Hi Volume

iTrader: (3)

I made a thread regarding this a while back, but now the time has come and i need specific answers so i can provide my welder with all the correct materials. What i plan to do is cut off the 5" V-band and weld on a stainless 4" V-band. I have very limited space in my engine bay and this is the action i have to take to make it work. I will cut on the tape line which is around 4" Dia on the turbine housing, which allows for the V-band to weld on will plenty of surface area. The 4" flange pictured is mild steel, the stainless one will be in next week. Soo for those of you that have done this, my questions are:

-Is the S475 turbine housing cast iron or steel?
-What rod is to be used? Someone mentioned nickel and another mentioned a 309 rod?
-am i crazy to be cutting up a brand new $1200 turbo? LOL



From what i researched, the stainless V-band flange welded with a nickel rod has similar expansion and contraction rates as the cast steel does. Which of course reduces the possibility of it cracking sometime down the road. IS this correct or am i way off?

thanks to all that help!

forcd ind

iTrader: (7)

isn't the turbine wheel right in that area, been a while since I looked at mine
if it were me, I would make something up to reduce the 5" to 4" right off the back vs cutting the housing-is their a flange that would fit the housing outside dia. but 4"-if not wouldn't be hard to machine one, provide a taper inside like some hose fittings

ken6881

Nickel rod is what I would use when welding cast iron also pre heat the exhaust housing and dont let it cool quickly when done welding will help it not to crack. but other than that I don't think I'm much help on cutting it off and how that will affect performance.

ls1curt

iTrader: (31)

I cut my turbine back far enough so it was 4". Then just tigged a stainless v-band on using stainless rod.

gixxerbob

iTrader: (3)

tig welding ss v-bands onto factory cast (steel) manifolds requires 308l ss tig rod. preheat, weld, bury in sand to allow the slowest/even cooldown possible in order to prevent cracking cast.

a98ws6

iTrader: (48)

Is your exhaust making a bend right off the turbo/v-band? If not i would try and use a reducer instead. Plus if you go to sell it later on, the 4" welded on might hurt its resale?

ScreamingL

309L is the rod used to weld dissimilar metals together

Hi Volume

iTrader: (3)

It is recessed in there plenty far enough to not cause conflict. Also, i just do not have the room to do a 5" to 4" reducer directly off the turbine. It would push the turbo forwards too much and just create poor fitment.

nice, how has it been holding up so far?

As stated previously, i dont have the room for all that, il post pics later. also, not worried about resale, this is the last turbo the car will ever need. which, it doesnt really need one in the first place! haha

forcd ind

iTrader: (7)

they all need boost, lol

Hi Volume

iTrader: (3)

heh, i know evil:

heres an old pic when i had the PT88. kinda hard to tell in this pic, but between the water pump and frame rail is about 4.5" and the 4" DP is very tight through there. Soo if i were to run a 4-5" transition on the S475 it will then move the unit too far forward into the radiator/core support.

ls1curt

iTrader: (31)

It's holding up fine albeit there's not much stress on it. I've never had any problems using normal 304 rod. My manifolds are the same way and have held up fine.

1bad03snake

iTrader: (16)

+ 1 on the 309L rod

MR2liter

iTrader: (11)

Use nickel rod and a hotplate to pre/post heat when welding cast to stainless.

Reject

iTrader: (24)

just wondering but why not just use a MS flange on it vs a SS one?

Sarg

iTrader: (6)

Did this on my S480 and used a 309 rod. It not had quite a few heat cycles on it and about 250ish miles. No problems. Also I am hanging my entire nowpipe complete with 4" magnaflow muffler from this weld...I meant to put in a support but never got around to it.

Hi Volume

iTrader: (3)

right on, good to hear info like this!
i will have a 4" SS braided flex section about 18" after the turbo and then the rest of the exhaust under the car will be supported off hangers.

superskaterxes

For anyone who has done this, what did you use to cut off the flange? im thinking a horizontal bandsaw would do it a little neater then a plasma.

Hi Volume

iTrader: (3)

i used an angle grinder with a 5" cut off wheel, worked perfect. make sure you use tape or something for a guide to ensure an even cut.

Krom

I would take it to a machine shop.

First see if they can just machine the outlet to work with a 4" v-band. If not, have them cut it off on a mill or lathe