So, a bit more of the exhaust story:
The new manifold is 4 into one, there’s a 200 cell sports cat which is a drop out unit that can be swapped for a decat pipe.
The box itself is a repackable 8x 32" and the emphasis of the system was to achieve noise test restrictions, particularly at my local circuit, Goodwood, but also to allow for a 300+ bhp output.
The existing (OEM) exhaust was gradually getting louder and was starting to trigger the interest of the noise Police. My static test at Goodwood recently was 95db (6000rpm), limit 98db. It’s the drive by (96db limit)that’s the problem and I suspect a good deal of this is induction noise alway. So, we’ll have to see in the next few months if that works.
Static testing of the new system was:
For the Anal:
The Total weight of ‘stuff’ removed from the car was 33.2 KG.
The weights of the new manifold and cat are not to hand, but the new box,which included the U-bend, was 12Kg, the weight of the OEM which doesn’t include the bend was 14.6Kg.
I assume you’re seeing a piccie upside down? Looks the right way up to me but I’ve just spent 15minutes persuading photobucket to rotate the picture (last one I take it??)
Anyhow, you get the idea, stand on your head or phone an Aussie mate.
Very nice fabrication skills from Tullet - as with all of their stuff.
Wonder if Frank has a comment on the 90deg bend off the header - he had plenty to say regarding my old 4-1 design?
3" bore and the bent perforated tube inside the silencer?
They used to use a bent perf tube, going across at an angle, but it only reduces noise by a bit over a straight pipe. As your canny eye has seen, the input is at the back of the cylinder and the output at the front. Both tubes travel straight within the box but meet at a perforated box (chamber) within the silencer.
As mentioned only time will tell and , I should mention, ‘other brands are available’.
[quote=661]They used to use a bent perf tube, going across at an angle, but it only reduces noise by a bit over a straight pipe. As your canny eye has seen, the input is at the back of the cylinder and the output at the front. Both tubes travel straight within the box but meet at a perforated box (chamber) within the silencer.
As mentioned only time will tell and , I should mention, ‘other brands are available’. [/quote]
Thank you if you want to meet some of these noise limits now a perforated tube + packing just isn’t enough for the hi-powered SC installs, that’s for sure. Chambers are good though!
I even considered a 9"dia can(!) but I’m done with 2zz-ge R&D, so was just curious.
if you want to meet some of these noise limits now a perforated tube + packing just isn’t enough for the hi-powered SC installs, that’s for sure. Chambers are good though!