Do I keep my HKS SPF kit or not?
 

Hi,

I've owned a 2001 bugeye WRX for just over a year, and in that time I've made just a few modifications.

I replaced the backbox with a Scoobyworld Racebox, added an HKS super power flow induction kit, and then style-wise I've gone for crystal indicators and reflectors, clear rear lights, and swapped the airbag seats for bucket seats off an earlier WRX.

Other than a twin Morette headlight conversion, I'm starting to think about more power mods (such as a sports cat); however, since fitting the HKS kit, I've read in some magazines and forums that tuners generally advise against fitting an induction kit and sticking with an aftermarket panel filter in the original airbox as the hot air generated in the engine bay can reduce rather than increase power when an induction kit is fitted.
I've also read that to get the maximum benefit from an induction kit you need to have an ECU remap done.

How much of this (if any) is true? Can someone give me some advice based on personal experience? I love the sound of the SPF kit but if it's going to affect performance that badly then I'll give serious consideration to selling it on and reverting back to the standard airbox which is knocking around in my garage. Is there another alternative - for example, a heatshield? I'm wondering whether it's worth buying a second hand airbox and butchering it to sit outside the HKS filter...

Any advice greatly appreciated