kevincnc

Okay, you long-timers probably know that's a joke and remember the old thread where some poor guy with that title got severely harassed and was told to sell his car..

I was able to do some fine tuning yesterday and turned the boost back up to 15 PSI. With the new 3" exhaust, the car is noticeably fasteter now. The wheels broke loose in a straight line in 2nd gear from a slow start when it
hit full boost just over 3k RPM, and it's never done that. Granted it was cold outside but the tires were plenty hot.

Now I want to dyno it again and maybe show what a 951 can do with the stock airbox and snorkel. It's never been so fast or spooled so quickly and I had the most fun drive ever on the twisty road up the peaks yesterday.

So enough of that and on to the question. After shooting for an AFR of about 12.5 until 7 or so PSI to help the turbo get going, it's no higher than 11.7, and closer to 11.5 at full boost. However, I still get get a couple of knock counts per WOT in each gear.

What is acceptable for knock counts? It's raining/snowing here so I can't do any more playing today

blown 944

You may want to verify when the counts are occuring. I have found that there are phantom counts after shifts. I like to use a hobbs switch to only register over set pressure.

I prefer to keep counts down to less than 2 per gear pull. With e85, I don't get any at though.

Dougs951S

Sid, out of curiosity what is the cause of the knock on upshifts? I'm running E85 also and the only time I see knock is on an upshift or a hard downshift.

blown 944

Not exactly sure. May be picking up unusual noise through the clutch or just unloading the engine abruptly.

kevincnc

Thanks Sid. I'll check the counts with a friend watching again at WOT but they seemed to be kind of random, and not during shifting.

Tom M'Guinn

Check out Vitesse's V-Knock too, which allows you to log the knocks to know when they are occurring. I disregard knocks on shifts, etc. and "try" for 1 or 2 counts or less when pulling under WOT. I honestly don't know how many is too many, but keeping it to 1 or 2 (or less if I can) has allowed my to run hard for quite a while now. I've always wondered if the counts on shifting (or just rev'ing hard in the driveway) are from something mechanical that looks like knock to the KLR, or if the tune just has a hard staying perfect on big transitions -- going from idle to WOT in a split second, etc. Seems like that may induce momentary lean or the spark advance may take a cycle or two to catch up. Nothing obvious from my logs though, so maybe it something mechanical that triggers the KLR -- I dunno...

kevincnc

Thanks I'll check into the V-Knock. I've been down so long that I'm kind of out of the loop now. Last time I remember checking into looging knock on my (Vitesse) SMT6 it wasn't fast enough to catch short puless. I was thinking about making a circuit myself back then but never pursued it. I'm guessing an Arduino would do it easily, but for the convienece and relatively inexpensive price I think it would probably be worth having John's customer service if I can log it with the old piggyback.