conaero
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Some of you may have noticed I have not been around much the past few days. I have been up with BennyD playing with exhausts and here is our findings:
Well guys, that was an interesting morning. I went to stay with that righteous pillar of our community and all round good guy BennyD last night and this morning we took my GS to his mate John, who had a spare ramp, and we fitted a new unsilenced X-pipe and modified GS rear boxes. The whole thing came apart pretty easily, although it was a bit of a faff getting the rear wheel arch liners out. Then we did a bit of messing about fitting, and videoing, various combinations of parts so that we have a video record of what does what with what. Here is a sequence of videos that is best listened to with earphones.
Firstly, this is what a GS sounds like as standard with the valves closed:
Standard GS with valves open:
I think you'll agree it leaves a lot to be desired! To try and improve matters we then fitted an unsilenced X-pipe, leaving on the standard GS rear boxes, and tried it first with the valves closed and then open:
Better! There is a bit more bass and volume and there is the first sign of the pops and crackles. But, whilst better, it's still not great. I suppose it would suit those who want a bit more, but not too much. We then fitted the heavily modified rear GS boxes and refitted the standard centre box/resonator. We thought this would make a noticable difference as they are virtually straight through:
We were wrong! It sounds a lot like standard and I guess it shows how much the standard cats and resonator kill the sound before the back end. Then we removed the standard centre box and replaced it with the unsilenced X-pipe leaving the modified rears on. First, valves closed and then open:
Success! With the valves closed it sounds a bit fruitier than the standard sport (valves open) mode but is still pretty quiet. With the valves open it sounds much better; very sporty, a lot louder and it now has a nice line in pops and crackles. Benny said it sounded fantastic when I went past him on the motorway. On the road in sport, the sound has now got a lot harder edge to it than standard and much more volume. However, and this is the good bit, there is no resonance in the cabin and very little increase in interior volume either, until you open the windows! I guess it proves what we have been saying all along; you need to change two of the three parts to make a worthwhile increase in sound volume and quality. (The three parts being; front pipes and cats, the centre box and rear boxes).
All in all, a very successful and relatively cheap mod which transforms the car into what it should have been from the factory. Thanks to John at GT Cars (Warrington) for the use of his ramp, technical input and coffee!
Well guys, that was an interesting morning. I went to stay with that righteous pillar of our community and all round good guy BennyD last night and this morning we took my GS to his mate John, who had a spare ramp, and we fitted a new unsilenced X-pipe and modified GS rear boxes. The whole thing came apart pretty easily, although it was a bit of a faff getting the rear wheel arch liners out. Then we did a bit of messing about fitting, and videoing, various combinations of parts so that we have a video record of what does what with what. Here is a sequence of videos that is best listened to with earphones.
Firstly, this is what a GS sounds like as standard with the valves closed:
Standard GS with valves open:
I think you'll agree it leaves a lot to be desired! To try and improve matters we then fitted an unsilenced X-pipe, leaving on the standard GS rear boxes, and tried it first with the valves closed and then open:
Better! There is a bit more bass and volume and there is the first sign of the pops and crackles. But, whilst better, it's still not great. I suppose it would suit those who want a bit more, but not too much. We then fitted the heavily modified rear GS boxes and refitted the standard centre box/resonator. We thought this would make a noticable difference as they are virtually straight through:
We were wrong! It sounds a lot like standard and I guess it shows how much the standard cats and resonator kill the sound before the back end. Then we removed the standard centre box and replaced it with the unsilenced X-pipe leaving the modified rears on. First, valves closed and then open:
Success! With the valves closed it sounds a bit fruitier than the standard sport (valves open) mode but is still pretty quiet. With the valves open it sounds much better; very sporty, a lot louder and it now has a nice line in pops and crackles. Benny said it sounded fantastic when I went past him on the motorway. On the road in sport, the sound has now got a lot harder edge to it than standard and much more volume. However, and this is the good bit, there is no resonance in the cabin and very little increase in interior volume either, until you open the windows! I guess it proves what we have been saying all along; you need to change two of the three parts to make a worthwhile increase in sound volume and quality. (The three parts being; front pipes and cats, the centre box and rear boxes).
All in all, a very successful and relatively cheap mod which transforms the car into what it should have been from the factory. Thanks to John at GT Cars (Warrington) for the use of his ramp, technical input and coffee!
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