High RPM Detonation?

Yesterday at the SCCA Event as I was riding along with my co-driver I noted the car sounded like it was detonating at high RPMS?? We had put super in it the day before.

It was a bit toasty yesterday and the turnaround time between drivers was quick. Not sure if that playing into the noises I was hearing. I know my co-driver was not being timid with the gas at this event. The temp gauge never moved.

Thoughts or suggestions??

I'm also thinking of switching the car over to E85 like my pal OZMDD would that help?? ;)

Check your timing.

PS
We all know you suck at reading the flywheel gauge. ;)

Quote:

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Originally Posted by sammm

Check your timing.

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I'll double check it but it has been set since I resurrected the car.

Quote:

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Originally Posted by sammm

PS
We all know you suck at reading the flywheel gauge. ;)

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An that is why I haven't touched it since we last figured out how to set it! :punchout:

I'm assuming the Super was 93 octane. I don't think a timing bump would cause detonation with 93 octane. When is the last time you cleaned your pistons? Maybe Seafoam would help.

It was 93 but like I mentioned I haven't adjusted anything on the car in recent history since I am a huge fan of the "If it works don't fvck with it" program.

It is about due for sparkplugs . But it has run on several other porly designed Jimmy Jan courses when I was up in the high RPMS for longer than my co-driver was yesterday and I never noted the detonation..... :confused:

I'd try Seafoam + a new fuel filter.

Cheater motor!! Didn't I mention the 15:1 pistons when I sold it to you?

Quote:

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Originally Posted by Mark52

Cheater motor!! Didn't I mention the 15:1 pistons when I sold it to you?

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I'm just glad I bought the extended warranty! ::Daisy::

protest

Banana in the tail pipe? ::BaHump::

Would this be a spark plug heat range issue perhaps??

Not that I know anything about spark plug heat ranges.... ::Clown::

http://www.ngksparkplugs.com/tech_su...2.asp?mode=nml

I have some electronic detonation headphones/amplifier if you want to borrow them short-term. You clip it on to the block and have a listen, you'll be surprised with what you hear. email me if you're interested.

mr. brg I don't think I'm skilled enough to know what your very cool electronic detonator headphones/amplifer would tell me.... But I greatly appreciate the offer.

First off I'm going try a few simple things I just got from Rockauto.com

https://lh5.googleusercontent.com/-V...0/IMAG0047.jpg

lol

You take the big aligator clippy, clip it to something on the block, flip the power button to "on", plug in your headphones, and listen for detonation.

They do a really good job of broadcasting combustion irregularities. The provide enough resolution that I managed to tune spark on a dyno that did not read output that day (bad dyno firmware) remarkably close to an "expert tune". We're talking so close that I did not go back and alter the table I made.

Well old plugs all looked exactly the same and didn't find any surprises when I changed the plugs and wires.

I'd classify them as normal based on this chart - http://www.ngksparkplugs.com/tech_su...qs/faqread.asp



No telling how old the fuel filter was but I can tell you when you are hot and sweaty and the gas runs down your arm into your armpit it creates a sensation that could be best classified as "undesirable"..... ::Rant::