Can we ask why?, you won't go any faster the engine managment will see to that.
You may find it hard to find a Y pipe for a V8 D2 without cats off the shelf you may have to get one build for you. There's a firm the builds their add is in the back of LRO mag.
reason why isnt to do with performance more cost. i cannot afford genuine cats (700ish) and i dont wanna go for cheap aftermarkets which will last a year so i figure best option is a straight through (decat pipe) as i dont needs the cats for an MOT as i have lpg.
cash is really tight and i have cats and centre box to replace.
although ive seen one centre box on ebay for £70