Building Custom Turbo for the RX-8
12-05-2004, 10:08 PM
#1
Building the turbo manifold
I know you guys like pictures. :D
I had some time today, so I started with the manifold.
First, I welded a set of supports between the inlet flange (engine side) and the outlet flange (CAT side).
This keeps the two flanges in alignment even after I cut out all of the existing manifold.
Then, I cut away the manifold parts that I don't need. The OEM manifold is stamped steel, rather than cast iron like most OEM manifolds.
It is also double-layer.
Then, I began welding small sections of pipe. I will build it up section by section just like this. I am stopping at this point until I have more time.
I had some time today, so I started with the manifold.
First, I welded a set of supports between the inlet flange (engine side) and the outlet flange (CAT side).
This keeps the two flanges in alignment even after I cut out all of the existing manifold.
Then, I cut away the manifold parts that I don't need. The OEM manifold is stamped steel, rather than cast iron like most OEM manifolds.
It is also double-layer.
Then, I began welding small sections of pipe. I will build it up section by section just like this. I am stopping at this point until I have more time.
Last edited by MazdaManiac; 04-18-2008 at 06:06 PM. Reason: ©® 2008 MazdaManiac
12-05-2004, 10:23 PM
#2
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Wow this is going to be a great way for me to learn more about Turbo plumbing. Maybe once you get it all together you can create a DIY forum post showing all the stages you went through along the way.
BTW, what kind of welder do you use, and how much would it cost to get my hands on one?
BTW, what kind of welder do you use, and how much would it cost to get my hands on one?
12-05-2004, 10:39 PM
#3
I use a Millermatic welder like this one:
It is also outfitted with an argon/carbon dioxide tank for welding steel and a pure argon tank for aluminum.
I know I'm a geek, but I really derive a great deal of joy from welding.
Learning to do aluminum a few weeks ago really put me on cloud nine. :D
It is also outfitted with an argon/carbon dioxide tank for welding steel and a pure argon tank for aluminum.
I know I'm a geek, but I really derive a great deal of joy from welding.
Learning to do aluminum a few weeks ago really put me on cloud nine. :D
12-06-2004, 12:15 AM
#5
Go Texas Longhorns!
How heavy is the stock manifold? The reason I ask is I figured it was cast iron like most as you said. I was thinking that a new header would give some weight savings but it sounds like new headers won't do much in the way of weight.
Last edited by brillo; 12-06-2004 at 11:01 PM.
12-06-2004, 10:24 PM
#8
Originally Posted by rotarygod
Is there a way you can trace the flange shape and port outlets onto a piece of posterboard and send it to me?
Originally Posted by nojooc
.........only a hundreth of the way there now. 
I'm in San Francisco for a few days. When I get home, I'll finish the manifold. That is the hard part. The IC plumbing is the next most difficult part, but I can keep the car on the road while I do that.
12-07-2004, 02:59 AM
#10
Registered
Originally Posted by MazdaManiac
Absolutely. Send me your address (e-mail is better than PM) and I'll send you an Illustrator EPS along with the tracing.
12-07-2004, 03:01 AM
#11
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Originally Posted by MazdaManiac
Well, not quite.
I'm in San Francisco for a few days. When I get home, I'll finish the manifold. That is the hard part. The IC plumbing is the next most difficult part, but I can keep the car on the road while I do that.
I'm in San Francisco for a few days. When I get home, I'll finish the manifold. That is the hard part. The IC plumbing is the next most difficult part, but I can keep the car on the road while I do that.
12-07-2004, 01:29 PM
#12
Originally Posted by nojooc
I meant that you're only a fraction of the way to completing the turbo setup.
Once the manifold is done, I will be nearly complete. Everything else is very simple.
12-08-2004, 02:39 AM
#13
what material are you using for the new pipe? for turbo manifolds it is std practice in australia to use steam pipe bends (seamless). they are thick walled and are suposed to last longer than exhaust pipe manifolds. you can get it in stainless or high carbon(?) steel.
I have a few pics but need to work out XP so I can up-load them :o
I have a few pics but need to work out XP so I can up-load them :o
Last edited by rotarenvy; 12-08-2004 at 02:43 AM.
12-09-2004, 08:34 AM
#14
Originally Posted by rotarenvy
what material are you using for the new pipe? for turbo manifolds it is std practice in australia to use steam pipe bends (seamless). they are thick walled and are suposed to last longer than exhaust pipe manifolds. you can get it in stainless or high carbon(?) steel.
I have a few pics but need to work out XP so I can up-load them :o
I have a few pics but need to work out XP so I can up-load them :o
I am welding them double walled just like the OEM manifold.
If it is good enough for Mazda, it is good enough for me.
12-09-2004, 04:43 PM
#16
Originally Posted by MazdaManiac
What you are describing are called "weld els". They are very heavy and difficult to cut. I am using 16ga aluminized and stainless steel mandrel bends.
I am welding them double walled just like the OEM manifold.
If it is good enough for Mazda, it is good enough for me.
I am welding them double walled just like the OEM manifold.
If it is good enough for Mazda, it is good enough for me.
I know your aware that the std manifold is only double walled for insulation and not strength.
weld els aren't hard to cut you can go through them with a hacksaw in under a minute.
I'm sure you have done the research and thumbs up for having a go.
12-09-2004, 10:23 PM
#17
Registered
Weld-els are super thick and very durable. It is really hard not to weld them good. Typically they are sold as schedule 40 carbon steel. It is possible but much more difficult to find thinner ones. Stainless is harder to weld and mild steel doesn't last as long. The most important reason why people use weld-els is because they are extremely cheap. A couple of bucks per. I built a turbo manifold for an RX-7 out of these. I spent $20 on the weld-els but $40 on the flanges. That is still very cheap for a manifold. There is a severe weight penalty though. They are very heavy. You can't cut through these with a hacksaw in under a minute. Maybe 30 if you're good.
12-10-2004, 04:30 AM
#18
Originally Posted by rotarygod
Weld-els are super thick and very durable. It is really hard not to weld them good. Typically they are sold as schedule 40 carbon steel. They are very heavy. You can't cut through these with a hacksaw in under a minute. Maybe 30 if you're good.
the manifold I made was a 4cyl split pulse design lots of bends/cuts and each was done by hand. I even butchered lots by cutting on the wrong angle or where I changed the design. :D
12-10-2004, 12:34 PM
#19
I takes me about a full minute to cut through a weld el with an 11,000 RPM angle grinder with a carbon steel cut-off wheel.
I've gotta call BS on the under a minute with a hacksaw.
It takes me more than a minute to get through an 18ga piece of mild steel 3" tubing.
The problem is the manifold is going to have a very complex shape for weld els.
The double wall design will function for strength and insulation.
I've got a pretty good handle on what I am doing. :p
I've gotta call BS on the under a minute with a hacksaw.
It takes me more than a minute to get through an 18ga piece of mild steel 3" tubing.
The problem is the manifold is going to have a very complex shape for weld els.
The double wall design will function for strength and insulation.
I've got a pretty good handle on what I am doing. :p
12-24-2004, 05:38 PM
#20
Turbo Santa came early...
Look what Santa dropped in my garage this evening:
Now I need to fabricate the insulating layer and the bracket for the WG actuator.
The insulation will be thin-gauge steel with a small section of header wrap to keep the heat away from the compressor and the passenger's feet..
I struggled for a few days with trying to make a sexy tubular manifold until I realized that I could get significantly more flow by going to a log with a bigger main tube. The main tube (though it is flattened which doesn't reduce flow, just the shape - the inside cross section still has the same area) is 3" compared to the factory 2.5". The collectors in my tubular design were 2".
The other struggle was getting the angle of the inlet flange (and thus the position of the turbo) right and get it tacked up while holding the whole thing in one hand and the welding gun in the other, all the while lying on my back under the car. Now I need a chiropractor.
BTW - the turbo is canted 25° from horizontal. Corky Bell says it is OK to go up to 30° and still have adequate oil drain flow.
Hopefully, I won't run out of CO2 before Monday. If so, I will switch over to the aluminum piping since I have a seperate argon tank for that.
Now I need to fabricate the insulating layer and the bracket for the WG actuator.
The insulation will be thin-gauge steel with a small section of header wrap to keep the heat away from the compressor and the passenger's feet.
.I struggled for a few days with trying to make a sexy tubular manifold until I realized that I could get significantly more flow by going to a log with a bigger main tube. The main tube (though it is flattened which doesn't reduce flow, just the shape - the inside cross section still has the same area) is 3" compared to the factory 2.5". The collectors in my tubular design were 2".
The other struggle was getting the angle of the inlet flange (and thus the position of the turbo) right and get it tacked up while holding the whole thing in one hand and the welding gun in the other, all the while lying on my back under the car. Now I need a chiropractor.
BTW - the turbo is canted 25° from horizontal. Corky Bell says it is OK to go up to 30° and still have adequate oil drain flow.
Hopefully, I won't run out of CO2 before Monday. If so, I will switch over to the aluminum piping since I have a seperate argon tank for that.
Last edited by MazdaManiac; 04-18-2008 at 06:06 PM. Reason: ©® 2008 MazdaManiac
