SyTy Downpipes

[rockvillespeed]

let's say i am an idiot.
someone please clue me in:
1 - i have a 20g and am keeping it. is someone gonna release a 3" pipe for it, in any number of pieces?
2 - what exactly needs to be done with the plug welded in to make the internal gate worth a shit (which i also wanna keep so the ultimate can do its thing) or other mods - stated earlier trapdoor is adequately sized - i mentioned porting it - it's hidden away behind a ledge - awful for airflow - is porting really worthless?
and, if pulling the plug allows/mandates a 3" pipe, back to question number 1 - who wants my money?
it's not cost effective for me to fab a one time deal for an item i can't produce - but for someone who can build it, my wallet's cracked - and i need it pronto if possible - damn near ready for new heads and xtruded manifolds to go on...and i imagine everyone and his brother would leap outta their scivvies to get one - those of us stuck with mitsu turbos, anyway...
someone wanna make me one?

 

[turbodig]

PTE housing with dual ball bearing Garret T-76 Q trim. Notice that the PTE style internal wastgate is 3.5"
Flapper valve is 1.5" and wastgate hole is bored out to 1.4" instead of the 0.875" that comes stock on the PTE housings.
]

Nolan

Silly Canadians... That's not a downpipe, it's a sewer system.
You'll need a cleanout in that thing, if you want it to meet plumbing code.



Dig

 

[turbodig]

The actual puck or swing valve is plenty big, nearly as big as TurboBuick. It's just the little ass downpipe and the two 90 degree turns for the wastegate exhaust is the restriction. Remove the service port and make a 3" downpipe and you'll have perfect boost control, I guarantee.

You might ask Dig how he can control boost on his setup.

Voodoo.

I do tend to agree with you... puck size isn't the issue.

There's some really ugly swirling going on in the stock setup, due to
the hard right turn the WG flow has to make.

I've seen a couple approaches to fixing this... Best one was the way
Waylon did on yours, which was eliminate the back part of the WG
housing entirely and make it look more like the Houston-style Buick
setup. I do wonder about the long-term leak potential of it, though,
since there were no bolts on the WG corner.

The other one was ok, too- ported the back side of the housing to the
maximum you could while still retaining the stock DP flange arrangement.
This controlled boost quite well up to 22 psi or so, but get it up to 24-25
and it was tough to control. This was also on a 60-1/20g hybred, so
that may have caused some of the issues.

There's really only so much you can do, as far as downpipe size, due
to the studs being in the way. I don't think you'd get a 2 3/4 pipe between
the stock studs , and if you did, you wouldn't get the nuts on 'em.

So, you'd have to taper-neck up to 3", which wouldn't be the worst thing,
you can actually use that taper-up to gain some velocity as the exhaust
exits the turbo.

It'd be pretty pointless, IMO, to go to 3.5". Also, a single-piece 3" would
be a royal PITA. The stocker is hard enough to get out of there, much
less a bigger pipe. Nice, stainless V-band joints would be cool.

Later,

Dig
turbodig@yahoo.com