So back in the gasser days, the first mod anybody did was get rid of the stock exhaust manifolds, replace with headers and then dual exhaust.

Why is it that you hear very little about anyone changing out their exhaust manifold for somthing better?

 

are all you high hp/tq guys still using the stock manifold?

 

The reason for changing manifolds in a gasser is for higher flow and decreased pressures...on turbo charged diesels there is the turbo creating backpressure and impeading flow so it is probably not that important (or flows well from the factory)...just a guess though???

 

i was making 540 with a stock manifold and sps62
i had to change my manifold when i went to twins, and am making 543(with a lot cooler egts).

an aftermarket manifold may reduce lag/increase spool, i cannot make a fair assesment since i changed everything at 1 time.

 

As stated before it would help increase turbo spool, also if it was pulse tuned that would create better turbo spool...this is a cool article to read about the subject even though its not diesel.

http://www.max-boost.co.uk/max-boost...lse_tuning.htm

 

I changed mine to an ATS when I went twins. It actually quieted mine down a bit I think. Hard to tell a difference because of the turbo upgrade though

 

i was just thinking that flow would be better, thus quicker spool plus maybe a little cooler.

 

If your gonna do the manifold you might as well do the turbo while your at it lol.

 

I can say a new manifold and turbo will make the truck sound different. More of a lower tone. My friend had the manifold&turbo done, and totally different tone!!

 

Yep, mine sounds a lot different now with a new turbo. I may have too look into the manifold thing for spoolage

 

I just replaced mine with an ATS. They seem hardly any different. I think you would be better off enlarging the manifold inlet ports and turbine inlet a little so there is no step in the flow on the stock one rather than use an aftermarket one.

 

If you look closely at a stock 3rd gen manifold(#4 and 5 exhaust ports),it looks as if they could be fighting each other letting gases escape. A guy I know has repaired a coulpe of 3rd gens with burnt pistons and both times it was the #4 or #5 cylinder. He seems to think it is the stock manifold(and a little driver error)