Hi all,

Does anyone know if a Catalytic converter is needed for the SVA? Is it needed for future MOT's?

If so does anyone know of a cheap solution for a fireblade engined Locost as i already have a non-cat system (see attached)?

Cheers
Rescued attachment MyKitCar.jpg

cat requirements go hand in hand with the age of the engine.. it depends how new the lump is, as far as i am aware, 1991 onwards have to have a cat, but i may be corrected on that!

The picture's a bit big.

Aug 1st 95 on sounds more like it.


Any advance on that?

a tad. or maybe my screen is small.. who knows

for mot, its def 91 onwards

quote:

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Originally posted by Ketchup
its def 91 onwards

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Sorry about the large picture.

Either way, it looks as though my engine will need a Catalytic converter as the fireblade is 1998 (i think).

Any ideas on an installation of one?

Hope the picture is better.
Rescued attachment MyKitCar-resize.jpg

MOT regulations seem to be are here:

http://www.motuk.co.uk/manual_730.htm

Don't have time to read them fully, but browsing quickly it looks like Catalyst test is done for 1 August 1992 and on (engine age). Don't know if this means you need a cat, or just need to pass the appropriate HC, CO2 levels.

No mention of the Q reg only having visual smoke test on first glance either.

As to why the SVA and MOT don't seem to agree, I have no idea. Seems mad to me.

THe ususal practice is to put a cat between the collector pipes and the silencer. On a BEC, you adjust the idle fuel mixture screws to adjust the lambda into the correct range (0.97 to 1.03 I think) and hope that the cat reduces the CO and hydrocarbons to an OK level. If not, you can lean out or enrich the idle mixture a bit to see if you can reduce the levels. I don't know what you do if that fails.

Pray.....

On some cars, especially those with custom ECU's, you can actually tweak the emissions to pass SVA in cat-less form (an SVA map?) A lot depends on the age and condition of the engine.

Like any other SVA detail, this can mysteriously 'fall off' the car on the way home from the test, especially if you have your laptop in the car

Sounds as though this is going to be a right pain in the back side!!!

When i source a CAT then the carbs will have to be adjusted at a garage to get the right emmisions. Then i will have to get it set up again once it has passed the SVA on a rolling road to get the power back up! doh.

have a look for "cut the cat " I cut one from a vw and made it to fit the gap

Bike carbs have 3 sets of adjustment (I think)
The pilot jet / air bleed adjusts the fuel misture at idle and upto about 1/8 or 1/4 throttle opening.
The needle jet and jet needle adjust fueling from 1/8 to 3/4 of throttle opening and the main jet sets the fuelling for 3/4 to full throttle.

That means that you can adjust the pilot air screws to set your mixture for SVA compliance without adjusting the other settings. I don't think that you'll need to retune.