V-Band clamp size for 76 turbo downpipe

[SPEEDSTAR]

I am building a stainless 4" downpipe for a future upgrade to a 76mm turbo, getting to play with my new Miller syncrowave Tig welder, and I need to know what size V-Band clamp to weld on, I"m thinking a 3" would be right if the inside dia. is a little larger than the exhaust housing opening...any help from the turbo experts would be appreciated...Jeff.......also what do think about me putting a slow twist divider inside starting 4 or 5 inches from the housing to keep the flow velocity up?

 

[Louie L.]

I dont have an answer but which Miller do you have . Is it the Syncrowave 180 SD? How do you like it? Im waiting on a machine myself. I have asked for a Thermal Arc 185..

 

[SPEEDSTAR]

180sd runner, It works great for welding on the car, it came with the foot control, next I will get the hand control,it can be difficult to use the ft.ctr. in some situations. I need an answer on the turbo flange, somebody on here has got to know, Cal, Joe anyone?

 

[turbodave231]

I am using a T-76 turbo. I have a 3.5" flange on the turbine housing. My DP is made from 3.5" SS not the 4". The 3.5" DP is very tight even without an A/C case. You won't have alot of room for 4".......but it will look GREAT and flow more than you will ever need.

 

[SPEEDSTAR]

Turbodave, nice looking dp, did you build it. Where can I purchase a 3.5" flange, I have found 3" and 4" , no 3.5"s.... I will probably get the t-76 ,how does it spool , drive on the street ok? Thanks for the reply....

 

[John Wilde]

Nice Pic Dave, thanks for sharing!!!

 

[turbodave231]

You can buy the 3.5 flanges and the V band clamp from Turbonetics and maybe other places like Burns Stainless. I made a mockup DP of of PVC and conduit then took the model to Wolfe Aircraft. They digitized the model and fabricated the pipe. They did a great job and it fits perfectly.

I had the V band flange welded on the DP after some careful trimming on the pipe. Turbonetics welded the flange on the turbine housing after a looooong wait......but that's another story.

The turbo is a T-76 BB Q-trim. It spools very fast for a large single turbo. I guess by today's standards, this isn't a large turbo. I have a fairly loose converter (the 2 step is set at 5700) and that helps too. I don't drive the car on the street (only around the neighborhood) so I can't comment on the street manners.

I'm hoping for a Lincoln 185 TIG for Christmas.....I've been good..., well mostly.

Dave

 

[chevyII]

Nice pics...clean

 

[Louie L.]

I made a mockup DP of of PVC and conduit then took the model to Wolfe Aircraft. They digitized the model and fabricated the pipe. They did a great job and it fits perfectly.


I'm hoping for a Lincoln 185 TIG for Christmas.....I've been good..., well mostly.

Dave

Dave ,
Do they have this design still on file ? Could they make it in a 4in?

I was given the green light to purchase my welder. I like the Miller 200 SD and 180 SD but just can help to still be impressed by the Thermal Arc prowave 185 TSW. Waiting on delivery as we speak

 

[SPEEDSTAR]

I just welded a piece of 1/4 alum. to 1/2 thk. , set at 130 amps, made a real nice weld. I like my 180sd runner, I added 60ft of 6/3 powercord to reach way out of the garage. I bought the 80 cu. ft. bottle and then upgraded to the full size bottle at the local welder supply. It makes a big difference in the projects you can do if you have your own Tig welder.I ordered mine thur. night and it was delivered mon. at work. Have fun with yours Louie.

 

[Alky V6]

I'm running a Turbonetics T76 SBB Q trim and I think the V-band flange on the turbine housing is only 3". At the time I got my turbo, 3" was common I guess. One important thing I learned during the tuning of my engine was that the slightest amount of back pressure, and I mean the slightest, would very noticeably affect the tune up. At least if your using a big cam. I also reasoned that if your going to try to push big HP numbers through one exhaust pipe, it had better be one hell of a pipe. If modified turbo diesel trucks are routinely installing exhaust systems using 4 inch piping, it stands to reason that if you want to push 800 to 1000 HP through one pipe, it ought to be larger. I use a expansion cone off the turbine housing that is about 4 to 5 inches long that expands from 3" to 5". I can't remember the exact length, but the included angle off the centerline must be no more than 7 degrees or unwanted turbulence may result. Just check out the new big diesel trucks and they have a similar expansion cone right off the turbine housing. Believe it or not, because of a 90 degree bend in the 5" pipe to get it to clear the front tire, I still have a bit of back pressure that causes exhaust to back flow through a slip joint in my system. If your going to run a stock routing for your piping, then you may be limited a bit. One Idea would be to incorporate oval shaped tubing in the tight places. Just some food for thought. With some creative designing you may be able to get that 4 inches in there. A divider through any sharp turn in the pipe is a VERY GOOD idea. Sharp thinking. I like it.