Decat / diameter of standard Exhaust - South Africa

Hello all!

Her in South Africa we have no laws against decatting our vehicles. When the guys here do exhaust on there Clio 197s and 200s there remove both cats, and they run 63mil piping, but they leave the standard branch / down pipe on as released by Renault.

I have spoken to many RS 200 owners and they say when they done this there is no such thing as engine lights coming or the car having any sorts of flats spots, the car revs cleans to 8000 rpm with a nice rally like tone. (Remember here in SA we do not install cat foolers or sports cats).

My question is, what is the stand size of the exhaust released my Renault on the RS 200? Is it perhaps 57mm in diameter? And also would it not just be best for me to remove the cats (both) and run it with the standard exhaust instead of going 63mil exhaust setup?

What will it do my cars performance if I go double decat but keep the standard exhausts running.

Regards and Thanks Nur
 
Ur best bet nur would be to use maths. Measure the circumference with a measuring tape. And work back using circumference=2pieRadius. Multiply the radius by two to get the diiameter. If u wanna be 100% sure
 
im tempted to keep the stock zhorst just remove one cat as i heard the the second cat is only restrictive
 
im doing the same thing Nur. Powerflow reckons its a R400 job. just a straight pipe from the joint between the two cats to the middle box with a hole in for the lambda