N
Nico
Guest
For those of you not already bored (parden the pun) to tears by this topic, here are some pics of that custom exhaust I've been harpin on about for ages, along with the results of the rolling road (see - I wasn't fibbing Tom!)
As much as I know about what to expect from an aftermarket exhaust (less then nothing) or any exhaust for that matter, here are the results of the comparative rolling road tests, that I produced those magical figures / unbeleiveable gains from. For all I know, I could be looking at it wrong. I'm sure (Tom) will have something to say about them
Obviously I went over the results to make them stand out more
I was led to belive that the standard exhaust was less then four months old when I purchased the car, so it would not have done more than a thousand miles before this test was performed. It'll not escape your attention for long that the claims I made about power gains were in addition to the strikingly poor performance of the standard one that had been fitted, and not in excess of the stated 155bhp as per the spec for the HGT!
Whatever the modest gain was over 155 (it drops off quite markedly before that last climb up to 159), I'd be more curious to find out quite why the std one only reached 142. I suppose any such reading has to be considered as a measure of the cars performance as a whole, and not merely a reflection on the exhaust!? The new one is a complete stainless cat-back. As to how the Jetex system is meant to perform differently, their blurb goes on about principles of absortion rather than filtering, to mininize flow restriction further.
It is supposed to be one of the quietest performance exhausts on the market, when you do purchase the system as a whole – designed to be car specific by Jetex themselves. But the garage that fitted this one didn't admit to me till after I piped up about the unwanted noise mid-range, that Jetex don't of course do a system for the bravo. Now all credit to the guy for doing what looks to my untrained eye, like a pretty neat job given all the welding that had to be done (fits my rieger rear perfectly too) but I aint guna rest till I've tamed the beast.
I say beast; it's just that there is unarguably excessive resonance once your cruising in 4th or 5th, at around 3 grand. From what most of you say about your custom jobs, they can get a little irritating above 4k. I must admit, that once you get above 3.5K, it's absolute bliss (goes nice and quiet – perfect for the motorway). If only it was like this throughout the rev range (am I really being too fussy dya think??).
Of course the garage thinks I'm nuts; I'm the only one they've ever had complain that their exhausts is too noisy. The guy tried an insert (in one of two places) and that did bugger all (havn't bothered taking it back for him to even try it in alternate section further up). Instead, figured I'd wait til Viper filter kit goes on and I've covered floor in sound deadening stuff (worthwhile doing in anycase I suppose) before finally resetting the ECU to see what the end result is.
It didn't surprise me greatly that there should be so much more noise from the new one, when I actually looked under at the silencers. The guy said he had to use the smallest one poss, in order to fit one in at all, in place of the one after the cat (instead of using the void left by Fiats triangular one, he positioned it up nearer the cat). I still can't quite believe how small the one at the back is though – barely bigger in section than the twin tailpipes!
My mother's got an SLK with a Brabus that is not much quiter than mine and it has a huge back-box in comparison. When I had the coilover kit fitted, I took it to another garage that had since been recommended to me, and explained my discontent about the exhaust, and invited them to take it for a spin and give me their opinion. When I returned later that day to collect the car I asked them if indeed I was being totally neurotic about it. Their response (accompanied by a nodding gesture of approval) was unanamous..‘it sounds bloody amazing'. Ahhh well.. , hopefully sound deadening will do the trick.
I had bought what stocks my local had of the cheap brand Ivanhoe 17 / roll (not inc.disc), till lack of patience (& offer of sale price) prompted me to buy some Dynamat. Realising immediately the difference in quality material, and hence the potential improvements in performance, I decided to go for the Bulk pack of Extreme Dynamat since I found Car Audio online selling them for £150 (9 sheets would cost 230 if you bought them in individual wedge packs), and I'll use the cheaper Ivanhoe stuff around the perimeter of the panels. When I do it all, I could take some pics n post em on here, if anyones really that interested!?
As much as I know about what to expect from an aftermarket exhaust (less then nothing) or any exhaust for that matter, here are the results of the comparative rolling road tests, that I produced those magical figures / unbeleiveable gains from. For all I know, I could be looking at it wrong. I'm sure (Tom) will have something to say about them
Obviously I went over the results to make them stand out moreI was led to belive that the standard exhaust was less then four months old when I purchased the car, so it would not have done more than a thousand miles before this test was performed. It'll not escape your attention for long that the claims I made about power gains were in addition to the strikingly poor performance of the standard one that had been fitted, and not in excess of the stated 155bhp as per the spec for the HGT!
Whatever the modest gain was over 155 (it drops off quite markedly before that last climb up to 159), I'd be more curious to find out quite why the std one only reached 142. I suppose any such reading has to be considered as a measure of the cars performance as a whole, and not merely a reflection on the exhaust!? The new one is a complete stainless cat-back. As to how the Jetex system is meant to perform differently, their blurb goes on about principles of absortion rather than filtering, to mininize flow restriction further.
It is supposed to be one of the quietest performance exhausts on the market, when you do purchase the system as a whole – designed to be car specific by Jetex themselves. But the garage that fitted this one didn't admit to me till after I piped up about the unwanted noise mid-range, that Jetex don't of course do a system for the bravo. Now all credit to the guy for doing what looks to my untrained eye, like a pretty neat job given all the welding that had to be done (fits my rieger rear perfectly too) but I aint guna rest till I've tamed the beast.
I say beast; it's just that there is unarguably excessive resonance once your cruising in 4th or 5th, at around 3 grand. From what most of you say about your custom jobs, they can get a little irritating above 4k. I must admit, that once you get above 3.5K, it's absolute bliss (goes nice and quiet – perfect for the motorway). If only it was like this throughout the rev range (am I really being too fussy dya think??).
Of course the garage thinks I'm nuts; I'm the only one they've ever had complain that their exhausts is too noisy. The guy tried an insert (in one of two places) and that did bugger all (havn't bothered taking it back for him to even try it in alternate section further up). Instead, figured I'd wait til Viper filter kit goes on and I've covered floor in sound deadening stuff (worthwhile doing in anycase I suppose) before finally resetting the ECU to see what the end result is.
It didn't surprise me greatly that there should be so much more noise from the new one, when I actually looked under at the silencers. The guy said he had to use the smallest one poss, in order to fit one in at all, in place of the one after the cat (instead of using the void left by Fiats triangular one, he positioned it up nearer the cat). I still can't quite believe how small the one at the back is though – barely bigger in section than the twin tailpipes!
My mother's got an SLK with a Brabus that is not much quiter than mine and it has a huge back-box in comparison. When I had the coilover kit fitted, I took it to another garage that had since been recommended to me, and explained my discontent about the exhaust, and invited them to take it for a spin and give me their opinion. When I returned later that day to collect the car I asked them if indeed I was being totally neurotic about it. Their response (accompanied by a nodding gesture of approval) was unanamous..‘it sounds bloody amazing'. Ahhh well.. , hopefully sound deadening will do the trick.
I had bought what stocks my local had of the cheap brand Ivanhoe 17 / roll (not inc.disc), till lack of patience (& offer of sale price) prompted me to buy some Dynamat. Realising immediately the difference in quality material, and hence the potential improvements in performance, I decided to go for the Bulk pack of Extreme Dynamat since I found Car Audio online selling them for £150 (9 sheets would cost 230 if you bought them in individual wedge packs), and I'll use the cheaper Ivanhoe stuff around the perimeter of the panels. When I do it all, I could take some pics n post em on here, if anyones really that interested!?
