I've been running super as I was trying to avoid issues with detonation, and I've noticed that lately I'm starting to get some of the pining under moderate boost loads 7-12 psi.

As this is close to factory pressure, I'm wondering if the gas companies are "watering down" or diluting product to get more revenue? I have noticed this with ARCO so I switched to Chevron, same result, but not as bad.

Anyone else notice this, or maybe I'm having an issue with my car.

 

The sudden knock could be attributed to few things. Gas or mechanical problem.

Try a different gas station, notice any difference. Add some Xyelene ot Tuolene to raise the octane rating..

Meanwhile, perform the followings:
- Check AFR, just in case your car is running lean. (bad injector, bad fuel pump,....)?
- Clean the intercooler. If it's clogged with debris, then it will not function properly. Internally, make sure it's not soaked with oil.
- Is your car burning oil? Oil reduces the octane rating of the fuel.
- Which spark plugs are you running. Would going to a 1 heat colder plug helps..
- Check your TPS. If it's picking malfunctioning, you might pickup the incorrect timing & fuel maps.

 

With updated BOV's, exhausts, turbo's etc. how is anyone able to hear knock over all of that???

I don't think I could.

 

Thanks for the ideas, I'll check those. As far as hearing it, yeah it's hard to hear, but I noticed it when I was going through a tunnel, after you hear it once, you're keenly aware of it.

I'm suspecting the problem is mine, and it's one that fast951 probably mentioned.

 

If it's really bad you'll feel it in the gas pedal.

 

i have been really curious about an earlier post I read, where some rennlisters said if you stay off the boost, you can easily run 87 octane....which makes sense with 8.5:1 compression


And I'll be the first one to say it's completely not worth it just to save a buck or two...but I'm still curious

 

I previously ran the 87 no problem, but it started to get warmer and I do like my boost, so I upgraded to 92. This reduced the issue, but it is still there.