I am going to start from the head out by fabbing up...
A new exhaust manifold that is either 1.5" ID pipe or 1.75" ID (depends what the local place has) and uses 1/2" steel for the mounting tabs and 1" for the turbo mount. On the mounting tabs to the head I will elongate the holes slightly to allow for any expansion/contraction. I will also plumb an external wastegate directly into the manifold that will be 40-44mm and bypasses the top turbo.

I am going to run a 14cm non-wastegated HX35 with the biggest HX40 compressor wheel I can get. I will use 3" ID mild steel for the hotpipe down to a 1/2" thick flange hanging a 76-77mm inducer BHT3B with a 23cm exhaust housing.

For the cold piping between the two turbos I am going to use 3" ID exhaust piping and try to use the least amount of pipe and radius bends as possible. I'll have 5" ID for the pipe that the 3B draws its air from and sit either a huge Nanofiber filter, K&N or AFE filter on there.

I will gasket match everything and all of the tubing that the exhaust runs through will either get coated by swain or get lots and lots of heat wrap around it. I also think that making the cold pipe smaller and as short as possible will help everything get going between the two turbos faster by keeping more velocity, as well as the hotpipe; smaller area less expansion = more heat retention and velocity.

What I am really hoping for is a great street driving twinset that will spool almost as fast as my stock turbo but "hit" a lot harder and keep it pulling way longer. Tow just about anything (up to 10k)anywhere without EGT concerns or super lag. And last but not least hopefully it can let me lay down 600rwhp with #2 and MAYBE the use of water and not too terribly high EGT (I would like to not peg the gauge).

Anyway I just thought I would post to see what anyone thinks since I am super bored getting ready to head out of town at 5AM lol.

 

Sounds good to me....make sure to support the weight of the chargers from something other than the manifold!

If you want a really big filter, like a 5" x 18" AFE, you'll probably need to lose, or relocate the second battery...at least I did!
Chris

 

Any reason why you chose the BHT3B instead of a B2? Sounds like a good plan...

 

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Muddin_dude06:

It sounds like you have everything pretty well planned out.

I was going to let you know that when I had the HX-40/16 as my top charger I had a Tial 38mm Wastegate plumbed into the ATS Manifold about in the middle section, near where the HX-40 hung on the manifold. I believe this was close to how you described wanting to do your set-up. Muddin, I had ALOT of problems with the welds cracking around the short steel pipe we plumbed into that ATS Manifold that the Tial Wastegate was sitting on! Three times it cracked on me which we believe was due to the vibrations of the engine. I got so tired of fighting it, that on my present set-up I went to that Schwitzer 62/12 with the "dual-flapper" wastegate and my drive pressures have not been a problem. I am not saying you should change your plans on your set-up, I just wanted to let you know about the problems I had with mine as "food for thought."

Also, I worry about your exhaust gas temperatures with that 14cm housing.
They spool real good, but I have also seen them cause higher EGT's especially while towing. But, you could always put a water injection system on there if that is a problem.

Anyway,......good luck to you Sir!

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John_P

 

stay with your hybred 35/40 turbo. 16cm housing is too big for any decent spool-ups. I would stay with the stock 35X and run the 3B. This is the cheapest twin set-up. The hot ticket is the 26cm 3B. How you building your hot pipe? I took off the holset exhaust cover and bolted up the PDR hot pipe. Set your wastegate up at the stock pressure of 20psi and make sure it opens all the way. If you don't you'll have killer egt's and laggy spool-ups. Another killer turbo is the garrett K-31 and it has a internal wastegate. For 600 HP, you should be in good shape. Also I would use 3 1/2in air tubes but no bigger. My set-up has the 4in. Happy welding. Also put in extra supports on the hot pipe so it doesn't crack and I also would put in studs the exhaust of HX-35, so the hot pipe doesn't wiggle loose. I'll also need a 3/8 spacer on top your exhaust manifold. I would studs into the manifold turbo exhaust flange. Bolts just come loose too often and drives me crazy.

 

I want to use a BHT3B because I have one here that has a 32cm housing and a buddy of mine is going to give me a heck of a deal on a 23cm, so I will just send mine off to get a full rebuild with a new comp. wheel that is as big as they have (77mm I believe).

Chris, I will most likely relocate both of my batteries to my toolbox in a protected (but vented) area in the corner, under hood is just so cluttered now IMO lol. I think I will weld a bracket that comes off of the engine mount and it will probably be about 10lbs. I like to make my braces/supports I weld extra beefy .

John P, I have heard of these problems with welds cracking before but I believe that since I am going to fabricate my own manifold (much like Hellmann's only smaller ID) with mild steel I shouldn't have to worry to much. The wall thickness would be about 3/16" IIRC, do you feel that would be sturdy enough? Was yours welded into a stock cast manifold?

I plan on building the manifold to kind of compensate for that extra space normally needed for the compressor cover-to-manifold clearnance. That is why I will use a piece of 1", I want the least amount of joints and edges in the exhaust stream. I figure if I make a nice wide base with the 1" that is almost large enough for a T4 flanged turbo, I can port the insides to help keep the flow nice and smooth on the inside. More of a "J" shaped bend instead of an "L".

To build the hotpipe I will probably position the 3B where I feel best with a good solid mounting bracket and then make LOTS of measurements and use a thick-walled 3" ID schedule 40 elbow with a V-band flange to attach it to the top HX35/40 hybrid.

Does anyone have idea what this setup should support given it goes along my guidlines? Is my goal of 600rwhp using only #2 and possibly water injection sound doable? Thanks everyone for reading the long posts and giving great feedback...!

 

My numbers are in my sig with a the same setup only I used a B2. My external wastegate is a Tial 38mm. I know it has 600 rwhp in it with some tuning. I didn't spray water either, that would have put me closer to 650.

 

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Muddin_dude06:

My Tial 38mm Wastegate was welded into a three piece ATS Manifold, not the stock one Muddin. The 3/16" IIRC should be good enough, but I will check that with my fabricator to see what he thinks too. As I said in my earlier post, it sounds like you have everything pretty well planned and it should come out good for you. IMO, you should be at or a little above 600 H.P. with your set-up.

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John_P

 

I think that you would start to run out of air for 600rwhp using those turbos. It might get toasty, IMO. I hate to say this if your going to use your 23cm housing, use your HX-35 top turbo. A 26cm turbo is pretty cheap upgrade down the road. I bought one for $600 this summer. I've seen HX-35/3B(26) combo set-up handle 700rwhp, on a p pump truck.

 

I will also be adding a Greg Hogue camshaft as well a little later or sooner depends on how I want to spend my money lol. My biggest thing is that I want a solid 600rwhp and daily drive as close to smoke free as possible with nearly instant spoolup. I am a hair on the greedy side haha

 

*taking notes*

 

That is why we are all here I think...

 

I thnk you ll lose to much heat fabricating your own header. Even coated and wrapped it will pale in comparison to a cast iron peice. That coupled with the 35/40 hybred, I think it will be lazy in comparison to a cast iron manifold and a stock hx35 . I tow around 18k lbs most of the time, I use a hx35/14 non gated housing and a ht3b 26. On the stock manifold....next week Im gonna try and get my ported/ coated three peice manifold on. For tow 10k youll be ok probably, but I think ultimately the hx35-3b -26 delivers a wider power band. Your raising the low end by going hybred and lowering the top end by going 23 cm housing.

Will it still work....you bet and probably fairly well.

 

I have YET to see ANYONE fab a exhaust manifold which will outperform any of the already established ones available.To me this is a waste of time which could be put to better use elsewhere.....

As HOHN said....Taking notes,Pass the popcorn Bowl Justin..........Andy

BTW Muddin Dude...
John_P's 891 was done with a ATS manifold,Offshoreracrs 852 with a ATS as was TiminVa's 875...See the photo being painted here?.

 

The ATS is a nice piece but it would be fun to build my own, and if it turns out as good or better than I would like it would be better than one of the others.

Joe Hellmann runs 10's and is 950+rwhp with a 2" ID manifold that has no coating inside-or-out and no heat wrap.

http://hellmannperformance.com/12%20...20manifold.jpg