My car is being tuned. A lot of knock appears as boost is increased past 25 PSI. Gas may be the culprit. Can anybody recommend a good source of pump gas in the Oaks/Collegeville/Limerick/Trooper PA area?

 

Before you start thinking it's the gas, your plugs are probably fouled out and need new plugs or the gap is wrong. At least that was my issue. What kind of plugs are you currently using? What kind? Gap? What's the gas octane you're being tuned on?

 

Plugs are the standard NGK Iridiums with stock gap (I think it is 0.026"). Gas is BP 93 octane pump gas.

 

The gas will change with every truck that comes to drop off the new supply. There was a company a few years back that tried to find the best gas and tested multiple stations over multiple weeks. Shell 93 was claimed as the best quality pump gas at that time

 

Close the gap down to .020 -.022. And see if that helps.

 

Thank you. Yes, I will try that. Last time I did a pull a lot of smoke came out of the tailpipe. It was night time, so I could not tell if it was black or white smoke. However, when tuned at lower boost I never saw it.

 

I'm thinking you're getting pre det and closing the gap should help/work