Tuning the 1.4t Cruze - A Mildly Scientific Approach

[Gh0st]

I zeroed out the 8 cylinder row, no dice, still "knock". Fuel trims are -3%. Weird.

[snowvette]

I bought a set of those "Magic" spark plugs. When I swap them out, I plan on doing before and after logs to see if there is any reduction in light load KR. I still have a little just cursing at a constant 65mph. Just little blips of 1 to 2 degrees.
Annoying.

[Gh0st]

I bought a set of those "Magic" spark plugs. When I swap them out, I plan on doing before and after logs to see if there is any reduction in light load KR. I still have a little just cursing at a constant 65mph. Just little blips of 1 to 2 degrees.
Annoying.

That sounds like what I'm getting too, almost always above 60mph. In regards to those plugs, I've been doing reading and apparently they are good for turbo motors, so they may help.

[snowvette]

Well, I put those plugs in Sunday gapped to .030. I had the stock plugs gapped at .032 and had blow out a few times. I seem to be getting a little more blow out with the new ones. I'll tighten them up a few thou and give that a try.
Mid range throttle response is a lot better. But no reduction in KR just from watching my Dashhawk. Still a couple degrees here and there. If tightening the gap gets rid of the blow out, then they will be a great improvement.

[Blue Angel]

Hey Snow, how much boost are you seeing when blow out becomes a problem?

Also, you guys are tuning automatics, what RPM does the torque converter stall at?

[snowvette]

I'm not sure if its the weather change or what, but I never used to see any higher than 20 psi. Yesterday morning I saw 22 psi twice in 3rd gear.
I dropped the gap down to .025, will see how that works.
I can foot break to about 2500 rpm and that builds a little over 5psi of boost.

[Gh0st]

Haven't logged in ages. Going to start seeing if VVT changes affect the top end power at all. Can't find the plugs anywhere so I haven't tried them yet.

[snowvette]

Autozone was the only place out of four parts stores that had them.

[Gh0st]

Damn this car is so frustrating with the knock. It is ONLY light throttle after cruising. If I hit the throttle "hard", no problem, no knock, nothing. It is like a transient fueling issue where the car starts to lean out and then is really slow to get back when you hit the gas again in a mild manner.

I really want to get rid of this thing and get maybe a Ford Fiesta ST, will never happen because I'm so upside down. Went to a dealership the other day for another car and the best they could offer me was $13.5 . What a joke!

[snowvette]

Holy ****, that's to funny. I did the same thing last week. Tryed to trade it in on a 2009 G8 GT. $13k for mine with 62,000 miles on it.

[Italianjoe1]

Hey Snow, how much boost are you seeing when blow out becomes a problem?

Also, you guys are tuning automatics, what RPM does the torque converter stall at?

Related note, what adjustments must be made to get that stall? Stock stall is only about 1500 on my Sonic 1.4T/6A and it's dead off the line until it builds boost.

Damn this car is so frustrating with the knock. It is ONLY light throttle after cruising. If I hit the throttle "hard", no problem, no knock, nothing. It is like a transient fueling issue where the car starts to lean out and then is really slow to get back when you hit the gas again in a mild manner.

I'm guessing you have the PE enrichment rate set high right? If not try going to max and see if it stops it from having that tiny lean moment.

[Gh0st]

Related note, what adjustments must be made to get that stall? Stock stall is only about 1500 on my Sonic 1.4T/6A and it's dead off the line until it builds boost.



I'm guessing you have the PE enrichment rate set high right? If not try going to max and see if it stops it from having that tiny lean moment.

It's not an issue with PE, there's something else either mechanically or within the tune. The only time I ever get knock is when cruising, which of all places I should not be getting knock. I've been battling this since May of this year, see this post -

http://www.hptuners.com/forum/showth...l=1#post322193

It happens no matter how much timing I add or pull, it is always the same knock retard.

[Gh0st]

I'm not sure if its the weather change or what, but I never used to see any higher than 20 psi. Yesterday morning I saw 22 psi twice in 3rd gear.
I dropped the gap down to .025, will see how that works.
I can foot break to about 2500 rpm and that builds a little over 5psi of boost.

How is it with the gap lowered to .025? Isn't the max GM spec for the plugs .28 anyways?

[snowvette]

.025 fixed it.
I'm not sure of the GM spec.
I ran the stock plugs at .034 and they were ok most of the time. I never tryed stock plugs and being tuned at a smaller gap. Probably should.

[Gh0st]

On stock tune and trying to get all the knock retard out. Three different tunes now, get knock retard on every single one. I'm down 3 degrees from stock in a lot of acceleration cells and I'm running what is supposed to be 93 octane....

[Gh0st]

No knock.

Do you mind posting your tune? I'm ALWAYS getting knock when accelerating.

[Gh0st]

There is no way in hell this isn't false knock.

1. No matter IAT, always knocking.
2. No matter fuel. I have run 91 and 93(even filled up at a different Amoco today).
3. STOCK tune!!!! So now extra boost or requested power.
4. Always while cruising and giving throttle from a cruise.

This is NOT RIGHT!!

[IMG][/IMG]

[ScarabEpic22]

Can you tell if it's burst knock or regular? (I admit Ive just been scanning/monitoring this thread)

Still, especially on premium thats really weird...

[Gh0st]

99% it's not burst knock. Yeah it is really weird, really damn annoying too and the primary reason I want to get rid of the car....sad.

[ScarabEpic22]

Have you put it on a dyno and used some muffs to see if it's actually knocking? Could be an issue with knock sensor sensitivity.