2015 ZL1 knock? Conclusion @ 4/27/15 - Page 24 - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Nor Cal ZL1 · 04-28-2015, 09:49 PM

I should have noted the document was to illustrate how cars fuel trims were different depending on the brand.

white ZL1 · 04-28-2015, 10:10 PM

Can I get you to use the attached config file and get 10-15 minutes of data?
Normal driving, and then if you can roll into it and go WOT in 2nd or 3rd gear (whatever is safer or wherever you can get usable data), I'd love to take a look at it.

Balasarius · 04-29-2015, 11:29 AM

Quote:

Originally Posted by ZO6 Bryan

You all do realize that that document is old? That is not the "no tune" Roto fab that was designed for the ZL1. It was the original Roto fab that was designed for the SS.

Everything on the internet should have a date.

Everything.

angryBits · 04-29-2015, 01:33 PM

Quote:

Originally Posted by Balasarius

Everything on the internet should have a date.

Everything.

+1

And free ice cream.

angryBits · 04-29-2015, 01:39 PM

Quote:

Originally Posted by white ZL1

Can I get you to use the attached config file and get 10-15 minutes of data?
Normal driving, and then if you can roll into it and go WOT in 2nd or 3rd gear (whatever is safer or wherever you can get usable data), I'd love to take a look at it.

Yes you can! I appreciate your help.
I probably won't be able to do it until this weekend though.

Just to make sure, do you want the log to include the 10-15 minutes, or just warm the car up for 10-15 with normal driving and then start scanning while doing the 2nd/3rd roll-into-WOTs?

I can say from my own experimenting that rolling into it helps in some cases, but if I keep the throttle down for more than a few seconds, it does end up knocking audibly in the 5 deg range.

In any case, I'll get you a log so you can take a look.

white ZL1 · 04-29-2015, 02:34 PM

Quote:

Originally Posted by angryBits

Yes you can! I appreciate your help.
I probably won't be able to do it until this weekend though.

Just to make sure, do you want the log to include the 10-15 minutes, or just warm the car up for 10-15 with normal driving and then start scanning while doing the 2nd/3rd roll-into-WOTs?

I can say from my own experimenting that rolling into it helps in some cases, but if I keep the throttle down for more than a few seconds, it does end up knocking audibly in the 5 deg range.

In any case, I'll get you a log so you can take a look.

Get it up to temp, then 10-15 minutes of varied throttle and driving. Get some WOT if you can, but by all means if the knock is audible don't hurt the car.

angryBits · 04-29-2015, 04:04 PM

Quote:

Originally Posted by white ZL1

Get it up to temp, then 10-15 minutes of varied throttle and driving. Get some WOT if you can, but by all means if the knock is audible don't hurt the car.

I don't think just because it's audible that it's "bad". I'm capable of hearing audible knock at 2 degrees of KR (I have dog ears).

At what point do you think I begin compounding damage that will affect the longevity or power-upgradability of the car? A 5 degree KR, or 10 degree?

In the 6 weeks I've owned the car:
It was babied during break-in, or run with race gas most of the time -- other than some tests, the car has been driven nicely (to avoid damage).

(Guessing)
Maybe a dozen times have I hit a KR 4-6 degrees during WOT.
Maybe 3-5 times have I hit a KR in the 8-10 degrees during WOT.

Do you guys think my engine is toast already or do you think it's mostly unaffected and should take power-mods fine without worry once I resolve this issue?

Six.Two SC · 04-29-2015, 04:10 PM

Quote:

Originally Posted by angryBits

I don't think just because it's audible that it's "bad". I'm capable of hearing audible knock at 2 degrees of KR (I have dog ears).

At what point do you think I begin compounding damage that will affect the longevity or power-upgradability of the car? A 5 degree KR, or 10 degree?

In the 6 weeks I've owned the car:
It was babied during break-in, or run with race gas most of the time -- other than some tests, the car has been driven nicely (to avoid damage).

(Guessing)
Maybe a dozen times have I hit a KR 4-6 degrees during WOT.
Maybe 3-5 times have I hit a KR in the 8-10 degrees during WOT.

Do you guys think my engine is toast already or do you think it's mostly unaffected and should take power-mods fine without worry once I resolve this issue?

The fact you didn't throw any codes, it couldn't be THAT bad??

angryBits · 04-29-2015, 05:20 PM

Quote:

Originally Posted by Six.Two SC

The fact you didn't throw any codes, it couldn't be THAT bad??

I'm not so sure. I was told that this car will not throw a code unless it feels it can't deal with it. Supposedly that's a KR greater than 20 degrees.

I imagine getting KR-20 repeatedly while at high rpm and load would cause long term harm. Or maybe the pistons can take it? I donno. Maybe it's all not as bad as I was raised to believe.

I'd love an opinion from an expert.

EDIT: maybe 20 degrees is the threshold because they felt the engine could handle occasional KR up to 20 without damage. That would be good news for me.

Six.Two SC · 04-29-2015, 07:40 PM

Just saw 8.7 degrees right now. 91 octane. Geez!

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angryBits · 04-29-2015, 08:10 PM

Quote:

Originally Posted by Six.Two SC

Just saw 8.7 degrees right now. 91 octane. Geez!

Sent from my iPhone using Tapatalk

Yep. Let me guess, you went WOT in 3rd gear at 2k rpm? That one always does it for me.

Did you hear a ping? If you're not listening for it, it's easy to miss.

Six.Two SC · 04-29-2015, 08:14 PM

Quote:

Originally Posted by angryBits

Yep. Let me guess, you went WOT in 3rd gear at 2k rpm? That one always does it for me.

Did you hear a ping? If you're not listening for it, it's easy to miss.

It was either 2nd or 3rd gear. Wasn't listening for pinging. My exhaust has the fuse pulled so it's pretty loud at WOT. I really don't think there's anything wrong with our cars, just not tuned for 91 octane.

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angryBits · 04-29-2015, 08:18 PM

Quote:

Originally Posted by Six.Two SC

It was either 2nd or 3rd gear. Wasn't listening for pinging. My exhaust has the fuse pulled so it's pretty loud at WOT. I really don't think there's anything wrong with our cars, just not tuned for 91 octane.

Sent from my iPhone using Tapatalk

Yeah me too.

white ZL1 · 04-29-2015, 09:14 PM

But weren't you having the same issues with your race/pump gas mix?
If so, its not an issue of 91 octane.

Even with 91 octane, the car is fully capable of adjusting between the high and low octane timing maps.
And I'll say again, I've got plenty of datalogs on my car when it was stock and there is 0 knock retard. None.
And "lugging" the engine at WOT isn't a great idea either.

04-28-2015, 10:10 PM	#324
white ZL1 Drives: none Join Date: Aug 2011 Location: DFW area Posts: 1,844	Can I get you to use the attached config file and get 10-15 minutes of data? Normal driving, and then if you can roll into it and go WOT in 2nd or 3rd gear (whatever is safer or wherever you can get usable data), I'd love to take a look at it. Last edited by white ZL1; 05-03-2015 at 11:44 AM.

04-29-2015, 07:40 PM	#332
Six.Two SC Drives: 2018 Summit White Camaro 1SS Join Date: Mar 2014 Location: Pasadena, CA Posts: 352	Just saw 8.7 degrees right now. 91 octane. Geez! Sent from my iPhone using Tapatalk __________________ '18 Satin White Vinyl Wrapped 1SS, 6MT, Low Gloss Black Wheels, NPP Dual Mode Exhaust Added: Diode Dynamics Black LED Sidemarkers, GM Dark Finish Tailights, GM ZL1 Black 3rd Brake Light, Black Plastidipped Bowties(front/rear), AFE Dry Drop In Filter, 12mm Spacers(front/rear)

04-28-2015, 09:49 PM	#323
Nor Cal ZL1 Drives: 2013 ZL1 M6 Join Date: Oct 2013 Location: Nor Cal Posts: 1,825	I should have noted the document was to illustrate how cars fuel trims were different depending on the brand.

04-29-2015, 09:14 PM	#336
white ZL1 Drives: none Join Date: Aug 2011 Location: DFW area Posts: 1,844	But weren't you having the same issues with your race/pump gas mix? If so, its not an issue of 91 octane. Even with 91 octane, the car is fully capable of adjusting between the high and low octane timing maps. And I'll say again, I've got plenty of datalogs on my car when it was stock and there is 0 knock retard. None. And "lugging" the engine at WOT isn't a great idea either.