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View Full Version : LOG - Stock 1.4t Cruze KNOCKING horribly on 93 octane



Boost
March 19th, 2012, 03:38 PM
In this log, I was driving my stock Cruze 1.4t with a tank full of 93 octane Mobil premium fuel. This car is very low mileage and automatic. I had such horrible audible pinging with over 12 degrees of KR at part throttle low RPM, that I suspect the fuel quality was absolutely horrible. It also happened right after many minutes stuck in traffic so it got a very good opportunity to heat soak the IC, in 85 degree afternoon temps. Please look and comment if you can.

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Boost
March 19th, 2012, 04:11 PM
1280012801

You can see that around frame 2722 the horror starts. What gives? :(

GMPX
March 19th, 2012, 04:33 PM
12 degrees, you win, we thought what we were seeing on the E39 logs (http://forum.efilive.com/showthread.php?18396-E39-GMH-3-0-SIDI-91-vs-98-Octane&p=166254&viewfull=1#post166254) was bad.
Have you tried reading the TCM? Should be a T76.

Boost
March 19th, 2012, 11:01 PM
12 degrees, you win, we thought what we were seeing on the E39 logs (http://forum.efilive.com/showthread.php?18396-E39-GMH-3-0-SIDI-91-vs-98-Octane&p=166254&viewfull=1#post166254) was bad.
Have you tried reading the TCM? Should be a T76.

:( :( yeah, it sounded very bad. The car is bone stock!!! :nixweiss: I will try to read the T76, if the process can't hurt anything, it's a daily driver. I guess it had to be bad fuel??

Gimpster
March 23rd, 2012, 04:40 PM
I've had audible knock on my 1.4T Sonic before, but only with really crappy gas.

GMPX
June 9th, 2012, 07:52 PM
I'm currently running E10 in our Cruze, I've yet to see over 1 degree of knock! However, I have removed around 3 degrees of timing from the stock tune and the air here at the moment is quite cold. Can't wait to get it running on E85, all the bits should be here next week to convert it over. :grin:

If you look at the log below (with E10 fuel), although it was just an easy drive to the shops, there was zero knock, that is pretty rare on a Cruze, more so when they are stock.

http://download.efilive.com/Staff/GMPX/CruzeLog.png

Boost
June 10th, 2012, 08:48 AM
Nice! Is E10 10% ethanol and 90% gasoline? In that case that is almost like what I was running. (All our gas stations here are "up to 10% ethanol). Another note, on my performance tunes I see very little knock also. This was bone stock and since I have also switched to Chevron which I think is the best fuel we have here. Many say the Mobil 93 I was running before is low quality. Although there are varying opinions about fuel quality, and some think it's all the same. I married a gas station expert that begs to differ. So far, no trouble with Chevron 93.

Thanks for sharing mate! Are those the PIDs you usually monitor on yours?

GMPX
June 10th, 2012, 10:34 AM
The PID's I have been working on, they are new ones we've been adding in.

Boost
June 10th, 2012, 10:47 AM
Sweet!!!

VTuner
June 29th, 2012, 04:56 AM
90F day today, 120F intake air temps logged, zero degrees knock retard :mrgreen: The joys of methanol/water injection!
This is the stock calibration, but I have a larger turbo installed so a bit higher boost at the top end then you would normally see.

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Boost
July 1st, 2012, 10:55 AM
That's really sweet Brian! How does it feel / pull? :grd:

VTuner
July 1st, 2012, 07:38 PM
It pulls smooth and I do not detect any bogging down with the meth/water yet. I just increased the jets today to see how much fluid it likes before it starts bogging down. The real performance will come later after increasing boost and timing and adjusting the fueling.

Boost
July 2nd, 2012, 11:33 AM
My vote for 1st 300 hp Cruzey!