Recent Frankie dynos
03-05-2008, 02:26 PM
#31
Nordschleife Master
Thread Starter
Engine #2 seems to run fine with only 10 discs, not so with #1. This is with the same chip, header, and exhaust.
03-05-2008, 02:32 PM
#32
Three Wheelin'
Join Date: Jul 2001
Location: San Francisco, CA Porsche: '92 968 Blk/Cashmere
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Maybe the valve timing is slightly different between the two engines and the resulting resonance combined with the additional back pressure of the muffler is causing a harmonic frequency at that rpm?
03-05-2008, 10:45 PM
#33
Rennlist Member
Tim:
All I was trying to say was generally if you race you tune a 968 engine for above 4k to redline or your shift point. What happens below 4k does not really matter as you are generally not there.
Mike
All I was trying to say was generally if you race you tune a 968 engine for above 4k to redline or your shift point. What happens below 4k does not really matter as you are generally not there.
Mike
03-05-2008, 11:12 PM
#34
Nordschleife Master
Thread Starter
No problem! Here's some more data from last year on the #2 engine. Three curves show 0 (open; red), 10 (green), and 12 (blue) discs. There is a slight gain in hp and tq around 2 to 2.5 k with more back pressure, all are similar betwen 2.5 and 3, after three, the more free flow the better.
03-06-2008, 12:23 PM
#35
Rennlist Member
I bought my first spec stage III through Lindsey and then found out that Spec is based in B'ham 
This time I just stopped by the shop and bs'ed with the guys for a few hours. 24 hours later, I had the new flywheel, clutch, and lightweight pressure plate for about 60% of list 
Of course, the discount is costing me a number of test rides the next time I'm instructing at Barber (but's that's ok). It didn't hurt that one of the guys at the shop has an S2 with LS1 engine tucked in it.
I really like the clutch. Turns out that I had a flywheel failure earlier this year (snapped all nine bolts going to the crank) and the flywheel than damaged the clutch and pp. They measued the clutch and over two seasons I only used 5 thousandths; which blew the spec guys away.
I had to increase the idle to keep the car from stalling. And yes, I do have the S2 harmonic balancer.
This time I just stopped by the shop and bs'ed with the guys for a few hours. 24 hours later, I had the new flywheel, clutch, and lightweight pressure plate for about 60% of list Of course, the discount is costing me a number of test rides the next time I'm instructing at Barber (but's that's ok). It didn't hurt that one of the guys at the shop has an S2 with LS1 engine tucked in it.I really like the clutch. Turns out that I had a flywheel failure earlier this year (snapped all nine bolts going to the crank) and the flywheel than damaged the clutch and pp. They measued the clutch and over two seasons I only used 5 thousandths; which blew the spec guys away.
I had to increase the idle to keep the car from stalling. And yes, I do have the S2 harmonic balancer.
