Good. If you are tame with the timing then it will run +ve correction spikes of +1 every time you floor it. If you are too aggressive it will run a lot of -1, -2 spikes. If you are silly then it will run -3 or worse all the time you are on boost, but still be safe as it can retard I reckon at least 8 degrees in the hot zones for det - 4000-5500 RPM on my car. These are just examples from what I have seen. Obviously if you tune for absolutely zero knock correction on a really hot day it will go positive on a cold day. Mine sits at 0 about 99% of the time because I tune it that way.

Of course it can also add fuel, and drop boost if it sees uncontrollable det, so -8 is not the limit then your engine pops.

Small changes also go a long way and the ECU over-reacts a bit - so if you see minus 3 degrees on boost it only takes a bit of fuel if necessary or 1 or 2 degrees to get rid of it completely. Hence I don't want it running -3 all the time as I think it will end up more retarded. Nice to see that your knock sensor is working occasionally though

[Edited by john banks - 6/7/2002 6:47:46 PM]

 

That's interesting, +ve timing spikes ???? why does it do that ?

I would have thought it would gradually ramp +ve but spike -ve to control det

 

Strange but true. The MY01 has whole plateaus of +ve knock correction, the MY00 just plays at it really.

 

John, a little birdy told me that the JECS doesn't do knock correction beyond 5.500 RPM, as it can no longer distinguish knock from engine noise... is that birdy correct ?

This would mean det in the higher region can be equal to blown engine anyway

Talking MY99/00 here.

 

Jim
ETA Greece is 8th July at Patras (off Ancona Patras ferry). I am motoring out this year, but not in the Scoob.

Wrexy. sound like id better bring some tools!!

Beastie

New Wheels as below - note performance exhaust etc. etc. This modifying bug is hard to shake!!



[Edited by Beastie - 6/7/2002 9:32:46 AM]

 

Dowser,

On second thoughts, are we sure that +ve is advance?
I'm looking at the sample graphs from the ECUTEK website, +ve looks like retard to me...

???


[Edited by RT - 6/7/2002 9:27:32 AM]

 

Beastie,

Congrats on the car m8. Looks lovely and in immaculate condition. Wheels suit it nicely. Nice colour too. You must take me for a wrap in it when you come out here.

No need to bring tools. I have them all. All I need is instructions off you and I'll do the rest.

Cheers,

Wrexy.

[Edited by WREXY - 6/7/2002 10:48:20 AM]

 

PE told me they had found that over 5500 on the earlier models it did not. However, I have seen knock correction up to 6000 RPM, so I am cautious what I do above that area - however, peak power on most cars has passed by then. I do find driving a lot in the 6000-7000 are that the intake temperatures climb a lot across the range - trimming the boost from 6000-7000 helped a lot and did not seen to lose power - just lost the hot air.

Notably the knock correction tables do contain retard values and they are populated all the way up. The knock correction code would be a long one to debug!

You are less likely to det over 6000 RPM. The hot zone is 4000-5500 from what I have seen. The amount of correction at 6000 RPM was trivial. Through det cans it is so noisy up to 6000-7000 it would be very difficult to pick up trace det. So as I say I am very careful with the maps up there and my fuelling looks like a ski slope in reverse.

[Edited by john banks - 6/8/2002 10:38:54 AM]

 

Very interesting thread. If I'm reading it right, if you don't have a programable ECU (say you only have a PPP ECU), there's not much you can do to change/improve the results displayed by Delta Dash. Correct?

 

All that DeltaDash can ever do is read the later (99+) ECUs anyway. Except modify idle speed & reset the ECU. But it will point to problems so that something can be done about them!