Structural Considerations for Twins...

[600 Megawatts]

Just thinking about the loads on the exhaust manifold from hangin a big honkin primary turbo, hot pipe, secondary turbo, compressor piping, and even a portion of the exhaust system and downpipe all on that manifold that was essentially designed to hang a single HX35 on ??

Anbody cracking good three-piece exhaust manifolds with the weight of twins?

Has anyone fabbed up a sprung support to the side/back of the block to carry the majority of the weight of the primary ?? This is what I in thinking of doing in the fall when I build the twins....

 

[JFlagg]

A brace to carry the weight is quit common...

 

[Scooter's Roofing]

most kits use a support bracket for the bottom turbo

 

[MAXTORQ]

Most use brackets , they mount in some cases from the two bolt holes in the tranny adaptor plate up to the motor mount.

 

[Scooter's Roofing]

I also know a lot of people who don't use a support bracket and no cracked manifolds

 

[carfichris]

Our TwinPlate has a spot to brace it to the rear of the manifold and the bellhousing. Takes the load off the center section. It also has a wastegate provision.

 

[renopker]

this is how my bracket looks the drain pipe is made with it

 

[BgBlDodge]

I know rip's kit has a bracket that mounts on the oil drain spot and incorporates the oil drain in to it. Pretty neat little thing.

 

[Diesel Freak]

yep, Rip's bracket fits a S400 and a GT42 (just have to gring on it to make it fit)

Next you may want to consider how much the hot pipe grows as it heats up. It's not much, but it has the ability to play havoc on gaskets.

Also, Hot pipe welds if not done correctly, will crack. If you use a non pre-heated workpiece, and a MIG, try to do a post heat treat on the pipe to anneal the welds.

If you dont have an oven, a rosebud works just as well.

 

[SINNER]

I made this bracket in about a half hour. 3/16 304 stainless. There is a third bolt to the rear of the bracket that is hidden by the ex. housing. s400 frame turbo on a CR block. When I get my oxy. bottle filled I will rebraze the oil drain to where I want it pointed.

 

[Jim Fulmer]

Simple but it works for me.



Jim

 

[600 Megawatts]

Yep, thats what I thinkin too. I cant believe those who dont have a support arent cracking manifolds....

Thanks for all the posts !!!!

 

[soulezoo]

I ran without a support for quite awhile with a BHT3B... I don't recommend it and I did get one eventually. I guess the downpipe and exhaust pipe provides some support; that 3b is no small turbo.

 

[95ram]

600, are you going with a 3b or 400. I think I've still got a couple 3b brackets around.

 

[Jim Fulmer]

I also know a lot of people who don't use a support bracket and no cracked manifolds

I ran Twins for years without a support bracket and zero issues but with this last setup I did build one for good measure.

Jim

 

[Scooter's Roofing]

oh definately... my last two setups have had supports. just sayin' is all