Derek W

Could somebody please advise if a MY03 STI backbox would fit as a direct replacement onto a MY01 WRX and be warranty-friendly?

In addition, would the STI backbox be louder?

Thanks in advance.

Dark

iTrader: (1)

Yes it should fit no problem.

However the standard STI backbox is very restrictive and very quiet so I doubt you'll notice any noise or performance gains. Only worthwhile doing if you fancy the look of the single round tailpipe.

Better option would be to look out for a second hand Prodrive WRSport or PPP backbox, less restrictive and will give you a proper burble. I recently sold one on here for ~£150 and I've seen several others advertised recently. Warranty friendly too!

Mark

Derek W

Thanks Dark, very helpful.

mutant_matt

I thought the STi BB was very restrictive too but at a Track Day @ Bedford on the weekend, to get Iain Litchfield's Type 25 under their noise limits, he had to put on a standard STi BB (which are extemely quiet (77dB mine was registered @ one track day at idle, 0.5m @ 45 degrees from the tail pipe!! )). This made the car sound virtually standard but it still managed to keep up with a Gallardo down the long straight and Iain said there was only a small drop in performance. Not as restrictive as I would have thought then!!

Matt