Exhausts

[Rdlangy1]

Hi guys,

So obviously I'm still a newb so excuse the niiave questions but I want to upgrade the exhaust system and still want to pass mot so what can I replace and what should I leave alone?

It already has an afterburner rear section, and from what I've read changing the downpipe to something like a ninja high flow cat downpipe is still an mot pass but useful.

So that leaves first cat from downpipe and centre section.

Which is best to de-cat and yet still pass mot or isn't this poss?

My thinking is leaving one cat on so mot tester can still see a cat etc.

Thoughts and feedback most welcome

[Steve_PPP]

The downpipe cat is the big one that does the most work. Yours is a Prodrive bug isn't it? If it had the PPP fitted, the second mid-pipe cat should have already been removed (but the original heatshields remained so it still looks like the cat is there!). Worth getting under the car and checking.

The bulge in the long straight centre pipe (about a metre long) is just a noise resonated section and does nothing for emissions.

You should be able to pass an MOT with only as sports-cat in the downpipe, but the car should be remapped to cope with the change from the standard downpipe.

[Rdlangy1]

Hi Steve - thanks for all the advice...
So something like a ninja sports cat downpipe and then two straight pipes to the back end should still pass?
And yeah won't be done for a few months yet and will be sure to get it re-mapped at the same time
Thanks for all ur help!

[Rdlangy1]

Hi all - just further to the great advise given by Steve above - but can I assume a 3" exhaust system would be more beneficial than a 2.5" exhaust system due to the increased flow due to bigger bore?
I think I have a 2.5" system now (did 8" circumference divided by Pi (3.1416) and it came to 2.54).

I will be getting a Ninja Sports Cat downpipe in the next few months, and looking at how rusty my centre section pipes were, was thinking of saving up for those two. So wondered - 2.5 or 3"?

Obviously my afterburner rear box is on a 2.5" pipe, so if I go 3", id need to swap the back box section aswell.

Pros and cons?

Cheers as always

Ryan

[The_blue_knight]

Hello Ryan. I got a high flow sports cat down pipe on my classic. The bore of the pipe is 3'' but then narrows to 2.5'' fitment to the centre pipe. Does sound misleading but it is a plus point as you get the benefit of a bigger bore, but you don't need to spend more on replacing the rest. If you are happy with the noise now then stick with it

[Hongkongfooi]

if ultimately you are going for more power than just this upgrade then go for 3'' bore and save buying an exhaust twice, otherwise 2.5 will suffice for now

[Rdlangy1]

Thanks for all the advice, cheers guys

[Rdlangy1]

HI All,
Sorry to resurrect an old thread - but next step is the exhaust, and probably upgrading to the 3" - but have seen on the likes of japspeed and scoobyworld a manifold section as well - are these worth upgrading?

Ryan