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2017 Rules Proposal Thread (1 viewing) (1) Guest
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AgRacer
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Why wouldn't you start with the best option if it was readily available. Please define best?
88 pistons are 10.2:1 compression ratio (otherwise known as HC or high compression) giving the best product for racing. All other pistons legal from 83-87 are 9.5:1 compression ratio (otherwise known as LC or low compression) which is why head shaving is allowed to bump up the compression ration when using the LC pistons. The two degree offset is afforded to the LC piston built motors to account for the difference in timing created with head shaving bringing the cam sprocket closer to the crankshaft. The prevailing thought is the HC pistons allow for a better starting point which is closer to maximum dyno power (140 avg) reducing the work required on the engine to produce optimum power.
And have we not set a precedent for allowing the aftermarket piston with the addition of the new "944 Spec approved" DME?
Negative.
The 944Spec approved aftermarket, new DME produced by Focus 9 Technology is being introduced at the end of the 2016 season in preparation for a 2017 rule change which will specifically allow the F9Tech 944Spec DME in addition to the currently allowed OEM, stock DME selection. The F9Tech DME utilizes a tune exact to that of an 88 DME, which is the preferred part just like the HC pistons due to the increase in rev limit by 150 RPM. Whether or not the 88 DME's tune produces better power is still somewhat unproven but the thinking again is since it is the latest and most improved parts available, it should be the better part. Only one F9Tech DME will be legal, and that is the 944Spec specific one which does not have a removable chip and has an exact 88 DME tune burned directly to a chip on the board. If these aftermarket pistons were created as an exact match in weight and compression ratio as the 88 HC pistons, that would be the logical comparison to the F9Tech DME.
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J. Stanley
NASA-SE Region 944 Spec Series Director
Yellow #60
Last Edit: 8 years, 1 month ago by AgRacer.
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dpRacing Dan
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KJZ78701- To answer your question- I am. Your acting national director.
After seeing several failures, I decided to look into solutions to the failing DMEs. Additionally, several DMEs were discovered illegally chipped this season, and racers were left asking what to do to replace theirs. OE units are not readily available from Porsche, and do fail from vibration and moisture.
I worked with Focus 9 Tech throughout the entire season to create a proprietary version of the one they already had on market. The biggest difference is that ours does not have the E-prom port, so an illegal chip cannot be loaded. The function of the DME is 100% as original. We dyno tested the units to make sure there was NO variation in performance over an original unit. I also worked with them on price to make them as affordable as possible. This unit is the CHEAPEST unit they offer- especially with the NASA discount. The units are marked from them, and are sealed. I also receive a list from them of everyone who buys one.
I think of this component more like an alternator or starter. Its electrical, and they are proned to failing. Unlike the mechanical nature of a piston, these ancient electrical components are fragile and fail often without the need of a catastrophic failure.
We are entertaining the idea of allowing replacement pistons.
The big things to consider behind this are:
-availability
-OE replacement accuracy
-price
And the biggest concern of mine
-verification
In other words, its easy for me to peek into a car and see a F9tech DME. Pistons?? Are you all ready to pull the entire front assembly and head off so we can inspect pistons? You ready to pull your pistons so we can weigh them? If you think this is an exaggeration, we had a car at Western that blew 11.7/1 compression. I promise you inspections will be more thorough this coming year.
These are just things to consider.
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dpRacing Dan
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code3pro
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Hi everyone,
I have read through the entire thread, and wanted to throw in a few thoughts. Admittedly, I am new to 944 SPEC, so I don't have the long history of knowing the evolution of the series or the cars. What I do know is that the reason I picked the series was because of its relative affordability and strict rule adherence, something I valued when running a previous spec racing class. What I have discovered the last two seasons is that, while I did buy a pre-built car from the Midwest, it required a LOT of updating and replacement of parts to get it competitive, plus reliable. Even then, we still had some expensive failures. To be realistic, the car that we won with at Buttonwillow has about 15k in it, mostly due to the many parts and labor hours involved to make it a car that could potentially win a championship while still being reliable. As we all know, Porsche parts are expensive, and racing a 30 yr old car means that things are going to fail. So, in the spirit of making the cars more reliable, easier for someone to join the series, and keep all of us from constantly be throwing money at these cars:
1. WHEELS - Having a 924S, acquiring phone dial wheels with late offset has been an adventure. They are pretty rare to find in good shape. I finally scraped together three sets, so I am good at this point. But if we consider bringing new blood into the series to be vital (which it is based on some car counts I have seen), then we have to make it easier for some of these parts to be sourced. I don't think anyone is advocating a $2000.00 set of wheels, but certainly a reasonably priced wheel option is out there somewhere. It's a better bet than taking a chance on a 30 yr old set of wheels that cost a few hundred bucks, are worn and may or may not be round.
2. SHIFT LINKAGE - Being that there are parts on our cars that simply can't be found anymore new, or are rarely found in good used condition, updating all of the shift linkage for reliability reasons is a good idea. Updating half of it with now-legal parts helps, but the remaining stock pieces can still cause headaches. I don't see this as a performance advantage. It could save someone an engine or a clutch as a result of stock linkage errors or failures.
3. 3-PIECE CROSSMEMBER - Having just done rod bearings prior to Nationals, if there is no safety issue, then I am for it if it makes maintenance easier while not disrupting alignment settings. As Charlie said, out here in AZ and CA, heat is much more of a factor relative to wear and tear. It will also reduce labor time for those racers who have to pay someone else to do their maintenance, especially someone new to the series.
4. DME - I have one of the prototypes and look forward to trying it out for its reliability and compliance advantages.
A few parting thoughts more specific to HC vs LC engines, and talk of adding weight or banning 88 engines. What I can say is that our 88 924S HC car won nationals this year making less power than the same car we took to nationals last year. 136/135 to be exact on the compliance dyno. We also ended up weighing 2650 on the scales at the end of championship race, the result of an uneducated guess on my part on how much fuel we might need. So, with more weight and less power than 2015, what really made the difference in my opinion was the suspension setup more than the power.Powerwise, the group of cars I regularly race with are pretty much dead even on the track. Suspension-wise is where the differences are. We had the car at Buttonwillow in June, and it was a handful (ask Charlie). So we made some alignment and spring changes, and the car was significantly easier to drive despite the very dirty track at Nationals. So, if someone needs to use aftermarket pistons on a LC engine to bring it closer to the existing cap, then fine. We have that cap for a reason, as well as other compliance rules, so if the aftermarket allows more people to rebuild engines, thereby increasing much needed car count while still being legal, then I am totally for it.
One last thought. We have an AWESOME series as it sits. People constantly tell us at race weekends that we are the best race of the weekend. The crew I race with out West are top notch, and we have some the best dogfights of any race series I have been involved with. What we need is more people in the series, and more drivers with existing cars to come back to the track. So, if we pass rules that make the cars more reliable and less expensive to run in the long run, without upsetting the existing competitive environment, then count me in.
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AgRacer
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code3pro wrote:
A few parting thoughts more specific to HC vs LC engines, and talk of adding weight or banning 88 engines. What I can say is that our 88 924S HC car won nationals this year making less power than the same car we took to nationals last year. 136/135 to be exact on the compliance dyno. We also ended up weighing 2650 on the scales at the end of championship race, the result of an uneducated guess on my part on how much fuel we might need. So, with more weight and less power than 2015, what really made the difference in my opinion was the suspension setup more than the power.Powerwise, the group of cars I regularly race with are pretty much dead even on the track. Suspension-wise is where the differences are. We had the car at Buttonwillow in June, and it was a handful (ask Charlie). So we made some alignment and spring changes, and the car was significantly easier to drive despite the very dirty track at Nationals.
All of this! Focus on the biggest impact to lap times: Driver ability and suspension setup! Thanks for the input Champ!
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J. Stanley
NASA-SE Region 944 Spec Series Director
Yellow #60
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KJZ78701
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Focus on the biggest impact to lap times: Driver ability and suspension setup!
Forgive me for being flippant, but tell that to Alonso and Button.
Jason, you have a car that is, shall we say, power optimized . I have yet to find it here, have you posted your motor build specs? What does it Whistle v what the motor builder told you the CR was? What cams? Pistons are late, I believe. Block sleeved? Block decked?
John, can you tell all of us why you chose to buy the car you now have and why did you pass on other cars, if you did? And congratulations!!!
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Last Edit: 8 years, 1 month ago by KJZ78701.
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