Volvo turbo T3 flange: Grassroots Motorsports forum: Grassroots Motorsports Magazine

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June 21, 2010 2:36 p.m. Pseudosport Reader

I’m in the middle of changing my set up on my turbo Miata. I now have a cast T3 manifold and I bought a T3 50 trim turbo off a Volvo. What I did not realize at the time was that the Volvo T3 flange was kind of odd and will not seal to my manifold without some machine work. If I can mill down the turbo flange 1/8” then it will seal fine. I don’t want to pay a machine shop to do this and I don’t want to buy another turbine housing. How would I go about milling this down myself? I was thinking about removing most of the material with an angle grinder then using a belt sander to get the flange smooth. In my head this sounds like it will work. Does anyone have a better idea?

Here is a pic of what the flange looks like. You can see how the flange is round but if it was milled down it would be more like a standard T3 flange and will seal on my manifold.
June 21, 2010 2:39 p.m. 16vCorey SuperDork

Pretty much anything would work, hacksaw, band saw, sawzall, angle grinder, etc. I'd probably go the saw route, just to cut down on the mess, but trim it down any way you can and you're good to go.
June 21, 2010 2:44 p.m. Sofa King Reader

I bought the same turbo for a long forgotten Miata project. I was planning to alter the flange on the manifold to match the turbo. Either that or I was going to try to find a donut exhaust gasket thingy that might fit and fill the gap.
June 21, 2010 3:07 p.m. dean1484 Dork

I would use my grinder to get it close and then follow it up with my belt sander. If you want I could do it for you. And if I screw it up I have spars on the shelf. While I am doing that I need your diagnosis talents for my MS2.
June 21, 2010 3:15 p.m. unevolved Reader

We used that same turbo on our '09 Challenge car.

Found this on eBay a couple of months ago, they didn't make them BEFORE the '09 Challenge, unfortunately. We bought it and installed it, unfortunately we need to find the right gasket for the Volvo side, because it's still not sealing perfectly. If you find some OEM gaskets somewhere, let me know.

http://cgi.ebay.com/ebaymotors/T3-2-5-Turbo-TRANSITION-FLANGE-VOLVO-Manifold-_W0QQ...
June 21, 2010 3:23 p.m. AutoXR Reader

make a gasket out of copper from your local hobby store
June 21, 2010 3:47 p.m. itsarebuild Reader

could you make a spacer out of 1/4 plate to mate the two together?
June 21, 2010 3:59 p.m. Pseudosport Reader

I saw that ebay adapter but I'm trying to avoid taking a hit to the budget. I was thinking about making my own adapter from 1/4" plate but I was trying to come up with a way to cut the shape and opening I need that would not put too much heat into it and have it warp.
June 21, 2010 4:35 p.m. turboswede SuperDork

hit up your local hobby machine shopists and offer up some of their favorite food/beverages and get it milled flat. If you were closer, I'd do it for ya. The trickiest part is getting it clamped to the deck relatively perpendicular to the head.
June 21, 2010 4:37 p.m. itsarebuild Reader

if you have room maybe you could leave the plate bigger than it needs to be to cover the turbo flange so there is extra material there. that might allow it to take more heat without warping. not very pretty, but possibly effective. i suppose you could also trim it down once it is attached between both pieces to to keep it from warping a lot.
June 21, 2010 5:14 p.m. unevolved Reader

Pseudosport wrote:

I saw that ebay adapter but I'm trying to avoid taking a hit to the budget. I was thinking about making my own adapter from 1/4" plate but I was trying to come up with a way to cut the shape and opening I need that would not put too much heat into it and have it warp.

For what it's worth, we spent about 6 months trying varying solutions, including the 1/4" plate idea, and ALL of them leaked. This leaks a little bit too, but significantly less than all our other ideas, and I decided it's worth the hit to what little budget we have left for this car.