Posted By: SimonN
sports cat - 27/02/2019 23:11
Hi, I've been investigating exhausts. I'm after a full exhaust from turbo back. I spoke to a bespoke exhaust place today, and they basically told me that there's no point having a sports cat on an "old-skool" car like the coop as it's not going to pass emissions (but it would be ok on a "modern-technology" car - he didn't seem very sympathetic towards the coop, tbh).
Has anyone any thoughts on this?
I have a sports cat on current setup which is great, but I have a bunch of mods queued up so need to upgrade the exhaust.
Posted By: Honza
Re: sports cat - 28/02/2019 06:58
unless you have camshafts with soooo much overlap, you are able to pass emmision even with sport cat.
However - I recommed to fit 100CPSI only with biggest body possible (I have 100CPSI -127mm body diameter in my 2l 16v NA beast) to reduce backpressure
Not many manufacturers give info regarding to max bhp its suits for, but 100mm diameter core with 200CPSI is good up to 150, mabe 180bhp, then it creates lot-of backpressure (in my case causing misfires under high load/rpm above 3500).
beware of cheap cats - they donīt do their job, or only for short time (the reason is amount of precise metals in them..).. only choice is HJS...
Posted By: kj16v
Re: sports cat - 01/03/2019 01:02
The best cat for a turbocharged engine is no cat. Anything else will lose a lot of horsepower and murder performance. But if you don't like the idea of having to refit the cat for the MOT every year, or don't have a - ahem - "friendly" MOT tester, then, as above: widest sports cat you can fit.