looking at my power fc. just came home and did a run. looked atthe power fc commander. have the knocking monitored and it read 150 which was the number. Is that bad or good.

it usually reads 90 at 10 lbs of boost. but i raised it to 15 and thats what knocking level it read!

 

What does your knock read with normal around-town driving?

Mine's around 30-40 in town - higher than that and it's likely real knock. But, every motor is different.

Dale

 

Normal Its In The 40 Range

 

when i was tuned by Steve Kan he said that there is real knock and fake knock. Real Knock is only between aceleration and the point at wich you let off the throttle. He said when looking at real knock you dont want to have any too much over 50. If you look at the graph mode on the fc commander you will see knock spike up sometimes after you let off the throttle from a WOT run. Mine normaly stays between 20 and 35

 

EVEN WHEN WOT ITS BETWEEN 20 & 35?

if thats the case i think my motor is going. need to check the compression

 

normaly yeah.... sometimes i see as much as 45 but thats about it. now if i drive for about twenty minutes in various conditions and then check the knock max it may be at like 80 or some other insane figure but its always from the fake knocking after a run or at decel

 

#1: when making your run, clear your peak hold values as you lay into the throttle by pressing -> and freeze the screen by pressing <- *before* you lift off so you're not getting "fake knock" in your reading.

If you're getting a 150 during your pull, it's real knock, of the will-kill-your-engine variety. Go to the PIM adjustment and bump the value up (default is 100%) by at least 10 points through the high-boost part of the RPM range before repeating the run. See if the knock value comes down (it should) and use the new value to judge how much more to add until you see numbers back under 60. If you can watch the knock value and RPM during the run you can fine-tune what RPM range needs how much fuel. This will put your knock in the safe range under boost, but it is an indication that the fuel map needs tuning.

I'n daily dirving, I've seen knock readings into the 70s and 80s under various loads and conditions, especially lift-throttle. I've never seen knock as high as 150; I have seen 141 and I heard an audible 'ping' from the engine - I was not at high RPM, under boost, or at WOT. That said, you can still break an apex seal under moderate load, leading-throttle conditions.

At high RPM, under boost, at WOT, I would not want to see more than 70s max at any boost level. I would say high 50s to 60 but that depends on your engine and mods. When I added an aluminum flywheel and ACT clutch (both previously stock) my knock readings went up across the board due to the resonance of the flywheel/cluth assembly. Slightly elevated knock readings do not mean that your engine is necessarily clapped out, but anything approaching 100 or over needs some tuning. Remember, the knock sensor picks up the general level of noise in the engine - actual pre-ignition, or "spark knock" will show typically a sharp spike.

Some advice on the PFC: Get familiar with the maps, especially the injector map, before cranking up the boost. The FD has a reputation for blowing motors because over-enthusiastic owners turn up the boost before making sure they have safe fuel and timing settings: don't become a statistic. You can compare your maps to ones available online - I think it's sticky'd on this forum.

Get to a dyno with a wideband O2 sensor and check your air/fuel ratios under full throttle acceleration. THe dyno guy should be able to give you advice on what you want to see -- rotaries like to run rich, a stock FD gets to 10:1 air/fuel and many tuners consider that a very safe air/fuel ratio for street-driven cars at full throttle, although some use 11:1 or even 11.5:1 - I would start with the safer (richer) tune. Tune it with 10 psi first. Then, make sure your numbers in the higher P rows are larger (richer) than the row you're in on the map at high boost - they should grow progressive larger as you approach P20. That way, you can be sure you won't blow your engine on the dyno when you go for high boost. Run again for high boost and tune to the desired air/fuel ratio.

If you see knock numbers higher than 60 under load on the dyno and your air/fuel ratios are in the safe range, there is probably too much spark advance in the IGL and IGT maps for your setup. I would bet that tuning your fuel as described above will bring your knock numbers down.