X5Jay, does your exhaust sounded like marbles in the pipes at higher RPM's after the X pipe mod??
Read the thread above to see what I´m talking about:
http://www.xoutpost.com/x5-e53-forum/...highlight=pipe

How about long time reliability, can this X pipe deliver a proper exhaust back pressure, at very high RPM??? All of you that made the X pipe mod didn´t thougth about this question?

I am interested on doing this mod, but I´m afraid of ended like MrLabGui. He took out the X pipe and went back to stock resonaters.
Is the X pipe just a crossover pipe, if so, i think a good shop can make this X pipe fo less than 80 usd.

J.Seven

J.Seven, what engine and year is you X.....Phil

It´s 4.4L from 2000.
Have you made X pipe mod yet?

J.Seven

Not yet...I'm going to the shop Tuesday to have the tech look at how involved the welding will be. Once he gives me the price...I'll order the X pipe. Hopefully it'll be done in the next 2 weeks.....Phil

No marble sound at all with mine. I do get a slight bit of gurgling and popping on a cold day after I've shut the X down for a while and then re-start and drive off again - but it's a good sound, not a marble sound at all, and it doesn't happen in the warm weather at all.

As for the back pressure question - I believe that's what the X-Pipe's designed to do - add a bit of back pressure where going with plain straight pipes wouldn't do that. As mentioned in my little write up, the sound change is very subtle compared to stock, but it's certainly there - a little deeper and sportier IMO. No change in power - not more and not less.

Can you confirm if the X pipe it´s just a cross pipe withouth anything inside in the place where the two pipes cross? I ask this because there was some tuners making a sport headers system for the Porsche 996 Carrera and although they looked all similar , there were two tuners who put inside the header where the air coming from three pipes would join, a small device which made the air to flow better. Headers with this device provide better result that others withouth it.

J.Seven

The X-Pipe that I have is just a simply hollow "X" pipe - nothing inside. Nothing to do with headers in this case at all. BUT, since you mentioned headers - I've never heard of aftermarket headers for the X5, but it sure sounds like a great idea!!

Header's should never be confused with an X-pipe.

I am not confusing headers with X pipe, I was just trying to figure out the complexity of the teh X pipe so that I can ask my tech guy to do one unit for me instead of ordering it from the other part of the world ;) .

J.Seven

Any decent exhaust shop should be able to make an X-Pipe for you for less than you can buy it for. There's not really all that much engineeing involved and good welding skills is the key...