Is backpressure overated?

[deftsound]

Hey guys,
I had a question about backpressure because im soon to be installing my offroad h pipe and at the same time im having cutouts welded in. Well i want to know if i have anything to worry about in terms of bowing my engine because of a possible backfire related to there not being any backpressure? What do you guys think?

 

[ponysarepretty]

I seriously don't see anything wrong with it.... People put too much importance in back pressure and the likes.

 

[SamMan]

I wouldnt worry about the backfire.

The main diffrence I saw from the removal of backpressure after switching to no cats was the loss of low end torque. I kind of miss it when Im on the street and traction isnt an issue but I dont miss it at the track because I couldnt hook that well before. Now it pulls alot harder up top end.

Im going to dyno it soon and I expect my HP numbers to come up and my TRQ numbers to go down which isnt a bad thing as they were ridiculously out of whack with the all the backpressure I had due to having 4 cats.

 

[ponysarepretty]

Does anyone make a variable backpressure setup for the mustang like what they have in the ferraris, porches and the Z06, the exhaust valves only open when load and RPM reach a certain point? Atleast I think thats who it works.

 

['13_ImpactBlue_GT]

When I had mine changed out it felt like I lost some low end torque and gained some high-end pull.

 

[Gearbanger 101]

Just swapping out to an O/R midpipe and adding cut-outs isn't going to create enough of a loss in backpressure to burn any valves. But in the same instance, if you've got next to no other mods done to your car, you're going to take a huge hit in bottom end/off idle torque, with very little gain at the top end as a result. Wait until you're making more power to start freeing up the exhaust system beyond an O/R mid-pipe or catback and your car will run better for it.

 

[squares98]

Does anyone make a variable backpressure setup for the mustang like what they have in the ferraris, porches and the Z06, the exhaust valves only open when load and RPM reach a certain point? Atleast I think thats who it works.

I think the FRPP exhaust does that? don't quote me on it though.

 

[tomustang]

they have in the ferraris, porches and the Z06,

what about a porch?

 

[KronicRacer]

I think the FRPP exhaust does that? don't quote me on it though.

man you reminded me of something:
the fr500 had some sort of variable muffler

http://www.fordracingparts.com/parts/part_details.asp?PartKeyField=6631

what cracks me up is that these mufflers are 375 each

 

[deftsound]

Just swapping out to an O/R midpipe and adding cut-outs isn't going to create enough of a loss in backpressure to burn any valves. But in the same instance, if you've got next to no other mods done to your car, you're going to take a huge hit in bottom end/off idle torque, with very little gain at the top end as a result. Wait until you're making more power to start freeing up the exhaust system beyond an O/R mid-pipe or catback and your car will run better for it.

well im not doing the cutouts for performance, haha i just want it to sound loud as hell when i want it to

 

[Four Point Six]

My 01 is stock except for dual cutouts and I haven't had any problems. I like it because its loud uncapped, but if I want it quiet for a while I just cap them up. You do take a hit in low-end power, though you do gain some up top.

 

[billfisher]

when i put the 5.4 in my car, i am putting 3" 90 degree elbows that exit under the doors. i am putting 4" super trapps on the ends. not the muffler, just the 4" plate caps. i can add or take away plates for quiet or loud. take them off for racing. open exhaust. less plates = quiet and torque. more = more HP and louder. just my thoughts.