Ohh contraire mon frere
I think we have too much air, engine starts knocking, ecu dumps fuel and subsequently dumps timing causing huge power loss
- Thread starter Jaffman
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Ohh contraire mon frere
I think we have too much air, engine starts knocking, ecu dumps fuel and subsequently dumps timing causing huge power loss
roofman
Purveyor of fine English buckets and mops
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Plenty of air but knocking (detonation) is going too lean so needs more fuel at injectors. Remap time baby
did the dyno guy have a AFR reading during runs
Barking Mat
Cuddler of hedgehogs.
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I know suprisingly little about all this.
But surely this must be engine mapping to ecu ?
What's the issue, I can talk to my neighbours, who are a bit special.
I'm sure you have local links.
But surely this must be engine mapping to ecu ?
What's the issue, I can talk to my neighbours, who are a bit special.
I'm sure you have local links.
Pete.
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When the fuel goes in initially it's pretty good then it gets progressively richer if it gets much more rich it won't even ignite.
Does that ECU use speed-density for fuelling or alpha-n or does it transition from one to the other according to RPM? Might be something in that to give you that big fuelling spike?
Does that ECU use speed-density for fuelling or alpha-n or does it transition from one to the other according to RPM? Might be something in that to give you that big fuelling spike?
I suspect it’s knocking @ 3250rpm or the lambda is going out of spec according to ECU due to turbos adding air. When that happens it dumps fuel in and retards the timing causing lack of power and subsequently lack of exhaust flow to spool the turbos further to add more air for the mass of fuel already in there
So you need to retard the timing around knock - 5 degrees at a time until it dissapears? Might be as much as minus 20 degrees, depending how much boost you're running.
I knew a clever young lad from Scotland who was squeezing 400 bhp out of a k series, in a mini. Normal timing up to boost, -20 degrees retarded from there on. He lifted the head a few times until he got it right.
Wideband lambdas don't like overheating - I guess knocking falls into that territory
I knew a clever young lad from Scotland who was squeezing 400 bhp out of a k series, in a mini. Normal timing up to boost, -20 degrees retarded from there on. He lifted the head a few times until he got it right.
Wideband lambdas don't like overheating - I guess knocking falls into that territory
I have no control over the ECU and the fuelling or ignition timing. This is why I’m at a bit of a crossroads where there’s not much I can do to improve it aside from going to a stand-alone engine management
Nout. Still using standard MAF.
Clearly has enough fuel if it can control the timing but it can’t control the timing once it starts knocking
Oh poo. Has anyone hacked those ecu’s? Like they did with the Honda ones?
If not, and simple pressure increases can’t stop it knocking, you’re into phase 2 of the project. But I forget - was this nasp and you added turbos? Or was it always turbocharged? I suspect I know the answer....
Pete.
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I dunno then if it's a N/A engine that you have added turbos to then it shouldn't be adding fuel under boost (unless the ECU has fuelling tables for boosted motors that are not normally referenced). It clearly IS adding fuel under boost only too much of it, seems to be a delay for when it starts to do so.
I don't believe this is a timing issue it's knocking due to lean mixture and trying to fix it by retarding is a dead-end street IMO it'll just push the EGT's up. The crux of the problem is that the fuelling is too lean at the bottom of the table.
I don't believe this is a timing issue it's knocking due to lean mixture and trying to fix it by retarding is a dead-end street IMO it'll just push the EGT's up. The crux of the problem is that the fuelling is too lean at the bottom of the table.
Don’t think so. Maybe but it’s not worth it I don’t think.
It was NA, added turbos, no brained with the end goal in mind
It’s fairly obvious that something happens at 3.2k rpm as the AFR keeps rising. The only control I have over that is turning the boost down but it’s already at 5-6 psi which is barely anything anyway so no point dropping it.
So realistic fix is stand-alone ECU so I have control over everything
Pete.
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You could use a secondary fuelling computer and second set of injectors. I don't know how it would interract with a MAF sensored input I have no experience of it. Probably the Lexus/Toyota ECU has several hundred reference/correction tables.
The very simplest boost-referenced fuelling I heard of was done on bikes using a powercommander but switching the TPS input over to a MAP sensor. Instead of increasing injector pulses with throttle opening it did it with increasing boost pressure. Very simple and very effective.
What does your tuner suggest? If he has no input I could ask my wife's nephew for suggestions he does this all the time.
The very simplest boost-referenced fuelling I heard of was done on bikes using a powercommander but switching the TPS input over to a MAP sensor. Instead of increasing injector pulses with throttle opening it did it with increasing boost pressure. Very simple and very effective.
What does your tuner suggest? If he has no input I could ask my wife's nephew for suggestions he does this all the time.
I don't have a tuner lol but I did have a good chat with the Rolling Road operator today and he recommended a standalone ECU.
tbh it was always the plan anyway to upgrade im just doing it sooner than I expected
I dont think its worth dicking about with a 40 year old ECU (that have a tendency to fail anyway) to try to make it work by throwing money at bits and bobs when there are solutions out these these days that will do it all and so much more
New ecu and a wideband too set it all up, looks like the turbo's are really starting too spool at 3000+ rpm
Yup, I’d go as far as suggesting these turbos might be the perfect size for this engine as it stands
Milkybars
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