I've been reading alot of twin threads lately and trying to figure out a good secondary turbo for me to use. I know its usually best to go with a 16cm housing but is it suppose to be wastegated? Also whats a good size comp wheel for a peformance set of twins? This truck is just a play toy so a little lag isn't an issue.
Thanks

 

Thread bump

 

I think a lot of people are running 14cm housing on the small charger, and 26's on the large. I could be wrong though.

 

If i go with twins

i already have a 14CM on the stock 35, and my 3B has a 26 cm exhaust housing.. SO yes, you are right...

Rick

 

I thought I heard that its best to use a 16cm for the secondary turbo? Also whats a good size comp wheel to use? Note this is for a performance set of twins

 

I plan to use my current turbo with the 40mm internal wastegate mod that got...diesel? did on his rig. His findings seem to indicate that combo will be good for a comfortable 500rwhp, which will put the torque at or above 900, which is just dandy in my book. I plan to stud the head w/out removing it to see just what a 400k+ headgasket will put up with. Got...diesel? is wastegated to 50psi and is having good results.

 

Yeah, it's working good so far. There is still quite a bit of room on top, but until I stud up I won't go there. I've accidentally pinned the 60 lb gauge a couple of times when setting the gate, and drive pressures were still down to at least 1:1 if not a little lower. Right now with the plate pulled back a little and the secondary wasting at 20, my peak boost at full throttle high gear is between 47 and 50. Very smooth, and no lag. We'll see how the gate works whenI dial it up some more and add more fuel. But for now, the internal gate is working flawlessly and is a great mod for the serious tow truck or street bruiser.

Chris

 

I don't think I wanna use a 12cm I'd rather use a 14 or a 16 if possible. Wouldn't a 16cm be better then the 12 once she spools? Would I have to use a wastegated housing on the secondary or could I get away with it? Would a 60mm comp wheel be about the best size to use?

 

As I understand it, you're gonna have to wastegate one way or the other when running compounds or drive pressures and boost will go through the roof. The beauty of the gate inside the housing (like the 12cm) as opposed to an external gate, is that the exhaust flow has a much smoother path to the primary, which, theoretically, helps it light quicker. Plus, in our case, we have to deal with the limitations of the VE pump. We have no plate to slide forward if we want more fuel. If I can mimic got...diesel?'s setup for about what he has into it (6-700?) plus a fair amount of fab time, I'll be thrilled. That's less than a good single and the little VE with some used (cheap) pod's is almost guaranteed to spool them. My goals are somewhat modest, with 450/950 that's USEABLE while pulling or thrashing ricers being where I want to land. Of course, bigger is always better, but there will be more trade-offs, most of which, I personally am not willing to make.

 

I always thought external wastegates were the way to go and the only reason people don't use them of because of the cost?

 

they are the way to go, simply because none of the stock turbos have a big enough WG valve. They really aren't that spendy in the big picture. I did what I did because I'm a tinkerer and wanted to see if it would work. But yeas, a large gate is mandatory if you wnat your compounds to work properly.

Chris

 

ID agree

doesnt rip rook sell a gated housing for a 35 aleady? with that huge tial gate?

Rick

 

Check this link--I feel like a kid in the candy shop!

http://www.sourceautomotive.biz/twin_turbo_parts.htm

 

After I get a bigger pump, I have a feeling that my 12 hsg even with its 40mm gate will be too restrictive......I'll probably go up to a 14 or 16 and an external. After all the hours I put into the gunslinger 12, I don't think I'll do it again. Hint Hint, it might be up for sale one of these days....and it's great in a set of mild street or towing compounds!!

Chris