car bogs leaving line

[alleyk]

what could cause this problem

[rabiddawg]

does it bog then catch up?
if so it can be your pump shot.
But without knowing what carb you have its gonna be difficult to diagnose.
also engine specs help too.

[alleyk]

yes it doe's pick up afterwards, the carb is a davinci 750,
engine sm blk 414,with 638 roller cam,brodix heads

[superstreeter]

I imagine, you are running jet extensions in the back, right?

[alleyk]

yes i am,with 88 jets

[superstreeter]

What kind of r.gear, compression, and stall ?

[alleyk]

538 gears,12to1 comp,6000 stall.

[superstreeter]

sounds like pump shot, you got lots of everything else! I kind a have a question to add to this, would a power valve in the back cause this same thing ? or would the jet extensions take care of that,,,I`m not exactly sure where the power valve draws its fuel from.I don`t run one so I have never chased that problem.

[Tod74]

aRE YOU FOOT BRAKING? Cause If you run a trans brake it wouldn't be the pump shot since the throttle is already wide open.

[cepx111]

Good point Tod.
Alleyk, we definetly need to know if your footbraking or leaving off a transbrake to help diagnos this problem better.
To answer superstreets question, the power vavle is supplied fuel from the bowls themselves and yes it can be a problem cars that leave real hard since the fuel in the rear (secoundaries) bowls is trying to climb up the back of the fuel bowls away from the jets and power vavle intake. I've always plugged them anyway to eliminate that possiblity and went up a few jet sizes maybe 4 at the most, not ten like everybody says.
Cp

[alleyk]

tod i do both, only happens when foot braking, i leave on a pro brake at 5400 and thiers no problem,just curious to know why on foot braking i have this problem.

[alleyk]

cepx111 my last reply is for u as well

[davis419b]

Im not sure what fuel you are running but can you deck the throttle while just setting in the pits without the hesitation?

[alleyk]

running c14,when i deck throttle in the pits it doe's hesitate

[davis419b]

I run alcohol and when mine wont deck clean i have to adjust the 4 corner ilde screws to richen it up so it will deck clean, shoudnt be any different with gas!

[hammertime]

I run alcohol and when mine wont deck clean i have to adjust the 4 corner ilde screws to richen it up so it will deck clean, shoudnt be any different with gas!

I agree its likely in the idle screws. A guy that pitted next to me @ norwalk this year had same issues and ended up being the idle screws.

[alleyk]

hey thanks guys i'm going to try adjusting the idle screws ,and see what happens.

[SST4530]

I think I would lean more toward accelerator pump, pump cam, and squirter size. Be sure when foot braking your not using all the pump shot when stalling at the line. also if your not running 50 cc accelerator pump on the front get one.

Don't need it with trans brake, but foot brake it's a must.

[youtellme]

spring on the rear pump is too loose.

[fishman1]

538 gears,12to1 comp,6000 stall.

with only 12/1cr why r u running c14 just curious....r u turning high rpms

as i have 13.5 cr and i use c12 will no issues and timing at 40 degrees total