67Satty
Well-Known Member
I drove out to Barona Dragstrip yesterday to get some runs in. One thing I tried and found out is that running an air cleaner does not slow the car down at all, so from now on I might as well run it all the time. I tried back to back runs and went 7.939 @ 86.193, then put the air cleaner on and went 7.930 @ 86.168.
One weird thing the car has been doing is popping/backfiring in the muffler. I uncork my cutouts at the track but it seems like some unburned fuel is getting back to the muffler and exploding when the car idles and loads up. Going down the track wide open it's fine. It just did it in the staging lanes and return road a few times. So I connected the vacuum advance, thinking maybe that would help ignite all the fuel at idle and it did seem to help but it still did it but just not as much. So I leaned out the idle mixture screws a half turn and that helped more. Weird, it's never done this before.
One weird thing the car has been doing is popping/backfiring in the muffler. I uncork my cutouts at the track but it seems like some unburned fuel is getting back to the muffler and exploding when the car idles and loads up. Going down the track wide open it's fine. It just did it in the staging lanes and return road a few times. So I connected the vacuum advance, thinking maybe that would help ignite all the fuel at idle and it did seem to help but it still did it but just not as much. So I leaned out the idle mixture screws a half turn and that helped more. Weird, it's never done this before.














