making boost but power is low
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Not sure I'd call it a basic procedure on an engine without existing timing marks, although it's easy enough. And if it's off, it was off with the factory ECU too. I assume the factory tune accounts for a variance or tolerance in the manufacturing process of the reluctor installation.
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From: Norn Iron
This is not a stock engine, it is not a stock ecu, and it's a setup with issues.
Assume nothing.
And whether the stock engine has timing marks is irrelevant, it IS a very basic first step to check after installing any aftermarket ecu.
If you cannot verify your timing is as you expect and at different rpm's ec, it's pretty much a waste of time even attempting to tune it.
Assume nothing.
And whether the stock engine has timing marks is irrelevant, it IS a very basic first step to check after installing any aftermarket ecu.
If you cannot verify your timing is as you expect and at different rpm's ec, it's pretty much a waste of time even attempting to tune it.
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Verdad Gallardo TECH Regular
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This is not a stock engine, it is not a stock ecu, and it's a setup with issues.
Assume nothing.
And whether the stock engine has timing marks is irrelevant, it IS a very basic first step to check after installing any aftermarket ecu.
If you cannot verify your timing is as you expect and at different rpm's ec, it's pretty much a waste of time even attempting to tune it.
Assume nothing.
And whether the stock engine has timing marks is irrelevant, it IS a very basic first step to check after installing any aftermarket ecu.
If you cannot verify your timing is as you expect and at different rpm's ec, it's pretty much a waste of time even attempting to tune it.
Last edited by SethU; May 12, 2017 at 08:40 PM.
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From: Norn Iron
Oh, I agree. It should be done. It's just not as simple as "put a timing light on it", as if it were an engine with a timing mark and tab. There's more to it, for those that aren't aware. And it's something that should be done even if the factory ECU is being used in a modified engine.
If you can build a 427...then throw a pair of turbos at it...then install a new management system etc etc
If you cannot then add a TDC pointer....something is seriously seriously wrong
There are problems here...never overlook the basics before dreaming up other ideas.
I just took a piece of coat hanger, bent it into a pointer, used one of the front cover bolts to hold it, installed a piston stop (made one) and rotated the engine in both directions, center of both marks is TDC-use timing light and see if it matches what the ECU is seeing-I use a dial back light.
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If you can build a 427...then throw a pair of turbos at it...then install a new management system etc etc
If you cannot then add a TDC pointer....something is seriously seriously wrong
There are problems here...never overlook the basics before dreaming up other ideas.
If you cannot then add a TDC pointer....something is seriously seriously wrong
There are problems here...never overlook the basics before dreaming up other ideas.
That's a valid question, with a fairly simple answer. However, not as simple as...
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If an engine is being dyno tuned, it doesn't matter much. Start conservative and add until gains diminish, pull it back a bit. If the reluctor is off a bit, it doesn't mean much as long as it's affixed in that position and isn't moving. It still measures a degree or portion of a degree just the same.
However, if you want to compare your tune to anyone else's and either one hasn't verified the timing, there's no way to know what is what. Let alone if one is off 6º advanced and the other is off 6º retarded... a 12º discrepancy could be disastrous at worst, and sub-optimum at best, if you're basing your tune on another.
If someone tells you they found that X timing made the most power on the dyno, it's absolute garbage information (even if your build is identical) if they didn't verify the timing... and/or if you don't.
It's very unlikely, that even with timing verified, accounted for, and adjusted for in the software, that it will be bang on perfect. There will always be some tolerance. Whether it's a whole, half, or a tenth of a degree... it won't be perfect and every engine's optimum tune will be unique.
Stevieturbo said it right, about not assuming anything. Well, "anything" is a little too far to take literally, but the point is valid. Especially so, when attempting to diagnose issues.
Last edited by SethU; May 13, 2017 at 01:48 PM.
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From: Norn Iron
Actually it very much does matter.
Whilst modern control systems are great...they can also introduce varying errors if things are wrong.
So it isnt as simple as just saying there's a number 100 in the table, but it seems to run ok so it must be ok.
Ultimately yes the engine doesnt care what numbers you have in your tables...but the absolutely critical part is that the numbers in the table always reliably offer the same outcome at the plug for any numbers entered.
If trigger settings for crank/cam are incorrect, if dwell tables or settings for coils are incorrect....you can end up with widely varying outcomes at the plug, at different rpms, and even during transient rpm changes.
Hence always check timing with a light at various rpms, never just idle. That way any odd behaviour can be noted and corrected where need be
So yes, any individual number on a table doesnt mean so much, but the correlation of those numbers to what happens at the plug is critical.
I learnt the hard way about 16 years ago after adding a MSD CDI4 to a Motec and it cost a few engines !
The car started fine, drove fine, even timing around idle and low rpms seemed ok...but not quite right which at the time we put it down to the multi-spark. But at higher rpms because the MSD was being triggered on the wrong edge...timing varied wildly at high rpm. And on a boosted engine...things go bang in a bad way.
Again at the time I didnt even trust the timing light because what was being seen just seemed too daft as for most part the car drove great
Lesson learnt, and never again.
Again it probably isnt the problem here...but when things seem really strange, go back to basics.
Whilst modern control systems are great...they can also introduce varying errors if things are wrong.
So it isnt as simple as just saying there's a number 100 in the table, but it seems to run ok so it must be ok.
Ultimately yes the engine doesnt care what numbers you have in your tables...but the absolutely critical part is that the numbers in the table always reliably offer the same outcome at the plug for any numbers entered.
If trigger settings for crank/cam are incorrect, if dwell tables or settings for coils are incorrect....you can end up with widely varying outcomes at the plug, at different rpms, and even during transient rpm changes.
Hence always check timing with a light at various rpms, never just idle. That way any odd behaviour can be noted and corrected where need be
So yes, any individual number on a table doesnt mean so much, but the correlation of those numbers to what happens at the plug is critical.
I learnt the hard way about 16 years ago after adding a MSD CDI4 to a Motec and it cost a few engines !
The car started fine, drove fine, even timing around idle and low rpms seemed ok...but not quite right which at the time we put it down to the multi-spark. But at higher rpms because the MSD was being triggered on the wrong edge...timing varied wildly at high rpm. And on a boosted engine...things go bang in a bad way.
Again at the time I didnt even trust the timing light because what was being seen just seemed too daft as for most part the car drove great
Lesson learnt, and never again.
Again it probably isnt the problem here...but when things seem really strange, go back to basics.
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So, lmt0705... where are we at? Whether it's the root of your issue or not, it's something you should verify, that the timing indicated in the software is reasonably close to the actual timing the engine is seeing. It's fairly simple, although can be a bit challenging in tight engine compartments.
