I'm not sure if this topic has ever come up, but being a drag racer and turning my Camaro SS into a drag car that was once a street car, this was an obvious concern of mine. Opening up the exhaust with a set of headers came to mind. Do they exist? Are they beneficial on a turbo diesel engine? This also popped into my head because I plan on doing gauges and considered doing the BD exhaust manifold. I figured, $300 for 1 exhaust manifold is a lot of money compared to a set of headers for the same price. Now again, the headers I have on my car were $1000, but they're stainless steel with a 3" collector. Anyhow, before I went ahead and purchased the BD exhaust manifold only for the purpose of not having to drill/tap into my existing factory manifold, I wanted to look more into headers for my '06 LBZ.

nobody makes them....FWIW, its not really worth it on a turbodiesel...

If your comfortable with removing the exaust manifold to swap it, then just remove and drill your stock manifold and reinstall it (whichever side is easier for you) and you can save yourself the $300.

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Well the main reason I was considering the BD exhaust manifold is because I don't want to run the risk of it cracking down the road from me drilling and tapping it. There's a member on here who experienced this. I just wana play it safe.

As a Racer myself, I've thought of the same thing.

I'm not into racing my truck, don't see the point personally, but I am interested in making more power and torque and making the truck more reliable with positive improvements.

For exhaust manifolds, Extrude Honing, may be just the ticket. You could also get the die grinder out with carbide tips and abrasive drum tips but that IS a lot of work on cast iron. Here is a link:
http://www.extrudehone.com/

You could provide more power using this technology by using it on the heads, the intake manifold, exhaust manifolds and fuel injectors.

Regards,
Mike

What about custom headers from someone like Kooks ?

I have a set of Kooks on my Camaro. Quality set of headers, hands down. However, they've mass-produced the headers for LS1 F-bodies and are still expensive. I'm sure they would charge me an arm and a leg to make 1 set of custom headers.

the cost to have someone make a custom set of headers for a Duramax would be pretty large id think...and you wont see any performance benifits.

think about it, a turbo (especially a VVT) relies on drive pressure (back pressure) to work. There is always going to be pressure between the exhaust ports of the cylinders and the inlet of the turbo hot section. Trucks with VVT's see upwards of 50-60 psi of drive pressure. So there is basically 50 psi of exhaust pressure in the manifold/exhaust risers/uppipes. The restriction obviously being the exhaust turbine/hot section of the turbocharger. Putting headers on is going to do nothing because the biggest restriction on the whole exhaust is still the turbo.......

JMHO.

You guys know that headers are a big pain in the ***. You're going to be burning spark plug wires off like crazy with our high EGT's. ):h

You guys know that headers are a big pain in the ***. You're going to be burning spark plug wires off like crazy with our high EGT's. ):h
Yeah, and it would be damn near impossible to change out the #5 plug!!!

the cost to have someone make a custom set of headers for a Duramax would be pretty large id think...and you wont see any performance benifits.

think about it, a turbo (especially a VVT) relies on drive pressure (back pressure) to work. There is always going to be pressure between the exhaust ports of the cylinders and the inlet of the turbo hot section. Trucks with VVT's see upwards of 50-60 psi of drive pressure. So there is basically 50 psi of exhaust pressure in the manifold/exhaust risers/uppipes. The restriction obviously being the exhaust turbine/hot section of the turbocharger. Putting headers on is going to do nothing because the biggest restriction on the whole exhaust is still the turbo.......

JMHO.

There could be an advantage if you moved a backpressure choke point from somewhere in the manifold to just in front of the turbo.

Also might be helpful for heavily modded trucks that have relocated the turbo.

There could be an advantage if you moved a backpressure choke point from somewhere in the manifold to just in front of the turbo.

especially on a LLY/LBZ, the VVT is the biggest choke point. Thats why VVT's sound like a vacuum cleaner out the tailpipeWHOOOOOOOOOSHHHHHHHHHHHHHHHHHHHHHHHHHHH. Lots of restriction and all the air is trying to rush by the obstructions of the vanes. VVT's are kinda more restrictive by design, but this kills two birds with one stone; the point of the VVT was for emmissions. More restriction on the exhaust forces more exhaust thru the EGR instead of out thru the tubro.

Also might be helpful for heavily modded trucks that have relocated the turbo

to where?:)

-Ben

Your missing the point. The restriction between the exhaust port and the turbo is necessary to generate the exhaust velocity (aka drive pressure) to drive the turbine. There is a balance point between restriction and flow that must be meet in order to have optimal turbo performance. This is evident when searching for a turbine housing with the ideal area ratio. If the A/R is to large the turbo wont spool. To small and it will over speed.

Sure go and get some custom headers made. I suggest 2.25 primaries and 3.5collectors feeding the two 1.75 holes on the back of your stock charger.

:exactly:

On a relatively stock application.....dont waste your time. Purpose built race...maybe.

We have found them to be helpful on the 7.3L Fords and have actually taken the steps to get them made for the Duramax. With the 7.3L we noticed cooler egt's and quicker spool-up. Here are a few pics of the 7.3L ones.

http://www.dieselinnovations.com/gallery2/v/tech/new73headers/

Ah, headers and turbos. :)

The big deal is gas velocity. Not so much tube length, tho equal runs help. Too big of a pipe and the gas velocity goes down only to have to accelerate it again at the turbo. This costs power. Keeping the velocity constant from port to turbo would be the ideal. Less restrictive turbos benefit from bigger manifolds.

Separation of the 3-1 and 8-6 overlaps would help those cylinders.

What size are the tubes on those 7.3 headers?

You guys know that headers are a big pain in the ***. You're going to be burning spark plug wires off like crazy with our high EGT's. ):h

HAHAHAHA...that is hilarious!