White 02 WS6

I know its been talked about 1000x and stickies etc, but my question is after running 2.25" pipe from each exhaust manifold is it better to keep them separate and merge them right at the turbo exhaust flange or is it a good idea to merge the 2.25" pipe into 1 maybe 2.5" or 3" pipe into the flange? I have one 50mm wastegate and I want to keep it that way...Any thoughts? Pictures would be great too! This is going a LQ9 motor with truck manifolds and a T6 S475 turbo.

Thank you!

truckdoug

iTrader: (25)

you could put the gate on the turbine housing. i'm a fan of that.

White 02 WS6

Do you have some pictures of that by any chance? What about the piping and the size above?

truckdoug

iTrader: (25)

so the piping is tough. each 2.25" diameter tube has roughly 3.9in^2 area so thats ~8in^2 together or so. a 3" tube has an area of about 7in^2 ...so it starts necking down pretty quick. probably fine for a short run into the turbine housing.

FWIW, I dont have a degree in thermal fluid science. I just weld stuff.

here's my hotside with the gate on the housing




and here's an s475 i did earlier this year for a fella back east. (Trey if you see this, make a build thread! that car is badass!)

White 02 WS6

Awesome. Thank you for the info!!

Also...are you using a mig to weld your stainless or a tig? I know a tig is preferred, but it seems no one around here had one lol

truckdoug

iTrader: (25)

I tig because thats what I'm most experienced with. People do put em on with mig though. The guy I got the idea from with the green chevelle migged his.

I do a pre and post heat. 300*f on the barbecue or woodstove nothin fancy

Suncc49

Looks good doug... love your youtube videos, but you need to upgrade the audio some!

truckdoug

iTrader: (25)

yeah man that camera is supposed to have a mic built in, but hell if I can get it to work.

newschool72

iTrader: (12)

Do you use high nickel tig rods, or stainless , or ??????

truckdoug

iTrader: (25)

so when I'm putting a stainless weld el or reducer on a cast iron (high carbon) part like a turbine housing or an exhaust manifold i like 309 stainless, low nickel. 309L rod. it's the opposite of what convention says but it works for me.

If I'm welding stainless els to a cast steel, or some other steel I like 316L as it has a little moly in it. 309 does not.

i've tried the nickle 55 rods...didn't feel right going in. dont know if it cracked out---it was a header repair on an irrigation pump---and that's what the fella insisted on me using :/

newschool72

iTrader: (12)

reason I asked was all the steps a career welder had us go through when welding my axle tubes on the 8.5 10 bolt in my car. I had to get a few sticks (stick welder, not tig) of nickel 55 rods, we used insulation and a welding blanket to hold the heat in as long as possible AFTER the welding, had to heat the housing and tube, used an air dimpling gun. It seemed to be a pretty strict set of rules for the cast welding to work, and it did so far. I just see alot of cast iron welding done in the turbo world and I never hear anything about special steps or materials being used to pull it off. It would make a good sticky if someone () would lay out what works and what is black magic BS . hmmmmm, wonder who would be qualified to do that....

truckdoug

iTrader: (25)

honestly I dont think there is an AWS weld procedure for welding such dissimilar metals. (cast iron and stainless) They'd just tell you to get the right materials lol.

I'm not the guy to do the write up. I'd post my way and 20 guys would cry and say that's BS all you need is a mig and er70s2 wire no preheat no post heat.

Welding is really a subjective thing. In my experience, if it's stupid and it works...then it's not stupid