Bog at the line

I´m runnig 3.92 because of the low profile tires (rules are for 225/50-15 DOT aproved tires max). I used to run a 27" tire with a 4.56 and the engine is in the same rpm (6800-7000 at the line).

About my secondary metering block, you guys opened my eys to something I wasn´t thinking: I use that old trick of not using a secondary power valve to have a bigger bowl and also make gas go by the jets and the PVCR...these ones are higher in level with the jets...may be that. This week I´ll close them, add a litlle more jets and add extensions.

Thank you all. As soon as I get to the strip and drop .2" of my ET I´ll post here!!

I had the same problem. As I tweaked my suspension and started getting more and more traction, my bog began to get worse and worse.

Turned out is was the primary bowl vent. The harder I hit, the more fuel would slosh rearward and into the carb.

I've got a Holley 4160. I added an extension tube to raise the vent level and no more bog.

But I also suspect I'm probably uncovering the secondary jets as well. I plan to upgrade to a 4150 so I can add the extensions.

My vote goes to the squirters.

People tend to overlook them, but I've found nearly a full TENTH on just my 60' time by trying different sizes.

Your datalogger has already told you it is going lean, so it seems pretty obvious you need to go up several sizes.

Lee

The bog is dead!!!!

Sorry it took so long to answer here guys, but due to weather we couldn´t test it sooner than this weekend, at a national event.

My first step was to enlarge the skirters, wat didn´t make any difference.
Then I swapped main bodies, from an 850DP to a 750. By this time the car picked up 3mph and a tenth, but still with the bog.

I messed a little more with the squirter cams and then took off a 1" tapered spacer I used to run....no more bog! Simple as that, by the next run .3secs shaved. I couldn´t believe it.

I also shaved about 80pounds of the car and the total gain for the weekend was .5s to the best ever 11.351s@119mph!

Just to remind you this is a 302 bored .040 with stock iron heads! Who would tell a 1" spacer could make that much of a (bad) difference?

Thanks all for the help.