SR20 turbo + FM Outlet = 4 out of 5 aint bad? WTF
 

I thought that the SR20 turbos were T25s and the FM outlets were designed for T25 flanges. I bought both parts used, and both sellers showed photos of these being installed on other standard parts.

So why do only 4 of the 5 bolt holes line up??? :vash: It sure looks like the same flange/bolt pattern!

http://delturcious.net/miata/IMG_0788m.JPG
http://delturcious.net/miata/IMG_0789m.JPG

It looks like I'll either need to:
a) drill out all 5 holes enough to be able to make it fit (I have a drill press)
b) find a halfway decent machinist around here that can mill that 5th hole into an oval.

I guess I could just use one big drill bit on the recalcitrant hole, but I'd be a bit concerned about integrity of that tab and the nut being large enough to not fall through.

I don't want to mess up the ceramic coating either, but I need to make it fit somehow!

Pics of both the turbo and DP might help. Your pics are REALLY close up.

back when I had my sr20 t25 on my nissan I had to drill out my cheapo megan racing DP.

Looking at the top picture, it looks like FM put all the holes a bit off. Either that or it kinda looks like something overheated and got bent.

Personally i'd open up the other holes a bit also to try to help align stuff otherwise you'll wipe off almost half of the wall.

The way I make oval holes is i take the correct drill and mount it to a hand drill, you want the drill to be roughly an inch from the inside end of the drill so it does not break. Turn up the drill and simply press against the side you want to make an oval. It will take time but it will open up. Local shops usually cost an arm and a leg to do half an hr worth of labor. If its too heat treated than you might want to use a dremmel with a grinding bit on it instead of a hand drill with a drill bit.

On my old SE-R when I switched from a t25 to a t28 I had to oval out one of the holes to get the turbo outlet lined up with all the studs. For some reason there is a slight spacing difference in some of the turbo flanges.

PS I used a drill bit to hog it out and never had any problems.

Ditto

I have the FM cast turbine outlet on my sr20 turbo. It fit like the guy's pants who had 5 penises did...like a glove.

That was the idea ;)

It does look... off... as you put it. Hmmm.

That's what it's looking like I'm going to do now. I figured I wasn't the first person to run into a problem like this.

I knew someone else would have a similar setup... these are incredibly common parts. Interesting you have no trouble with yours. Wanna trade? :D

I have a crappy Ryobi drill that I'm not concerned with beating on. Drill bearings typically aren't designed to take a ton of force from the side, but as long as I go slow it'll be fine. I'll also likely open up the other holes a wee bit on the drill press to give me a little more adjustment.

Then again, Lowe's will have a $28 Dremel on Friday... Thanks for all the quick responses!

The grinding wheels go by fairly quickly so get few. I dont know how hard that coating is but you'll probably need 1 per hole. I'd get a package to be safe though especially since the dremels are quite useful for all kinds of projects.

I had to enlarge the holes on my FM downpipe. I just used my drill press and progressively went up in size on the drill bits.

So maybe I should have bought BEGi parts if I wanted it to be easy :)

I knew I was doing somewhat of a "DIY" build so it's no big deal. Figured I should ask before hacking up an expensive part!

Drill baby drill :D

BEGI ovals that hole for you FYI. Thats how it was on my old BEGi downpipe anyway.

Every downpipe i've built (for my SR20 T25) had to have that hole hogged out with a drill to get it to fit. Not a big deal but the SR20 turbine outlet does seem to have a slightly different spacing there.

You're absolutely right... FM has something to learn!

http://www.bellengineering.net/image...e/P2125685.JPG

Hope you get it to work meng. If you want some rene-41 or a-286 bolts for the outlet, you can have em for free for the trouble. You need to run a tap through those 5 holes, though, but that's it. Really easy. And they don't stretch, even if you're at 1800 degrees. woo.

Wasn't anything a drill press couldn't fix... I'm glad I didn't try using a hand drill though. I made all the holes one size bigger and the evil hole 2 sizes up in a small, cheap, crappy drill bit set. The ceramic coating flares out on the back sides of the holes when you drill through, but it only took a few seconds with a file to fix. I had to file down a run in the flange coating anyway. I'll probably still end up using a gasket just in case the flange faces aren't perfect.

If anyone is wondering, the manifold is an older FM piece drilled to accept an EGT sensor. Unfortunately one of the studs is a hair too long so it'll either have to be cut or replaced. I may be able to swap the studs around to make it fit though.

http://delturcious.net/miata/IMG_0794.JPG
http://delturcious.net/miata/IMG_0796.JPG


Buy the rest of this guy's stuff! </shameless plug>

I don't think the hole is off -- as I understand it, there are two flanges from Garrett, that are very slightly different from each other. No idea why.

--Ian

wat^^^

my that's a mighty fine looking turbo :giggle:

Yeah, just one of the holes is a few mm out of position versus the others on at least one Garrett T25 housing. Don't know why. Garrett does have dimensioned prints for inlets and outlets of all the turbos on their site. You can fit the downpipe with an $8 round file, just oval it the required amount, rather than drilling it oversize. You definitely shouldn't make all the holes oversize just because of the one.