back in the spring when the weather was good, i could run 13.50's all day long. i went a few weeks without racing and then ran 13.60's. then i went a few weeks more and couldn't get it out of the 13.80's and 90's. i just attributed that to the warm weather and humidity. then it cooled down again but still13.80. i put headers on it and gutted the converters and got a few 13.47 passes. if i could find where i was loosing 3 tenths i could be in the 13.10's. any ideas on where to start. the car runs good though it has 103 passes on it now. not that many miles and i havent hurt it any.

 

there are alot of things that can raise your time .1 or .2. The weather, plugs getting more wear, traction is probably the biggest. You could have spun the tires just a slight bit more and not even really realized it, but you'll see it in the times. Now if you lose something like a second then i'd be worried.

did you ever try changing tire pressure up or down on the other nights to see if you could get back down to your original times?

 

i replaced the plugs when i did the headers. ive been running 21 psi in the back tires at the track and run 1.87 to 1.90 60' times. the car doesn't spin

 

you can have differances in your et,since it is depended on traction, shift points, etc. look at your m.p.h., did that change? if the m.p.h. got lower, then i would be concerned, because the engine lost power somewhere, or the weather had something to do with it.