Right Now I Have Flowmaster Headers On My 86 F250 With A 400 In It. I Was Thinking About Removing My 2 Glass Packs And Replacing Them With A Pipe And Running Straight Pipes. I Do Not Have No Converts On This Truck Now But I Still Dont Think Its Loud Enough With Glass Packs And Tips.
Runing Staright Pipes Will This Hurt Anything And Will I Still Have Enoguh Back Presure In The Exhuast?
Thank You

 

That depends on your pipe size. You do not need any backpressure, what you need is exhaust velocity. Straight pipes will flow and perform better than glasspacks, which to be honest, are among the most restrictive mufflers you can get.

 

I dont think it would try it and if you notice something slap on the packs again but i dont think it would

 

ok. my pipes are 2 1.4 i beleave

 

2.25" is a good size for that application. I say try it and if you don't like it, you can switch back. Personally, I wouldn't want to drive a rig that loud, but to each his own.

 

most glasspacks are a straight through design...not restrictive in any way...time for some research Bear River...

 

Nope. There are glasspacks that have huge louvers sticking out into the exhaust stream. Not free flowing at all. Measure the I.D. of most glasspacks and you will see it is smaller than the pipe size its meant to hook up to.

Glasspacks suck. Time to do some research......

 

I know very well they are a straight through design. But they also have an aggressive shark gill pattern that while it creates good sound, it also create substantial turbulence. Dyno tests show they are restrictive as compared to Magnaflow, Flowmaster, Dynomax, resonators, and some factory mufflers. They are great for sound, but not for flow. Besides, flow is not really the only requirement for power anyway, velocity and induction are equally important. Resonators are different, they flow very well, and also tend to be loud.

 

well then, i stand errected...i mean corrected... the SIDO on my truck is a straight through design, no louvers in it. i looked. but i guess thats just one... sorry.

 

I second that 2.25 is a good size i have that on my truck

 

Louvered glass packs should be relabeled as rpm governors, the higher the exhaust flow or higher throttle applied the higher the flow restriction due to increased turbulence. You would be better off running them backwards for better flow but louder plus one size larger than your exhaust pipe.
Better yet if you must run glass packs is get those that have a perforated center vs a louvered center.
Old school here? Lets bring back the flat head.

 

thats what mine looks like. guess thats why there doesn't seem do be much restriction.


[/QUOTE]Old school here? Lets bring back the flat head.[/QUOTE]

there are a couple of guys in our sask. chapter who would love you right now!!!

 

96sherm, my brother inlaws family at one time had a muffler shop and auto wrecking business that started back in the 20's. I recall back in 75 when the wrecking business shut down due to the city fighting them they had 5 Mercs from 48 to 51 and 4 of 5 flatties ran. They sent the motors out for scrap iron, hell they didn't make $30 each motor. This flat made me cry as I would of gave them any money they asked for just to pass them off to someone in need. My retired radiator friend now age 79 helps pit a friends nitro injected digger powered by a flatty that runs in the 8's. Sad they go thru many blocks a year. I think is was the Hungarian or some other near by country that had the rights to cast and use flatty motors for their army trucks, they ran them up to the 90's and offered brand new crate motors for sale. I recall something
like $2,500 each I may be wrong. Said radiator friend is one of the original street rodders from the late 40's and still active plus a friend of his at 72 a 'ex Ford truck painter that can lead in any body part, chop channel cut, chop or add a roof to make look factory stock. Them guys are a lost art unless it's a Chip Foose crew.
I respect old iron and motors even if it's not what I have an intrest in, FE's I believe in and they can run built right.
.....Carl......