Help! Amuse exhaust doesn't make noise
09-02-2004, 10:19 AM
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Help! Amuse exhaust doesn't make noise
Help me please!!!
I bought an Amuse Dual Titanium and had it fitted last week. A couple of days later, I had an HKS racing header fitted too. The noise was fantastic but now it's all gone wrong.
basically, over the last 2 days, it has got quieter and quieter and now I have a car sounding like stock. It also "feels" to be down on power too.
What can my problem be?
Has my shiny new exhaust collapsed on me hence no noise and reduced power?
Has my cat packed in?
I'm hoping someone can help as sending the exhaust back to America with all the associated shipping costs is not my idea of fun.
I bought an Amuse Dual Titanium and had it fitted last week. A couple of days later, I had an HKS racing header fitted too. The noise was fantastic but now it's all gone wrong.
basically, over the last 2 days, it has got quieter and quieter and now I have a car sounding like stock. It also "feels" to be down on power too.
What can my problem be?
Has my shiny new exhaust collapsed on me hence no noise and reduced power?
Has my cat packed in?
I'm hoping someone can help as sending the exhaust back to America with all the associated shipping costs is not my idea of fun.
09-02-2004, 10:29 AM
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That's certainly not amusing (
). Usually it's the other way around and the exhaust will get louder over time, I would give it a few more miles before you start to worry. It could just be bedding in.
). Usually it's the other way around and the exhaust will get louder over time, I would give it a few more miles before you start to worry. It could just be bedding in.
09-02-2004, 10:48 AM
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Thanks Neil,
The thing is though it was loud "out the box" for a few days and is now really quiet. If you drove the car without knowing the Amuse was on, you'd have no idea, it really has lost ALL it's noise, not just a bit. I know it should change sound as it beds in but only a little and perhaps it should get slightly louder.
Honestly, this thing is now night and day........plus I feel down on power like there is a blockage.
My not so scientific solution is to race another quick car in a straight line and then do the run again after switching back to the stock exhaust - a pain yes but if it pulls further with the stock, then it's a lot a cash to pay for something that is killing power.
It has to something blocking airflow to be noise and power related?
The thing is though it was loud "out the box" for a few days and is now really quiet. If you drove the car without knowing the Amuse was on, you'd have no idea, it really has lost ALL it's noise, not just a bit. I know it should change sound as it beds in but only a little and perhaps it should get slightly louder.
Honestly, this thing is now night and day........plus I feel down on power like there is a blockage.
My not so scientific solution is to race another quick car in a straight line and then do the run again after switching back to the stock exhaust - a pain yes but if it pulls further with the stock, then it's a lot a cash to pay for something that is killing power.
It has to something blocking airflow to be noise and power related?
09-02-2004, 02:21 PM
#6
Exhausts normally get a little quieter after the initial running, as the packing soots up a little. Then later in life, they get louder as the packing get past it, baffles fail etc. Neither of which is going to have happened over the length of time mentioned here.
The HKS exhaust manifold isn't that great. One of the problems is that being a 4:1 (instead of a 4:2:1) design like the standard one and most aftermarket one, it's ideal air fuel ratio and ignition timing are more different to the standard requirements than other exhaust manifolds. To put that in a simpler way, the standard ECU's maps aren't ideal for it.
The ECU's fuel learning is based solely upon tweaking the mixture to acheive stoichometric. So it adjusts at low rpm and throttle load (think cruising). Then it applies whatever correction it has to the map at all rpms. So it might be saying, enrich 5% or whatever. It just applies that one correction factor though.
The Amuse will have little impact on the shape of the fuel curve needed, only changing the amount of the fuel. So the ECU's learning might do quite well with that.
The HKS exhaust manifold though, will have changed the fueling requirements quite a bit. So the ECU would need far more advanced learning capabilites than it has to tune to the manifold properly. So it's likely to be running quite rich in some places, and lean in others.
Now, this isn't going to make a huge difference to the sound (ignition timing has a bit more impact there and it shouldn't have changed), but from the performance point of view, the changed fueling could be giving you a flatspot where there wasn't before.
I'd suggest jsut resetting the ECU first off. And see what it sounds and drives like just after that. Much simpler than messing with anything else, when so far it's unlikely to be anything else.
BTW Racing another car is useless. If you want to have any chance of a repeatable test, measure in gear acceleration on the same section of road between a wide speed band (so it takes a while reducing the percentage error from timing inaccuracy.).
-Brian.
The HKS exhaust manifold isn't that great. One of the problems is that being a 4:1 (instead of a 4:2:1) design like the standard one and most aftermarket one, it's ideal air fuel ratio and ignition timing are more different to the standard requirements than other exhaust manifolds. To put that in a simpler way, the standard ECU's maps aren't ideal for it.
The ECU's fuel learning is based solely upon tweaking the mixture to acheive stoichometric. So it adjusts at low rpm and throttle load (think cruising). Then it applies whatever correction it has to the map at all rpms. So it might be saying, enrich 5% or whatever. It just applies that one correction factor though.
The Amuse will have little impact on the shape of the fuel curve needed, only changing the amount of the fuel. So the ECU's learning might do quite well with that.
The HKS exhaust manifold though, will have changed the fueling requirements quite a bit. So the ECU would need far more advanced learning capabilites than it has to tune to the manifold properly. So it's likely to be running quite rich in some places, and lean in others.
Now, this isn't going to make a huge difference to the sound (ignition timing has a bit more impact there and it shouldn't have changed), but from the performance point of view, the changed fueling could be giving you a flatspot where there wasn't before.
I'd suggest jsut resetting the ECU first off. And see what it sounds and drives like just after that. Much simpler than messing with anything else, when so far it's unlikely to be anything else.
BTW Racing another car is useless. If you want to have any chance of a repeatable test, measure in gear acceleration on the same section of road between a wide speed band (so it takes a while reducing the percentage error from timing inaccuracy.).
-Brian.
09-02-2004, 11:47 PM
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We were speculating whether it could be the Cat screwed up in some way.
It sounds logical to me.
Any thoughts guys?
From what Mark's saying it definitely sounds like a problem. I'm not experiencing any noise "drop off" with mine.
And while I suppose he could be loosing his hearing
I'm thinking there's more to it. 
It sounds logical to me.
Any thoughts guys?
From what Mark's saying it definitely sounds like a problem. I'm not experiencing any noise "drop off" with mine.
And while I suppose he could be loosing his hearing
I'm thinking there's more to it. Trending Topics
09-02-2004, 11:55 PM
#8
there's no way he's losing his hearing, Mr T took me out in his. I think the Amuse is definitely a better daily car, less booming at low revs, but the trade off seems to be not as much exhilarating noise at the top end. Not better or worse, just different aural characteristics. I suspect the Mugen is similar, hence Brian's use of the Mugen unless he's feeling raucous and slaps his Spoon single exit exhaust on (have you still got that Spoon exhaust Brian?)
EDIT: I should point out Mr T still has his PRM on which somewhat dominates the noise (but I don't think it would up against my T1R).
EDIT: I should point out Mr T still has his PRM on which somewhat dominates the noise (but I don't think it would up against my T1R).
09-06-2004, 08:12 AM
#9
My opinion of the Amuse aural characteristics has jumped up - Fletch and I had a good blast at each other on the weekend and Fletch's sounded 
Certainly would be top of my twin pipe shopping list if funds permitted. Puzzled by the stainless steel-esque finish to the pipes, but makes for a nice set of shiny tail pipes! I personally still think the T1R edges it for top line sweet noise, but the Amuse still sounds raucous and with less resonance 
Certainly would be top of my twin pipe shopping list if funds permitted. Puzzled by the stainless steel-esque finish to the pipes, but makes for a nice set of shiny tail pipes! I personally still think the T1R edges it for top line sweet noise, but the Amuse still sounds raucous and with less resonance
09-06-2004, 08:16 AM
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Funds didn't really permit me either, but that didn't stop me, Craig..... 
I'll be interested to hear what mine is like once the PRM is removed - at the minute, it drowns out the exhaust above 6k rpm. Around 500 miles since mine was fitted and so far I'm really pleased with it.
Mark, are you any closer to identifying where the problem lies?
I'll be interested to hear what mine is like once the PRM is removed - at the minute, it drowns out the exhaust above 6k rpm. Around 500 miles since mine was fitted and so far I'm really pleased with it.
Mark, are you any closer to identifying where the problem lies?