Logs vs tubular headers?

[nocutt]

Well I don't know if you care to hear or not...the fact is that for v6 like this that fire once per bank, you will do better with a well designed log. I am trying to refrain from using the name "log", because ppl always associate them to stock flowing hardware. In pulsed turbocharging, you take more advantage of the exhaust energy and velocity...something a tubular "equal length" cannot do, plus you have more material radiating needed heat which is lost to the turbine. If you were building a race car that would see 8-9grand (RPM) wise then I would consider tubular ELHs, if not as Aaron stated go with logs, make sure the cross section of the pipe compliments the turbo and also logs work VERY well with twin entry turbos. You just have to get creative with WG positioning...

[Nightingale]

hmm well if my original order didn't go through then I might reconsider. I will have to call and see if my original order cleared or not(might have messed up the checkout on there site). In the end I am gonna get them jet coated so heat radiation shouldn't be a big problem weither I go log or tubular elh. If I go logs it'd be 1.625 from the heads down into a 2.5-3" tubing then into crossover and into turbo or downpipe for temporary until I gather turbo stuff.

[IsaacHayes]

nocutt: That makes perfect sense for turbos, but what about NA? And for a turbo log manifold, would having very short primarys that went into the log at an angle that was with the exhaust flow be better than just a fatter style of OEM log? I would imagine so...

EDIT: I'd hold off on coating them until you decide if you are staying NA or going turbo. It would suck to have to hack on coated manifolds to edit them for a turbo flange and better flow.. Also you could build shorty headers that would be a comprimise. It would be better than oem for NA, and better for when you go turbo than long tubes..

[Nightingale]

Does jet hot need them to be cleaned before you send them in or do they blast them there no matter what? If they have to clean them anyhow for prep then I might just coat them in a decent DIY headerpaint just to protect them from rust.

[RacerX11]

Jet Hot will clean and prep them, so don't worry about it.

[onefastV6]

How about something like ZZP's Power Log?



Easy to manafacture and if designed properly should outflow the stocker by a nice amount.

[IsaacHayes]

ya that would be easy to make and be better for NA than stock and great for a turbo. I would personally make the primaries more of 45 degrees so it kind of forces the air from them into the log at less of a right angle..

[nocutt]

This was how I had WCF design mine...(unfinished pics)



...And they empty into a twin-entry housing...


IsaacHayes...a "log" will hinder an NA motor...importantly scavenging properties will be less than optimal...

Don't know much on how the ZZp manifold was designed...

[IsaacHayes]

nocutt: ok I thought so. Didn't know if you were talking strictly boos or not about the firing once per bank statement... Your manifolds look good, especially the primaries on the ends. The other ones I'd think a little more angle to them would help, but that takes up space..

[Superdave]

I'd just send them out and get them dipped. For the amount of time and money you put into making your own headers, it doesn't cost much to get them proffesionally done. Plus they have cleaning and coating processes that make them more durable that you just can't do at home.

I've got all the equipment to do it at home... that's why i'm doing it myself

I Paid $40 for 12oz of matte black 2,000F header paint... Just need to break out the sand blaster and go buy some acetone... then i gotta find my stupid paint gun... haha

Price from Jet hot was around $250-$275 including shipping... Price from the local place was about $150 (same stuff as Jet Hot).. I've got $40 and a few hours prep invested...

[Nightingale]

Looks like my order might have not gone through so I think I might just compromise and make a set of shorty headers. I can probably get away with about 8x 1.625 2.5" radius U-bends, and a length of 1.625 tubing, which would set me back a tick over $100 for tubing and bends.

*Edit*My original order did go through at Magnum Force Racing and is being shipped out today because I called them and confirmed it. Looks like logs are out of the question since I already have a crap load of bends coming so it will be either shorties or long tubes. If I can plumb it right I might still find a t3/t4 turbo with a divorced exhaust tang. It still makes sense that having the two banks fire into a crossover and then into the turbo would cause them to work against each other and slow the exhaust gases before they reach the turbo, where as keeping them seperated would allow better exhaust gas flow.

[AaronGTR]

I've got all the equipment to do it at home... that's why i'm doing it myself

I Paid $40 for 12oz of matte black 2,000F header paint... Just need to break out the sand blaster and go buy some acetone... then i gotta find my stupid paint gun... haha

Price from Jet hot was around $250-$275 including shipping... Price from the local place was about $150 (same stuff as Jet Hot).. I've got $40 and a few hours prep invested...

Thats not what I'm talking about, and no you don't have the equipment at home that I'm talking about either. You're just talking about painting the outside. That won't stop rust on the inside and it won't thermally insulate them to hold in heat (which increases your exhaust energy ya know. good for turrbo or NA both). It also won't be as durable as a dipping process and I know you don't have equipment for that.

I used to work at a powdercoating factory that was a tier 2 supplier to the big automakers so I learned quite a bit about performance coatings. Thats not what this thread is about so I won't go into it further but believe me when I say you can't do anything remotely like what they do.

[Superdave]

Is that a challenge?

j/k, i know what you're talking about. I do realize that i can't coat the inside which frankly, i'm not too worried about. I've ran headers on a 350+ HP 350 w/o coatings for years, they're Headman longtubes and yes.. they have surface rust but it's never gotten worse. The car is never driven in the winter so that probably helps...


Bottom line, the coating and prep i'm going to do will last probably longer than i'm going to keep the car. under-hood temps will be reduced and it will prevent rust on the outside (which will rust MUCH faster than the inside). With any luck i won't have to drive this thing in the winter either... too much power to get around in the snow and ice.

[Nightingale]

Welp I got my bends a couple days ago and started making progress on the firewall side headers. Looks like everything should clear including the steering rack. All the primaries are nearly equal length coming in at around 18". They are just tacked in place for now using flux core, but for final welding I think I am going to get a cylinder of Co2 so the welds look cleaner. Please excuse the horrible quality pictures, but I was using an old polaroid 0.3mp camera and bad lighting. I just use that camera for garage work so if it gets all dirty no one will mind. They look worse in the pictures then they really are, but these are my first attempt at headers and welding so don't be too harsh lol. I plan to copy this side for the front side of the motor for a matched set or atleast try and match the primary length. These are being mocked up on a 3.1L MPFI, but I plan to swap heads out to a 3400 or 3500 setup.

[Superdave]

Nice!

One thing i learned during that whole project.. don't ever assume anything.. test fit over and over and over untill you are absolutely sure everything will fit.


I had to go back and adjust my rear header because my engine wasn't sitting level (i had the trans mount off and i had a jack under the oil pan). No biggie.. i just cut out 1/8" with my angle grinder across all 3 primaries at the top, left a little metal on the bottom and bent them to where i wanted them...welded and they fit perfect.