header or manifold

Another test from the same guy. 790 hp Cup-engine. The manifold followed the curve of the normal best race 421 header. It never got closer than 8 hp but never was worse than 13or14 hp. There was really no serious dip or spikes. I tell people that I show this too that 40 years of header development amounts to 13-14hp!
 

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Okay..... I don't think I'll have you build headers for me but it's an interesting opinion which we're all entitled to. Leaving 14hp on the table is a lot at that level. I guess I could sum it up by saying there must be a reason PS headers don't look like the pictures you posted.
 
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Grudgeguy said:
Okay..... I don't think I'll have you build headers for me but it's an interesting opinion which we're all entitled to. Leaving 14hp on the table is a lot at that level. I guess I could sum it up by saying there must be a reason PS headers don't look like the pictures you posted.
Click to expand...

Of course they take 14 hp if possible but the idea behind those tests was to show how little meaning pulsetuning has. Add a turbocharger and you only loose because of extra volume, heatlosses and harmful pulses.
 
Leiffi you hit the nail on the head, but I will think we can find other places to add power from the exhaust side of things, hoping for gains. If they happen to aid whichever anyone becomes successful with it just may free up something earlier in the flow path.

Good thread OP.

Food for thought, if a slightly smaller header (than needed) on a N/A gas or diesel exhaust can out perform a larger header. Can the same be said for low boost to high boost apps in regards to smaller than intended (low boost) versus larger than in tended (higher boost)?

Regardless of engine fuel or aspiration we have these in common

Similarities
Exhaust valve
Valve seat
SSR
LSR
Runner floor
Runner walls
Runner roof
Bowl area
Blowdown phase

Differences
Combustion chamber design on the cylinder head side
Physical valve position
Valve design
Valve stem diameter
Bowl transition
Runner shape
Runner length
Actual valve angles
Intensity of the blowdown phase

The first thing you need to focus on is the formation of the exhaust runner starting at the venturi area.

As far as building, I would say it may be the easiest DIY build performance-wise if you have the math done correctly. I will watch and listen to the man I plan to have build my Pro Street Cummins headers since he has been building them (racing headers) for 40 plus years. It will be his first set of diesels but probably not his last :Cheer:
 
Grudgeguy said:
Okay..... I don't think I'll have you build headers for me but it's an interesting opinion which we're all entitled to. Leaving 14hp on the table is a lot at that level. I guess I could sum it up by saying there must be a reason PS headers don't look like the pictures you posted.
Click to expand...

I quess those F1 engineers don't know what they are doing : a very compact exhaust manifold that focuses on turbo performance, not exhaust tuning,
http://www.enginelabs.com/news/mercedes-f1-engine-wins-powertrain-innovation-of-the-year-award/
 
I bet their compact exhaust manifold looks more like a cast header than a log manifold.
 
kjpcummins said:
I bet their compact exhaust manifold looks more like a cast header than a log manifold.
Click to expand...

I bet it looks like bigrig manifold, they are very efficient. In the video he says its a logtype. Theres not much space under that heatshield for something else.
 
Leiffi said:
Of course they take 14 hp if possible but the idea behind those tests was to show how little meaning pulsetuning has. Add a turbocharger and you only loose because of extra volume, heatlosses and harmful pulses.
Click to expand...

Not going to get to a much higher level of engineering than the Audi R18 team.
These guys just took what you said and threw it out the window. Not only are running what looks like a equal length tubular exhaust they are running a intake plenum with also looks like a tuned length runner.

audi_r18_e_tron_quattro_turbo_small.jpg


Kinda comforting seeing a team like that implementing those designs considering what's under my hood.

P4060195_zps4c1f5ad4.jpg
 
I'd love to know who makes that twin inlet turbine housing. Would make for some nice packaging on a big single gasser v8.
 
Makes you think, are we moving on mass flow or is there a little more motion to the mix from seat to turbine wheel.
 
After reading all of the post i think it all depends on your set up and what you are looking for. Each has its place. Each has pros and cons. It really comes down to your set up and how you wany things to respond. Just my opinion, i could be wrong or maybe i am right
 
Shouldn't weight also be a variable in this discussion? Specifically in a drag racing application. A heavy turbo would have to have additional support, of course.

We are running a stainless manifold and even after porting this thing is heavy. I didn't weigh it but I'd guess 30+ lbs. ...and I've never seen the weight of a thin walled header. Even with the header wrap, a nice log style header would have to save at least 10lbs, maybe????
 
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I think if guys were worried about weight they wouldnt be drag racing 4500lb+ trucks. I actually posted weights in another thread where you asked about weight comparisons between a log manifold and header. I think you have a ways to go to be worried about 10lbs.
 
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Joesixpack said:
Not going to get to a much higher level of engineering than the Audi R18 team.
These guys just took what you said and threw it out the window. Not only are running what looks like a equal length tubular exhaust they are running a intake plenum with also looks like a tuned length runner.

audi_r18_e_tron_quattro_turbo_small.jpg


Kinda comforting seeing a team like that implementing those designs considering what's under my hood.

P4060195_zps4c1f5ad4.jpg
Click to expand...
doesnt mean they use the best design possible, factory race engineers are not always the smartest guys. Like I said, when others see that MB has found out what amateur racers have done for years, turbo manifold design will change in every team.
 
kjpcummins said:
I think if guys were worried about weight they wouldnt be drag racing 4500lb+ trucks. I actually posted weights in another thread where you asked about weight comparisons between a log manifold and header. I think you have a ways to go to be worried about 10lbs.
Click to expand...

http://www.competitiondiesel.com/forums/showthread.php?t=158458&page=9

The link will take ya to said thread. I forgot I posted over there. The reason guys are racing 4500+ lb trucks is :rules: The 'Mud Racing Association class' we run in has a weight minimum. We are a little north of 350lbs heavier than we have to be. Additionally, the diesel dirt drags have no weight minimum. Come on out and play this season and we'll see who has a ways to go. :Cheer:
 
Leiffi said:
Another test from the same guy. 790 hp Cup-engine. The manifold followed the curve of the normal best race 421 header. It never got closer than 8 hp but never was worse than 13or14 hp. There was really no serious dip or spikes. I tell people that I show this too that 40 years of header development amounts to 13-14hp!
Click to expand...

LMAO! I've seen dyno runs back to back with different headers on a N/A BBC that was 34 HP from the worst set to the best set... That was on a 1000-1100 HP range engine.........
 
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