Removing muffler question

[MJRKat]

Ok, just kind of curious how much of a HP gain I would get removing the IMCA muffler from my exhaust and going with the open header. I'm running a smaller motor. Its a 355 with high domes(KB Cheapies), and double hump heads with no machine work done to castings. 750 carb on gas. I'm running a 7101 intake, but thinking of switching it to a victor jr 2975.

Any ideas? Roughly? I got thinking about it because of recently putting mufflers on my suburban. I know the mufflers are different as far as restriction and all, but just got me thinking..

[rubbinsracin]

you will feel little to no gain honestly. maybe a couple of HP. the real gain will be putting a few bucks into your top end of the motor. if youre running a stop and go track, the performer you are running now is better at the lower RPMs because it has a power band suited for 2000 to about 6000(Jegs.com says only good to 5500). but if you are running a bigger track, you might be better off going with the victor, because it has a power band of more like 3000is to 8000ish.

we used to run the performer and switched to a victor, with no changes other than putting the new intake on and a little bit of tuning(timing, carb, plugs) we found the car ran way better at the upper RPM ranges.

[MJRKat]

Thanks rubbin..I'm leaning more towards the victor..I'm usually in the 6500-6800 range for RPMs I think at the end of the straight. I think I need a little more top end, plus the tracks are probably gonna start getting slick soon, so being under the powerband might help a little bit there..Just guessing though..lol

[Egoracing]

Thanks rubbin..I'm leaning more towards the victor..I'm usually in the 6500-6800 range for RPMs I think at the end of the straight. I think I need a little more top end, plus the tracks are probably gonna start getting slick soon, so being under the powerband might help a little bit there..Just guessing though..lol

The numbers are for reference ONLY!! We dyno'd 3 motors one year and 4 or 5 intakes on every motor. The 2925 super victor ran better on all of them, one was a 450 lift hyd cam with flat tops and a 4412 carb and was in the 400hp range, the big motor was 431ci and 700hp and the intake made better power from about 2000 rpm up!

[MJRKat]

Thanks for the info Ego!