Cheers for the info Chris. Yeh I did have the air feed like in the pic but I don't think enough air was getting in. I've just been out for a little drive after adapting it some more - I've got the air feed feeding onto the large inlet (shown on your pic above) for the Viper but not actually connecting to it - so if it can't get enough air from the feed its got external air too. Seemed better. Haven't tried disconnecting the battery yet. Will try in a
mo. I've got mine chipped too - shouldn't overwrite it should it?