... you're going to need to hurry up and read some more internet articles. These debate points are kinda weak.

 

I do not need to read any internet articles. None of the manifolds I have seen have ideal placement. You simply asked for pix and I provided. The ideal position for the turbo is buried low. However then the cool kids cant show off their over sized turbo. Im also not gonna waste my time arguing about whether top mounts melt BMC's and oil lines.

 

Well how low do you want it? Into the motor mount? Into the AC compressor? Just remember that a GT2540 on a stock bottom mount manifold has to be trimmed up to clear the motor mount, and it might not clear the block depending on how you have the compressor cover, IIRC. Bottom mounts can also melt brake boosters. That's why there are things called heat wrap and heat shields.

Your problem is that you're trying to win all arguements, all the time. You can't possibly take the general statement that bottom mounts are better, more efficient, melt less stuff, etc and convince anyone with half a brain of it. Show me a setup, and we can discuss it. It's that simple. If it was so much better, hardcore companies like Full-Race would have done it like that. They brought the first T3 twin-scroll manifolds to market, and talking with Geoff, it was a hell of a lot harder than mounting the turbo in a different place.

So while you're trying to win "KA vs SR" over here, what I can do is shoot holes in all of your arguements until you give up.

 

epstein (far left)

 

Holy shit that has to be the funniest thing I have seen all day and its almost 6pm so points for that one. hahahahahaha holy shit I am literally on the floor laughing typing this.

 

the 2nd one is a Phat KA-T (now AMS) manifold. their downpipe actually is efficient and very smooth, but a properly designed 3" downpipe off of a top mount can still be pretty smooth, and comparing the two, it's not entirely much of a difference.

the phat ka-t manifold is a bitch and a half to work around though, esp when hot. mounting top or bottom is all about packaging. anyone with enough R&D and space can make an efficient turbo manifold that mounts under the oil pan if they wanted to, but people trying to sell mass produced manifolds take into consideration tool clearances, hot handling, space requirements, etc.

i'm not even sure what the argument here is anymore :gordy:

i'll just enjoy my log, it flows well enough and it won't ever break, and i can reach everything i want, even when hot. but i do miss that 25-40hp up top LOL...ah well.

 

this is case in point a good argument against people who say that top mounts get the BMC hot and stuff...a non-log bottom mount (excluding shitty ass SSAC manifolds that rarely support anything bigger than a gt2 will require runners that still have to interfere with the 'heat clearances' of the BMC...as shown in that staircased abomination of sheet steel haha.

 

Lets break this down:

a) True or false: Full-Race is a company, they sell what people will buy, no one wants to spend $1200+ on a bottom mount manifold. And people that buy full-race manifolds are more likely to run very large turbos.

b) True or false: Top mounts are more likely to melt the BMC?

c) True or false: Top mounts are more likely to melt oil lines?

d) True or false: Top mounts generally don't run water lines (yes I know many large turbos are not water cooled).

e) True or false: If the turbo manages to avoid the a/c compressor and mount, the intercooler piping will have less bends being run along the bottom.

f) True or false: If the turbo manages to avoid the a/c compressor and mount, the downpipe will be shorter, and have less of a bend.

 

I agree, one of the very first things I said, was that there really wasnt much difference, the top mount is chose for looks not function.

 

A - First part true, second part not true, third part true
B - False
C - False (should be phrased "top mounts are more likely to cause oiling problems")
D - True, but this depends on the turbo and not the placement
E - Depends on how the housing is clocked
F - Not sure what you're trying to ask...

How about servicability on that bottom mount manifold, eh? Having fun replacing those banjo bolts behind the compressor housing?

Regarding the manifold at hand:
I'm sure you can work the runner design and collector out. A straight shot with a more gradual collector will help spool, but it may be pretty negligable.

As far as the welding goes - backpurging is always preferred when possible, but using the proper current setting and proper amount of filler may be your best bet for the winning combination of strength, pennetration, looks and flow. Your welds look superb, but with that degree of undercut you may run into issues with cracking at the weld. Schedule 40 is a wonderful sizing system to use since it just about welds itself and is easy to work with, but too much undercut and you effectively reduce the wall size.

What diameter are your primaries? Do you have a shot of the header flange from the port side? (sorry if I missed these things)