Masochist

iTrader: (1)

I purchased an '05 C6 from Illinois that has a Torquer V2 cam, full bolt-ons and a dyno tune on Illinois gas which I believe is 93 octane.

After driving it back to Oregon where we have 92 and what many describe as "crappy" gas I've noticed what sounds like knocking under harder acceleration. The elevation difference is minimal(~100ft) and the car feels strong.


Could the tune and the difference in gas create a knock condition by itself?

gametech

iTrader: (1)

The tune and different gas could absolutely cause knock. The good news is that N/A the LS style motors generally make the most power before they start knocking. This means you may be able to lower your timing without losing ANY power. The bad news is your motor probably has a hack job of a tune in it anyway.

Masochist

iTrader: (1)

So the quality of the tune is called into question here? When it was tuned it made good power (430whp~ on a Mustang dyno)

Now this is a question I was hoping to not have to ask but since it's coming to this... is there any way to interface with the pcm without a laptop to upload a tune?

a05c

For an N/A car I wouldn't be too concerned, but for a turbo, blower or nitrous car I'd definitely be scanning it while driving and seeing how much/if any knock is being picked up.

If you want some piece of mind, see if anyone local to you can scan it while you're out driving.

gametech

iTrader: (1)

The tune is of unknown quality at this point, but the fact that minor gasoline quality variations are causing audible knock is worrisome. Some tuners will just bump up your spark advance until it knocks, then back it off a degree or two and call it a day. Other changes are also sometimes made that lower your safety margins considerably in order to get a good dyno number. Most people would not want to pay for the real amount of work and time it takes to nail down a really good tune, so most dyno tunes aren't all that. As for an interface to the computer without a laptop, that is a no-go. Some tuning software allows their interface to load preprogrammed tunes without being hooked to the computer in the car, but the tune still has to be loaded into the interface with a computer.

ctd

iTrader: (1)

With my C6 LS2 while tuning on the dyno the knock became very frustrating. I had read on the HP Tuning forum how a simple change to TR6 plugs would correct the issue.

Plugs are cheap so I thought what the hell lets give it a go. It was that simple

Darth_V8r

iTrader: (4)

That's a good post. Lots of people forget to go to a lower heat range plug when they do cam swap. TR6 plug might be just the trick!

Masochist

iTrader: (1)

I will definitely keep that in mind.

Will an Android app like Torque Pro with a bluetooth obd2 connection be able to tell me if the engine is knocking?

foxsl

iTrader: (1)

Let us know how it goes with the tr6 plugs. In all fairness to the tuner, it could have been tuned with absolutely no knock as the dyno usually has large fans and is usually much cooler than a hot open road. Once you sit in traffic for a bit and/or experience hotter conditions, certainly then would you see knock when giving a fair bit of throttle.
To absolutely never see knock, the tuner would have to give you a very conservative tune or make sure you run non pump gas.

brobinson216

iTrader: (11)

Run AC plugs on the corvette, NGK plugs can and will cause voltage drop issues. Do a little google search on "Service Charging System", this can lend some helpful insight.

gametech

iTrader: (1)

If your NGK plugs caused a voltage drop issue, you have a poor understanding of the word "cause". There would absolutely have to be an underlying electrical issue for any sparkplug change to coincide with a charging system problem.

brobinson216

iTrader: (11)

Guessing their confused as well? For your education purposes only!

gametech

iTrader: (1)

Of course they aren't confused. They are trying to BS gullible customers into believing a legitimate warranty issue is caused by some fictional sparkplug with "pulse technology". This type of claim denial and blame shifting nonsense is way too common.

brobinson216

iTrader: (11)

I've had the issue happen twice on Corvette's only. Changing back to the AC Iridium plugs cured both. My 08 had 18k when I swapped to NGK TR55 after H/C/I.

The service charging system began immediately after the startup drive. Figured it would go away after all was dialed in. Never could understand the voltage drop or determine where the issue was coming from. Found some threads where many had the same issue, problem solution was swapping to AC Iridiums.

Put my stock AC's back in, problem never presented itself again.

Second occurrence was with my 21k 06 C/I, noticed on the drive home in August 2015 the "Service Charging System" display came up. I thought wonder if the plugs are NGK? Made it home pulled #1 and NGK it was. Swapped the next day to AC and have never seen the message or voltage fluctuation again.

Coincidence?

Masochist

iTrader: (1)

Confirmed that the car is running NGK TR6 plugs.

This must be proof that the west coast is running the equivalent of water for gas as compared to the east. Ontop of that, what was described in this thread is likely how the car was tuned... advance the timing 'till she knocks, dial it back a bit and done. I added an octane booster and the knocking stopped.

Seems like the only solution is to get her to a tuner and knock the problem out once and for all or keep running octane booster forever lol.

gametech

iTrader: (1)

Tuning for yourself would be ideal, but any good tuner should be able to get you REAL useable street power (not dyno numbers) without engine damaging knock. BTW, anywhere west of San Antonio has shitty pump gas. I once drove my Whipple charged work truck to El Paso, and I had to back the timing down as soon as I filled up with western gas-like swill.