Hey guys, putting my downpipe back on and had one of the studs come back out on me when I was putting the nut back on.

I'm switching to just a bolt to simplify things but have a quick questions. Does anyone know what length bolt I should be using?? I picked up a M10-1.5 x 40mm but am just worried it might be too long.

Picture shows my stock stud w/nut compared to the bolt I just picked up.

DP Bolt.jpg (77.8 KB)

 

I may be wrong but i think the studs are made on inconel, which is very heat resistant. I'd just buy a replacement stud and thread it back in and call it a day.

 

That stud looks to be in pretty bad shape, you might want to make sure the thread on your twins is ok. To replace it, just order new stud and nut from Ray at Malloy, regular bolt won't be able to take the heat.

 

it may seem like the stock ones are weak because they failed after 20 years, but any hardware store bolt is going to fail much much faster.

 

Any reason why you want to use bolts? Its going to be much harder to like up the gasket and the larger head will have clearance issues with some downpipes. That also looks like a generic 8.8 class bolt which is much weaker than stock. I use m10x1.5 studs and copper clad top lock nuts from either ATP turbo or clipsandfasteners.com. Both are much cheaper and don't seize like the stock hardware.

 

I use the same thing for the same reason. Right now I have the 14mm hex split type nut from clips and Fasteners but next time the DP is off I'm going to try the 15mm hex ones from ATP turbo since the nut is a little thicker.

IMO one of the main problems you want to avoid is having to drill out and extract a fastener from the turbo manifold. If one of your bolts sticks and you break it off trying to remove it and have to extract it you won't want to do it again. That's why I run different nuts and shortened studs (shortened so it will fit under the bend) on the DP.

 

I spent some time deciding what to run after spending the $200+for the turbo and DP gaskets and all the time it took to extract a broken stud from the turbo mani. In the pic the copper has burnt off the nuts.

 

Not a good idea, as others have noted, for various reasons. The stock studs (or equivalent) are the way to go.