Exhaust Note

preacherman · March 25, 2011, 08:49:33 AM

Hi all
I just had my new exhaust system fitted to my Ser1 1750 GTV. I replaced my old one as it was not an original one and the exhaust note was really muffled. After having the new exhaust fitted i was crushed to find after starting the car that it still lacks the Alfa 'RASP'. I ordered the system from a well known Alfa spares outlet. I fear that i might have been sold a dud rear section although it looks like the real thing according to spares photos and fits as it should.

Am I right in saying the 'rasp' comes from the undulations in the rear muffler? I have had a Ser1 1750 before albeit with a 2 litre motor and the 'sound' of the motor was quite different.
What is wrong or missing??

Lindon

preacherman · March 26, 2011, 02:45:13 PM

I put this thread on another Alfa forum and got some interesting responses. What I want to know is whether aftermarket Alfa exhausts has got it wrong with the rear muffler?
I spoke with the exhaust who showed me a number of mufflers for the rear and pointed serrations on the inside of the pipe which caused turbulence and resonance.The more prominent the serrations the louder the noise. The Alfa exhaust however on my old GTV 1750 was not just 'noise' but a RASP under hard accelaration and a pleasant distinctly Alfa sound even under normal driving.

I would really like my Alfa to sound like one and not like a Camry!!

Anthony Miller · March 26, 2011, 08:37:45 PM

maybe your confusing exhaust note with induction roar

preacherman · March 26, 2011, 08:48:14 PM

I am quite certain that it is exhaust note I am talking about. The rasp or blat as some call it is distinctly Alfa. The stifling of the sound detracts from the joy for me of owning such a car. I have heard that the new mufflers are really laden with fibreglass compared to o;der exhausts hence the change of the sound. I am of the opinion that the serrations in the pipe of the muffler is also wrong. Has anyone recently replaced their exhaust? Any problems?

105s alive alfa parts · March 28, 2011, 09:54:21 PM

Lindon,
Mate you should have called us first we would have told you the best way to get that sound is to put a hotdog on it before the rear muffler, it gives a very strong rasp, i can send you some video of the one Tony and I built for my car.

Angelo

giulia_veloce · March 29, 2011, 06:58:32 AM

Hi Lindon

Remove the front resonator-muffler = the one under the passengers floor,and put a straight bit of pipe there.
That might excite you some more.
Or remove the rear muffler and put in a straight bit of pipe.
Genuine Alfa mufflers are straight through= you can see straight through them.
Maybe you were supplied with mufflers that are not straight through and make it quiet,and can loose a lot of performane as well,but only a dyno can realyl tell us of performance gains and losses,as every engine behaves differently.

Robert

scuzzyGTV · March 29, 2011, 09:39:20 AM

QuoteRemove the front resonator-muffler = the one under the passengers floor,and put a straight bit of pipe there.
That might excite you some more.
Or remove the rear muffler and put in a straight bit of pipe.

Doesn't this start to much up the resonant frequencies/exhaust pulses? I'm sure I've seen on here before somewhere, that you can remove the mufflers, as long as you replace it with a "straight through" type hot dog or similar.

Scott.

Davidm1600 · March 29, 2011, 08:05:55 PM

Yet another alternative is to buy a system from Alfaholics, Classic Alfa, or some of the suppliers who advertise on the BB or locally perhaps through Pace Automotive and I am certain you will get all the Alfa exhaust rasp you could desire, the only way you really will get the full induction noise is to remove the air cleaner and replace with Ram Tubes and sport filters, or alternatively upswept tubes as per GTAs. Nice but really not practical to live with on a daily basis

preacherman · April 01, 2011, 10:28:59 PM

I contacted Alfaholics with this problem and one of the bosses replied to me and said he too was disappointed at a system he bought for one of his cars. He said the modern mufflers/systems cannot replicate the factory ones totally and suggested a stainless system. In research I have done re stainless systems they can actually do harm re heat disappation and valve damage. They also cause issues re resonance. I am hoping to go down the track proven by Tony Lucente and Angelo Vito

giulia_veloce · April 02, 2011, 05:43:09 AM

Hi ScuzzyGTV Scott.

The question from Lindon (preacherman), was noise, not performance.

There is always the technical side to everything,so try anything and dyno it.
Id rather spend a few hundred and get the desired exhaust note,than thousands believeing I have the required exhaust note
I used to believe that everything had to be done the expensive way,but not now.

As an example,28 V8 Super Cars with 28 different extractor and exhaust systems,and the top 20 cars split by 1 second.
How do I know,cause I crawled under every one of them and saw every car was different.
And also,2 cars in the same team,had different exhausts.eg,DJR,SBR,GRM etc

I think its time to remove 6 litres of fuel from the fuel tank,cause it will definatly go faster.
Also time to MRS Sheen the paintwork,cause it will slip through the air much better.
Oh,and if the car aint RED,it will be slower.
Lots of opinions,which makes great reading.
Robert