Tuning the Phoenyx....

[Phoenyx]

All:

Ok, I've begun the tuning process. My goal is to get rid of knock or at least lower it to the point where knock is not threatening (I know knock isn't good period, but..).

From initial tuning, I'm running extremely lean! I don't know why Vishnu leaned out the SAFC so much, but I'm getting enormous knock (upwards of 30+) during the hotspot 5800rpms. My O2 is reading .88 during that range. I am richening up the SAFC slowly and the timing is getting better (ECU retarded back the timing to below 11.0).

Here's what the graph looks like currently:

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Any comments or suggestions are welcome!

-M

 

[OMN_DSM]

Give it some fuel! Why did they tune it that lean?

 

[Phoenyx]

Originally posted by OMN_DSM
Give it some fuel! Why did they tune it that lean?

I'm not sure why. According to the graph though, it looks about right:

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I'm going to shoot for 0.94 at 17psi. Hoping to get some really good power at that airflow. Hopefully I can get rid of the knock totally and even advance some of the timing on the upper rpms.

-M

 

[OMN_DSM]

Just for assurance pull one of your spark plugs and see how it looks(white for lean) to make sure you are running lean. Try tuning to get your logger happy with the settings and see how it feels on the butt dyno. I will almost garantee that it will feel much better, cause with a log like that you are losing some serios horsepower.

Mike

 

[Phoenyx]

Originally posted by OMN_DSM
Just for assurance pull one of your spark plugs and see how it looks(white for lean) to make sure you are running lean. Try tuning to get your logger happy with the settings and see how it feels on the butt dyno. I will almost garantee that it will feel much better, cause with a log like that you are losing some serios horsepower.

Mike

Yea, will do. Just with that run (the 2 previous runs were worse), I could feel the difference in power. The car pulled with no hesitations on that log and the previous ones would hesitate a lot.

-M

 

[Phoenyx]

All:

Well, I can't believe how much of a difference cool weather can do. I am on the brink of maxing out my injectors! My boost goes to 13psi and creeps to about 15psi from this run. Any more boost and I'll knock like crazy. This is interesting but the car pulls much better and is very happy! What I can't understand is how they were leaning out the mixture when I've got a maximum of about +10% at 7krpms!!! From 3k - 7k the range is between +3% to +10%. I am starting to feel that a dyno tune isn't representative of a realworld scenario. On the dyno, the ambient air is so high that boost is tamed and one is less prone to running lean. However, outside where the air is hitting the intercooler and able to allow more volume of air to enter the engine it is more likely that one could run lean...

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Comments?

Btw, I richened up the upper rpms after that run since 0.86 is way too lean. And maximum Karmen was 1958Hz.

-M

 

[kpt4321]

Are you still on 450's?

I told you thoe SAFC settings were whacked.

If you're still on 450's, +10% would make perfect sense for a 1g. However, with IDC's less than 90%, you have a little room to spare. I say you turn the boost level up to about where it's creeping to, no sense in running it at a lower level down low where you have more fuel to spare anyway.

Have you tested for boost leaks at all yet?

 

[Phoenyx]

Originally posted by kpt4321
Are you still on 450's?

I told you thoe SAFC settings were whacked.

If you're still on 450's, +10% would make perfect sense for a 1g. However, with IDC's less than 90%, you have a little room to spare. I say you turn the boost level up to about where it's creeping to, no sense in running it at a lower level down low where you have more fuel to spare anyway.

Have you tested for boost leaks at all yet?

Yes, I still have 450s.

Well, I may advance the timing a bit during those lower rpms which should give me a tad more boost.

I haven't tested for boost leaks yet although I seriously doubt that I have any...

-M

 

[kpt4321]

Originally posted by Phoenyx


Yes, I still have 450s.

With 450's and a hacked 1g MAF, you will need to go into the positive corrections to eliminate knock. However, this brings you closer to fuel cut and retards the timing, which is why bigger injectors are so important.

Originally posted by Phoenyx

Well, I may advance the timing a bit during those lower rpms which should give me a tad more boost.

I'd like to hear the reasoning behind this. First of all, if you are getting knock, or are around the threshold of knock, then advancing the timing will just make the knock worse, and you will end up with less overall timing advance than you started with.

Also, with the boost controller set at a certain level, you probably won't be able to effect it much by advancing the timing. If anything, advancing the timing will decrease your boost. Retarding the timing, on the other hand, give the exhaust more energy because combustion takes place later in the cycle, and hence boost will go up.

Originally posted by Phoenyx

I haven't tested for boost leaks yet although I seriously doubt that I have any...

-M

WHY do you "seriously doubt" you have any? EVERY stock-ish car that I have EVER seen has had boost leaks. I test my car religiously, and I very often find leaks that weren't there three weeks before. There is no reason why your car wouldn't be the same, especially if it has never been tested.

It's not hard to build a tester.

 

[Phoenyx]

Yes, I'll be getting bigger injectors in the near future. Right now, I'll settle with what I have which is just boost and exhaust.

I'd like to hear the reasoning behind this. First of all, if you are getting knock, or are around the threshold of knock, then advancing the timing will just make the knock worse, and you will end up with less overall timing advance than you started with.

Also, with the boost controller set at a certain level, you probably won't be able to effect it much by advancing the timing. If anything, advancing the timing will decrease your boost. Retarding the timing, on the other hand, give the exhaust more energy because combustion takes place later in the cycle, and hence boost will go up.

I disagree here. Yes, I'm going to enrichen the fuel some more to eliminate the knock. However, I think that advancing timing makes boost pressure rise if the boost is set to a certain psi (i.e. if I know I'm bleeding off a certain psi). My boost would peg at 17psi which it was set to, but because the dyno tune place leaned out my AFC instead of enrichening it, and my base timing was already advanced 3 degrees, it would hold and knock like crazy. Leaving the boost controller exactly where they it was and enrichening the fuel did two things: 1) Started to bleed the boost back (due to timing being retard now and more fuel) and 2) started to eliminate knock.

I seriously doubt I have any leaks because there is no indication that I have one and it is easy to spot under my engine bay:

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Hehehehe

-M

 

[Blk_99gst]

Um, just because you have a clean engine bay does NOT mean you can't have boost leaks and not know about it. We're talking about boost leaks on the compressor side, not the exhaust side. Yes on the exhaust side you would see them; burned spots or plastic or whatever due to the hot exhaust gases. But you are just compressing air on the compressor side. If you had even a bit leak, it wouldn't show it; it wouldn't leave any residue or any big signs. You might be able to hear a big enough leak. Otherwise, just pressure test it and you will probably have some, may be minor but could be still there.

 

[Phoenyx]

Originally posted by Blk_99gst
Um, just because you have a clean engine bay does NOT mean you can't have boost leaks and not know about it. We're talking about boost leaks on the compressor side, not the exhaust side. Yes on the exhaust side you would see them; burned spots or plastic or whatever due to the hot exhaust gases. But you are just compressing air on the compressor side. If you had even a bit leak, it wouldn't show it; it wouldn't leave any residue or any big signs. You might be able to hear a big enough leak. Otherwise, just pressure test it and you will probably have some, may be minor but could be still there.

True. The next time I take it to the shop, I'll get a leak test (which won't be anytime soon). Better to assume I have none than to assume I do. As it is, the car is struggling with so much airflow right now. I logged 1958Hz at 15psi tonight - sheesh

Come to think of it some more, if there were a boost leak on the compressor side to intake manifold (meaning anything from the turbo through the intercooler to the intake), the car wouldn't idle right since the MAF would be giving the computer a reading for measured airflow but the intake manifold wouldn't be getting that air.

Nevertheless that is on my *todo* list!

-M

 

[kpt4321]

Originally posted by Phoenyx

I disagree here. Yes, I'm going to enrichen the fuel some more to eliminate the knock. However, I think that advancing timing makes boost pressure rise if the boost is set to a certain psi (i.e. if I know I'm bleeding off a certain psi). My boost would peg at 17psi which it was set to, but because the dyno tune place leaned out my AFC instead of enrichening it, and my base timing was already advanced 3 degrees, it would hold and knock like crazy. Leaving the boost controller exactly where they it was and enrichening the fuel did two things: 1) Started to bleed the boost back (due to timing being retard now and more fuel) and 2) started to eliminate knock.

You just proved my point. When you richened up the SAFC, you brought the knock down, and the timing advance increased. The boost also went down.

Like I said, if you have more retard, the combustion takes place later in the motor's rotation, and hence the exhaust gases have more energy when they hit the turbine blades. I would like to hear some scientific reasoning behind why timing advance would make boost go up.

Just build your own damned pressure tester. You need like 15 bucks of home depot parts, and a bike pump. Ask any fast DSM'er, and they will tell you that it is crucial to pressure test.

And, assuming that you are *not* leaking is NOT the right way to think about it. That's like "assume that you don't have a fuel leak, until your car lights on fire." The odds are that you are leaking boost, so why deny it?

Also, yes, a boost/vacuum leak would effect the A/F mixture at idle. However, with a hacked MAF it's already whacked anyway, so you won't notice much of a difference.

 

[autronicDSM]

You could leak only when pipes are pressurized too. Timing won't change your boost level. If it's manual then it will bleed same amount of air no matter how much timing.

Now...I remember your thread that timing was way too advanced. Where do you see that? From the first log you barely break 10 degrees. That's pretty low. I would advise that you 1) do pressure leak test 2) turn down your boost until you get bigger injectors.

 

[Phoenyx]

Originally posted by autronicDSM
You could leak only when pipes are pressurized too. Timing won't change your boost level. If it's manual then it will bleed same amount of air no matter how much timing.

Now...I remember your thread that timing was way too advanced. Where do you see that? From the first log you barely break 10 degrees. That's pretty low. I would advise that you 1) do pressure leak test 2) turn down your boost until you get bigger injectors.

Yeap, you are both right. Sorry for the misunderstanding. As it turns out (once I got the datalogger), I was running lean afterall. We are still trying to figure out why Vishnu had such lean settings on the SAFC-II.

Thanks for the suggestions..

-M