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2017 Rules Proposal Thread
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TOPIC: 2017 Rules Proposal Thread

Re: 2017 Rules Proposal Thread 7 years, 6 months ago #21313

  • KJZ78701
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Is it JD or John?

Can you educate me please. I thought the 924 and 944 had the same suspension pieces. Is that so?

I'm guessing you are running the 52mm offset? Why not the 23s?
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Re: 2017 Rules Proposal Thread 7 years, 6 months ago #21314

  • rd7839
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When I changed from phone dials to cookie cutters I picked up a full second at Thunderhill, same weekend so there is a big difference in performance.

The rules for this class are intended to keep cost down and prevent rules creep. Wheels are the very definition of rules creep. Same with the shifter but one may have an advantage and one most likely will not.

JP, the 924S has always been the outlier, stuck with late offset but a theoretical advantage in aero. Plus, do you feel you need more wheels? I know you don't need a rain set in Arizona! For your car i'd be more concerned about pressed in balljoints. I know the cost is VERY significant but i'd be willing to allow late cars some sort of aftermarket a arm provided the geometry stays stock. That's a proven weak point and the results can be catastrophic and very dangerous. For the price of 2 sets of wheels you can get some Charlie Arm knockoffs.

In the 9 years I've been doing this I've seen the costs go way up and the rules get more complicated. Whoever thought I'd be running a plastic windshield?(that rule made sense, at least in rocky California). I would love to see the days of street legal cars with junkyard motors again but it seems like I'm the minority. These cars are far from perfect but very, very fun, let's stop trying to build a better race car and enjoy the ones that work for us.

Maybe it's time to split the class in two, those that want to move towards 944 cup rules and those that want a low cost, non builder class.
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Re: 2017 Rules Proposal Thread 7 years, 6 months ago #21315

  • KJZ78701
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rd (would you be kind enough to remind me of your name),

Didn't you tell me: "Man, you are WAY overthinking things!"

I have a feeling we both suffer the same overthinking disease (based on your take with the wheels). I know you know this, but just in case others don't. The best way to move the wheel mass to the middle is to go from cast to forged, since forged wheel cylinder sections can be made thinner. Not an issue here as any inexpensive aftermarket wheel would also be cast. As I suggested, make a spec and let the market do its thing.

I just weighed my four ATS 15x7 CCs. 2 (old mold 12/'83 manufacture date) at 14#14.0oz, 1 (new mold 11/'84) 14#14.6oz, 1 (new mold 4/'86) 15#5.2oz. So, we have at least 7.2 oz of spread in what is currently allowed and that's just with a sample of four wheels. Also note that the heaviest wheel had the worst wobble to the inner portion of the rim than the other three lighter wheels. Can't draw much from that other than, "heavier CCs bend too."


Dan,

I just checked the car-parts.com site (thanks for the link). There are only four pages or about twenty sets. What if we can build enough interest to get 100 people to build cars in the next 12 months? I sent you an email....let's talk. I think you may have misunderstood about the committee. Happy to hear about your shifter and sad to hear about your run in with the Miata. I look forward to racing against you.
Last Edit: 7 years, 6 months ago by KJZ78701.
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Re: 2017 Rules Proposal Thread 7 years, 6 months ago #21316

  • AgRacer
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rd7839 wrote:
When I changed from phone dials to cookie cutters I picked up a full second at Thunderhill, same weekend so there is a big difference in performance.


The weight of the early offset phone dial versus the late offset phone dial is not the same. Both phone dials are also slightly heavier than the cookie cutter.

The only consolidated source of wheel weights I have found is at the below link, no telling how accurate it is based on wheel coating, paint, grime, etc but it about matches what I have been able to research elsewhere although I was under the impression that the early offset phonie was heavier than the late offset phonie, and both are heavier than the cookie.

www.944racing.de/wheelweights.php

Early Offset Cookie Cutter: 6.9 kg (15.21 lbs)
Early Offset Phone Dial: 7.4 kg (16.31 lbs)
Late Offset Phone Dial: 7.0 kg (15.43 lbs)
J. Stanley
NASA-SE Region 944 Spec Series Director
Yellow #60
Last Edit: 7 years, 6 months ago by AgRacer.
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Re: 2017 Rules Proposal Thread 7 years, 6 months ago #21319

  • KJZ78701
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Jason

Please edit your post. It's a little misleading.

We only care about the 15x7 wheels.

The 23mm offset CC is listed at 6.9Kg or 15#2.9 oz
The 23mm offset PD is listed at 7.4Kg or 16#4.5 oz
The 52mm offset PD is listed at 7.0Kg or 15#6.4 oz

Here are my four 15x7 CCs again (free of lead weights, thanks USPS)

14# 14.0 oz
14# 14.0 oz
14# 14.6 oz
15# 5.2 oz
Last Edit: 7 years, 6 months ago by KJZ78701.
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Re: 2017 Rules Proposal Thread 7 years, 6 months ago #21322

  • KJZ78701
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"In the 9 years I've been doing this I've seen the costs go way up and the rules get more complicated. ... let's stop trying to build a better race car and enjoy the ones that work for us."

rd,

Please explain what costs have gone way up.

What do you want me to do? I am building a car now. Do I just throw a cage in there and head to the track. Done that. Lost the clutch in qualifying and had to work like mad to make the race. NO FUN. Where does it stop? I suspect even you would do it differently if you could start again. The extra up front cost to a complete build is more than offset by the maintenance / fix its in the first year of racing if you start with a less expensive build.

The motor is the biggest cost (see the build topic on this site) and a huge percentage of the total build cost and I see all of us getting there for one reason or another if we race long enough. You are right though, motor costs should be top of the rules makers' list. The power cap is a great start, but without using current data (which does not look the same as when you started: compare Jason's dyno data to all the dyno data Joe collected several years ago) to stipulate maximums through the entire power curve, you might be more frustrated in five years.
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