After several issues with turbo studs gasket failures etc I tried to belt sand my flange, totally fu*ked it up, needed a flat surface, searched the net.

Here in Sweden we got (what feels like) a handful of people/companies that do this daily so I'd figure I try something myself.

Teenage days lapping CPUs with sandpaper thought me something, why not do the same with a flange?

Bought 3 packs with self adhesive paper 80/120/320grit and used our flat bench we use for setting cylindrical cutting units (I work on a golf course) and off we go.

Before anything,
Tried to clamp it down onto turbo and I could easily fit a 0,05mm (dunno derp units) feeler gauge thru the wide side in-between flanges. 0,1mm would also fit at some places.


Used some welding clamps to get even weight on the flange.

Too bad no picture from start but this were about 20min later.

Some deep pits that took forever

Should I be happy or what?

Total cost, my time and about $15 with plenty of sandpaper left.

Yes, I have tried it with studs on turbo and it's more than perfect.

Just wanted to share this.
/Thomas

 

Should be good to go. I do it this way with optical parts at work using diamond sand paper/polishing film and a glass plate.

If it measures flat, it's flat.

 

I did something similar when I was on a shoestring budget K24 build a decade back. Measured flat and the gasket worked to offset any slight imperfections i could't pick up when measuring if it was flat. Ran it that way for 20k miles and no leaks/issues. YMMW.

 

I have done similar to re surface a motorcycle head. I use a leftover chunk of granite from when i remodeled my kitchen. Its flat and hard works well.

 

Looks good. If you want it to stay that way, stop using a gasket there

 

^This.

 

Yep, I'm done using gaskets, have tried the thin stainless and the thick soft stainless, felt great with the thick one until two studs broke off and the turbo fell of like 30km from home. This took some toll on my mentality and I were close to part the car off and sell it all.
Ran the car without turbo for 4 months during the last summer but now I've decided I'm done with the headache, now using inconel/stage 8 locks and resbond.

Like always, got a problem? Throw money at it.

 

TIL that no gaskets is the way to go in the Miata world. I ran a gasket between the turbo/mani and the DP/turbo on my k20/k24 hybrid Accord years back since that was the preferred option (and i was an idiot in my early 20's), but it never made sense assuming the mating surfaces were flat and was introducing a weak point for no reason. Either way, it worked fine in that application for 20k miles.