As a generalisation the quality of so called sports cats is something of a lottery to the uninitiated.
A 4.0" dia 100 cell cat will deliver an equivalent flow rate of around 72.25mm once cross sectional area has been calculated and laminar flow corrected.
With regard to the road legality it's true that the value lies in the amount of precious metal in the cat washcoat - a 5 gram washcoat will get a cat through an MOT once maybe twice and then its going to start to struggle due to basic entropy...
In addition the quality of European fuel also has a knock on effect with regard to its long term effectiveness, when compared to say US fuel.
We offer a larger 125mm 200 cell cat which gives a genuine corrected flow ratio of 79.0mm in addition we offer a 40grm washcoat to provide complete road legal conformity with current MOT legislation and to ensure the durability of the cat.
For guys looking for big power we recommend the new 100 cell variant which definitely out performs a cat delete with a corrected flow ratio of 88.0mm and again comes with our massive 40grm pm washcoat.
Again for cars wanting to go beyond 450 bhp we offer a 90.0mm downpipe and our 140.0mm 200 cell Mega Cat - which has a true 90.0mm flow ratio.
Ultimately the 2 questions that need to be asked are what is the diameter of the cat and what is the wight of the PM washcoat, if this cannot be answered then fear the worst.
It maybe true that there are very
marginal gains to be offered by opting for a cat delete against one of our 200 cell cats, but there are also other considerations such as the road legality of a cat delete and the consequences of knowingly running one.
One of the ways that we will be further enhancing the performance of our downpipes is by the introduction of the new 'Softflex' on all 76.0mm downpipes from 2018.
The benefit here is that it has a genuine bore of 76.0mm as opposed to the braided 76.0mm flexis which in truth have only a 70.0mm bore.
Our downpipes and cats are not the cheapest but I think you will not find it possible to source a better one by application once you have determined your individual requirements.
Hope this helps
Nige
76.0mm Downpipe with 200 cell cat90.0mm Downpipe with 200 cell MEGA cat and 76.0mm Downpipe with 200 cell cat and OEM downpipe for comparison purposes76.0mm Downpipe with 100 cell cat and softflex