Turbo mounting with bolts?
 

So this dilemma has been weighing on me for a while now and I seek the advice and wisdom of others to calm me down.

Short story is I have a complete ARTech setup that was built for me years ago that I have never installed. I'm getting around to finally getting it installed but the manifold isn't threaded for studs, the holes are sized for M10 bolts. The turbo I'm using (factory WRX TD04) is drilled to accept studs.

Therefore my only mounting solution is to use a nut and bolt setup. I realize this isn't ideal, but is this going to be a huge problem? I'm also trying to figure out what type of nuts/bolts to use that will withstand the stress and temperatures associated with this setup. I was looking at stage 8 fasteners with titanium bolts?

Am I overthinking this? Should I seek out replacing the manifold flange with one using studs?

Thanks in advance!

Are you tracking the car?

If not use nuts and bolts and be done with it.

Tap it for studs. That is the correct thing to do.

You're gonna stretch those bolts if you push the car hard.
Otherwise should work

Welcome back to turbo, Karter. Will this be going on the '00?

I still love my TD04, when the manifold is not cracked. With EBC, torque is between 200 and 215 from 3.4K - 6.5K.

Yes, going on the 00. I've been sitting on it for years for multiple reasons but am just now getting serious about getting it done.

It's always just bothered me about the mounting situation. I'd much prefer studs, but will make due for now until I start having problems.

Glad you still enjoy yours, I've been missing having mine. Will be rectified soon.....

Even with only daily driving (granted .. . a LOT of daily driving), I always had issues until I popped for Trackspeed's Inconel studs. I've driven on those studs for ~40K miles now, including an occasional track day.

Titanium bolts might work, I don't know if anyone has tried it. My biggest issue with bolts is that if you use a material that doesn't work out and they shear, they could be a lot harder to get out than a stud -- especially if they shear nearly flush with the manifold surface.

Well, he has the issue with the holes being already 10mm clearance, if I am reading the question correctly. That means he would have to tap to 12mm. I doubt a TD04 inlet flange would work with that. Maybe a stepped stud?

A picture would be worth a thousand words here so we understand exactly what you have.

One other thing with Titanium, there is a bit of a mismatch in thermal expansion coefficient between Titanium and typical Irons and steels. Titanium doesn't expand as much and would tend to tighten the connection with heat, raising stress. It's not a huge mismatch though, but Inconel is much better.

http://www.engineeringtoolbox.com/li...ents-d_95.html

I tried to get a quote on Inconel 625 bolts and nuts. Vendor wanted to know exactly what you would need. I would think 3/8" UNF, hex head bolts, qty 3. He suggested it would be cut treads, not rolled.

If you want me to get a quote, give me a length.

Yes, pics would help.