200: Akropovic system - far too loud?!

[matt9566]

After seeing this the other day I also downloaded the app and tested it out. With the phone mounted in the front of the car, it registered around 75 db whilst cruising at 70mph on a flat motorway, rising to 81 db when accelerating. Going uphill on the motorway is almost at a constant 80 db. Just pulling away normally around town and going through the rev range/gears, it registers up to 80 db. It would be interesting for other Akra owners to download the app and see what their's registers at as I think this is excessive.


Yeah that does sound as though it's quieter than mine. Mine is a late 2011 model which I believe will have the later gearbox?


The car is currently in the garage having the swivel joint done so I will ask the guy to check the manifold whilst it's up on the ramp. I can't see anything in the service history to suggest that it's had a replacement manifold though.

Which app did you download and where did you put your phone ? If I remember I'll test mine out on my way home from work.

Yes yours will have the later gearbox with the longer ratios (I think)

Definitely get your mechanic to check the manifold, maybe even get a photo then we can have a look ?

 

[AndyBMX]

Which app did you download and where did you put your phone ? If I remember I'll test mine out on my way home from work.

Yes yours will have the later gearbox with the longer ratios (I think)

Definitely get your mechanic to check the manifold, maybe even get a photo then we can have a look ?

It's just called 'sound meter', and the phone was just above the head unit where my mount is.

 

[petercronin]

The problem with these phone apps is that they are wildly inaccurate and things like different mics in different phones are going to register certain noises differently. Say a S9 might be more sensitive to high frequency noise compared to a iPhone X which might sense low frequency noises as louder. Even different model phones from the same manufacturer are likely to have different mics and will sense differently.

I tried measuring exhaust noise (like they would on a track day) once and I can remember it was showing something silly like 105 / 107 ish and was different every time you tried when in fact if measured with a proper dB meter it’s way way lower.

I’ll try this when I get a chance to give you an idea but don’t take any of the reading as anything but guesswork.

 

[bedoef]

The problem with these phone apps is that they are wildly inaccurate and things like different mics in different phones are going to register certain noises differently. Say a S9 might be more sensitive to high frequency noise compared to a iPhone X which might sense low frequency noises as louder. Even different model phones from the same manufacturer are likely to have different mics and will sense differently.

I tried measuring exhaust noise (like they would on a track day) once and I can remember it was showing something silly like 105 / 107 ish and was different every time you tried when in fact if measured with a proper dB meter it’s way way lower.

I’ll try this when I get a chance to give you an idea but don’t take any of the reading as anything but guesswork.

I agree that using a phone to get an accurate reading is not optimal (which is why I said estimate in my first post) I wouldn't call it guesswork. Yes, these are not scientific results we are talking here, merely reference points. I think thats still pretty useful, no? The range I saw for accuracy in a few studies which tested iOS and Android devices was a Std dev of 5-8 dB. I would say that helps you establish an understanding of how loud its going to be in relation to the OEM system only.

At the end of the day, sound is subjective so really only the owner will be able to say what is too loud. This helps to establish a range that they can work with I would think?

 

[Micah]

I remember when I had my dodgy Scorpion fitted, it went off the scale of that app at 99+
It was unbearable!

 

[petercronin]

I agree that using a phone to get an accurate reading is not optimal (which is why I said estimate in my first post) I wouldn't call it guesswork. Yes, these are not scientific results we are talking here, merely reference points. I think thats still pretty useful, no? The range I saw for accuracy in a few studies which tested iOS and Android devices was a Std dev of 5-8 dB. I would say that helps you establish an understanding of how loud its going to be in relation to the OEM system only.

At the end of the day, sound is subjective so really only the owner will be able to say what is too loud. This helps to establish a range that they can work with I would think?

You’re right that it might give you a rough idea but bare in mind that a 5-8 dB tolerance at those levels is quite a difference in what you’ll ‘actually hear’. I’ll give it a try later and let you know.

But there’s a few simple things I’d suggest you check too. Do you have a standard or oem manifold, have you got a cat fitted either as part of the oem manifold or a separate cat if you don’t have the oem manifold, has the Akra got its centre silencer fitted?

 

[AndyBMX]

I agree that using a phone to get an accurate reading is not optimal (which is why I said estimate in my first post) I wouldn't call it guesswork. Yes, these are not scientific results we are talking here, merely reference points. I think thats still pretty useful, no? The range I saw for accuracy in a few studies which tested iOS and Android devices was a Std dev of 5-8 dB. I would say that helps you establish an understanding of how loud its going to be in relation to the OEM system only.

At the end of the day, sound is subjective so really only the owner will be able to say what is too loud. This helps to establish a range that they can work with I would think?

You’re right that it might give you a rough idea but bare in mind that a 5-8 dB tolerance at those levels is quite a difference in what you’ll ‘actually hear’. I’ll give it a try later and let you know.

But there’s a few simple things I’d suggest you check too. Do you have a standard or oem manifold, have you got a cat fitted either as part of the oem manifold or a separate cat if you don’t have the oem manifold, has the Akra got its centre silencer fitted?

Yeah it'd be good to know everyone's just for a reference. If they all come back being similar, then it may be like Bedoef says and it's subjective, with others happy enough to deal with it being this loud. My old 182 had the Scorpion RS192 system fitted and this is much louder than that.

I've asked the mechanic to check the manifold when the car is next on the ramp and tell me whether it's a standard Renault one or whether it's aftermarket. The system does have the centre silencer fitted.

 

[petercronin]

Right, just been out. This is an iPhone 7 mounted to the centre dash vent using an app called Decibel X. I have a oem manifold with the full Akra evo exhaust:

Idle - reads around 80 dB

30mph in 4th gear - reads in the high 80 dB’s

60mph in 6th - reads around 90 dB

70mph in 6th - reads in the low to mid 90 dB’s

I can say hand on heart that it is ABSOLUTELY NOT this loud. Most of the noise it’s picking up is road/wind/general cabin noise. One thing to note though is the roads are wet, so the with additional noise off that you can probably reduce the readings a bit. The only time out of those examples above when you can hear any exhaust noise is at 70mph and even then you could easily have a quiet conversation.

As for your manifold, if you’ve got the car you can see it by looking down the back of the engine. No need to mess around getting it on ramps.

 

[Dumdum]

Right, just been out. This is an iPhone 7 mounted to the centre dash vent using an app called Decibel X. I have a oem manifold with the full Akra evo exhaust:

Idle - reads around 80 dB

30mph in 4th gear - reads in the high 80 dB’s

60mph in 6th - reads around 90 dB

70mph in 6th - reads in the low to mid 90 dB’s

I can say hand on heart that it is ABSOLUTELY NOT this loud. Most of the noise it’s picking up is road/wind/general cabin noise. One thing to note though is the roads are wet, so the with additional noise off that you can probably reduce the readings a bit. The only time out of those examples above when you can hear any exhaust noise is at 70mph and even then you could easily have a quiet conversation.

As for your manifold, if you’ve got the car you can see it by looking down the back of the engine. No need to mess around getting it on ramps.

I can hear my standard 200 exhaust at 25mph, so to say you can’t hear the Akra at low speeds is not accurate...

 

[petercronin]

I can hear my standard 200 exhaust at 25mph, so to say you can’t hear the Akra at low speeds is not accurate...

Well sorry to disagree but I’ve just done it and the only thing I can hear is road noise. If you accelerate or go down the gears you can hear it then, but a constant speed in 4th I can’t.

 

[AndyBMX]

Right, just been out. This is an iPhone 7 mounted to the centre dash vent using an app called Decibel X. I have a oem manifold with the full Akra evo exhaust:

Idle - reads around 80 dB

30mph in 4th gear - reads in the high 80 dB’s

60mph in 6th - reads around 90 dB

70mph in 6th - reads in the low to mid 90 dB’s

I can say hand on heart that it is ABSOLUTELY NOT this loud. Most of the noise it’s picking up is road/wind/general cabin noise. One thing to note though is the roads are wet, so the with additional noise off that you can probably reduce the readings a bit. The only time out of those examples above when you can hear any exhaust noise is at 70mph and even then you could easily have a quiet conversation.

As for your manifold, if you’ve got the car you can see it by looking down the back of the engine. No need to mess around getting it on ramps.

Interesting. You must be right about the different phones different readings. It is crazy that you say you can only hear your exhaust at 70mph, I've forgotten what that's like!

Unfortunately the car's still at the garage so I can't check the manifold at the moment. I did have a look down there the other day but I don't really know how to identify it as OEM or aftermarket?

I have also contemplated stuffing my spare wheel well/under the boot carpet with sound deadening, as the all of the noise seems to come from that area. I can't remember whether it has any there from factory?

 

[matt9566]

OEM manifold is on the right, which has 2 flexi's and a cat at the bottom. All aftermarket ones (like the one on the left) have a single flexi or even none at all and also won't have a cat attached.

If you look down the back of the engine you can see the flexi area.

 

[AndyBMX]

OEM manifold is on the right, which has 2 flexi's and a cat at the bottom. All aftermarket ones (like the one on the left) have a single flexi or even none at all and also won't have a cat attached.

If you look down the back of the engine you can see the flexi area.

Perfect, cheers mate. Will have a look when I get the car back.

 

[petercronin]

Interesting. You must be right about the different phones different readings. It is crazy that you say you can only hear your exhaust at 70mph, I've forgotten what that's like!

Unfortunately the car's still at the garage so I can't check the manifold at the moment. I did have a look down there the other day but I don't really know how to identify it as OEM or aftermarket?

I have also contemplated stuffing my spare wheel well/under the boot carpet with sound deadening, as the all of the noise seems to come from that area. I can't remember whether it has any there from factory?

It’s not so much the speed it’s the engine rpm and how much load it’s under that determines how loud it is. I’ve just had a thought too though, exhausts often get a bit louder as they get used and mine only has a couple of hundred miles on it. So what I’m saying here might be different in a few months. I’m guessing yours has been fitted a while and I know I’ve seen a few people on here that have them fitted so they might be able to answer that for you.

I don’t know about the sound deadening either I’d have to check. I’ll try and have a look when I get a chance.

 

[Cossers]

Ktr induction kit, decat and Ktr system, just tried that app above, @89 at idle and @93 outside at rear of car on idle, driving gets a bit louder again, sounds well but is a racket! Lol, I’ve heard Turks Akro and it’s reserved compared to mine, I’m sure he will confirm this

 

[john_walker74]

Ktr induction kit, decat and Ktr system, just tried that app above, @89 at idle and @93 outside at rear of car on idle, driving gets a bit louder again, sounds well but is a racket! Lol, I’ve heard Turks Akro and it’s reserved compared to mine, I’m sure he will confirm this

That's really high compared to a track day calibrated noise meter test at 50% throttle.

 

[AndyBMX]

Checked the manifold when I got the car back last night and can confirm that it is standard. At a bit of a loss with the exhaust. It's not so much the noise when cruising as that's sort of bearable, it's just when I want to drive normally around town, going through the gears at anything above 3k just gets anti-social loud. It's hard to know whether it's as loud outside of the car, or whether it's just amplified inside which makes me think it's worse than it is.

I may try putting some sound deadening under the boot carpet, but if it's still too loud it may be time to take it off and replace it with something quieter.

 

[Marsch]

To my experience the Evo is foremost setup for improved sound inside the car. I was actually astounded when I heard mine flying by from the outside. Measured outside (standing @ 3750 rpm) it's only about 4 dB louder than the standard exhaust.

That said I actually don't want anything else because it's a perfect compromise (great sound inside with some pops and bangs here and there but nothing so extreme that you can't drive around town without getting hated or stopped). I'm by the way running mine without backseats and assume that it therefore is a little more intrusive.

Oh, and just to mention it. I've the car for about two years now and the Akra was basically new when I bought it. It got and still seems to get louder as longer you run it. I've also heard that it may become necessary to refill the silencers (with steel wool or what ever) at some point because they've the tendency to "burn out" over time. Maybe this is the problem here?

 

[matt9566]

Checked the manifold when I got the car back last night and can confirm that it is standard. At a bit of a loss with the exhaust. It's not so much the noise when cruising as that's sort of bearable, it's just when I want to drive normally around town, going through the gears at anything above 3k just gets anti-social loud. It's hard to know whether it's as loud outside of the car, or whether it's just amplified inside which makes me think it's worse than it is.

I may try putting some sound deadening under the boot carpet, but if it's still too loud it may be time to take it off and replace it with something quieter.

The last thing I can suggest now is try and find someone local to you with an Akra fitted who is willing to meet you, then you could compare and decide if there is something wrong with yours.

It may just be that the exhaust isn't for you, there was a thread on here at one point with someone saying they found their Akra too quiet, and I even agreed to a certain degree. But on the other hand, I have known people have an exhaust which everyone found quiet but a couple of people found it loud and intrusive.

 

[john_walker74]

The last thing I can suggest now is try and find someone local to you with an Akra fitted who is willing to meet you, then you could compare and decide if there is something wrong with yours.

It may just be that the exhaust isn't for you, there was a thread on here at one point with someone saying they found their Akra too quiet, and I even agreed to a certain degree. But on the other hand, I have known people have an exhaust which everyone found quiet but a couple of people found it loud and intrusive.

That's what I was going to suggest.