At the track tonight, on my last two passes, the truck lost 1.5 MPH from the prior runs, while my buddys (three of them) all remained consistent, so I know it wasn't weather related.

I'm thinking a plug went bad, although there is no miss felt anywhere in the RPM band under all different type of load situations. Just the MPH is suddenly down.

Could I have hurt a plug with no detectible miss fire? Anybody else have performance suddenly drop off yet the truck feels fine?

 

This is what my TR6IX plugs looked like running a ported blower with a 5# lower and 2.8 upper. The TR6IX runs cooler than the regular TR6. I think you need to look at your plugs. TR8IX seems mighty cold to me.

 

I've had the TR8IX's in for about a year now, and no probs before last night. Since my truck seemed a little detonation prone, that's why I went with the cold plug. Never any fouling or rough idle. I am just wondering if my 1.5 MPH drop-off last night was from a plug becoming minorly hurt.

 

Just ordered NGK TR6IX's (2 heat ranges warmer) from Advance Auto Parts because they are $59.00 for the set, and will arrive by 5:00 PM today (Saturday).

 

some trucks are prone to more heat soak then others

especially if you have had detonation issues

when you have detonation you can lose moly in your rings

when you lose moly in your rings you will lose mph after a few runs.



just my 2 cents

 

I hope it isn't anything like the above-mentioned. How bad, and how long would the detonation have to occur for what you said to happen?