Bog And Backfire with 950 Street HP

[splicer]

Hi Guys:

I know this has been covered numerous times but I'm hoping one of you has a setup similiar to mine...
Last year I ran an 870 Street Avenger and had no issues but car wasn't giving me drag strip times that it should...0 to 60 times good at 1.66 seconds
but was going a bit flat beyond 3000 rpm to end up at 11.86/113mph..
Felt a bit strangled...
Now I have a 950 Street Hp on the engine and it works much stronger except for one little problem... mash the throttle from idle in gear and it hesitates badly,backfires, then goes like mad all the way thru the gears...
Some Background: 64 Polara, 3700 lbs, 3.73 gears, 727 with 2600 stall..
Engine is 505 stroker, Eddy heads, 10.5 CR, Comp Cams flat hydraulic with .494 lift, Eddy Torker 440 intake with 1" spacer on top
Timing is 13 Deg initial with 38 Deg total...all in at 3000...

I've set the carb up to make sure both accelerator pumps are working properly and even tried a 50cc pump on the front. It actually seems worse with the big pump...

Maybe too much pump shot????
Any of you solved a similiar problem ???

Thanks,
Splicer

 

[IQ52]

You may have answered your own question, try different pump squirter sizes. Go bigger first, its safer. If it slows up, use a smaller squirter. Also the cam may want more initial timing. Hold the total timing at 38 but increase the initial to 15-16 degrees and see what happens.

 

[70rr-brian]

2600 stall for that kind of power? Maybe your secondaries are not closing all the way or coming in too soon.

 

[Meep-Meep]

If I had this problem at or near sea level my guess would be too much carb (CFM). What is your elevation?

 

[splicer]

1) 950 Street HP is a mechanical double pumper.

2) Elevation here is about 1,000 ft.

Splicer