Hi. My 20vt has a stage 3 remap with a 3 inch down pipe and straight through longlife exhaust. My problem is it's just too boomy for my liking and can be a bit much on long journeys, I just want to quiet it down a bit. I went to the longlife centre and they suggested putting in a centre box but a friend of mine did this and said it made no difference (not a coop or longlife) what to do? Put a sports cat on, will that affect the (flea) re map? Go for a whole new system? Thanks in advance.

Change the exhaust and see how you get on. You could argue that changes to breathing on the car in any form would require a remap.

What power are you running?

You will probably see a drop in performance as a result of the additional silencing/baffles - but whether you notice it is another matter.

A good exhaust that provides decent power doesn't need to be boomy/loud - you can see more benefits with straighter angles.

At the end of the day it comes down to what you want and what you are expected to pay.

Cheap - Sling a centre section on and see how that improves things.
Expensive - Replace the whole system with a new one
Become road legal and put a sports CAT on ;--)

Thanks RusH, running 320bhp. Think I'll put on a centre section and see how that goes.

if you didn't want to risk upsetting the mapping etc... then try attacking from a different angle...

have you considered sound proofing the pas anger compartment of the car.. by stripping out the interia trim and seats you could sound proof it to reduce the noise and it will also reduce the road noise swell. it would also be a good chance to asses the condition of the otherwise hidden metal parts of the car for rust etc.

the stupid suggestion to fix it... turn up the radio lol.

When Motormech built my 3" system for Ten of the Best, it had no centre silencer - it made a lovely noise, but it was boomy at motorway speeds

I got Paul to fit the largest centre silencer he could find (its two feet long!) which improved matters a lot

There's still a resonance point at just over 2,000rpm, but its not bad and it doesn't annoy me, as motorway cruising is a few hundred rpm higher than this

It didn't change the performance, as its a straight-through silencer, with a perforated pipe and wadding to absorb the sound

A agreed. Fit the longest, widest straight-thru centre silencer you can. It will be quiet when cruising and loud when you put your foot down, without losing performance.

Update: Took it to the local Longlife garage and had them fit the largest possible centre box. It's worked a treat, much quieter but still a nice burble with no notable loss of power. It no longer feels like i'm sitting on the engine which is nice... thanks for the advice chaps