Front pipe to midpipe exhaust leak, help please

[justin6280]

Okay so, I recently switched from a Perrin catback to an Invidia Q300.

I have a massive air leak between the stock front pipe and the Q300 midpipe, and I'm not sure why.

Currently I'm just reusing the OEM donut gasket.

Is there some kind of special gasket / adapter needed to fit into the Q300 midpipe properly? Do I need to add a flat gasket in addition to the OEM donut gasket?

Would it be safe to just ditch the donut gasket and opt for flat gaskets and NON-springy bolts?

I'd appreciate some opinions here, thank you!

[BirdTRD]

As long as the donut and mating surfaces are in good shape, you shouldn't have a leak. Are you sure (I have to ask) that you installed the springs in the right place...i.e. bolts go thru the springs first then the bolt/spring combo goes thru the holes from the q300 side and screws to the midpipe, so the springs are pushing the Q300 pipe against the donut?
If they are installed correctly, remove them and verify the 2 sides fit together relatively well, there shouldn't be a whole lot of pulling going on.

[justin6280]

you have me second guessing myself, but I am 90% sure I have the bolt/spring going through from the Q300 side towards the Front pipe haha.

I want to say they are fitting pretty well. It's not a struggle to get enough bolt thread showing on the other side so that I can screw a nut onto it.

With my perrin exhaust, I had to use a clamp just so I can get enough threads showing for the nut.


If all else fails, do you think I can just run the setup with a flat gasket and normal bolts?

[BirdTRD]

I'm sure you could rig something up but if it were me, I'd try to figure out what's causing the leak with the set up as it was designed. The donut and spring setup allow for some "flexibility" so if you use a flat gasket and bolt it tight, you will lose that, which will put stress on you exhaust somewhere else.

Maybe try a new donut.

[Kodename47]

I found my OEM donut gasket failed the 2nd time I refitted my frontpipe. New gasket sorted it out. Seems like it doesn't like being reused too many times.

[justin6280]

I ordered a new donut gasket, and should be here tomorrow. Will update you guys on whether that fixed the problem!

[norcalpb]

Originally Posted by justin6280

I ordered a new donut gasket, and should be here tomorrow. Will update you guys on whether that fixed the problem!

You should use some Permatex high temp silicone sealant on the new gasket just to be sure.

You can get it at any auto store.

[justin6280]

new donut gasket and the high temp silicone sealant did the trick! no leaks at all.


thank you to everyone who helped, I appreciate it!