So i installed the catback and everything worked out great, sounds amazing. But then when i starded testing it out, around 4500 RPM and on, a loud hissing noise kicks in. I dont thnk this is normal but i dont really know. While removing the old exhuast the header was moved around quite alot, and the noise does seem to come from the front of the car. Hopefully im wrong but maybe i broke somthing around there.

Has any one heard a hissing noise around 4500RPM before? Im really not sure, i checked for leaks and didnt find any, didnt see or hear the heat sheild hitting either. Any ideas? Thanks.

 

Take the heat shield off at the back of the motor
and look to see if its split at the precat
Ive seen them do that before.

 

At high RPM under load, the exhaust sounds like a jet. This is the same sound that that the stock exhaust makes, but with the Alta, it happens at lower load and lower RPM and is much louder. Could that be what you are hearing?

 

The way you descibe it, yes it could be. Ill check the header tommorow. I mean it could be normal but i just dont feel like it is. Thanks for the input

 

Thank you for the purchase! Sorry you are having any concerns at all!

Check the heat shield as mentioned above of course. If that doesn't work, PLEASE PM me so I can help further.

Thanks again!

 

Im fixing the resonator rattle on the heat shield tommorow, after that ill test it again. I checked the header from the top and didnt see anything messed up. Can anyone post a video of the noise on the inside on there car? Youtube needs some more videos of this catback anyway but i dont have a camera.

 

Okay well when i am under there and i move the the exhuast around nothing hits. and i shake it WAYYY to much. it doesnt move that much at all when running but im just trying to make sure its not hitting the sheild.

So i start it up and the resonator still sounds like its hitting the heat sheild, somewhere around 1800RPM you can hear it a little and it sounds like heat sheild rattle, but as i said im pretty sure its not.

That leaves me to belive that maybe my resonator is faulty? the 4500rpm hiss and low rpm rattle make me think this. Have these resonators been known to break or anything? Thanks again everyone

 

I had an Alta exhaust that the resonator failed (melted the perforated internal pipe) between 2-4k miles. I thought it was the heat shield so I pretty much modified the hell out of it to hopefully fix the issue but no dice. I tried to get mine warrantied but through having a non-alta header that "possibly" caused the resonator failure I was unable to get a replacement. I know for fact the EGT's for the MINI can be very high in certain circumstances ie spirited driving. But to cause the resonator to melt internally seems to cause suspicion of cheap low grade/quality materials. Because for a $215 Megan Racing header to out last a $800 exhaust it just seems weird and causes products to be of questionable quality even with a lovely polished "High Quality" appearance. From a professional opinion I design hand built brass lighting fixtures so naturally I have a razor sharp eye for quality no matter what the material is.

 

So the noise it made sounded like the heatsheild? Guess i have the same problem, except mine was broke as soon as i installed it.

 

Correct but no matter what you did to the heat shield it was still there. So I ended up taking it off and doing a tap test where you stand it up verticle and tap the ground not very hard to see if you hear a some sort of loose metal sound.

 

Oh K wait a minute! There is NOTHING low quality about our exhaust! But the lack of a catalyst along with EXTREMELY high EGT's from the supercharged motor combine to make even 1200 deg packing withstand the abuse. Approx. four resonators have failed when combined with a catless header.

Our systems are covered by a lifetime warranty and other than abuse, outside damage from obstacles etc. (original purchaser etc.)

I would like to know more about your situation. Please PM the details to me.

Thanks again for choosing ALTA!

 

Very unlikely! Not the same set of circumstances. PM me with more details so I can help further!

Thanks in advance!

 

I had the EXACT same problem you are having. I was sent a bad resonator. I went around in circles trying to see if was hitting the heat sheild. It turns out my resonator was perforated when I got the system. Sorry you are going through this, I know its a pain. It sounds like a kazoo if I remember correctly.

Im sure Alta will make it right

 

Thats what we strive to do!

 

Yes and they are working it out with me, props to alta. Ill let you guys know how it goes.

 

jollyroger927, here is a sound recording I just made.
http://home.comcast.net/~rwkeating/auto/other/Alta1.mp3
The car is a 2006 MSC with no engine mods other than the Alta v2 2.5" catback (with dual tips.) The recorder was in my shirt pocket because anywhere else I put it, it rattled. The windows were closed to better hear the exhaust and not the noise of the wind rushing through the windows.

There are no rattles from the exhaust, but you can hear the sound of rushing air (jet like). I believe I have no leaks. I think that is just the sound of the exhaust under load at higher RPMs.

Is that how yours sounds?

In case you are interested, here is a write up of my install. Part 2 to come soon:
http://home.comcast.net/~rwkeating/auto/altaexhaust.html

 

It defintly makes me think mine is normal, but i guess i hear mine louder when the windows are down, because i had mine up to compare the noise to yours and all i heard was supercharger wine becuase of the alta intake. With the windows down its slightly louder i think. But i guess its normal. Thanks alot for the sound clip! made me feel alot better.

The only problem now is the rattle which alta is working with me on. I'll let you guys know what happens.

 

Thanks guys!

 

So alta told me to take off the resonator and hit it, and listen for noise. There was in fact somthing rolling around in there so Chris is going to send me a new resonator when they get the new ones in. Great help from Alta!!

I even asked if i could cut this resonator off and have a straight pipe put in untill i have the new resonator and he was fine with that, i just have to send back the broken resonator when i get my new one.

Straight pipe was installed today and the rattle is gone, hissing seems to have gone down also but i only drove to work so far, ill post later after i test it out some more. The resonator delete does add some more noise.

 

jollyroger927, post a sound clip without the resonator if you can. I'm curios to hear what that sounds like.

Mine developed a very slight rattle somewhere way in the back. I don't think it is the exhaust. It sounds like a heat shield but I haven't been able to find it. I now have very good clearance all around the exhaust so I am kind of surprised that a rattle showed up.

I have to get this sorted out before winter.

 

I recently installed an alta catback on my r53, makes a noise under load in high rpms as well. Was it definitely the resonator? the page with the sound clip is not there anymore so I can't be sure it's the same. thanks for any help

 

jonnyshipwreckjonnyshipwreck are you asking me? The sound clips I had where a comparison to the original and then smaller resonator.

Here is my story. Installed the Alta and the resonator had a bad internal rattle. Alta replaced it and that fixed the problem. My exhaust only had a year warranty and after a year the muffler developed a slight rattle. It is slight and it comes and goes so I just deal with it.