trying to make a turbo manifold....??
 

we're in the middle of making a turbo manifold for my car and just wanted to see what you guy's thought of this....
I know most everyone uses Schedule 40 piping, which is preferred... But I have a local shop that sells .090" thick roll cage tubing. I've got a mandrel bender and it will bend up to 1 5/8 tubing and wanted to know if you guy's thought:

-a wall of .090" would be thick enough to take the high heat of high boost race pass's

-also, what size diamater tubing do you guy's run? I think 1 5/8" would be enough for a slightly ported B18C(GSR) head.. (ie. the piping should be large enough to accomidate the large port exhaust volume.)

As alwayse, thanks guy's for the help. Figure'd I'd ask here first since I know there's gotten to be alot of DIY Mani making

Re: trying to make a turbo manifold....??
 

Chances that .090W will hold up are pretty decent... I would brace the manifold just for some extra assurance.

Another thing you need to consider is how tight your radius is on your mandrel bender, and then look at the bend radius on the plumbing bends.

Re: trying to make a turbo manifold....??
 

yeah def brace it. but whatever tho, if it sucks, at least you tried.

Re: trying to make a turbo manifold....??
 

woow i think that's the nicest thing i have ever seen hotrex say. :o

Re: trying to make a turbo manifold....??
 

i braced this pig just because

finished her tonight for a buddy.

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Re: trying to make a turbo manifold....??
 

so again... even you josh, what size diamater piping do you guy's use for all your manifolds?

Re: trying to make a turbo manifold....??
 

schedule 10 1.5 inch weld els

Re: trying to make a turbo manifold....??
 

just fyi, gravity pulls down, not foward

THIS is a brace:
http://gurneyflap.com/Resources/DSC03767.jpg

Re: trying to make a turbo manifold....??
 

i made mine out of 16g 1.75" tubing with NO braces. i just added some gussets. no cracks and i don't expect any. much easier to work with and quicker to build. no straight pipe required if the u bends you get have legs on them, which most do. a lot less prep work and much fewer welds.

http://img208.imageshack.us/img208/1127/dsc046679ww.jpg
http://img208.imageshack.us/img208/3885/dsc046648se.jpg
http://img101.imageshack.us/img101/7360/dsc046666qd.jpg
http://img80.imageshack.us/img80/879/dsc047205jd.jpg
http://img80.imageshack.us/img80/841/dsc047222ig.jpg

Re: trying to make a turbo manifold....??
 

His brace is still better than nothing and will add strength to the manifold.

Re: trying to make a turbo manifold....??
 

Definately takes some stress off of the manifold when starting and stopping. That brace you showed is a little over the top.

Re: trying to make a turbo manifold....??
 

Lol, thats a joke right? :o Make sure your company doesn't build any parts that require engineering or try and build suspension components, you might end up killing someone.

Re: trying to make a turbo manifold....??
 

I thought this was the mani you were whoring out on H-T?

Re: trying to make a turbo manifold....??
 

no, if he made it for a friend its okay. But when whoring it as a product thats a no-no because he's banned from selling. He's advertising but not making it seem like he's advertising. Get it? :S lol

Re: trying to make a turbo manifold....??
 

Most likely isnt. Hotrex isnt known to be smart. :1

Re: trying to make a turbo manifold....??
 

im thinking that brace is gonna brake off eventually.. also.. prolly weakend the ---- out of where it was welded to the runner.. also.. why didnt u just run it all the way up to the flange :-\ i wouldnt have welded it to the turbo flange either.. i would have had some kind of sandwhich plate over the turbo flange and ran the brace from that over to the exhaust flange..

http://img139.imageshack.us/img139/5750/turboek0.png

also, instead of welding it to the exhaust flange u can just weld some washer to the end of the brace and say bolt it to the manifold bolts.
like this..
http://img104.imageshack.us/img104/671/turbobb9.png

also, ill prolly never build a manifold in my life :P


ok ill shut up now :1

Re: trying to make a turbo manifold....??
 

you have to allow the turbo room to move around as the manifold expands and contracts...hence the heim joints on the brace i posted.

Re: trying to make a turbo manifold....??
 

yeah josh's topmount looks nice, but i'm thinking it may crack eventually. Think of all the vibrations you get when you go over ---- ass roads and how much everything moves, especially at higher speeds and in a car with rough suspension. That 25lb turbo is gonna have a lot of leverage over all those pipes and welds. Granted the brace is a nice attempt, but yeah not sure if it'll be enough. Hope i'm proved wrong cause it is nice, but holy ------- tight fit josh. Hope the next one tucks it in a little more.

Re: trying to make a turbo manifold....??
 

if welded properly it wont crack.

Re: trying to make a turbo manifold....??
 

Josh's mani is bad but I think it would be better if it didn't extend so far out cause thats alot of stress thats being cantilevered out brace or not. I think if it was closer to the block then it'd be perfect.
Buk your idea on those braces is...ahhh...kinda ssauto'ish. I think it's the turbo that you should be bracing not the manifold to itself. Make a bracket that uses the existing holes in the block as there's enough of them from the ps or ac mounts. I used a piece of 1/8 steel and it held the good size turbonetics snail I had held in a vice and wasn't sagging whatsoever.

Re: trying to make a turbo manifold....??
 

will hotcheeks defend his stirling intraweb rep ??? ;D

Re: trying to make a turbo manifold....??
 

If hotrex did a decent job of welding the manifold, it should last quite a while. We are still talking about very thick material which helps prevent quite a bit of problems as far as cracking is concerned. That brace is a piece of ---- though. It probably going to do more harm than good. Just weld some sort of bracket that supports the turbo in place and has some ability to move around a bit. That way when the manifold moves and shifts, twists and turns, the load will be minimalized on the weld joints. Right now, the brace is poorly attempting to keep the manifold put. Let the manifold shift and shake. You can't really prevent that do to the engine is going to shift and shake, just make it so you minimalize the loads

Re: trying to make a turbo manifold....??
 

this was a mani i asked for feedback on in the h-t fab forum. i decided against this design, and sold it to one of the local kids. you wont see another one like this from me. he wanted the piece of steel there, so i pt it there for him.

and lastly, i dont forsee this manifold cracking. the welds are butter.
heres a pic or 2 of it with the dp. and a turbo on it. it fits really nice in his eg hatch.

our new design is much better and will include a nice brace with it. ala renaulter styles. hate on brothas.
Attachment 32990
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Re: trying to make a turbo manifold....??
 

for one reason or another the design that you asked for feedback on and the new one look quite similar? ???

Re: trying to make a turbo manifold....??
 

what are you talking about, i havent even built the new design yet. this is the same manifold i posted on h-t

Re: trying to make a turbo manifold....??
 

I must have read it wrong or something. I assume the car pictured is the local kid?

Re: trying to make a turbo manifold....??
 

yeah, this is the manifold that i posted on h-t. we wanted feedbakc, after some deliberation we decided we wanted to use a longer collector and work on runner length. but since this mani fit pretty well, and was already fabbed, i prepped and welded it fora local kid. you wont see this manifold ever built again.

i must say in person on the car it looks sexy as hell with the 3 inch dp and ssautopoopie turbo.

Re: trying to make a turbo manifold....??
 

i agree it is pretty sexy :y

Re: trying to make a turbo manifold....??
 

looks good and i doubt it would break with or without the brace

Re: trying to make a turbo manifold....??
 

I love all this talk about 'stresses' and what braces will work and which ones will not.

A funny thing about 'engineering' something is customer perception. If it looks tough, it probably is tough.

I was not real sure about the comment about gravity pulling down and not forward... what that was supposed to mean.

If you weight the turbo, and measure the distance from the block, that is a 'moment arm' and it will produce a bending moment about the flange. Along with this, there will be a direct shear force on the welds of the flange due only to the weight of the turbo. Welds are also weakest in shear.

If you would really like calculations to verify whether it may break or what (if any) factor of safety gaurding against failure, I will get out the ti-89 and some graph paper and go to town.

Re: trying to make a turbo manifold....??
 

There is no possible way you can sit down with a calc and just come up with what kind of brace will be optimal in this situation since you don't know a lot of variables. Honestly, its not worth calculating. On a product like this, its simply best to go way overkill and be done with it. Calculating a moment based on 3 axis on each joint will take forever to do by hand. You'd absolutely need to throw it in a 3D modeling software in order to be atleast somewhat effective. Again, a waste of time. Just make it so the turbo can sit on the brace in the position you want it to be and can also move a 1/4-1/2" in every direction. Problem solved.

Re: trying to make a turbo manifold....??
 

not the best way to build a brace. a trully functional brace should go from the engine to the turbo not from one part of the manifold to another. look at hotrex's manifold do you really think that thing will break anywere but off the head flange witch would make that little "brace" absolutly worthless. but that harly matters because with this thick ---- the import world has embraced, if it is welded correctly and not designed with too much excess legth in runner the pure strength of the material is already overkill.

Beau

Re: trying to make a turbo manifold....??
 

Thanks for repeating what I already said a few posts up.

Re: trying to make a turbo manifold....??
 

no problem just dont want so poor bastard thinking he can make a brace out of 1/8 rod and because the turbo can sit there and be flexed around a 1/4-1/2 " that hes doing the job overkill.

Re: trying to make a turbo manifold....??
 

Lol, did you just get done an engineering statics class and looking to impress people with technical terms. :S The problem isn't a bending moment, its a stress concentration problem. You don't want to build a brace to prevent the runners from cracking by bracing them to the runners you are trying to brace. You support a roof to the ground, not to the shingles.

Re: trying to make a turbo manifold....??
 

I really like the gussets on Aarons manifold, pretty sweet looking, I know he used some pretty thin stuff so I hope it holds up ;)

Re: trying to make a turbo manifold....??
 

my cats name is mittens

Re: trying to make a turbo manifold....??
 

I made mittens from a cat.

Re: trying to make a turbo manifold....??
 

I agree. In fact, I have a question about that (not really directed at you abaz, at aaron). What guage steel were you using for the runners and what guage of steel were you using for the gussets? Could this be a possible ssautopoo hack fix to stop their mani's from cracking?

Re: trying to make a turbo manifold....??
 

it was 16g for the runner. dunno about the gussets