RPI Exhaust Droning
04-21-2009, 07:50 AM
#101
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Originally Posted by pointerman' post='853846' date='Apr 21 2009, 10:53 AM
How the heck did I miss all of this? Anyway, Krozi PM'd me a week or so ago asking if I had this problem and I told him I hear the same thing. Yes, there is droning in the RPM range he refers to. It happens during NORMAL acceleration (normal meaning general leaving a stop light type of acceleration, e.g. there is a police officer in the lane next to me). It bothers me a bit, but it goes away quickly. You definitely hear it puttering around town while driving in "D" mode.
Krozi,
Sorry I took so long to notice this thread. Might have saved you some grief if you had someone else with the same issue.
Krozi,
Sorry I took so long to notice this thread. Might have saved you some grief if you had someone else with the same issue.
Anyway, it was not too late and since you have this too I can breathe again.
Thank you for posting this 
you just saved me $200 (shipping charges)I don't think I am going to send the exhaust to RPi now. I will take a good look at that cone from B&B that FlyingPuck told me about though.
04-21-2009, 08:00 AM
#102
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Originally Posted by Krozi' post='853921' date='Apr 21 2009, 08:50 AM
I thought that your drone was quieter than mine.
Anyway, it was not too late and since you have this too I can breathe again. Thank you for posting this you just saved me $200 (shipping charges)
I don't think I am going to send the exhaust to RPi now. I will take a good look at that cone from B&B that FlyingPuck told me about though.
Anyway, it was not too late and since you have this too I can breathe again.
Thank you for posting this you just saved me $200 (shipping charges)I don't think I am going to send the exhaust to RPi now. I will take a good look at that cone from B&B that FlyingPuck told me about though.
So let me understand this.
You fuss about you have drone.
Drama ensues because we dont have a sound clip for a few days.
We get a sound clip that proves there is some drone under load.
RPI wants you to send it back to them so they can look at the exhaust.
You decide not to send it because of shipping charges.
Im sorry man but all of this should have stayed between you and RPI and other members with the same exhaust.
Now if you just wanted 545i members to know they will get some drone then thats totally cool. We all would like to know that info prior to purchase.
$200 for shipping?!?! no way man. I shipped wheels and tires for $130. You shouldnt be paying more than $50 each way for that exhaust to ship
04-21-2009, 08:05 AM
#103
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Originally Posted by PraiseTheLowered' post='853932' date='Apr 21 2009, 12:00 PM
So let me understand this.
You fuss about you have drone.
Drama ensues because we dont have a sound clip for a few days.
We get a sound clip that proves there is some drone under load.
RPI wants you to send it back to them so they can look at the exhaust.
You decide not to send it because of shipping charges.
Im sorry man but all of this should have stayed between you and RPI and other members with the same exhaust.
Now if you just wanted 545i members to know they will get some drone then thats totally cool. We all would like to know that info prior to purchase.
$200 for shipping?!?! no way man. I shipped wheels and tires for $130. You shouldnt be paying more than $50 each way for that exhaust to ship
You fuss about you have drone.
Drama ensues because we dont have a sound clip for a few days.
We get a sound clip that proves there is some drone under load.
RPI wants you to send it back to them so they can look at the exhaust.
You decide not to send it because of shipping charges.
Im sorry man but all of this should have stayed between you and RPI and other members with the same exhaust.
Now if you just wanted 545i members to know they will get some drone then thats totally cool. We all would like to know that info prior to purchase.
$200 for shipping?!?! no way man. I shipped wheels and tires for $130. You shouldnt be paying more than $50 each way for that exhaust to ship
04-21-2009, 09:11 AM
#104
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Originally Posted by Krozi' post='853944' date='Apr 21 2009, 11:05 AM
The reason I am not shipping it back is because another member confirmed that he gets some droning when he gives some light throttle input at cruising as well. If they exhaust is found to have a defect then RPi would cover the shipping charges. But at this point I don't think the exhaust has a defect. I guess that's just the way they are built.
Aftermarket such as RPI are straightthrough designs with perforated core and stuffed. You will get drone. The cones reduce the drone by limiting the exhaust flow from the engine. What you have is a case of too much flow at low rpm and probably even or more than enough at high rpms. That's why your stock mufflers are absorption and chambered design with a butterfly valve. That valve only opens up at higher rpms.
People who do aftermarket exhaust do not mind the drone at low rpm because they do not hover around there. If the droning gets to you after awhile, you need to look into new mufflers. The cones will restrict your exhaust flow at high rpm. Depending on your current ID for the piping, I think the cones only fit 3 -3.5 inch pipes.
Many people think exhaust is simple, but to get the sound you want without the loss in torque or HP at any rpm with a NA engine, you really need to know the science and art of cat back exhaust system.
04-21-2009, 09:27 AM
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Originally Posted by Bimmer32' post='854010' date='Apr 21 2009, 01:11 PM
Krozi,
Aftermarket such as RPI are straightthrough designs with perforated core and stuffed. You will get drone. The cones reduce the drone by limiting the exhaust flow from the engine. What you have is a case of too much flow at low rpm and probably even or more than enough at high rpms. That's why your stock mufflers are absorption and chambered design with a butterfly valve. That valve only opens up at higher rpms.
Aftermarket such as RPI are straightthrough designs with perforated core and stuffed. You will get drone. The cones reduce the drone by limiting the exhaust flow from the engine. What you have is a case of too much flow at low rpm and probably even or more than enough at high rpms. That's why your stock mufflers are absorption and chambered design with a butterfly valve. That valve only opens up at higher rpms.
04-21-2009, 10:23 AM
#106
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Originally Posted by Bimmer32' post='854010' date='Apr 21 2009, 01:11 PM
Krozi,
Aftermarket such as RPI are straightthrough designs with perforated core and stuffed. You will get drone. The cones reduce the drone by limiting the exhaust flow from the engine. What you have is a case of too much flow at low rpm and probably even or more than enough at high rpms. That's why your stock mufflers are absorption and chambered design with a butterfly valve. That valve only opens up at higher rpms.
People who do aftermarket exhaust do not mind the drone at low rpm because they do not hover around there. If the droning gets to you after awhile, you need to look into new mufflers. The cones will restrict your exhaust flow at high rpm. Depending on your current ID for the piping, I think the cones only fit 3 -3.5 inch pipes.
Many people think exhaust is simple, but to get the sound you want without the loss in torque or HP at any rpm with a NA engine, you really need to know the science and art of cat back exhaust system.
Aftermarket such as RPI are straightthrough designs with perforated core and stuffed. You will get drone. The cones reduce the drone by limiting the exhaust flow from the engine. What you have is a case of too much flow at low rpm and probably even or more than enough at high rpms. That's why your stock mufflers are absorption and chambered design with a butterfly valve. That valve only opens up at higher rpms.
People who do aftermarket exhaust do not mind the drone at low rpm because they do not hover around there. If the droning gets to you after awhile, you need to look into new mufflers. The cones will restrict your exhaust flow at high rpm. Depending on your current ID for the piping, I think the cones only fit 3 -3.5 inch pipes.
Many people think exhaust is simple, but to get the sound you want without the loss in torque or HP at any rpm with a NA engine, you really need to know the science and art of cat back exhaust system.
So what happens if exhaust flow is restricted at high RPM's?
04-21-2009, 10:39 AM
#107
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Originally Posted by Krozi' post='854097' date='Apr 21 2009, 02:23 PM
Since the exhaust does not have a constant drone I think I will get used to it and notice it less in the future.
So what happens if exhaust flow is restricted at high RPM's?
So what happens if exhaust flow is restricted at high RPM's?
04-21-2009, 12:06 PM
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Originally Posted by PraiseTheLowered' post='853932' date='Apr 21 2009, 08:00 PM
$200 for shipping?!?! no way man. I shipped wheels and tires for $130. You shouldnt be paying more than $50 each way for that exhaust to ship
04-21-2009, 02:38 PM
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Originally Posted by dirksqjaw' post='854281' date='Apr 21 2009, 04:06 PM
Man, mine was $280... and that was to the freakin middle east. No way will it cost 200, unless you're fedex'ing it or something. Didn't get a chance to pick up my car today, will pick it up tomorrow afternoon and will very anxiously listen for the same thing. There is a big stretch of Sheikh Zayed road where I'll be cruising in that rpm range due to speed camera's every 10ft so I'm sure to notice it big time if it's there. If it's background I won't mind but if it's as loud as your video made it sound.. ouch!
04-21-2009, 02:38 PM
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Originally Posted by Krozi' post='854097' date='Apr 21 2009, 01:23 PM
Since the exhaust does not have a constant drone I think I will get used to it and notice it less in the future.
So what happens if exhaust flow is restricted at high RPM's?
So what happens if exhaust flow is restricted at high RPM's?
Do a couple really fast acceleration and high speed, and you'll notice your drone will be louder.