wrex

First off I am a Power FC noob so go easy on my lack of knowledge here, heh...



Out driving around town today I hit about .5 bar and had like a 130 peak knock at the same time. I know that there are other factors that play into the knock reading(road noise, bumps, the transmission noise) but I just don't know how to make the distinction between normal knock readings and serious(problematic) readings. 1) When should I be concerned? Putting around town with no boost I usually see anywhere from 0 knock to somewhere in the 30's. 2) Does that seem right?



I am also getting rather conflicting boost readings and am trying to figure out if my boost gauge is flaking out of if it's just the PFC lying. I have not had a chance to do a good pull, but I will try to do it this weekend and record/compare the gauge reading to the PFC's boost reading. I have heard that the PFC is a little off in this area. I have not had a chance to test the gauge to see if it is working properly or not. Anyone else have the problem?

wrex

Reading the pinned Basic Engine Tuning thread at the top of the ECU Discussions page. It is helping out a lot. Would anyone happen to know of a good deal for a wideband and PFC Datalogit combo?

j9fd3s

the innovative lsm-1 wideband is really nice, and its relatively cheap

jspecracer7

all of the Japan guys are using Tech Edge Wideband. I think the newest version is out(or will soon be) and cost right around $470~ with sensor.

Tim Benton again

The PFC displays boost incorrectly on the commander, but does get the map sensor voltage correctly from the stock sensor. It deals with the PIM offset and the calculations going from PIM voltage calculations converted into BAR amounts.



The knock number of 130, is high, but you need to look to see when it happens. Is it actually during the WOT or heavy load run or does it show up after you let off the throttle? Most of the time it's after you left off, just need to make sure there's no negative splits on your map since when you left off and coast down, you are still in the higher rpm cells coming down through the pressure cells.



Putting around town, I'll top out around 25ish....WOT is around 40ish, but I do see 80's after I left off after a hard 3rd or 4th gear run.



Tim

jspecracer7

After my first rebuild, I would get knock reading in the 140+ range...at 3800 rpms~ and -500 vacuum. No way that's knock. It just depends on WHERE the knock occurs. Even still, the best street tuning tool is a wideband O2

wrex

Thanks for the replies guys. I am new to all of this, so I appreciate any help I can get. I read all about the widebands posted above in this thread. I still want to read up on a couple more then I will have one on the way for sure.

wrex

I think I will pick up the PFC Datalogit while I'm at it too. It's just too hard to pay attention to the commander and drive at the same time. I will do some more tests this weekend to see when the knock happens exactly.



As for the boost being off on the Power FC... I have done some more searching and come up with the same thing as Tim stated. However it the boost off as in low or is it displaying higher? i.e. if the PFC shows 1.2, is the actual/real boost higher or lower?



Thanks again for your help guys. -Mike

jspecracer7

The power FC reads lower than my Defi gauge. But I always go with what the power FC says since it's the ECU.

wrex

That's a good point jspec.



Did a couple runs this weekend after I changed the oil and filter. I only noticed the really high knock numbers when I depressed the clutch during a shift, so my fears have been eased a little. I'll keep a close eye on it though. I have decided on the Innovative wideband(even though it looks like an old Nintendo Gameboy, heh). So far, the car has been great and I am loving it!



Thanks again.