Our NA combo ran 3" Dynomax race bullet header mufflers. We decided to leave them on with the ProCharged combo. I just installed 3.5" Dynomax race bullet header mufflers. Both set-ups add about 16" of collector length; the only differences are the dia. & the 3" mufflers had no packing.

While I could do some testing at the track with the 2 different dia. mufflers. With only (2) time hits during points races, I'm not going through the hassle of swapping them. I mainly changed the mufflers to quite the exhaust a little more & they do that.

Does anyone think there will be a performance increase? I'm not really concerned if it makes more power or not, we do that with boost or fuel/timing map changes.

2BKING

I would bet the only difference between the two is the larger ID one might be quieter with the packing.

My car has 3.5” ID Dynatech mufflers that are 5” OD packing and have a flat perforated baffle inside the full 6” length of the muffler. I think these type mufflers help with noise reduction and no performance loss. I like mine and one of the reasons I would not have fender exit exhaust.

quote:

Originally posted by markemark:
I would bet the only difference between the two is the larger ID one might be quieter with the packing.

My car has 3.5” ID Dynatech mufflers that are 5” OD packing and have a flat perforated baffle inside the full 6” length of the muffler. I think these type mufflers help with noise reduction and no performance loss. I like mine and one of the reasons I would not have fender exit exhaust.

The larger dia. mufflers are definitely quieter & they have the same basic features of your Dynatech's.

As for a performance increase, we'll see. I think any power adder motor is more sensitive to back pressure than a NA motor. I hope to test/race in July, if the car gets back from body/paint.

2BKING

One other thing I like with mufflers is that I have 16” of pipe behind the O2 sensor located in the collector. This aids in using closed loop and learn to get the idle map programed to the desired AFR with an ECU.

I have 23" of collector/muffler after the O2 sensor. Holley wanted a minimum of 18" if I remember correctly.

2BKING