Catalytic Converters - Race Cats

[Walter]

Hello:
Any recommendations for racing cats (2.5in pipes) for the LS7 ? I need to pass annual inspection for EU emission (< 0.3 percent CO).

I'm considering a pair of MagnaFlow 2,5 Zoll/64 mm Universal High Flow cats 200 cells #59956. Any experience with this model?

Expensive but surely better are the HJS 90 95 0070 cats. Any experience with these?

Thanks in advance.

 

[Walter]

To partially answer my own question: the pair of High Flow 200-cells cats #59956 let me pass the emission test with ease.
Nevertheless I'll install a muffler with custom integrated HJS cats. I thereby hope to reduce the amount of heat emitted into the engine bay while keeping CO values low.

 

[Jochen]

Hi Walter, sorry for reopening an older topic, but did you pass the emissions testing with the HJS cats? I assume you are running an EFI system, not carbs? Which country are you in and which Euro norm did you have to go through? I’m currently exploring all options to understand what it takes to get a GT40 road legal in Switzerland (fortunately not the EU). Emissions are a big topic. Reading across manufacturers it seems that with a carb Euro 2 is not possible. Having you talk about HJS custom cats makes me curious as this looks the route I might need to go (after solving a myriad of other questions)… and if anyone else can chime in with first-hand experience of making a Ford 302 Euro2-compliant, I’m all ears And not to forget, happy new year to all of you in the forum! Many blissful and accident-free miles this year!

 

[Walter]

Hi: I have not taken the car to emission test with the HJS cats, however, I'm confident I will pass come spring (in Austria). They are much beefier than the MagnaFlow cats which let me pass. I have Kinsler EFI using Fast-XF software I (see my build log). My car, first road registered in 2015, should comply with Euro ~4/5. For the annual inspection, It needs to pass the standard stationary emission test (analysis of the exhaust fumes at idle and 3000rpm): i.e. mainly CO less than 0.3 percent, which requires a cat. Not sure what the limits are for HC etc. I'm pretty sure well-tuned carbs + cats will let you pass Euro 2 annual inspection. For testing details you should consult with the vehicle registration authority in Switzerland. They have the final say Emission test for the initial title (street registration) likely is different than the one for the annual inspection. Information on Euro 4/5/6 etc test procedures for street registration can be found online.

 

[Jochen]

Hi Walter, thanks a million for your quite detailed reply, much appreciated. So far the Swiss DMV answers have been less than satisfactory, they are not helpful at all. So I am discussing this now with an import/US car specialist, waiting for answers what needs to be done. Congratulations to getting such a new car registered, super cool! Have fun and maybe I’ll see you on a mountain pass in the alps some time

 

[Walter]

Consulting with an experienced Swiss registration agent is the best bet, indeed. The newer the car the harder it will be. Good luck!
Yes I do feel fortunate and would not want to do it again, let alone spending the money for getting the Austrian papers (NOVA)!