ok call me stupid but should i purchase a panel filter or an induction Kit i want a bit more noise and power wich is the better option and wich one isn't going to invalidate my waranty????

Neither will give you any real power increase by itself, if anything a cone filter may lose you power in the wrong conditions. A cone filter will give you a better sound than a panel filter though.

Neither will invalidate your warranty completely (a panel filter is theoretically less easily detectable) but speak to the service manager at your local dealership and see what their view is on these sort of mods.

how do you mean it will lose power in the wrong conditions??

if its too hot it will result in power loss and not power gain. make sure if u go for a cone filter to get some cold air feeds with it. the k&n 57i comes with 2 cold air feeds and is about £90. i brought the viper to start with for £200 and the lack of cold air feeds resulted in power loss. made a bloody good noise tho. im booked in a pumaspeed 2morra to get the full miltek system and to have my viper replaced with the k&n. also gettin sports cat and the magnecor leads aswell. should be a nice expensive day lol. at the end tho should be about +25 bhp.

Again, its more theoretical than anything else, but the engine bay in the ST is incredibly cramped, meaning that it gets very hot in there. Engines need plenty of cool air to work at their best, so if you've got a cone filter without a decent heat shield (or cold-air feed at the very least) then its just gonna suck in all the hot air from the engine bay and (potentially) lose you power. This isn't normally gonna cause you too much of problem in the British winter but its a potential concern for when the few weeks of summer come round again, or if you live in a slightly warmer climate.

I know of plenty of people who have now fitted stuff like the K&N 57i without any real complaint though, but if I was looking to get a proper induction kit then I'd be inclined to put my hand in my pocket and get something enclosed like the Pipercross Viper or BMC CDA. The K&N Typhoon should be out before much longer too.

Didn't realise that Todge had also replied in the meantime, so some of that may not make sense...

the vipers ok dont get me wrong but at times the car didnt feel as punchy as it did. noise tho was a head turner.

whats the warranty situation on getting an induction kit?? or am i asking to much??

Exactly the same as this!

http://www.fordfiestast.co.uk/showflat.php?Cat=0&Number=19023&an=0&page=0#19023

ok well i think il drive around for a few months to see if there are any probs wit the engine if not then ill fit one!

You will "get away" with having an induction kit as far as the warranty is concerned, its when you begin to mess about with manifolds, throttle bodies, etc that it begins to get very complicated. I've come to the conclusion that I'm not really gonna do much with mine until the warranty has run out anyway (if I've still got it by then...)

A performance air filter will effect you warrranty of the fault is related to it.

Just keep the ford one and swap it over if you have a fault though.

Fair comment, but no so easy in practice.

You will need to declare it to your insurer though.