Okay, so I posted earlier about a stumble at mid to high range RPM's and at high boost. Well, I drove my car again today, and guess what? The stumble was gone, it was as smooth as a baby's ***!

The only thing different between today and the last time I drove it is...the temperature was like 40 today, and I filled up a little leaded racing gas.




One thing I started to wonder though, tell me if this sounds plausible. I installed a silencer in my exhaust to control creep. On normal "nice days" my boost only gets to about 12psi(yes I have an ECU!), and I noticed tonight since it was sooo cold it climbed to about 13-14psi.
So here's the thing, I went to all 9's a few weeks ago, what I'm thinking is when it's warmer out, the car doesn't boost as much and the colder plugs aren't working as well.....?

 

it coudl be a number of things, you didn't list your mods. but you plugs just coudl have been loaded up a bit if you were in traffic, etc. This actually happened to me 2 weeks ago. My car always runs great, I haev 9s too. except one day, I gunned it , and same **** happend arounf 5k it started to stumble and buck like a fool. I ran it for a bit, and disappeared and has never returned. I hgad been driving my car in traffic, stopo and go.