First impressions on cold start, the Spec-L made the FA20 sound much like a 4G63 found in an Evo. With the idle at 1500 revs for the first couple of minutes, the exhaust note was profoundly bassy with such a ''bad ass'' noise. To me, it was an experience of adrenaline rush that was simply exhilerating from both outside and inside the cabin. Yes, it was pretty loud, way louder than stock.
Considering the fact that the cabin of the 86/BRZ had practically no sound deadening material, anything louder would have been unbearable, especially for rear passengers.
On the road, the Spec-L remained bassy when throttled, particularly from the 2500 to 4500 rev range. On higher revs beyond 4500 , the bassy drone goes away and the 86 sounds much like stock in the cabin. While I am sure it was audibly different on the outside, the car certainly sounded stock in the cabin with absolutely no drone whatsoever after 4500 revs, all the way to redline. Perhaps this was due to the higher flow that's now available, way more than what the stock FA20 could deliver. On freeway cruising, there was little to no drone if you keep your foot light on the throttle under the 2000 rev limit, a good thing if you want to enjoy some music from your car stereo.
According to HKS, the Hi-Power Spec-L offers up to 60% reduction in backpressure to accomodate flow requirements for engine outputs up to 350bhp. On a regular chip tuned FA20 with a high flow filter, there was an improvement in mid range torque as the car pulled more effortlessly from 4000 revs.
I must admit that I am a fan of HKS but while that is true, it is without a shadow of a doubt that the Hi-Power Spec-L was beautifully built, sounds really good and is street legal. Retailing around S$2000, the cat back exhaust comes complete with documentation for LTA compliance in Singapore.
Last but not least, with the huge stock muffler under the spare wheelwell gone, you can expect an overall lowered trunk temperature with the new Spec-L cannons.
Love it or hate it, the HKS Hi-Power Spec-L does turn heads both in the parking lot and on the move.