Catalytic exhausts

[Grahame W]

Well with all this talk of upgrades for next season the only one on my mind at present was the upcoming need for a catalytic exhaust ( looks like will have to shake the piggy bank harder).

I presume several of us will be in the same boat so do not know if a mini bulk buy might be an option.

In the meantime any advice or experiences from the assembled experts with low power loss catalysts preferably built in to a single repackable? silencer hopefully running off standard Caterham 4 into 1 primaries yet still with enough space to squeeze in a 4 to 2 to 1 collector would be welcome

[Alan Bowler]

No advice, but am in the same boat. Talked to a few people about the options (4 into 1 long primaries), and will probably try and get a quote to (a) fit a cat in the silencer, and make it repackable, or (b) try and mate my old noisy/thin/standard cat + silencer to the longer primaries. Or I just refit the complete old system for sprints. Depends how much is in the piggy bank. Would rather spend it on go-faster bits though.

AB

[Jason Plato]

I have copied this over from the Castle Combe site. The question was how would the MSA monitor the fitment of a cat.

 

Some useful info -Monitoring the temperature of the converter at the entry and exit points can also check operation. In a working converter the exit temperature will always be higher than the inlet temperature due to the catalytic reaction. The actual temperatures are unimportant, just check for a difference. Ensure the vehicle is fully warmed up and use a non-contact (infra-red) type thermometer. The temperature difference is also, to some extent, unimportant. Later vehicles or lean burn engines will have much smaller temperature increases than a vehicle running at a higher exhaust gas concentration. This test will not highlight any emission faults; merely confirm if the catalytic converter is working.

 

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a second response received from the MSA stated that cats have lambda plug holes and removal of the lambda would allow inspection of the internals.

 

As we know this is untrue. But apparently the infra red gun and heat detection when exiting the circuit into the pit lane is the favourite method.

 

I've a 1997 chassis car and glad of it

[RichardO]

That method won't check the regulation they have in place though - there is no minimum conversion efficiency stated in the rule. The temperature change could be unmeasureably small but the exhaust could still have a cat and so be legal.

[Jason Plato]

so what was the method employed by the MSA to check the fitment of a cat ?

 

here is my Duratec R .... C7 TOP

Taffia joint AO with Al

 

[u01rsb]

The rules do not state where the CAT needs to be fitted on the car or that it needs to be working or that it needs to reduce emmisions. Some chap (it wasn't me) at my last event had clamped one to his roll-bar to highlight the futility of this rule and was allowed to run.

 

I have mine fitted in my silencer.

 

Rob

 

 

[Adrian Williams]

Dave, from memory the only place that checked in a serious way so far has been Llandow. they measured the temperature of the cat or cat part of the silencer against the surounding exhaust system and looked for a differential.

 

Adrian

[Mike Molloy]

"had clamped one to his roll-bar to highlight the futility of this rule"...

Ha-ha! Brilliant piece of lateral thinking. 😬

 

According to the MSA Blue Book Section C(b)- 22 "Exhausts":

"Exhaust catalytic converters must be fitted to all petrol engined production based soloon, touring and sports cars, including specialist production and kit

cars, manufactured after 31/12/99. They may be specified for certain other formulae. Competitors are reminded of their obligation to maintain such

equipment on a vehicle used on the highway where government legislation requires it."

 

It only says "fitted", not "fitted and operating correctly"!

 

I hacked up an old Subaru exhaust centre section to create myself a free cat, but figuring out how to fit it has been a problem. Maybe I'll just plonk it in the boot somewhere...

[GrahamV]

I think scrutineering regarding Cats will tighten over the next few years. I was at the Llys y Fran hillclimb on Sunday and had my Cat checked for the first time.

 

The way they checked this was that as you finished your first practice run, they stopped each car for the normal noise level check – then as one scrutineer checked the noise level with a sound meter another scrutineer checked the pipe temperature before and after the Cat. This second scrutineer had some sort of hand held thermometer that he pointed at the pipes taking two readings - before and after the Cat. He didn’t stop me so I assume my differential readings were all OK

 

I suppose that as the scrutineers become more practiced in taking Cat temperature readings and know what they are looking for, then there will be more challenges.

 

But I don’t know how they are going to check Cats that are inside the silencer …

 

Graham

 

[Racing Snake]

Give me a shout re more details

As sorting a bulk buy re silencers with 100 cell cats inside from Good Fabrications

Quality product and minimal loss of power without the need for the second ugly box which is in the wrong place anyway

A few of us are planning on going over on saturday morning 1st of August

These guys make F1 and nascar systems so the workmanship is first class but not as expensive as you might think

 

Mad Hatter Racing - Feel The Duralight R Torque 😬 Carl Van Baars

 

Edited by - Mad Hatter on 21 Jul 2009 19:51:01