3sgte downpipe bolts

The short answer:

Use studs.

Will bolts work, yes.

Reason: it's to do with how studs distribute force, clearance and working loose.

I have extra studs from when I did mine if you go down that path.

I should also have copper plated lock nuts which are the right ones to use, a PITA to find and not cheap. I think I might just have enough (6) to get you by.

I can also tell you the proper installation method to ensure they don't work loose or seize.

Can you tell I've well and truly been down this road...

-I would give you the studs (or postage) but I'd recommend using the same type nut on all studs?

-manifold to turbo studs; I'll check

-installing studs: thread lock on head/manifold/turbo end 'finger tight' (the way a stud can outperform a bolt in clamping efficiency has to do with the even distribution of stress across the engaged threads), anti seize on nut end

Some of this might be obvious to you but...

-use new gaskets

-replace oxygen sensor gasket (these are normally falling apart)

-there are 2 'water inlets' on turbo, one is a block off plate, but both use the same gasket

-DO NOT use any gasket maker on any of those surfaces, particularly the oil feed/return

-clean the head surface really well (I used a wire type head on a rotary tool

-if you have an A/M dump pipe it will foul on studs by a few mm if you leave the air con compressor in place and install it with turbo/manifold in place

-the turbo oil feed (on block) uses unique sized washers (2x)

-do oil cooler gaskets/hoses if you've got that off

Thread lock doesn't so much 'glue' the stud it just makes it more resistant to turning out of the thread. Hence why you don't tighten the crap out of the stud like most people do. Once you get to the shoulder (unthreaded section) your not doing anything by tightening it. The issue is normally the nut seizing to the stud (hence copper plated nuts and anti-seize).