Custom exhaust manifold build

[bastarddsm]

Gonna use the internal. If I do decide to by one ill run it from the exhaust housing.

Don't know if anyone caught this, but I'm not sure that you can run the internal gate on a T/S manifold. It only bypasses one scroll.

I use the internal gate on my HY35, and it works marvelous, but its single scroll.

 

[99gst_racer]

Don't know if anyone caught this, but I'm not sure that you can run the internal gate on a T/S manifold. It only bypasses one scroll.

I use the internal gate on my HY35, and it works marvelous, but its single scroll.

Wastegating from one scroll would be no different than from one runner or one pair of runners.

 

[Fehrion_sit]

The bundle of snakes is born!

 

[AwD4g63TsI]

awesome work brother

 

[SlowChild3]

Don't know if anyone caught this, but I'm not sure that you can run the internal gate on a T/S manifold. It only bypasses one scroll.

I use the internal gate on my HY35, and it works marvelous, but its single scroll.

Its the factory holset gate ill be using.

 

[bastarddsm]

Wastegating from one scroll would be no different than from one runner or one pair of runners.

This is a divided manifold so it really only bypasses two runners, and those two runners should have less back pressure than the other two. An open mani that gates off of only one runner like the turbonetics mani still lets the other runners release some too. It also the keeps back pressure equal on all cylinders, where the op's setup might not.

This could make the two wastegated cylinders run leaner. It could possibly have trouble controling boost.

I'm just saying that ALL divided manifolds wasegate from both sides. Maybe it doesn't even matter, but it just something to keep in mind, if it acts funny.

Its the factory holset gate ill be using.

Yeah I knew that. Thats what I run on my HY, and it works great. I have no doubts yours would work great to if you were running an open manifold, but with the divided, I don't know.

 

[99gst_racer]

Gating on only one "scroll" would definitely cause uneven backpressure. I'd bet about 50% difference. But I'd also bet it wouldn't have any negative affects on function and/or performance.

 

[SlowChild3]

Gating on only one "scroll" would definitely cause uneven backpressure. I'd bet about 50% difference. But I'd also bet it wouldn't have any negative affects on function and/or performance.

I agree. I'll put my faith in holset engineers.

 

[bastarddsm]

Gating on only one "scroll" would definitely cause uneven backpressure. I'd bet about 50% difference. But I'd also bet it wouldn't have any negative affects on function and/or performance.

I agree. I'll put my faith in holset engineers.

I guess we'll find out. I feel it will affect things, but probably not a lot. It does work for diesels, but a diesel is a completely different animal.

Not to keep beating a dead horse, but what cylinders feed the WG? I'm pretty sure #1 allready runs lean because of bad air distribution in the intake... Something else to keep in mind.

 

[SlowChild3]

I guess we'll find out. I feel it will affect things, but probably not a lot. It does work for diesels, but a diesel is a completely different animal.

Not to keep beating a dead horse, but what cylinders feed the WG? I'm pretty sure #1 allready runs lean because of bad air distribution in the intake... Something else to keep in mind.

#1 #4. Why would less back pressure cause it to run lean? The valves are closed when the cylinder fills with air right?

 

[SlowChild3]

Here is some more photos of my exhaust setup im working on. I couldn't find the size of the holset flange so i welded a new one on.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

 

[tron2119]

Love it man! I can't wait to see how good it runs.

 

[SlowChild3]

3" rear exhaust with 3" electric cutout to side exit. You might not see it but I do. Hopefully i'll get started by the end of week.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

 

[SlowChild3]

Playing around with some straight tubing. Came out great to give me an idea what needs to be done. I'm going to pie cut my 90s to tighten things up.

I haven't decided if I want to put the cutout at rear of car or out the front bumper. If I do the front bumper i'll have to route under the motor. I realized some of the side exits are 2.5". I bought 3". : /

You must be logged in to view this image or video.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

 

[RWD4G63]

I'm pretty sure you'll spool quite a bit slower and/or have trouble controlling boost with only one side wastegated.

Think about it. You're going to have to open that gate A LOT sooner to control boost spikes because you can only vent half of the gasses that are going to the turbo at any time. The other half is going to deliver their energy to the turbine unhindered. If it were to pop open at anywhere near full boost with the pedal on the floor, there's no way it can vent enough of the two cylinders to slow the turbine. Maybe if you're running really low boost.

Heck, other stock internal gates have this problem even though they grab from all four!

I'm betting they were going for smooth power delivery on the cummins vs max spool and power.

 

[ed1380]

It doesn't matter if a wastegate vents from 2 or 4 cylinders. A X mm wastegate can only flow Y cfm of exhaust. It doesn't matter if it takes 50cfm from each of 2 cylinders or 25cfm from 4. It'll still only flow as much as it can. That's why the internally gated hx35 only gates from one scroll.

 

[Gamble97]

/

You must be logged in to view this image or video.

I wish I knew how to do this!

 

[RWD4G63]

It doesn't matter if a wastegate vents from 2 or 4 cylinders. A X mm wastegate can only flow Y cfm of exhaust. It doesn't matter if it takes 50cfm from each of 2 cylinders or 25cfm from 4. It'll still only flow as much as it can. That's why the internally gated hx35 only gates from one scroll.

I feel like this proves my point, but I've put my theory out there. I'm interested to see how this turns out, as I've never seen it done before.

 

[SlowChild3]

You must be logged in to view this image or video.

I didn't use my elbows because i didn't want to waste them. You can't roll them 180 like a straight tube to oppose the angle. So far looks like i'll be able to run between my ofh and frame.

 

[ed1380]

have you considered getting a forward facing ofh?

 

[SlowChild3]

No. Bought a b&m oil cooler

 

[1983gsp]

Updates?

 

[SlowChild3]

You must be logged in to view this image or video.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

Its done for now. If the internal gate doesn't work ill be adding flange for external. Then I'll get it coated. I would have it running this weekend but I gotta go to the shootout!

Here is what i did to internal wg. http://www.dsmtuners.com/forums/showthread.php?t=444239

 

[SlowChild3]

You must be logged in to view this image or video.

Here's the final manifold. Forgot about this thread!

 

[GST2012GSX]

Wow, thats nice!