jskup1

iTrader: (7)

Does anyone know what the purpose of the spring washers that hold the exhaust to the cat pipe? The guy at the dealer said that they were for shock resistance, but I could tell that he really wasn't too sure and was just taking a guess. I thought that maybe it was to allow the pipes to expand and contract at different exhaust temps. When I put my Borla on, I easily torqued them until the springs were fully compressed. Manufacture specs are 40 ft lbs but I didn't even have any resistance at all until the springs were completely compressed. The same thing happened on vIce's Corksport. I'm thinking of just taking them off and installing lock washers in their place.

staticlag

They are so the exhaust can flex as you go over bumps and such. I don't know if you noticed, but the cat is connected to the header which is connected to the motor which is connected to the chassis, these are rigid connections.

Now, the muffler is suspended by rubber hangers and does sway around while the car is moving.

That would be an awful lot of stress on the header/motor.

The springs should not be fully compressed.

jskup1

iTrader: (7)

Can someone answer without being a smart-*** please.

Brice-RX8

Didn't sound like a smartass reply to me, sounded pretty informative.

jskup1

iTrader: (7)

Maybe I'm just being a little too sensitive today but the 2nd sentence in his reply struck me the wrong way (I don't know if you noticed, but the cat is connected to the header which is connected to the motor which is connected to the chassis) like I didn't know that?

apotocki

Doesn't appear to be a smartass comment to me either...but....

anyways, I echo the above...the springs allow for the necessary flex at that point in the system. Don't fully compress them. When I replaced my cat-back I did not have a torque wrench and simply tightened the nuts to where the spring was about 1/2 compress and I have no leaks that I'm aware of.

Napboy

i think he's asking about the washers and not the springs themselves.

jskup1

iTrader: (7)

Thank you, I'll loosen mine up some.

kwolfman

I replaced my stock exhaust with a Mazdaspeed dual sport a couple of weeks ago. If I remember correctly, the bolts attached to the flange have a small stop on them. The threads also don't go the length of the bolt. So, when you put the springs on then the nut/washer you can only tighten down the nut until you either hit the stop or run out of thread. At that point you can torque the nut. My springs looked ALMOST compressed all the way. I think that still allows the joint to flex, but only a little bit. I am sure Mazda is concerned about exhaust gases leaking out the joint, so they need a tight but flexible fit between the pipe and cat.

TeamRX8

iTrader: (25)

the nuts are suppose to be tightened all the way until they hit the end of the threaded stud area. The springs will not be fully compessed once this is accomplished, but they will be at the proper tension point, it's designed to work this way. There's no way to overtighten them unless you put a bunch of washers between the nut and the spring. You can only undertighten them by not cranking the nut down to the end of the threads ...

ps: even my 10 yr old niece isn't that oversensitive ...

jskup1

iTrader: (7)

Rough day at work today.

jskup1

iTrader: (7)

I didn't put any washers in there and mine are compressed fully. Here's some pics.

woodysjh

So does anybody know? Should we be tightening them all the way to the end of the threads or should we be leaving them so the springs have some gap between coils and just pressure?

kwolfman

I think TeamRX8 and I made it pretty clear. Yes, tighten the nuts down and torque them to spec. The springs will be at the proper tention and life will be wonderful. So crank and torque away!

jskup1

iTrader: (7)

Mine are torqued to spec which is 40ft/lbs. It just didn't happen until the springs were fully compressed. Would it help at all if I took them off and tightened from the other side?

TeamRX8

iTrader: (25)

sorry, I just have to say it:

I hate stupid people

jskup1

iTrader: (7)

I know you're talking about me saying to tighten from the other side. The reason I say that is I've heard some people say that when changing the exhaust, you should remove the bolts on the stud side and not the nut and washer side due to the way it seats. I didn't see why this would matter except so you don't strip the studs when pulling the pipe off. That was a good one though.