KNOCK?
 

hi , just had an apexi power fc ecu fittted and i dont know how to use it properly, its on the 4 channel setting with knock and its quite regularly reading 10 mmhs i think, can anyone tell me just how bad this is, (is engine fukced or can it be rebuilt ect) any info very welcome....

...cheers dan

Who fitted it? Has it been mapped to your car?

i think scooby clinic fitted + mapped it for him?

knock of 10 is nothing.. the ecu should have been set up to flash the engine light if genuine knock is detected

I have a small user guide on my website www.jollygreenmonster.co.uk under the "help pages" hope that helps

Simon

mine reads 27-29 when driving hard nearly reads 10 (7-8) when i start it so i wouldn't worry about it :)

Yeah, as JGM says, 10 is nothing to worry about.

Mine, as yet, has failed to get past 20 when giving it the beans (under normal driving it doesn't get beyond single figures).

However, there's an issue with mine in that the 'det threshold' CEL light flashes... even though it shows a lowly knock reading of c.19 or less. :confused:

Each mapped engine is obviously unique, but the early v.1/2 motors start to properly knock - i.e. potential engine-destroying detonation - between around the 30-40+ mark I think. However, not sure of the v.3 engine's ballpark.

mine is 9-10 with normal driving

would like to know how forged pistons afect this?

Yeah, I have STi v.3/4 forged pistons and see similar figures too.

general rule of thumb being -
v1~2 - 30-40
v3~4 - 20~30
v5~6 - 10~20

in normal full rev range driving.

forged pistons depending on clearances can increase that and every engine varies

Simon

There you go. Simon tells it how it is (as always). :)

thanx for all the quick , helpfull replies which have put my mind at rest...
car was mapped last week by scooby clinic

cheers, dan:thumb:

I have a V4. My Power FC read a peak of 47 at some point today during the day.... from the looks of this, that CANNOT be good.:( Tonight with a little spirited driving on the way home, it read 22 max.

The Power FC is still on base map, some say the base map is very aggressive though APEXi claims it is tuned to 92 octane. How worried should I be?:Suspiciou

the base map is fairly aggressive.. it needs mapping

Ok Simon, thanks A LOT! Is the Power FC base map safer than the Stock STi ECU though?

no not really.. the standard ecu pulls timing if it hears knock.. the powerfc doesn't.

If you go to SETTINGS --> IGN/INJ and set the IGN to -5 you will remove 4degrees timing from the whole map.. but it will only do that until you turn the ignition off.. then it shouldn't in theory be detting and the highest knock reading then is just engine noise.
Then try it at -4, -3 etc until the knock readings increase.. if they do then it is detting, if they don't and remain the same then it should be okay det wise..

Is the car standard?

47 is a bit high.. 22 more like normal

Simon

Yep it is pretty standard except for a cat-back exhaust. I will try what you said though... hopefully it's ok.

Simon, I tried it on -3 the knock peaked at 17 in one run and 19 in another but on the way home with a spirited drive I was getting 17 peak.

Clearly it doesn't feel quite as good as on base map(but still better than the stock ECU). Probably due to the reduction in timing. Any advice on how to get back that feeling while still keeping her safe. I'm at such a limitation living so far from the UK.

How do I actually save this setting though as opposed to it always being erased after I turn the car off??

From memory, you either:-

- Press 'NEXT' immediately after making the change, or...

- After making the change, then come back out of that parameter using the 'PREV' button (but whilst still in the "Ign/Inj" menu)... and then press 'NEXT'.


'NEXT' acts as a 'save' parameter function (to the non-volatile memory), too.

I think I tried that and it still didn't work. Will try it again though.

Weird that it wouldn't work. :wonder:

Yeah.... No matter what I do, once I turn off the car and turn it back on, it just goes back to +0. That's it.

Bugger. :confused:

If desperate, contact Simon.

Hopefully though, he'll see this thread again soon enough and tell you how to do it, etc. (...if indeed it can be saved on the Commander! :confused:).

Hopefully... I've been reading this very long FAQ. There is a way to save it but I'd rather be told by somebody that tunes Imprezas rather than guesstimate from an FAQ made by a GTR owner.

The strangest thing happened today. I did a resonator delete, and whereas the car pulled better with the improved air flow. With the A/C on it gave me some pretty high knock readings at -3, We're talking like 80 and so on in mid to high RPM in 3rd. I then tried a retardation of -5 and it seemed to help.

It's just so weird because I made a few pulls after the delete without A/C (clearly) and the knock was around 20 at -3. Which was within Simon's determined safe range and probably expected with the increased air flow now and higher daytime temperatures.

Really hope somebody can help.

What's that FAQ then?

Is it complicated to make an adjustment and to make sure it's saved permanently :wonder: then?

Yes it will always do that, but that is to the values that are in the map.

If you have saved the changes already then they should be saved, for example timing in a certain row/column is 14, you do the global pull of -3 and save it, it will now be 11. Turn the car off and on and will now be 11, but if you go to the global ign screen it will say 0, but 0 relative to the map, which is noe 11, not 14 anymore.

So what you're saying is if I try what joz says above there it would actually save?

I was thinking about it the way you said it too Jay that maybe a change was being made and saved so then after restarting the car this would then become the 0 value.

Here's the FAQ being referred to though:

Apexi PowerFC FAQ

and here's the section that talks about adjusting the IGN/INJ values:

Apexi PowerFC FAQ

Cheers!

Hmmm thinking about it I'm not sure you can 'save' a global ign pull, I think you have to change every cell individually...

Hi Jay. I was that bloke having the MOT done at ZEN's whilst you were waiting for your RA's corner-weighting. Remember?

How's it going with your car?

Nemesis, we've been a couple of numbnuts - we should both learn to read! :brickwall!:-

So it will only be altered between the time it was changed with the engine running, until when the motor is shut down i.e. what you've been experiencing!

Yes, I remember. Corner weighting didn't go as planned since both front adjustment collars had seized - but geometry was good - got me 4th in class at Scoobysprint the following weekend :)