very NOISY x flow....

[Jam Mad]

as some of you may know, i'm the proud owner of a x flow.

 

it's loud. as you all know. no more so than other x flows that i've come across, but it's still 'turn heads at 50m' loud. i like it teeth.gif

 

the only problem is, if a k or a vx can have problems with noise levels on track days, what hope have i ever got ?

 

do i need to restrict myself to days with no restrictions, so to speak ? or is there a way around this ?

 

cheers,

 

j

[Roger King]

There should be no problem silencing it with the right sort of silencer. Power loss should not be a problem - unless you've got something very odd for an engine.

[Gary G]

I've got a 1700 X/Flow with rear exit exhaust. It too is noisy.

 

I went on a Track Day at Castle Combe where the noise limit is 100dB at 4500rpm. My car was knocking out almost 110dB!! I borrowed a baffle which attached to the end of the exhaust pipe and I scraped though on 100.1dB.

 

I couldn't tell you if this affected performance coz it was my first track day. Obviously this is only any good if you have a rear exit exhaust, as I don't believe the baffle would fit the pipe of a sidey.

 

Hope this helps?

 

 

 

C7 GAR

[cskip]

I have a 1600 X-flow and also only just got onto Castle Coombe. I measured it the week before and it was kicking out 105db @ 4500rpm. This is running the standard Rear Exit exhaust.

 

I am currently in the process of changing (well when the wife allows!) to a 4:1 side exit using the Tech-craft silencer. I am sure that should reduce the noise, but not take away the sound! Plus it looks the Dogs!

 

 

 

Clive.

 

Crossflow - Loud and Proud!

 

[Graham Perry]

Cskips noise level sounds about right. Mine has been tested many times and is about the same. Silencers are funny things because what you think might be quiet is not always so. When I moved from the Caterham standard rear exit to a 6 inch bespoke side exit system that was supposidly tuned to quieten noise, the db's went up by 2 on average. I changed it for a carbon one last year, that was a third the weight and the db's dropped by about 4 on average.

 

The problem with the cross-flow is that a great deal of the noise is generated by the inlets to the Carbs, (mine shows 106 db at the carbs at 5000) so at some stage in the future when noise limits really come down I suspect an airbox will be needed to make them compliant

 

Edited by - Graham Perry on 30 Jan 2002 07:06:00

[Jam Mad]

hmm.. side exit exhaust, and i'm not sure i'll be doing enough track days to merit the expense of a new silencer.

 

cheers for the advice though, roger et al.

 

so ! track days without noise limits methinks... i noticed that there are a few of them about....

 

j

[allen]

I have not done a track day, yet, but was running X flow 4 inch rear exit silencer (modified to become side exit) which was VERY NOISY.

 

It didn't get quieter with the 1800 Zetec conversion.

 

I have just converted to a 2Litre VX side exit silencer 6 inch.

 

Upside is it was bought second hand from this website.

 

Down side is that it weighs two and a half Kilo more and the engine is now far too quiet.

 

I think i might have got away with a five inch silencer.

 

allen

[ashaughnessy]

I've never understood this. I've got a 1700 supersprint with standard rear exit exhaust and it isn't particularly noisy, not when compared with many other cars. When I started racing I asked advice about whether it would be quiet enough and was told several times that it wouldn't be, but I've never had a problem on a race track with noise levels and I'm sure most of the other racers are much noisier than I am. Perhaps there's something different about my car.

anthony

[groutledge]

I had a 1600 SSprint on a rear exit, and coverted to a 1700 155bhp on a side exit techcraft. The side exit used to be 101dB the side exit is now 96db which is great for most circuits.

 

What you have to rember is that a lot of circuits use a weighted measurement (dba). Which concentrates on frequency as well as volume. The upshot is a lot of very good silencers are very boomy!, techcraft included. So much so that it's actually painful with the roof on and that includes earplugs AND ear defenders, these can't block out very low frequencies which the quiet silcencers seem to produce.

 

The rear exit was quieter to live with is the noise was allways "left behind". I am going to investigate convert my tech craft to a rear exit if possible.

 

Graham

[Andy G]

I am a bit puzzled by the above postings. I run what I would consider to be a noisy 1700 Xflow with side exit exhaust, however at the last Brooklands day it only measured 99/98db.I thought rear exit exhausts were supposed to be quieter. It would be worth getting your car checked before cutting yourself out of a considerable number of trackdays.

 

Andy G

 

Edited by - Andy G on 3 Feb 2002 21:21:56

[Jam Mad]

cheers andy g,

 

i didn't know it worked on frequency too... i'm less worried now.

 

all i have to do is sort out that fia rollbar !!!

 

but every time i get ready to spend on a 'frivolous' accessory, i end up needing to spend time/ money to fix/ maintain something.

 

ah well, i'll get there eventually !!

 

laters,

 

j