It could have something to do with the scavenging of exhaust gasses in sequence to its pulse. Fine tuning plays alot in the design of a header.

 

usually when we have put headers on our turbo cars and turbo trucks we have seen a slight increase in spool up and lower egts. no loss of power on the dyno.

 

here is a post from another site-

saw a dyno sheet from back to back testing with the same truck same mods and used a 3 piece manifold compared to a tubular header. not the one above but similar and it made 12 more hp on the top end but lost almost 200 under the curve

From the guy who made it-

Yep, it was one of mine. It was a thrid gen style, it looks like smaller id tubing will help the velocity, and splitting the pulses may help as well.

All I can think is its got more volume to fill, therefore loosing the low-end power, but freer flowing up top. I will try a different design or just stay with the second gen style on all trucks. JP definitely got me some good info though.

 

Maybe on something that was poorly designed, I could see a power loss with a header.

But if I were to buy a $1000 header and I lost power...

That would = !

 

TTT, anyone with pics of a 2nd gen setup please post em. I'd like to see as many different angles possible so I know what I need for my grocery list. Thx!

 

hey Howling, awesome pics of your engine bay,it looks great. i sent you a pm about your setup

 

What is required to put it all together after the 2nd Gen manifold is on? Does it just require a 2nd Gen downpipe? I know you have to re-clock the turbo and some fab is required to get the intercooler and oil return connected, but other than that?

 

I've been researching this subject and a lot of threads I've been seeing involve the use of a 2nd gen turbo. I have a 3rd gen turbo so could someone let me know if the following items are the only things that I need

1) 2nd Gen Manifold
2) 2nd Gen Down pipe (Not sure if it bolts up directly or if some fab work needs to be done.)
3)Longer oil drain line
4)A Little fab work on the stock intercooler pipe

My truck is an 05 w/ a six speed and a Silver Bullet (in a couple days)

 

Hey gentlemen!! I don't post much because i have been in afghanland/iraq since march of last year and will be for another couple years before I can come back and buy another truck to bomb out, but it keeps telling me I don't post enough so I thought I might have some input for this....

Two things I would consider on the subject of manifold vs. stainless header: 1. Volume as has been mentioned since this and might be one cause although I think it would pale in comparison to number --> 2. I would think that Cast Iron due to wall thickness and its metallic properties would hold heat much better. That possible loss of heat might cause a drop in pressure driving the turbines.

I would like to see a flow chart done on the manifold vs. the header on an engine. Maybe (and I say maybe because I don't know what type of negative effects if any might be caused by this) you could wrap the header with exhaust wrap to contain the heat and thus counteracting the temperature drop.

 

You said it gained 12 peak but lost 200 under the curve!!!!!!!!!!!!!! Could they have meant to say 20. You can make a dyno say what you want it to say, but I am not buying 200.

 

From what i have learned in boilers and turbines im going to agree with statement #2 but hey im an average student not certified yet.

And guys how does the 2nd gen sound different from the 3rd gen. Anyone got video of the difference. Does it give that diesel clank that is slowly disappearing with every year? Because i sure would love some more diesel clatter haha... thanks yall

 

Well guys, id like to comment on this matter, and explain some of the benifits of this header. The builder at Overkill is a very good friend of mine, and i have this same header on my truck, 2nd gen style flipped.
First of all(not on my truck) hp gain were a success. 16hp at the rear with a dyno dynamics. All though we didnt measure drive pressure(witch will be tested this summer) we didnt think at the time it was an issue and still we dont. I know of several trucks running this header. All were agreed with beneficial results. #1 EGTs were about 300* cooler, a huge plus with huge hp truck. I myself went from normal driving at 1250* and having to back off the throttle on a slight grade, to being able to climb the same grades after install at 900*. Guys this is with flux 5.2s. I can see better spoolups, and a better throttle responce.
A friend of mine also is running this header with a huge single, and his results are the same with a auto, and flux 4 something, and is soon to up injector size on his 05.
Now Matt at Overkill isnt a Diesel buff, but the dude knows stainless, although he is a small shop in a small town he builts custom products for guys like us, cause we asked him to. I guess if someone wanted to pick his header apart thats great, go see what the end result is. But for me and everyone else that has one we really dont care, what those end results are cause it WORKS! These header are on truck across the midwest that are some of the top truck in there class, with no complants. (and one badace tractor). There was even a case where a 12v had this header so hot, it drooped 3/8" from origanal build and never cracked. Im not sellin Overkills product, i just wanted to shead some light on this subject, now to the one at hand.
I think every truck should of come from factory with a 2nd gen manifold, so much easier to work on. Benifits? not sure if there is some, but I like it and thats just my OP................. Ill post pics.

 

Under construction AGAIN, so forgive me for the mess.

 

coreydr2003 - that setup you are building looks GREAT.


I am going to be putting a 2nd gen mani on my rig, it will be ceramic coated, but my plans DO include twins.

I currently have a 3rd gen header from the Fab Shop, I really like it's performance, saw a little lower EGT's, slightly better/quicker spool, and even a little fuel mileage increase overall (.5). If I wasn't going to twins, it would def be a keeper, nice change overall.



CD

 

coreydr2003,

Have you or anyone you know running this header and big hp melted down any pistons since having it installed?

Dropping 300* is a big plus for any truck!