mattt 29 Report post Posted October 23, 2018 Morning all I have the TD NA package (UEL) with the secondary cat in place and an Invidia Q300 catback. I'm considering forced induction in the future but want to retain a cat for MOT friendliness. When I spoke to Mike about this he indicated it wouldn't be possible with the TD turbo setup as the standard cat would be restrictive and would likely fail in time. Has anyone achieved forced induction with a cat that allows an MOT pass? Cheers for the replies. Sent from my ONEPLUS A5000 using Tapatalk Share this post Link to post Share on other sites
lintgfx 3 Report post Posted October 23, 2018 If you're that concerned you could always go catless and switch it out before your MOT. Just make sure it's nice and hot before they test it or it'll likely fail. Share this post Link to post Share on other sites
mattt 29 Report post Posted October 23, 2018 Sorry I should have mentioned that I don't have the space equipment and time to swap the cat in and out, hence would prefer a solution that has a permanent cat.Sent from my ONEPLUS A5000 using Tapatalk Share this post Link to post Share on other sites
chris_9011 24 Report post Posted October 23, 2018 I've got a HKS V2 supercharger kit on mine, with Borla UEL headers and a stainless exhaust and mine sails through the MOT at respectable MOT test centres... Share this post Link to post Share on other sites
nerdstrike 186 Report post Posted October 23, 2018 The standard cat is specified for 200 bhp of exhaust gas flow (and headroom - we know you can gain 10-15% just be derestricting the exhaust). You can try to pump 300 bhp through it, but it'll choke it down and get crazy hot. I recall the Cosworth stage 2 claimed 260 bhp without a change of exhaust, but 280 if you took the matching exhaust. I can only imagine you'd have to get custom piping done and get a bigger/higher flow cat fitted, but you'd have to find the space to mount it, and would it pass the MOT? Perhaps a cat the last Impreza or another higher power boxer would suit? It all sounds time-consuming... Share this post Link to post Share on other sites