tech

I have a C&L street intake with a 93 octane Predator tune made for the C&L. When accelerating hard above 4k RPMs I hear pinging. I rolled back the timing from 4k-7k roughly 3 degrees (15%) on the predator and it seems to have helped. But, I don't feel that I should have to do this anyway. The gas isn't BP(Amaco) or anything, but is their that big of a difference in the quality of gas?

At one point I re-installed the old air box and stock tune and it still did it. Why does this happen? Should a factory setup experience pinging? I would think this is damaging to the engine.

I was thinking of putting in the HT0 plugs, but not sure if this will resolve the problem. I just don't see why that would be necessary since there are no power adders. Any help would be appreciated.

adnlyn

subscribing

sodaman

well sounds like you could be running too rich for some reason is this in the hot weather by chance? I would try and do some data logging etc, and get the tuner your using as much info as you can, temperature, when it happens, anything you can think of. Hopefully they can help you out.

ski

Also, try different brands of gas, if you've not already done so.

tech

Yeah, I live in Georgia, it's just now beginning to cool off. I logged the IAT coming from the intake and it wasn't outlandish.

You may be right about it running too rich. I'm just curious about how that would cause pinging though? I do notice fast carbon build up on the tailpipes, but can't tell from that if it's actually running rich.

Slofoot

Bad gas! Run Amoco/BP 93 or walk! LOL. Seriously I wouldn't run any other brand. I had detonation with Exxon and Shell but never with Amoco! I'd also stay away from the "Muhammed" owned stations and only buy from corporate owned stations. Sounds like alot of hassle but you can always go back to an 87 octane tune. A rich mixture will cause rough running and perhaps fouled plugs. Too much timing and not enough octane and sometimes excessively high IAT's cause detonation.

Dysan

I really think each car likes different gas. My car hates BP gas but really runs well on Sunoco or Shell.

theedge67

I've had bad experiences with BP myself, I tend to get lower MPG's with it, and just this last tank that I ran the fuel gauge suddenly went to "E" with 1/3 tank left...then slowly went back up over about 15 miles or so. I've had good results with Mobil gas though. They make good oil...why not good gas too?

thump_rrr

In Canada I stick with Petro Canada 94 octane (the only one over 91 octane). In the U.S. I usually go with Exxon/Mobil or BP.

Cali HP addict

+1
Also, once you know you have good fuel, Load your 93 tune and run it for a while. If it starts to ping, back off but keep driving. Slowly push it harder but still back off if it starts to ping. Your computer will actually learn to pull timing on its own and correct its self. If you switch the tune or reload it you will be back at square 1. Do not get excited and dump octaine boost into it. If you do, be ready to buy $100. worth of plugs!

00Vert54X

If the engine program is running rich (and many stock GT's are) it will be picked up by the o2 sensors and the computer will try to lean out the injectors to cut down on the unburned fuel thus causing the detonation.