Supersprint system - 102db - any ideas on quietening?

[titan]

as title says.

stock CSL headers, supersprint centre (with resonator), SS sports cats and lightweight racing backbox.

Measured 102db static at Oulton. Thats a bit high, I want to do woodbridge next week and thats a 102db limit so all it takes is a different angle or less friendly equipment and I'm fooked.

Anyone else have this same system and know what theirs produces ?

I guess there aren't many options. I wonder if the supersprint "normal" backbox would help with noise ?

bit disappointing really.

[funtime]

The lightweight racing backbox is the loudest that Supersprint do, so yes any other Supersprint backbox would quieten down the system.

If your interested in selling let me know as I'm looking for a lightweight box :smokin:

[glendog74]

I guess there aren't many options. I wonder if the supersprint "normal" backbox would help with noise ?

I would swap out the SS cat before you touch the back box. When i had a Milltek full system, the 100 cell cat made the car very, very noisy but once removed was a fair bit quieter (albeit still boomy in typical Milltek style...)

I currently have OEM manifold, OEM cats, SS unresonated centre, and SS Race Lightweight back box = 100dB

Previously i had OEM manifold, OEM cats, OEM centre, and SS Race Lightweight back box = 97dB

I will be fitting the SS manifold in April so it will be interesting to see how this affects the noise - i'm not expecting any great change though tbh...

Ditch the 100 cell cat - you'll get better fuel economy too :thumbs:

[titan]

Hmm, interesting. So swap out the expensive SS cats for OEM eh ?

:bigcry:

bit disappointed its this loud. Its not like i went out and ordered up a 4" Blitz Nur Spec R boombox or something. Live and learn as always.

[AlexGTT]

I would swap out the SS cat before you touch the back box. When i had a Milltek full system, the 100 cell cat made the car very, very noisy but once removed was a fair bit quieter (albeit still boomy in typical Milltek style...)

I currently have OEM manifold, OEM cats, SS unresonated centre, and SS Race Lightweight back box = 100dB

Previously i had OEM manifold, OEM cats, OEM centre, and SS Race Lightweight back box = 97dB

I will be fitting the SS manifold in April so it will be interesting to see how this affects the noise - i'm not expecting any great change though tbh...

Ditch the 100 cell cat - you'll get better fuel economy too :thumbs:

What Rob said. I ditched my 100 cells as well. :banghead: Fuckin' things drove me nuts.

[shimmy]

Last year I was running 100cell plus race back box and most I had was 96db static at Snett where they make you rev to 5500-6000

At Bedford where you can rev to 4500 it was 93db

Was the car warmed up?

[AlexGTT]

Std cats, SS silenced centre section, BB lightweight BB = 98db @5500rpm at Snett last year.

[O'Neill]

Is the system new? maybe once there is a bit of carbon build up it will be quieter.

[titan]

I had driven around 5 miles to the track from the hotel, plus did 2 sighting laps. So whilst it wasn't red hot, it wasn't exactly cold either.

To make matters worse, I've just had the "dubious emissions detected" light come on. I presume the car has a lambda sensor or similar just past the cats to make sure they are working?

I've still got the csl cats so could swap them over, I presume that section of exhaust is a simple drop in....although its the principle, i think the cats were around £1200.

does anyone know how these noise meters work? Is it a constant reading, or does it register the max recorded? Cos from idle when you get it to 5k it goes through some more noisy bits of the rpm range...

one of my titan guys runs the sxoc, i think they have a noise meter, might ask if I can borrow it. Although that won't help the emissions light issue !

[glendog74]

The emissions light is a common issue on the CSL after the cat section has been replaced by a 100 cell version. Causes no real issue AFAIK but is annoying all the same. It will come back even when the fault code is erased...

I swapped out the centre pipe on my own car and it was more fiddly than you'd think - a few of the nuts/bolts are a real pain to get to... :banghead:

[titan]

Hmmmmmm

one of the guys here runs the SXOC and has brought in their sound meter.

OK so distance and angle may be different to what the guys at Oulton do, but we measured 95.3db at 5k rpm. Somewhat different to 102db.

The OEM cats are going back on today, so we'll get another measurement where at least the method/meter/person is the same so I can see if the OEM cats do bring it down a bit.

[glendog74]

That's the snag with circuit noise testing - they all vary in measuring device/method and of course end results... :banghead:

When i had just the Super Sprint race back box fitted to the OEM system, i was measured at a consistant 97dB at various circuits including the Ring and Oulton Park. At Cadwell Park, however, they claimed it was running at 101dB... Pah!

[shimmy]

Make sure it is measured outside without other sound sources.

It needs to be held at 45 degrees to the direction of the tail pipe and 0.5m away.(they have a 0.5m stick)

Climatic conditions make it very different on drive by and rpm makes it different testing as they seem to ask for different rpm levels

[DuncanR]

I never failed a noise test yet with my set up !

http://www.youtube.com/watch?v=YC_gwIrOiDs

[titan]

heh thats pretty good, might try that :-)


To add insult to injury, the local garage we use for stuff couldn't get the csl onto their ramps so looks like i'll be changing those cats out myself from underneath the car in the freezing cold. nice.