L6 Turbo Header Group Buy

[stprasinz]

I think the copy of the stock manifold would mean that it was the same place the turbo would be located... I think that would work. I have a stock manifold but there is a extension approx. 1.5" to allow for the clearanse of my large compressor... but the header they would make would be of tubular design I am asdsuming(not cast) meaning it would flow significantly better.... even log style would flow better.....

 

just my 2 cents...

[jeffer949]

they are talking about making a log style copy out of stainless. which would flow elot more then the stocker but not as much as a tubular one.

[TrumpetRhapsody]

If it's only going to be a log style instead of tubular, they'd better be offering it pretty cheap.

 

I was expecting this to be a tubular GB.

[78280z]

If it's only going to be a log style instead of tubular, they'd better be offering it pretty cheap.

 

I was expecting this to be a tubular GB.

 

Agreed. Like I said in my previous post (page 6):

 

I would not want to pay $200 for the addition of an external wastegate and slightly better than stock flow characteristics when stock headers can be found for $50.

 

We have the opportunity to design a turbo header, have it produced for us, and be able to buy it for around $200. Given the opportunity, why not design the best performing header we can (that also best accommodates everyone's interests)?

 

At the very least, if we don't want to design one from scratch, we should find someone who has a custom tubular header (like the ones shown in pics earlier in this thread) and have that one replicated.

[jeffer949]

The Guy at ssac says he cant promise that it wont have to be cut up to make a copy of...

[78280z]

Hmm...then I'd say we should design one and give them dimensions.

[sticky280zx]

im with you all the way 78z...i sent a link to the pic of the one me and im thinking many others would like to have back on page6....now we need to know who has it....if we can borrow it...or just get the demensions....

[jeffer949]

allright so if we are going to make our own manifold where does that put us? i dont have the capabilities to design one. so im gonna need help.

[TrumpetRhapsody]

Would the best way, assuming we have to design it, be to give them a CAD model? You might ask them if they can even make stuff based off CAD, or if they are just hack-and-copy creators. I can think of several CAD gurus around there that might have a little fun designing a header and having it actually mass produced (don't look at me though, I'm amateur at best).

[78280z]

Yes, it will be an enormous undertaking, but I'm sure the many experienced and skilled members of this forum will be willing to help out and lend their knowledge if we ask them.

 

I have some CAD experience, and I'm sure many others do too, so I'm sure we could throw it down if need be. We should check into how they would want our design prepared (CAD, SolidWorks, etc.)

 

But anyway, before we even think of starting to design, we should really nail down exactly what we want.

 

Obviously, we should go for a tubular design for best flow (and since that's what most everyone is after). Here's some advice from Nigel (page 3) on that:

 

TUBULAR MANIFOLDS

 

When designing a tubular manifold, the goal is to keep as much thermal and kinetic energy in each exhaust stream as possible. Short tube lengths are better than long ones. A minimal number of bends is also preferred. Where bends and turns in the tubes are required, keep them gradual and smooth. Large radii are better than small radius bends. It's also important to keep the individual tubes as equal in length as possible. The closer they are to each other, the faster the turbine spool-up will be.

 

Note, too, that the individual tube diameters on a properly engineered manifold tend to be slightly smaller than on a similar NA engine. Usually the cross sectional area of the exit port on the cylinder head is a good starting point for sizing the runners. For tubular manifolds, it's better to err on the small side, which will maintain gas velocity and reduce the exterior surface area, helping to minimize heat loss.

 

It's better to group cylinders that are far apart in the firing order together in the collector.

 

 

Based on this information and other posts in this thread, I'd like to take this opportunity to help organize the design process. I think we should take things step by step and not try to throw everything together at once.

(Disclaimer: I do not intend to give the impression that I know everything about the design process nor do I intend to be bossy, I just thought it would be nice to have a clear cut plan. Let me know if you think I should have added anything else.)

So, here's my plan:

 

First order of business is to size the thickness of the manifold flange (that mates the header to the cylinder head) and the location and size of the holes for the exit ports of the cylinder head (should match locations of and cross sectional areas of the exit ports of the cylinder head).

 

Second order of business is to size the runners (inner diameter and wall thickness). Again, we need the measurement for cross sectional area of the exit port of the cylinder head.

 

Third order of business is to decide about the pulse tuned and equal length dilemma so that we may decide exatly the path of each runner and how they will come together in the collector. Careful consideration will need to be taken here to ensure that everyone will not have turbo clearance issues. This phase will involve much cooperation among members to ensure proper measurements and to start the ball rolling on drafting the design in CAD.

 

Fourth order of business is to decide what type of turbo flange to use.

 

Fifth order of business is to decide what type of external wastegate flange to use.

 

So, there's my five step plan to turbo header success. Again, if you feel I have left anything out, don't hesitate to let me know.

 

 

If you guys all like the plan, then lets go ahead and start with our First Order of Business.

[JIM73240Z]

1/2" flange. cold fusion made a run of them before and some one can do it again. i know the cad file is out here somewhere.

 

match the diameter of the runners for the diameter of the pipes and as equal length as possible.

 

jimbo

[OlderThanMe]

I'd design your header in Solidworks in trade for one of the tubular headers or the cash to renew my solidworks subscription that runs out in like September...

 

If everyone pitched in a couple bucks that could get a good design going.

 

BTW I do have a stock turbo header (the one with the more mid-mounted turbo flange, there were at least 2 different USDM turbo L6 headers)

 

The first order of business is easy... there is already a turbo flange designed that you can download from HBZ.

 

Second order...

What sizes of stright and curved tubing and thicknesses are available?

 

Third order...

Eh... you aren't going to do equal length tubes unless you want it to end up looking like Monzter's header. lol The SFP header is a good design I think.

 

Fourth order...

T3 or T4

I vote T3 because the wide range of turbos, including big Holsets up to the HX40.

 

Fifth order...

I vote use a JGS precision 50mm or 60mm wastegate with the V band.

[JSM]

Fourth order...

T3 or T4

I vote T3 because the wide range of turbos, including big Holsets up to the HX40.

 

Fifth order...

I vote use a JGS precision 50mm or 60mm wastegate with the V band.

 

I'm okay with all except 4th and 5th. T3 or T4 should be an option.

 

Also 60mm is to big in my opinion and WG get very expensive in this range for a quality one. + $500 is crazy in my mind for a WG.

[OlderThanMe]

The JGS 400 series wastegate is a nice unit at $239...

http://www.jgstools.com/turbo/index2.html

 

T4 being an option wouldn't be that hard........

[jgkurz]

I'm okay with all except 4th and 5th. T3 or T4 should be an option.

 

Also 60mm is to big in my opinion and WG get very expensive in this range for a quality one. + $500 is crazy in my mind for a WG.

 

I agree. T3 or T4 should be an option. There is even a flange posted earlier in this thread that would do both.

 

Secondly, big wastegates are typically used when you have a relatively BIG turbo for your application and want to run low boost like 10psi or so. We should have a couple options here as well. I need 40mm but I can always modify if the masses want something different.

 

For the tubing I highly recommend 1 5/8 primary OD with 1/8 wall mild steel.

[78280z]

Again, I don't want to be bossy or offend anyone since I'm a relatively new member (you guys have been around for much longer and know more than I do about cars). But, I think it will be much easier to get this done if we really stick to the plan and take care of things step by step. Let's leave the discussions of equal length runners, turbo flanges, and wastegate flanges for later.

 

First Order of Business: Manifold Flange

As stated above, there is a CAD file of a manifold flange in the downloads section of this forum. So, we have the exact dimensions we need as far as the shape of the ports and placement of bolts. After doing some research and looking at recomendations of forum members (JIM73240z, ColdFusion, 240hoke), we also have a flange thickness of 1/2". Is this agreeable to everyone?

[Slow_Old_Car]

flange thickness should be on par with stock intake manifold flange thickness in order to prevent needing washers IMO.

 

i'll bust out the micrometer and measure a spare intake manifold flange later tonight and report back. but then again everyone may be o.k. w/ washers.

[OlderThanMe]

I think there is an interference problem with the downloadable header flange and 1 5/8 tubing with a 1/8" wall.

Here is what I mean (#1 cylinder looking from cylinder head side):

The overlap inside is fine as it can be ground down and such, but look at the top left at the bolt hole. The tubing actually overlaps the flange cutout. Don't mind the angle of the tubing bend, but the actual part of the tubing that is overlapping the hole for the bolt.

There isn't much room for a weld either on that flange.

I'll check my turbo manifold when I get home to see if it is like this and what can be done.

[Slow_Old_Car]

coming back to that though, don't most guys deform the end of the pipe before welding to the flange anyway? pretty sure every manifold i've seen so far has had a hammered out end to resemble port shape. i think one thread even detailed how they achieved it.

[Tony D]

Is the manifold sent in the stock US/JDM spec manifold, or the vastly superior European Spec manifold?

 

The Eurospec Manifold has internal passages that are at least 1 5/8" diameter in the log section (larger than the O.D of the SFP header group buy of several years ago). It does come in three sections, that can be joined by a manifold connector available at the Mercedes Dealerships Worldwide (thanks JeffP for that legwork)... Adding an external wastegate to that manifold should easily support 600+HP flow-wise, and if you 'thickened' the stock flange mounting area by 1/2" that would make the clearance similar to the stock one with the 1/2" spacer everybody seems to add to them to get the compressor clearance with the larger scrolls.