back pressure?

[oktogo]

i have true dual exaust on my truck with 2 glasspacks on it no cats and im buying headman long tube headers do i need to worrie about not haveing enough back pressure? o and the pipes are 2 1/4.

 

[RBuffordTJ]

i have true dual exaust on my truck with 2 glasspacks on it no cats and im buying headman long tube headers do i need to worrie about not haveing enough back pressure? o and the pipes are 2 1/4.

I put those headers on mine, ran back to individual pipes, two turbo mufflers and out, no issues at all. Plenty of back pressure for the truck.

Rick in Orlando

 

[Seabronc]

i have true dual exaust on my truck with 2 glasspacks on it no cats and im buying headman long tube headers do i need to worrie about not haveing enough back pressure? o and the pipes are 2 1/4.

As long as you don't need your emissions system to work, you don't need any back pressure. Think about an engine used for drag racing, do you think they have any? Back pressure is a robber of power. That being said, I refer you to your local emissions control station /emoticons/[email protected] 2x" width="20" height="20" /> . In most states doing anything with the stock exhaust technically makes it an off road only vehicle. So, "Don't worry Be happy / ".

 

[Krafty]

if you really want to be sure, dyno it before and dyno it after and have a look see at the results, with small pipes like 2 1/4 you will be perfectly fine.

also the headers are usually designed to accommodate for running either small pipes or no pipes so thanks to the engineers you don't need to worry about it.

Finally back pressure in certain applications are essential for optimum performance of the engines in those applications. case and point are Motocross bikes, and formula 1 cars.

 

[Seabronc]

I make a slight retraction of what I stated before. Krafty has a good point there. I think mostly in terms of engines using carborators, and also it is late for me and my brain isn't up to speed. Most engines today use the effects of back pressure in their design. Even yours was designed to make use of it. If your engine had no back pressure the EGR function would not operate. With the introduction of the EGR system, the engineers realized that one of the side effects of this gadget would lower the combustion chamber temperatures and allow more aggressive timing curves to be used with 87 octane gas without causing knocking. The possible result of not having enough back pressure on an EFI engine could be piston damage.

>-

 

[oktogo]

im in south Carolina and we have no emission at all no checks or regulations i could run a drag car up and down the road if i could aford the gas so thx for the help buy what yall say 2 1/4 is good

 

[Rons beast]

Federal regulations still apply: modifying, deleting, or defeating emissions controls is illegal in the US, and generally bad for performance anyway. The engine will run better the way it was designed & built to.

And the correct amount of backpressure is necessary on all modern engines. Try unbolting the exhaust manifolds & see how long the valves last. This is from an engine with too large of ex.man. runners & a big fart cannon muffler.

Interesting...but I would think if you unbolted the exhaust manifolds, alot of other things under the hood would burn or melt before the valves.

The pic is of valves is from an Acura. How does it relate to a 5.0 or 5.8 L Ford. And do you know what the time frame was that the said car had the "too large ex.man. runners & and big fart cannon muffler" ? Is the result something that is a result of short term, (10k miles or less) or longer. Was there any other problems and mods to the car that may have contributed?

Finally how large is too large when speaking of the mainfolds or related exhaust equipment?

 

[Rons beast]

Anything other than stock is the wrong size? You must be a blast with SEMA guys.

 

[Krafty]

as long as you have the right amount of restriction somewhere , aka engineered headers, then you can go 3" no problem. the biggest header tube size I would go is 1 1/4 or 1 3/8 and no bigger than that. but usually thats what they are unless you get custom headers. after that you can run anywhere from 2" to 3" pipes comfortably. anything more and your motor will feel gutless, and anything less it will be obviously restricted.

I have stock manifolds on my 429 ( which will be headers by april ) and true dual 2 3/4 " pipes to and from magnaflow mufflers, runs like a champ at 400 hp for the last 2 years.

also just for thought.. in the formula 1 cars that push crazy power and speed. they're headers have to meet this requirement . for both exhaust headers, each one has to at some point restrict to the size of a nickel before they can reach the rest of the pipe work.

 

[Rons beast]

as long as you have the right amount of restriction somewhere , aka engineered headers, then you can go 3" no problem. the biggest header tube size I would go is 1 1/4 or 1 3/8 and no bigger than that. but usually thats what they are unless you get custom headers. after that you can run anywhere from 2" to 3" pipes comfortably. anything more and your motor will feel gutless, and anything less it will be obviously restricted.
I have stock manifolds on my 429 ( which will be headers by april ) and true dual 2 3/4 " pipes to and from magnaflow mufflers, runs like a champ at 400 hp for the last 2 years.

also just for thought.. in the formula 1 cars that push crazy power and speed. they're headers have to meet this requirement . for both exhaust headers, each one has to at some point restrict to the size of a nickel before they can reach the rest of the pipe work.

Thanks for the header info. Do you know if I run aftermarket cats in front of the mufflers is that sufficient for the fed guidlines. We don't have any state inspection here in Fla. If the sound is not too loud they let you run anything...the locals anyway.

 

[Krafty]

I don't know of a reason why you wouldn't be able to use a cat or dual cats on a system with headers. I know that both my bronco and my Thunderbird don't/ didn't have cats on them anymore, but out in the boonies we don't have to do e testing.

also the emissions level set out that your vehicle has to pass is only the emissions level for the year your engine was produced.

older engine has more slack levels to follow, and newer ones obviously more strict. but then again it might not be the same in your area.

 

[oktogo]

ok well y yall are arguin all throw sum fuel on the fire what about paint like the balck painted or the thermal or the ciramic is the money worth it or do i just replace the painted ones every few years?

 

[Rons beast]

ok well y yall are arguin all throw sum fuel on the fire what about paint like the balck painted or the thermal or the ciramic is the money worth it or do i just replace the painted ones every few years?

While I haven't used the ceramic coated products, friends who have hotrods and show cars swear buy them.

But they also recommend painting the inside of the tubes with VHT. They say it won't stop rust completely, but will slow it down and give longer life to your headers.

I'm curious what some other guys have experianced.

 

[RBuffordTJ]

While I haven't used the ceramic coated products, friends who have hotrods and show cars swear buy them.But they also recommend painting the inside of the tubes with VHT. They say it won't stop rust completely, but will slow it down and give longer life to your headers.

I'm curious what some other guys have experianced.

Mine are ceramic, been on for over 3 years and look brand new. They also cut down on heat under the hood...made a big difference in mine.

Rick in Orlando

 

[oktogo]

well what about the headman thermal coated ones there 285 vs the 437 for the cirmaic

 

[RBuffordTJ]

well what about the headman thermal coated ones there 285 vs the 437 for the cirmaic

I have the Headman, long tube, thermal ceramic coated ones and after 3 years they look brand new

 

[muddrivermike]

My opinion of SEMA can be summed up in 2 classic lines:

"Chrome don't get ya home."

"You can't bolt on experience."



Your right you cant bolt on experience,BUT you can bolt on performance.. $-)

 

[Rons beast]

You're missing the point. Without the experience to use that performance, you've only created a rolling coffin. That's the whole meaning of that line. http://broncozone.com/forums/public/style_emoticons/#EMO_DIR#/wink.gif

Are you stating that one with performance is one without experience? That's pretty assumptive.

 

[Rons beast]

No, I didn't say anything remotely similar to that. Stop trying to stir $#!+ up.

I thought you told be earlier you were relaxed....doesn't sound like it.
Try taking a deep breath .