Sports cat & air pump?!

[Ricco_04]

In the quest to simplify and take a couple of kilos off I was also thinking removing the cats and air pump.  This will be way in the future as I think this will require a new ECU and some mapping to make it safe?

So the car has an airpump to make sure the standard cats dont get blocked up over time.  Could you in theory use a sports cat with no air pump and have no problems with it blocking up due to the cells having a bigger spacing in them (I think you can get 200 cell minium now as it used to be 100 cell)

There are a lot of exhaust fabricators which sell 200 cell sports cats - Is there any need to have something rotary specific or is that just marketing?!

[m1tch]

Its easier just to remove the cat and leave the air pump, the only emissions control on my car is the port air valve (ie the air pump is just pumping air into the exhaust via the housing) I have no cat (hasn\'t had one for over a decade) emissions are 0.18% CO out of a max of 3.5%. Also its not just the cat being blocked, rotary EGTs are MASSIVLY higher than piston cars, so the air fed into the cat also cools it to stop it imploding!

[Ricco_04]

I was looking at the sports cat as with the FD it was borderline to get through the same emissions test with a decat and I just didnt want the hasle of changing stuff.  My FD also uses the air pump in the same way you have yours set up.

Wonder why the FC is so low on co then?  I was talking to PT and he said his (orange) one never had a problem either.  Maybe worth a go then to see what happens! :cheers

I do however question the EGT temperatures - Having looked at Supras and MR2\'s they tend to be around 900-980deg on hard acceleration with the sensor in the downpipe.  I have seen a few readings posted on here for FD\'s and they tend to be the same? :confused:

Does anyone have any readings from cruise and WOT? :confused:

[papercutout]

Because pre \'92 (I think it\'s \'92 anyway) cars have much more lenient emissions regulations.

[Ricco_04]

Non cat test limits 3.5%co 1200ppm
cat test limits 0.5%co 200ppm

Yeah I know what you are saying and yeah the limits are different - I was comparing the emissions betwene the cars saying my fd would only just pass the non cat test (regardless of what it should be tested on) and was therefore wondering why the fc seems to be that bit cleaner - unless its just down to my car! lol