Noise after replacing Shannon tube

StevenWilliams · 10th August 2009, 18:32

I've just replaced my Shannon tube. I used some High temp 70mm Air hose from eBay. http://cgi.ebay.co.uk/70mm-2-3-4-Sil...mZ130317088184

I've noticed that now the engine has a much stronger suction sound coming from it.
Is this normal? The engine sounded much quieter before but now sounds like it's got an induction kit fitted.

Also all the threads I've seen recommend using 70mm ducting. But 70mm is slightly to small and cannot fir over the existing fittings. I had to fit it inside the current connectors. I know this will slightly reduce the air throughput but not enough to raise the sound so much.

Departed · 10th August 2009, 18:40

The Shannon tube has a semi porous wall, which is designed to reduce the noise. Do a search on the net of inter for interesting info!

T-Cut · 10th August 2009, 18:47

It could also be due to the tuning of the inlet system. I understand one function of this duct is to 'tune' the inlet air stream. To do that, it's made a specific length. That's usually irrelevant I suspect, but maybe you're getting a standing resonant wave? It may just be due to the compromised fit.

Here's the Shannon company's explanation: http://www.shannon.co.uk/noise-reduction.htm

All engines bar the 190 use a 70mm bore system. If the 70mm duct you got won't screw onto the threaded unions, I guess it's a 190 engine. In that case you require the 80mm bore. The HowTo was amended recently to cover this variation.

TC

davidbooker · 10th August 2009, 20:16

IMO, my 51 2.5 V6 has suffered from excessive induction roar over the past couple of years. When I removed the bumper to replace the fan motor, I found that the tube had virtually disintegrated, like most of them, and was certainly not ducting any air to the intake.

Is this a known symptom of not having the tube, as well as having one of the wrong acoustic spec?

StevenWilliams · 10th August 2009, 21:30

Quote:

Originally Posted by davidbooker

IMO, my 51 2.5 V6 has suffered from excessive induction roar over the past couple of years. When I removed the bumper to replace the fan motor, I found that the tube had virtually disintegrated, like most of them, and was certainly not ducting any air to the intake.

Is this a known symptom of not having the tube, as well as having one of the wrong acoustic spec?

Mine was lovely and quiet before I added the tube and as it had disintegrated form the bottom it was not ducting at all.

suty445 · 10th August 2009, 22:35

i have to admit although i dont generally like them a friend of mine has just fitted a full induction kit to his ZS 2.5 and it does make a lovely noise on song so i will be getting one bet it sounds good though

Mike · 11th August 2009, 08:15

R40 had the ebay 70mm tube fitted a few months ago. Engine sound is as quiet and as smooth as always has been. Fitment was straight forward iirc .

hth

10th August 2009, 18:32	#1
StevenWilliams This is my second home Rover 75 Saloon 2.5 V6 British Racing Green. 81,000 miles and counting Join Date: Apr 2008 Location: Crawley, West Sussex Posts: 6,183 Thanks: 0 Thanked 2 Times in 2 Posts	Noise after replacing Shannon tube I've just replaced my Shannon tube. I used some High temp 70mm Air hose from eBay. http://cgi.ebay.co.uk/70mm-2-3-4-Sil...mZ130317088184 I've noticed that now the engine has a much stronger suction sound coming from it. Is this normal? The engine sounded much quieter before but now sounds like it's got an induction kit fitted. Also all the threads I've seen recommend using 70mm ducting. But 70mm is slightly to small and cannot fir over the existing fittings. I had to fit it inside the current connectors. I know this will slightly reduce the air throughput but not enough to raise the sound so much. __________________ [SIGPIC][/SIGPIC] Rover 75 2.5 2000 Club SE. British Racing Green. MEMBER NUMBER: MMMDCCXXVI Looking for: 7 seater

10th August 2009, 18:47	#3
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,753 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	It could also be due to the tuning of the inlet system. I understand one function of this duct is to 'tune' the inlet air stream. To do that, it's made a specific length. That's usually irrelevant I suspect, but maybe you're getting a standing resonant wave? It may just be due to the compromised fit. Here's the Shannon company's explanation: http://www.shannon.co.uk/noise-reduction.htm All engines bar the 190 use a 70mm bore system. If the 70mm duct you got won't screw onto the threaded unions, I guess it's a 190 engine. In that case you require the 80mm bore. The HowTo was amended recently to cover this variation. TC Last edited by T-Cut; 10th August 2009 at 19:24..

10th August 2009, 22:35	#6
suty445 Avid contributor mg zt-t 190+ Join Date: May 2009 Location: Rochdale Posts: 135 Thanks: 0 Thanked 0 Times in 0 Posts	i have to admit although i dont generally like them a friend of mine has just fitted a full induction kit to his ZS 2.5 and it does make a lovely noise on song so i will be getting one bet it sounds good though __________________ ZT-T in Black ink with straights

11th August 2009, 08:15	#7
Mike This is my second home Rover 75 V8 Join Date: Oct 2006 Posts: 3,448 Thanks: 0 Thanked 206 Times in 32 Posts	R40 had the ebay 70mm tube fitted a few months ago. Engine sound is as quiet and as smooth as always has been. Fitment was straight forward iirc . hth __________________ Mike [SIGPIC][/SIGPIC]

10th August 2009, 18:40	#2
Departed Retired -- Join Date: Jan 2007 Location: -- Posts: 3,785 Thanks: 0 Thanked 4 Times in 4 Posts	The Shannon tube has a semi porous wall, which is designed to reduce the noise. Do a search on the net of inter for interesting info!

10th August 2009, 20:16	#4
davidbooker Gets stuck in '51 Rover 75 2.5 V6 Conn. Purchased 02/05 Join Date: Dec 2006 Location: Whitby Posts: 571 Thanks: 8 Thanked 33 Times in 22 Posts	IMO, my 51 2.5 V6 has suffered from excessive induction roar over the past couple of years. When I removed the bumper to replace the fan motor, I found that the tube had virtually disintegrated, like most of them, and was certainly not ducting any air to the intake. Is this a known symptom of not having the tube, as well as having one of the wrong acoustic spec?