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Bedford in a Tiger Avon
andy996tt - 20/7/12 at 08:03 PM

Got black flagged today in my Tiger Avon. They said I was 104db on drive by but their limit was 98dbs.
Gutted but that's life. My car is track only so could only test static.
Bought second hand so don't know how old the exhaust is.

Mates are doing Bedford in a month and I want to go. What will I need to do to it low enough for Bedford ??

Cut open my current 5" can and put in new wadding then reweld ?

Mate willing to give me standard bike muffler

New rapackable larger can

Any help appreciated

CRAIGR - 20/7/12 at 08:16 PM

Book a different circuit or drive at half throttle like they told us we had too after being black flagged..
Luckily for us (unfortunate for the owner) a 350z decided to demolish the pit wall and they said that was it for the day so off home we went never to return.

laptoprob - 20/7/12 at 08:49 PM

quote:
Originally posted by andy996tt
Cut open my current 5" can and put in new wadding then reweld ?

Mate willing to give me standard bike muffler

New rapackable larger can

Any help appreciated


All really depends on the engine spec mate.

5" cans are a bit on the weak side for noise muffling so would suggest swapping for a 6" can as long as possible.

Forget the bike can it will be even louder.

My last C20XE 225bhp kicked out 102db`s at Cadwell last year with a Westfield 4into1 manifold and a WUNOFF 6" can.

My new engine kicks out close to 260bhp now with a Tony Law 4to2to1 manifold and a slightly longer can and tipped the noise meter last Tuesday night at a jaw dropping 106db`s which they let me off with

Bare in mind they were all relativly new so are only going to get louder.

IMHO if you have over say 190 bhp then you need a 6" can to gain access to most track days.

Other thing to mention can be the internal bore of the can which i went from 1 3/4" to 2" this time round which wont have helped.

andy996tt - 20/7/12 at 08:53 PM

Ive got a blacktop tuned up to 200 bhp

laptoprob - 20/7/12 at 08:57 PM

quote:
Originally posted by andy996tt
Ive got a blacktop tuned up to 200 bhp


The its a definate 6" can mate.

This is mine, great company to deal with WUNOFF EXHAUST

iank - 20/7/12 at 09:00 PM

Fit a turbo Amazing how much noise they absorb.

bowood14 - 21/7/12 at 06:02 AM

Ive been to many track days and Bedford is the only one that has black flagged me for noise If you going to other tracks you will be OK.i will never go to Bedford again

laptoprob - 21/7/12 at 07:55 AM

quote:
Originally posted by bowood14
Ive been to many track days and Bedford is the only one that has black flagged me for noise If you going to other tracks you will be OK.i will never go to Bedford again


Donnington has been one of the worst for me.

maccmike - 21/7/12 at 08:02 AM

locate the db measurer and lift off going past

greenwood03 - 21/7/12 at 08:17 AM

Bedford is indeed a 'mare - went with a pal a cple of years ago - he took a bog standard elise and was black flagged on drive by had passed the static with no probs whatsoever - wasnt even close to being an issue - ruined the day as he had to drive like Miss Daisy anywhere near the nopise meters....

personally fwiw i wouldnt mess around with a 6 inch can, i'd go straight to a 7. my zetec with a 7 inch can from powerspeed when its freshly packed records 95ish and after a year or so thats out to 97-98 - thats tweaked to 225ish.

depends really how much you want to pay for an exhaust against the hassle of noise issues.....powerspeed in ashford kent are worth a chat and will sometimes do a bit of a deal, their boxes are easily accessible for re-packing......

laptoprob - 21/7/12 at 08:26 AM

quote:
Originally posted by greenwood03
personally fwiw i wouldnt mess around with a 6 inch can, i'd go straight to a 7. my zetec with a 7 inch can from powerspeed when its freshly packed records 95ish and after a year or so thats out to 97-98 - thats tweaked to 225ish.

depends really how much you want to pay for an exhaust against the hassle of noise issues.....powerspeed in ashford kent are worth a chat and will sometimes do a bit of a deal, their boxes are easily accessible for re-packing......


Interesting.....

How much was the 7" can if you dont mind me asking?

I was always told not to bother going any more than 6" by quite a few of the Westfield Sprint guys as it didnt make much difference between 6 and 7 but better to go as long as possible which i already had.

And what is your internal bore?

mark chandler - 21/7/12 at 08:45 AM

You can pass the static as they are just listening to the exhaust, drive by also captures the inlet roar as well so you need to pay attention to both ends.

Decent airbox, not open filters (even if they remain inside) ducted via some tubing to the front.

Decent can and take a DB killer just to be sure, but should not need it for the exit.

Unfortunately this will be more common as people try and shut down tracks the noise limits will be enforced, I went to Goodwood and never made it to the track with my little car so had to tramp around in the tow car.

Donington was borderline with a side exit exhaust so have now taken the exit out via the rear as noise does not like bends so introducing a couple and moving away from any induction/engine noise helps.

I expect that in a few years time 93db will become the norm.

Regards Mark

laptoprob - 21/7/12 at 12:05 PM

quote:
Originally posted by mark chandler
You can pass the static as they are just listening to the exhaust, drive by also captures the inlet roar as well so you need to pay attention to both ends.


Totally agree. The db`s i was quoting were for static on the exhaust side. My induction noise is cronic but havent been to any places this year with the new engine that will cause me grief yet on a drive by test. Obviously i havent booked any Bedford,Croft or Donny dates for this reason

greenwood03 - 21/7/12 at 03:23 PM

i didnt just buy the can alone - they made me a comp system - 2.5 inch headers, no idea i'm afraid about the 'thru bore'......
i think a 6inch is about 300 with a bit of neg, i know i had a deal with them 3 yrs or so ago and the whole thing was 750.

laptoprob - 21/7/12 at 03:43 PM

quote:
Originally posted by greenwood03
i didnt just buy the can alone - they made me a comp system - 2.5 inch headers, no idea i'm afraid about the 'thru bore'......
i think a 6inch is about 300 with a bit of neg, i know i had a deal with them 3 yrs or so ago and the whole thing was 750.


Seems a fair price to be honest.

I paid 450 for the bespoke manifold and 225 for the 6" can.

greenwood03 - 21/7/12 at 04:12 PM

it was a bloody good deal, the Caterham boys had a bulk buy and i slipped in on the back - well i nudged Powerspeed to say ' come on fellas i've got a similar type car'......so mine was made on teh car as well. They sugg the 7 inch can and have been happy with it....not sure why there wouldnt be any difference between a 6 and a 7....given that there's clearly a diff betwene a 5 and a 6 ?

andy996tt - 21/7/12 at 04:28 PM

Anyone recommend an exhaust specialist around Berkshire or Surrey ?

pmc_3 - 21/7/12 at 07:13 PM

How about a db killer? one of the things you clamp on to the exhaust outlet might knock a little performance off but should bring down noise levels

andy996tt - 24/7/12 at 12:09 PM

Got the 7" can from CBS.
Will fit then fingers crossed

greenwood03 - 24/7/12 at 08:09 PM

ha ha likely an indirect route to getting some form of Powerspeed exhaust.....cos i'm pretty sure they used to make a slightly spec'd down version for cbs........