Exhaust Donuts

[Crazy_pilot]

They're used to allow the joints to flex a bit. The SVX exhaust doesn't have any flex pipes, so it's the joints at the cat that allow for engine movement.

[Conn SVX]

Thanks . Do u know the nut and bolt size. I see no reason Y stainless nuts and bolts can't be used , Do YOU? do you think Impresa or any other springs will work? Also any idea what donut from what car will fit the rear of the cat pipe?

[1986nate]

Originally Posted by Conn SVX

Thanks . Do u know the nut and bolt size. I see no reason Y stainless nuts and bolts can't be used , Do YOU? do you think Impresa or any other springs will work? Also any idea what donut from what car will fit the rear of the cat pipe?

The bolts used on the spring bolt assembly are not standard bolts. They are collared. I can't remember what the reason is for right now-If I remember right it has to do with the spring setup, but my mechanic said it was best to use stock bolts because of that. He has a die set so we just re-threaded all of mine and put new nuts on.

Edit: Think I just remembered. The bolt is thicker through the middle so that it fits snuggly inside the 'brackets' off of the downpipes and the ones on the cat. It is to prevent any unwanted movement and rattling but the nut that fits on them is smaller so that it can be removed easier-you can make more of a turn of the nut by having it 12mm I believe-rather than if it was a full width bolt the whole way, it would need a 17, possibly 19mm nut which would be more difficult and possibly even impossible to remove.
So in theory you could use any bolt but it will leave a LOT of play in the exhaust components if utilizing the stock set up-Not a good idea unless you like rattling exhaust, or worse, you lose the cat and your gaskets(donuts)