMs that would allow a 14%~ increase in diameter while still considered to be within 'OEM spec'? 14% tolerance sounds REALLY high but just thought it was a question worth raising. I'm sure SCCA will also have an opinion on whether this variance is considered legal or not.

If determined to be illegal I wonder if Koni will have an updated model/model number or if they're going to provide a machined insert to make existing shocks legal.