Power upgrade with cats?

I was wondering today about the future tuning potential of my TT supra.

I would like at some point to grab some more power out of it but I really don't want to be messing around once a year putting cats in to pass the MOT.

What I'm asking is, is there ways of tuning the Supra with the cats still in place, or are they just that restrictive that its not worth keeping them in at all?

For example, would it ever be worth me converting to a single turbo conversion with the cats still in?

i think decatting makes a massive difference, totally different drive with the cats out. i believe it also increases the bhp by 20/30/40 ish.

If you replace both cats with 2 separate de-cat pipes (such as the ones that Chris Wilson sells), it is a 15 minute job to refit the second cat come MOT time.

The 1st cat is the most restrictive, so just removing this one will free up power and yet should still pass emissions test come MOT time.

The other option would be to replace with an after market free flowing cat, they are not cheap though.

The stock cats are very restrictive so upping the boost with both cats still in place will result in dangerously high exhaust temps.

You can get away with upping the boost to 1.2 with a boost controler with the second cat in place (it will pass the MOT with just 1) but if you are going to do this, I would suggest you get an EGT guage so you can keep an eye on things.

The other alteritive is to remove both and when MOT time comes round, book the car in to have them put the second cat on the car, MOT it then remove it again.

Thanks for the replies fellas, I need to go away and have a think.