We are struggling to figure this out. We have had this issue since the start of the season. Car runs great first few rounds. Saturday for example the car went 9.190 - 9.197 - 9.200 - 9.197 then started falling off 9.215 - 9.230 - 9.263

Sunday the car went 9.158 - 9.158 - 9.203 - 9.277

DA was pretty stable between runs only changing a few hundred all day and this is a methanol setup so it should not affect it this much.

On the majority of the passes the car just stops pulling, I can feel it lay over and struggle to get to its 6800 shift point. Fuel pressure is a steady 7.5# so fuel delivery to the carb does not seem to be an issue.

Float levels are 50% into the glass front and back.

We have checked valve lash and its perfect compared to where we set it a couple months ago. We replaced plugs, wires, checked and cleaned cap and rotor, installed new pick up in distributor, tested MSD and coil with MSD tester. Timing is locked out at 35* Installed new intake gaskets also.

Pump is Magnafuel 500. Front mount fuel cell and all lines, fittings etc. are new at the beginning of the season (-10 from cell to pump and pump to regulator, (2) -8 from regulator to carb).

We are going to try a different carb this week as one of the big changes this season was adding the Alky SV1 from prosystems. Not sure why the carb would be the issue since it runs great the first few passes but we have got to try something. We also disassembled the carb and cleaned it thoroughly just in case there was something floating around in there blocking a passage?

Trans shifts good and the car still 60's great it is generally at the top of second and in third when It lays down.

Anyone have any clues as to what might be happening?