comatb wrote:
Kinda short notice to come from here.
But best wishes in firming up the rules/tech process.
Well, the first notice was actually posted here several weeks ago. You would have found the meeting to be very interesting. I'm sure you would have had some good questions for Mr. Behe.
John was very helpful and well informed with the 944 ECU, eproms, and other devices out there on the market that can be use to improve engine performance of engine mamangemnt systems.
He was quite enlightening on the boost limiter and the DME chip . While the KLR chip controls the boost, the DME chip serves as a secondary control with a boost limiter. This limiter sets the car into protection mode when the boost reaches limits programed in the DME chip. The factory limit is not set at one psi settings, but rather changes depending on the engine rpm. For example, the factory limits for a Turbo S are set at 8.2 psi at 2000 rpm, 13.75 at 4400 rpm, and 15.17 at 6200 rpm. Aftermarket chips can be easily designed to change or remove these limits.
The problems previously discussed on this thread with overboost occur at the lower rpm levels that can occur when a fresh engine and open exhaust allow the turbo to spool up quicker at lower rpm' s and trip the limiter when the protection setting is relatively low and yet below legal boost setting used by PCA for testing purposes.
The boost is an important part of the formula for the power produced by Turbos and does need to be kept at factory settings as set forth in our rules. While we did checked overall power at its max, we have done nothing to directly determine if Turbos were running boost at factory or lower settings throughout the entire power band.
Certainly the overboost limiter is one way do that if we know the chip boost limiter is set at a level that kicks in if the factory boost is exceeded at any rpm. Of course we need to know that the boost limiter is set at proper levels to not exceed whatever limits we set as legal, and still not interfere with the proper performance of the engine at lower rpm's because of a free exhaust and/or fresh engine.
I see two ways to keep a check on the boost: a telltale boost guage that we could require for each Turbo car, or an aftermarket chip that we have made for competitors by a certified source that kicks in at our legal limits. These measures would take the tech compliance assurances for the Turbos to a much higher level for minimal costs and effort. A racer could choose which ever option they prefer.
And of course to better enusre the entire SC field is legal, the one map certified aftremarket chip would be required for all models.
The chip would also be certified to contain only one map setting which takes care of the notion that cars are switching map settings between the track and the dyno.