Case Shape

[NSdartSW]

I’m looking at redoing the exhaust system for my car and have a question needing answers I don’t have. I swapped a 360 into my ‘66 Dart wagon and I’ve got a set of Doug’s D450 lined up, I’m looking to put Flowmaster Fx’s behind that but see they are round or oval case shape. Is there any difference in the 2, resides the obvious ones round ones oval. Does one preform better than the other? I plan on doing 2.5” true duals, without a H or X pipe(probably).
Thank you

 

[VOETOM]

Depends upon interior volume. Larger volume, when packed, are typically quieter and smoother.

 

[Oldmanmopar]

H-pipe will improve performance through RPM range. I han a 3 1/2 exhaust with a 2 1/2 H-pipe. The car ran 10.67 @ 128 through a full exhaust

 

[NSdartSW]

Ya, I’m just not sure on the amount of space I have under the car. I’d like to run a H-pipe but I need to do some more looking and thinking under the car where everything’s gonna go.

 

[jeff alder]

We always picked them based upon the install. If we needed ground clearance, we went oval. If we needed lateral clearance we used round. If you're putting a basically stock 360 4 BBl with headers on a dart wagon fitment and placement would be the important issues. That is a sweet wagon...I remember it from when you first came aboard. Thanks for saving that ole girl.

 

[NSdartSW]

Ya, I’m just not sure on the amount of

We always picked them based upon the install. If we needed ground clearance, we went oval. If we needed lateral clearance we used round. If you're putting a basically stock 360 4 BBl with headers on a dart wagon fitment and placement would be the important issues. That is a sweet wagon...I remember it from when you first came aboard. Thanks for saving that ole girl.

Oh ok that’s kinda what I was thinking. To my knowledge it is stick besides pistons but it could have more then that the guy I thought it from didn’t know what his father-in-law had done to it.

 

[jeff alder]

th

 

[jeff alder]

1966 Dart dual exhaust

 

[NSdartSW]

Oh ok thank you, I was going to do some searching trying to find some examples isn’t to get a look how it was done. Thanks i appreciate it.

 

[33IMP]

The oval case will flow the same as the round, but with more packing, the oval will be quieter. (If that's what you want.)
Edit: looks likeJeff Alder is using glasspacks as resonators to quiet/kill a drone.

 

[VOETOM]

This was the original system.

 

[VOETOM]

I suspect you can fit 18" oval cases under the car but not sure if 5" by 11" ones will fit. Good luck. Tom

 

[NSdartSW]

Thank you need to find some time to roll around under her and figure it out, get some measurements.