Now that it's winter I'm going to change the manifold WG runners a bit. With the manifold in it's current state I get boost creep even with a 46mm WG fully actuated. I have a few pic's of what it looks like after 3500 miles. It has held up awsome! The only thing that has changed is the color a bit. But anyways... Tell me what you think I should do to get better control over my boost.

 

Here is another angle.

 

dual WGs??

Looks good btw, I subscribed to your old thread and watched it anxiously.

are you planning on just modifying your existing manifold? or rebuilding from scratch? (I want your old mani. )

Good job on this Setzep... looks like it held up nicely.

 

Thanks for the complements.

I want to mod this manifold so I don't need to make a new downpipe and IC tube. I've thought about going with two WG's but I'd rather stick to just one because I already have it.

I have a idea in my head but I'm not sure how well it would work out either. I was thinking of tapping in right before the turbo flange on the inside of the manifold (outside would probably be better but my fender well is right there). Any ideas??

 

Here is what I was kind of thinking about. Think I have a future in photoshop?? haha

 

Didn't you save the pics I sent you with those you could get all that you asked for.

-Sean

 

I'm trying to remember what you said, that was about 2-3 months ago right?

Damnit, I just checked and I must have deleted them.

 

You need to get the exhaust to flow easily into the wastegate. Air is stubborn and will always take the easiest path. it doesn't like to make hard turns when it can just go straight. Do you follow? It's hard to explain it, better to show you. I'll look for some pics..

 

I know what you're saying but I can't think of a good way to route WG runers out of my manifold setup.

 

I will send you new ones tomorrow

-Sean

 

It's hard for me to describe but how about on the main runners on the outside of the bend right as they take the "S" turn. This is only about halfway down the runners. The exhaust would fire almost straight into them. I hope you can tell what I mean.

 

thats exactly what i was thinking too.. he doesn't really have many other options.

 

Thanks Sean

I know what you are talking about rotarygod but how can I tie them both together and go into one WG? Or are you saying keep my current configuration but move it down a inch or two so it will be in the bend?

 

I am in no way an expert, but I have seen many a manifold that is setup the same way as you have illustrated, and it works. My own manifold is run this way and I get no boost creep.

 

That's the thing... maxthe7man has a manifold that is almost exactly like mine and he doesn't have a problem either. I can't figure it out. I know the wastegate is operating correctly but once I hit ~6300rpm the boost will climb. The only thing I can think of becides the runners is timing. I have it set at 11 deg at 15psi. Could that be too retarded for a stock port 13B-RE, TD07 and my exh manifold??

 

Okay. Im not a photoshop expert but i hope this helps.
you want to plumb wastegate on each runner at the location i colored in. you will then need to merge these two tubes together smoothly into each other and into the wastegate. This should clear your boost creep problems.

As for why it's happening on yours and not your friends could be many reasons. Are your turbos the same? It sounds like yours is more efficient. Also do you guys have the same exhaust setup? Or is yours bigger? Downpipe?

 

What are you using as a boost controller? How much boost creep do you get?

 

Enzo250 has a good idea... One thing that I will add, since you obviously put effort into getting the main runners the same length, you should try to do the same for the W/G runners. With all the researching that I did before building my mani, I learned a few things:

1) equal lenght main runners important (we all know this by now)
2) maintaining the W/G runners as equal length is also important since this will affect the pressure waves inside the manifold. Unequal internal volume will change the characteristics from the ideal.
3) Lastly, and Ihave read this several places on this forum from respected manifold makers. if you are using a single W/G, ideally, and this is more difficult... the length of the W/G runner tube from the engine flange to the WG should be the same length as the main runner tubes. As I understand it this, since the gasses are essentially being combined at the WG, maintaining the same length as the main runners will reduce the tendency to combine the rotors' pulses and reduce the energy.

That said, part of the reason I went with two W/G's was b/c I figured it was easier to mount two W/G than to screw with trying to get 4 tubes exactly the same length.

-Chris

 

??

why wouldn't you need to make the WG runners the same as the main runners when running dual WGs? I would think in the "perfect" manifold you would want to make everything the same so that everything was moving at the same frequency. I am sure that the WG runner length and placement plays a huge role in how the manifold is tuned and how effective it is, I just haven't come to any conclusions...

setzep, if I were you (even though it may cost more $$ and time) I would go to using dual wastegates to take full advantage of the divided setup. As I see it, you essentially have an H-pipe balancing the flow and pulses between the runners.

If you modify the manifold like rotarygod is stating, it seems like to me you would NEED to make the WG runners the same as the main runners. I would treat the WG as another turbo...

 

In my case the WG runners are very short almost non existant. The flange is practically welded to the main runner on the pipe with only a very small straight section (1"), to direct flow to the valve. I was shooting for equal volume within the chamber and since the pulses aren't ultimatley being combined as they are in the turbo or at the junction of a single WG design, I didn't see the need to treat it as another turbo in the system. However your point about treating the singe WG as a turbo is, IMO, spot on.

I also agree with the "H pipe" comment..

FWIW, there may be advantages of a dual WG setup with 4 equal lenth pipes, I think with the really short WG runners that the system will act as though there are only main runners. Now if you have 15in mani runners with separate 8in WG runners... I have no idea how that will affect thing

 

Sent you a e-mail

-Sean

 

ya, that's what I meant in reference to him only modifying his setup (retaining the single WG) per rotarygod's recommendation for the placement of the WG runners.

That's a pretty interesting idea making the WG runners so short - I hadn't thought of that. Is it angled 90* from the runner or at an angle? I guess I'll have to do a search and find some pictures...
IIRC, your manifold is the one that is fairly straight and long and projects the turbo very far forward and up?

Back to setzep, but on a completely seperate note, the manifold looks pretty good...you're making me really want a TIG welder again....it's been on a very lengthy wish list for many moons, but we have to have goals right?
must...save...money...for...christmas...

ZeroR, enzo250, IGY -
let's hear more "real world" results from your manifold designs and experiences....

-Nic

 

The WG runners are angled slightly, I was afraid 90degrees, which could essentially eliminate the need for a tube, wouldn't have a good flow path.

Mine is fairly straight and long and forward.... which was namely a result of my own requiremnt for the pipes to be single piece mandrel bent and equal length. I was limited by the grip length on the bender and my desired length so that drove the shape. The cool thing was that I sent XYZ coordinates from my CAD design to a shop, the pipes came back, I had them welded to the flanges and put it on the car. Very simple process and fairly cheap except the welding (which I need to learn)

BUT, one feature of Setzep's mani that I really like and didn't achieve with my own design is to maintain 3" of straight runner immediately after the engine. I have a few ideas to incorporate this onto my next design. while retaining the single mandrel pipe... I think......

Setzep, could you remind me what turbo you are running A/R's and such, DP size and what the boost response looks like? There are finally enough people chiming in with expereince to get better and better ideas for the mani designs


couple of pics of mine:



-Chris

 

First off, thanks for the replies everyone!

enzo- thanks for the rework pic's, I'll have to take your ideas into consideration.
maxthe7man's manifold actually looked a little worse as far as WG runners go. He plumbed them from the same place but used more of the "T" method.
I'm not sure what exhaust he had but I have 3" mandrel bent all the way to the tail pipe, only one muffler at the rear that is straight through.

igy- I have no boost controller. I have a line running from the outlet of the compressor housing to the side of the diaphragm on the WG, top port is open. 7.25psi spring. Here is typical log of my boost creep:
8-9psi steady up till 6100rpm
6200- 11psi
6300- 11.5psi
6400- 12psi
6500- 12.5psi
6600- 13psi
6700- 13.5psi
6800- 14psi
6900- 15psi
7000 - let off
this is in 3rd gear.

carx7- I'd love to get the WG runners the same length but don't know how I will with my setup.
I'd rather stick with this single 46mm tial for a few reasons. One is I already forked over the dough for it. Two is I'd rather keep the plumbing down to a min. It's easier to plumb in one WG dump tube into a DP than it is two. Three is I don't know if I have physically enough room to put two WG's in there.
The turbo is a TD07-25G, 17cm divided turbine housing. I'm not sure how to convert the 17cm into a/r. From what I hear it's a tad bigger than your standard 60-1, p-trim turbo.

suganuma- You are right, it does kind of have a H pipe effect. I tried to get away from that a little with the bend in rotor #2, I gave it more of a Y vs a T.

I'd love to get more ideas from anyone. If anyone wants to see a picture from a different angle or on the car just let me know.

Thanks guys
Cam

 

CarX7:

Did you buy your 10 anniversary from Brian in Sacramento? If so, id love to see how your project is going!!!

Graham