Exhaust Cat + Silencer Options

[Mostro]

 

Hi all

 

I'm looking for some guidance through the bewildering array of exhaust setups and some recommendations on replacing my existing silencer with a cat + silencer combo.

 

I have an original 1.6K Superlight with the competition/race 4-1 primaries, no cat and a 5" silencer which needs replacing.  As the car is a 2002 model, I do also need a cat for MOT time and at this stage I'm happy to run with it all year as the car for is road-use only. There was a cat on the car at some point in its history but not when I bought it.

The other concern is ground-clearance - a previous owner swapped to a 5" silencer because of grounding on hard right cornering, and would ideally like to keep the current clearance as I only have mms to spare when exiting my drive and negotiating the plethora of speed humps around here.

 

I was interested in the Meteor Motorsport cat-in-the-can solutions but sadly they are no longer supplying them.  I'd be grateful for any BC wisdom on the subject for a mechanical novice...

 

thanks

Paul

[Mostro]

Should've said, I can't find any reference to a K-series competition exhaust + cat combination in the archives - I did try!

[Alan Bowler]

For MOT, assuming you can't find a "sympathetic" tester locally, and need a catalyst, I think Powerspeed can make you one in 6" or 7" with a cat, or supply a complete 4-2-1 system. You could also butcher the silencer from a standard 5" short primary system to make it fit with your long primaries (which a few speed championship competitors have done). Not very pretty but cheap and functional.

The collector on my 4-1 system was modified to add a kink, to raise the silencer about an inch, because of ground clearance issues. Works with a standard Caterham silencer, plus I have the Meteor cat-in-can. (Possibly all for sale as those Powerspeed 4-2-1 systems do look nice and shiny...)

[Simon.Rogers]

Alan - you should add that your CAT is an FIA standard and does not have a hope in hell of passing MOT.  Its only meets the MSA regs of having a CAT fitted.  It also maintains flow and power.

Good for someone competing but not for passing MOT.

[Alan Bowler]

Its so loud the MOT tester can't get near enough to check properly 

[James7]

Paul,  

I have a Powerspeed 4-2-1 with Cat in can on my 7.  Let me know if you want to view/take any measurements.  

James

[Mostro]

I was hoping to avoid the added expense and hole-trimming hassle of changing the primaries to 4-2-1 but it's beginning to sound like that might be the easier off-the-shelf solution without resorting to custom-made kinks etc

James - thanks for the offer, I might take you up on that. I haven't had chance to speak to Powerspeed yet - is it a case of taking the car down there for bespoke fitting or can it be done remotely / by post?

[Simon.Rogers]

I could supply a Sports SpecCATfor Alan's system for you to swap out.

They were meant to be noisy Alan = prevents you from hearing the passenger shouting slow down!

[SM25T]

If you have external primaries, shouldn't be any need to change them or modify the sideskin to go 4-2-1. Worked on mine. Powerspeed can do cat in can. Hopefully they can do it without the car .... but call and ask. Important to use the centre support bush too.

[Alan Bowler]

From Powerspeed website, looks like they can supply can only which could work with existing primaries. Would think that would need them to have the car for precise measurements, especially if you want it mounted higher for clearance.

[James7]

My car didn't originally have external primaries so I enlarged the cut out from the single round hole when I fitted my exhaust. I used a drill powered nibbler and files. Trial fit and cut away as necessary.