I have had 2 calls recently from MEVABUSA owners who are having difficulty with the IVA test. One is noise as most bike engine cars have the engine in the front with exhaust outlet at the rear. The problem seems to be that with the MEVABUSA that the decibel meter is picking up induction noise due to the exhaust outlet being near to the air box.
Emissions seem to be an issue as they have to meet car standards although the donor engine management was designed for a bike. Unfortunately I have tried but failed in convincing the authorities that they should be tested as bike emissions as it is a bike engine. I spoke to an examiner recently and he said the map is usually so poor in order to get a BEC through the test that they will hardly even tick over. Clearly we need to find a solution. Could those that have passed the test please help others by explaining how they got around these issues and any more problems they could suggest that may make life easier. Your help is much appreciated. Experience is king.
First tip, do not remove any of the emission reducing stuff like 02 sensor pairs valve and airbox mods, all this stuff will help keep emissions down for the test. I failed my iva on emissions even with a friendly examiner who let me spend around half an hour remapping with the laptop whilst connected to the gas analyser. I could tweak the fuelling to get any one of the readings down, but not all 3 at the same time.bringing the co down pushed htdrocarbons up. I have now made a new exhaust, with o2 sensor and refitted a pairs valve. Hopefuly this will do the trick when I get around to booking the retest. Also be careful what you put down for maximum power revs, RTR advised 8000rpm but dvsa would not accept that,saying it was far to low for the type of engine. lots of emails back and forth resulted in them asking for a dyno print out to prove it, so eventually settled on 9750rpm as max power revs, there tech department was not going to be conned ! On the day the noise test was done and passed with 0.3 of a decibel to spare, although by this time it was running so weak below 3000rpm the throttle was more like an on/off switch, so the revs probably went way above what they should have. The examiner I had to deal with at Bristol was actually from Exeter and was very fair with everything, all in all the test was nowhere near as bad as I was expecting, and my only real problem was emissions, and the examiner doing donuts behind the test centre in the wet !