Yeah, I saw you're car, but I didn't get to meet you. You left before we had a chance to talk. Hope to meet you at another meet.

 

so you think you're detonating based on sound only, without an afr measurement?

 

What kind of sound do you hear when an engine "pings"?

 

as has already been mentioned at least two times in this thread, BBs in a can.

 

False

 

Detenation to me sounds like Sand hitting the firewall.. but is different to everyone Just throw a wideband on. Mossy perfornace stock 2005 car was detonating also its not a fluke your the second person ive heard say this. It seems different with every car. Once again i think its CAM Phasing constently adjusting timing..

 

I would bet that somehow your new exhaust is rattling against something, or causing some sort of hamronic resonance.

Also, pinging/detonation usually happens under load, so rev your motor up, and listen for pinging between 2500-4000 rpm.

Good luck,
Frank

 

i just put in 1/2 a tank of Sunoco 100 octane. The other 1/2 is the "93" I purchased this afternoon.

The detonation is now gone.

Likely it's carbon deposits in the combustion chambers increasing my compression ratio.

Does the de-carbonizing service the Nissan dealerprovides work? Is it worth it?

I will try to remove the "suspected" carbon deposits either with the Nissan service, or I will try a couple of Techron treatments, and try to use Chevron with Techron from now on.

We will see if that helps.

I guess the 3" exhaust leaned the A/F just enough to cause the detonation.

Respect
JET

 

odd........ maybe you got bad gas?

 

Could very well be bad gas..... BUT

Here is a link someone just posted of someone with only a 3" JIC exhaust and a TN reflash running lean.

LINK

TN said to take off the exhaust and he will be fine. Soooooo 3" maybe a problem with the TN kit and reflash.

Respect
JET

 

how dirty was your fuel filter...? doubt it would be the cause but just wondering

btw wonder how good that techron is.. anyone ever evaluate if it really works or if its hupla?

 

Porsche evaluated it and said it was good stuff. Porsche issued a Techincal Bulletin about adding 20 ounces of "Techron" to a full gas tank and refilling the tank at half empty with fresh gas. This should then be done 2 additional times. Your are not to use more than 20 ounces of "Techron" within 3000 miles. Then add the "Techron" to every 5th filling of the car.

I will replace my fuel filter... good call.

Respect
JET

 

Rofl that reminds me ill add that to my list of crap to buy tomarrow. I ordered some New NGK sparks also just in case 1 step colder

 

I was gonna stop using chevron Techron gas (92 octane) but i guess ill keep it up......

I have a Raspy sound at and only at boost but I believe its my exhaust screaming for dear life....Im at 10.8/9 AFR and EGT says all is good (850).....

Detonation can be monitored with A/F.....as a lean condition???

I would also guess by that statement EGT would be hot as hell too....

Ive never heard Ping or detonation before so this info is important to me...

 

The Z doesn't have a fuel filter just a littl emesh bag in the fuel tank at the bottom of the fuel pump.

I tried some stuff called Sea Foam on my 300ZX which is great in removing deposits, I put one can in through the brake vacumm hose to clean out from the plenum side and then half a can in the oil and a can in the fuel, the car will smoke for a couple of miles as it burns the deposits.

But on another note I would be surprised that you rZ would have that much build up with only 19k miles.

 

thats what i ment the fuel pump baggy how was it when you pulled it was it dirty??? also yah 19k on a Z is still mint i doubt its carbed up

 

I am pretty sure that detonation causes a DROP in EGT but a rise in Cylinder HeadTemperature (CHT) since during detonation (when the 2 flame fronts meet) the combustion chamber is flooded with heat which conducts into the head.

 

How come nobody threw out the possibility of a fouled plug? His AFR is EXTREMEMLY rich, off the chart rich. He could have fouled a plug and what he is hearing is a misfire. Though, be it a misfire or knock, you would think he would be throwing a code.

 

Completely off-topic.....but Jetpilot, whereabouts on the "Treasure Coast".....I live in Stuart and work in PSL and would love to see a Turbonetics set-up.

 

+1 He was very RICH to start, never even got near 11's. I have a hard time believing that the exhaust alone changed his AFR so much as to cause it to ping like that.
I would put a AFR gauge in immediately. I seriously don't know how you could drive around this long without it.