Questions on building Turbo Manifold

If I were going to build my own manifolds, using a 1pc intake/exhaust flange, am I going to be able to get away with using 1 5/8" round tubing for both intake and exhaust?

I have drawings for such a flange.. (attached) and then the other day I was reading a thread in the big six forum area and spotted this
Foxbody with Turbo 300
I really like the exhaust side of his manifold, I'm not quite feeling the love on the intake side.. Sort of thinking that I'd replicate the exhaust side, then use a throttle body on the front and weld on some injector bungs right before it goes into the head. Or if I attempt it with a TBI first, maybe replicate a 4bbl manifold.

Big6Turbo":1m5uyqsm said:

Click to expand...

thoughts?
-ron

I just finished building both for mine, but I used schedule 40 steam pipe for the exhaust manifold. The intake was made out of 14 ga. mild steel.
My 250 has a crossflow head on it,..but you get the idea.

I

that turned out beautiful, mike.

is that mandrel bent steam pipe or are those 'weldbend' style elbows just very neatly welded together?

i love the idea of using sch 40 for a turbo manifold, but at $30-50 per, those weldbend style elbows would have me looking for a way to package with fewer bends

either way, beautiful work

I got questions for Mike as well.
What diameter tubing? (ID/OD)
Where did you get your injector bungs?
It looks like you used 1/2" exhaust flange and 3/8" intake? (or is it 3/8" exhaust and 1/4" intake?)

I like the appearance of that top cover for the intake manifold, are those just 1/4" square bar that you bent and welded on?

-ron

CoupeBoy":1z791gap said:

I got questions for Mike as well.
What diameter tubing? (ID/OD)
Where did you get your injector bungs?
It looks like you used 1/2" exhaust flange and 3/8" intake? (or is it 3/8" exhaust and 1/4" intake?)

I like the appearance of that top cover for the intake manifold, are those just 1/4" square bar that you bent and welded on?

-ron

Click to expand...

The Steam pipe els were mandrel bent. They are mild steel, not stainless, and I bought them for 4.00 ea from a supplier here in Birmingham. They are listed as 1-1/5", but they actually measure 1-5/8' I.D. and they are thickwall ( I think something like .140 wall).


The injector bungs came from ebay. Only one supplier making mild steel inj bungs that I could find Ross machine:
http://www.ebay.com/itm/Steel-Fuel-Inje ... 0941398514
The intake port runners are made up of 1.75 od exhaust tubing ( actually measures about 1-5/8 i.d.), and the plenum is made from a combination of 2.5 od straight 14 ga tubing, and one 2.5" mandrel bend split in half.
The exhaust flange started as 1/2" thick mild steel, and the intake is actually 5/16".

Lastly, yes the detail on top of the intake is actually 1/4" square bar stock, bent by hand and tacked in place.

wowowowow

that is awesome, care to disclose your supplier? every time i've had to buy those el's they are expensive as heck!

thanks

motzingg":29h4ywjr said:

wowowowow

that is awesome, care to disclose your supplier? every time i've had to buy those el's they are expensive as heck!

thanks

Click to expand...

I would but I can't remember their name. They weren't really set up to sell retail but the counter salesman took pity on me. I bought 26 of those 90's and used about 20 of them to make the header.

How are you hooking your fuel rail up to the injectors?

honestly, I hadn't gotten that far. From just casual browsing, it looks like you can buy DIY rail and fittings.

The ebay link from above
Steel Fuel Injector Boss Bungs Holders Cups Qty 6 RMR-101 $36

And then pick up something like
Holley 534-78 EFI Fuel Rail Universal L-12 in.

In my world, I start big.. this is what I'd like. Rough out the plan for how to do it, assume the next piece is available from somewhere, and start working.

Big picture
Turbo/MPFI/coil on plug

Start breaking it down.
I should be able to scare up a 36-1 wheel for the harmonic balancer (or I'll have to have one built )
Looks like Megasquirt II with extra code will handle all the electronic needs (although the ms3 pro with 8ft wiring harness is available as well)
Need an intake manifold for MPFI
Need an exhaust manifold for turbo

Then things will start actually getting interesting..
Set HP goals, select injectors based on goals.
fuel rail shouldn't be that bad, buy some universal rail, cut to fit, drill as necessary, weld on some bolt down tabs to the intake manifold.

Start working on fuel delivery and regulation issues.

Or maybe MPFI/Coil on plug/turbo goes to he1l and I just build a custom header, 4bbl manifold, and use a Duraspark 2 with HEI module :rolflmao:

clintonvillian.. I sent this to you in an email. This should roughly approximate 1.625" (1 5/8") hole approximately centered over top of the factory intake/exhaust hole openings. Seems like it would be a good fit, welding the stubs into the 1pc flange may get a wee bit tight between tubes.
Stock intake and exhaust manifold holes (rectangular with rounded corners)

I created some 1.625" circles and hand approximated where they were centered over the stock intake/exhaust holes.

And then I deleted the stock intake/exhaust holes and am left with just round holes

nevermind