Tom's exhaust drone
 

Hello,

I just got the Tom's Barrel Exhaust for the IS250 and also installed it right away. There was also an O ring included (I believe it suppose to be between midpipe and Y pipe), but as the Ypipe and the original pipe are coned, i didnt use the O ring spacer. Should I use this?

Therefore, The exhaust should be very quiet, but I experience drone (It's very noticable) when just hitting the gas gently.

The drone isnt there when the exhaust is still cold, but it's gaining by warming up.

Alan

Most aftermarket exhausts will have some sort of drone. My Tanabe, which is one of the quietest available, has a noticeable drone when light throttle is applied. It comes with the territory really, if you want a louder exhaust, you're going to have some drone. If it's that's bad, I'll trade you your Tom's for the quieter Tanabe ;)

The Tom's Exhaust suppose to be quieter than Even the Tanabe, that's why i am surprised about the drone.

Is there some reason for not using the O ring spacer? Tom's is rated at 85db, which is close to stock.

Well the aluminium O ring seems to be a spacer for aftermarket midpipe, because the original exhaust has the same cone as the Y pipe of the Tom's kit. And the midpipe fits just fine with the new Y pipe, thats why.

But I am not sure if it is required. so if anyone know?

I think the o ring you're talking about is the gasket which is suppose to stop air from leaking. That might be where you're getting that drone. You should try installing it again with that ring and see if that drone is still there.

The factory gasket is a crush type. Kind of looks like a donut that fits between the midpipe and the y-pipe. The factory recommends replacing it with a new one if the exhaust is changed but I reused the old one without issue. Besides, it was stuck on the midpipe anyway.

So there should be no exhaust gas leaks but I would guess it would create a hugh drone if no gasket at all was used.