I have found that if you map to eradicate ALL traces of det then you can end up with a sub optimal map.
This transient det, if infrequent, may well be sustainable by the engine ??
I hold the view that the det you mention (after a period of cruise) is due to oil/carbon build up in the combustion chamber.
The high vacuum at cruise causes more oil to pass the valve seals and piston rings. The relatively mild combustion conditions support carbon build up.
When you go WOT after cruising for a period, the oil present efectively lowers octane and the carbon residue provides a hot spot.
This may take only a few cycles at WOT to clear. I allow this to happen and it hasn't broken anything yet !!

The good thing about the J&S is that it should allow for this and correct as required

Andy

 

I like Andy's description - it's something I also regularly see, and ignore, too.

However, I now have a larger problem - intermittent 'real' det (kind you don't need KL or det cans for ). I thought it was charge temps, but it's still doing it now it's cooler. A wide-band shows no fuelling problem...that I can see anyway. FP gauge will go on next.

I'm running stock injectors and FPR. If the FP gauge doesn't show anything then I guess I'll still fit my new manifold/550's/FPR to this engine just to see.

If the J&S works it would be useful - especially for mapping with untested turbo's and the like....I have a hell of a time creeping up to, or beyond, the limits

Richard

 

Richard, welcome to the world of Subaru tuning...

Mark.

 

the thing here is that there's no signal processor yet that compares to the one between your ears, in terms of discriminating different noises out of a seemingly homogenous din. so in terms of speed, by all means the computer's got us beat--but in terms of determining what's actually detonation and what is normal engine racket (like piston slap) i think the advantage goes to human beings... for now at least.

of course, this is all IMO

ken gilbert

 

That is the test I want to do, see if J&S is better at detecting det than a doctor and a farmer doing their best with ear defenders and fuel hose

 

Agreed on the spike during cruise although cruise will/should generate quite high temps which could also contribute.

Love the processor analogy, my point is simply that they go wrong, so you are then back to watching for det "just in case".

I think what John reports will be very useful to many and I'm certainly looking forward to some feedback.

However, as with anything relatively different in a given application, I am, as usual, urging prudence until its completely understood.

cheers

bob

 

Skassa,

Your mates mapping Audi's and VW should have told you some people experienced some major failures on this "active non learning" system. The wrong side is that a faulty sensors shortly turns plugs, pistons (and even more) to dust... and it happens sometimes (well, even once is too much to me).

It seems there is a mfr notice about this issue.

 

Re " the thing here is that there's no signal processor yet that compares to the one between your ears, in terms of discriminating different noises out of a seemingly homogenous din. so in terms of speed, by all means the computer's got us beat--but in terms of determining what's actually detonation and what is normal engine racket (like piston slap) i think the advantage goes to human beings... for now at least."

I think it really will depend on what sort of knock sensing systems you are considering. Certainly, the regular OE knock control systems I have seen so far are not extremely sophisticated, however, more sophisticated systems are available.

For a simple example, certain aftermarket ECU's with a knock control option use (at least) two transducers, one is used to listen to general engine/mechanical noise levels and the other is used to listen for engine knock.

You can obtain ECU's equiped with dedicated DSP hardware designed specifically for engine knock detection... These will do a much better job than the simple and cheap systems used in many ecus.

I don't think humans have quite the advantage that you think.

 

Depends on the Human Moray

 

Btt

 

Review on NASIOC: http://forums.nasioc.com/forums/show...hreadid=469617

Update in my project thread: a bit of soldering http://www.scoobynet.co.uk/bbs/threa...179486&Page=17

 

John,

You are not using boost retard are you?.

I can see that there is a knock retard only safeguard,can this be used in the Scooby or is it the 1/2channel version that scould be used?.

Thanks,
Skassa

 

Not using boost retard but the unit will do it - I just have it turned off.

 

Well,

I´m going to order a J&S Safeguard,to work together with the Link ECU
and hope to be able to make good use of this,maybe make a few hp,but also for safety,
as it´s a bitty to know how well the car drives with the advance upped,
to what it can be when the car is cold,and then what the advance needs to at when it´s driven on track.

Skassa

 

Hi
John
why do you need 2 chanels ?
there is only one coil on the subaru turbo models

 

actually there is two coils on the 98 - 00 cars

It looks like one, but phsically contains two coils as the car runs wasted spark.

David

 

I'm going to get a J&S safeguard also since the Autrnoic ecu don't have knock retard, I think i will be a good safty to have one.

Perfect that you tried it out John...now we only need to now how much boost the 2.5l Block will handle before it gives up



Jan

 

I have just had a mail from J&S,
No TAX for my J&S (he he)

I will get one when we get into the new year.


Skassa

 

skassa.. order two and cough cough.. my christmas pressy

 

LOL




Skassa

 

Skassa, how much have they quoted you ?? i may be interested if thier Price is Right ??

Chris.

 

Chris,

YHM


Skassa

 

Skassa

Now I now what I will order

So they are like most Yanks, god on adjusting the invoice

ps. order 3 I want a x-mas gift to

Jan

 

The price i have been qouted is just list price,but it´s also a cheap product.

Just get it send as a present,like all the US company

Skassa

 

"now we only need to now how much boost the 2.5l Block will handle before it gives up"

The weakest link is the gearbox unless you have an STi gearbox IMHO.

 

Yup your right...but since you have that on the way...we will se how the block will handle the power your after...and you tend to want more..and raise the boost

Happy New Year to you all

Jan

 

I am not intending to run over 20 PSI on this block.

 

Bob Rawle, YGM. Sorry to hijack but I need a tiny bit of help!

 

and so it came to pass

 

I've had my 450/400 target for almost a year now, trouble is in that time I've hardly had my car and every time I get it back on the road it feels quick enough. Targets may be revised without warning