I know you all love to talk turbo, but surely someone here has opened their intake, turned up the fuel a flat, and have headers running into a 3" or better exhaust system. Is it worth the price of buying headers, I've got the itch real bad to buy a set, so I'd like to hear some exeperianced input. Thanks a bunch, maybe I should just get some Lanacane.

 

Have seen many posts re a waste of time to do headers, most expected better performance but no real gains for the price. I think Stan's headers in upper western USA is one of the only builders of headers.

I have oem manifolds and went to 3" exhaust with a much less restrictive muffler and found more power became available......

 

the stock manifolds are really restrictive. if you did headers with a turbo i am sure tehre would be a gain there but without i doubt it.

 

i really don't see how you could get any benefit from headers and a turbo.
the purpose of headers is high flow of the exhaust gasses. a turbo bottles everything up, so it would neutralize the benefits of the headers.

 

TJC, A turbo bottles everything up, true. But only the compression side of the turbo. The side the exhaust flows through only turns the wheel, so that the other side may suck air in. If you have less restrictive headers, that flow more air quicker, i think you would see boost quicker, possibly more boost, and for sure less egt's.

However, I am not sure whether or not it would be worth it, as the differences would probably be small.

 

yea, i understand how it works. but look at it this way. you have headers with 3 inch collectors. then you bottleneck those dual 3 inch collectors back down to a single 2 1/2 inch pipe to go into the turbo. it is basically like putting a 2 1/2 inch single exhaust with cat and muffler back on after the headers.. and as far as turbo lag goes, i don't see any with my banks unit. with the free flow exhaust i have i get instant boost. i don't know about the ATS or hypermax units, but i would imagine they are the same way though.

 

I see four rather large problems with a set of headers and a turbo.
1. You have to come out of the headers and get the exhaust back to the top of the motor where the turbo is mounted, talk about plumbing nightmare.
2. The extra internal volume of the headers and exhaust plumbing to get the exhaust back to the top of the motor would induce turbo lag and decreased boost. The extra surface area would allow the EGT to drop much more before it got to the turbo which drops the exhaust volume to spin the turbo. Without going into hard math if you are getting 15 pounds of boost out of a turbo you have 15 pounds of exhaust back pressure going into the turbo. So the bigger pipe size would mean more volume to have to compress to 15 PSI to get the boost.
3. There would have to be a lot more pipe connections between the heads and the turbo which means more potential exhaust leaks before the turbo, my ATS unit has 7 connetions between the heads and turbo.
4. If you use a pipe to flow 100 cubic feet of air through you have two options.
Use a small pipe which means the air will move faster at higher pressure.
Use a bigger pipe which will flow a bigger volume but the pressure and speed will be lower.
The faster the exhaust gasses are moving the faster it can spin the turbo which in the end results in more boost.

A=3.1415(r*r)
So the area of a 2" pipe is 1 times 1 times 3.1415 = 3.1415 Sq. In.
The area of a 3" pipe is 1.5 times 1.5 times 3.1415 = 7.068375 Sq. In.

At the same pressure the exhaust will be moving 225% faster in the 2" pipe than it will in the 3" pipe. Yes there are a lot of factors that are not in my calculations, but it does show the basic idea.

 

Sounds like its time for the Lanacane

 

Yeh, I've already scatched the itch, will not bother with the headers, but I still find it hard to believe how a no one who actually has headers with NO TURBO or what is known as a N/A IDI has anything to say here, we seem to be able to stretch any other subject out for miles LOL.

 

I did the pipe upgrade to 3" from the stock manifold downpipes to the stacks back when mine was NA.

At that time I knew there was going to be a turbo in my future.
So I saw no use to waste money on headers that I would be trashing shortly anyway.

I can not see how the extra scavaging of burnt fuel that headers provide can increase the HP much above what a good free flowing exhaust can. There is no way the headers can force more air into the cylinders under pressure like a turbo can.

 

obviously you wouldnt use long tube headers, headers can come in what ever shape or size you want. you will obviously pull more boost if you are pushing more air into teh exausht side of the turbo. The stock manifolds are really restrictive at the bend in the manifold.

 

I don't know how Banks routes the turbo up pipe, but on the ATS system it bolts directly on the passenger side manifold. The header would have to be the exact same layout as a stock manifold to get it to work.

 

the banks setup has a y pipe between the 2 manifolds and it goes into the turbo. it looks like the setup you are running would create un equal cylender preasures?

 

If you put 15 pounds of air pressure in a pipe, it has 15 pounds pressure everywhere in the pipe.

The ATS system uses a tight radius in their Y at the rear of the passenger side manifold to match the radius of the drivers side manifold. I am very pleased with the ATS system performance.

With the fuel setting I am running right now I am getting 18 PSI boost at 2600 RPM and 900 EGT with almost no smoke at all.

That is good enough for me till I turn the fuel up a bit more.

 

i bet that thing moves with 18 psi