I'm doing a back to back test on Gallardo Exhaust upgrades
Discussion
Alpinestars said:
Will you be uploading sound clips?
If you would like yes. I'm more into power myself as most of these aftermarket exhausts tend to lose power and some of them throw the fueling out massively with guys driving round with a great sounding exhaust running at 13.8:1 at full throttle.
On my last test only one gave power with the usual high end upgrades both losing power, one 14hp and the other 17hp.
Edited by ZeusF on Tuesday 25th February 00:35
Alpinestars said:
ZeusF said:
If you would like yes.
Yes please. Those power loses are shocking!The extra noise gives a placebo of having more power but it is very rare that an exhaust makes power on a car simply because almost all of the aftermarket makers fail to flow test their systems.
ZeusF said:
Alpinestars said:
ZeusF said:
If you would like yes.
Yes please. Those power loses are shocking!The extra noise gives a placebo of having more power but it is very rare that an exhaust makes power on a car simply because almost all of the aftermarket makers fail to flow test their systems.
I've never been a fan of loud aftermarket exhausts, and manufacturers go to an awful lot of trouble and expense, far more than aftermarket people can, to make them work properly.
Fascinating experiment though.
It always makes me laugh when people want to put aftermarket on their BMW M Class cars in the search of power yet BMW make some of the best systems of any vehicles even though they don't like like they do !
I have always been able to look at any BMW exhaust and find an area that isn't right, somewhere I could improve on yet its false, the factory exhausts are truly awesome on many levels and its once in a blue moon you will get even 5hp from one.
I have always been able to look at any BMW exhaust and find an area that isn't right, somewhere I could improve on yet its false, the factory exhausts are truly awesome on many levels and its once in a blue moon you will get even 5hp from one.
mad4amanda said:
would itbe possible to do a proper noise test too, this would be very useful to anyone considering an exhaust change but still wanting to meet track Db ?
If you want to meet track limits and also have true F1 sound then you should get the Frequency Intelligent system.Question about the aftermarket exhausts causing a drop in power. Was the car tuned for the new exhaust? I'd imagine adding a much more flowing exhaust would wreak havoc on the a/f. Tuning the car for it would likely take care of the issues and probably give you power gains. I know in the bike world doing a "full system" (headers back), will make the bike run like crap until you dyno tune it, at which point you realize the gains.
Often aftermarket exhausts are not better flowing though, just louder.
With a closed loop system with lambda feedback I would have expected the ECU to self adjust in the same way it does for barometric pressure and fuel.
Bikes don't have such sophisticated closed loop feedback systems as they don't have to meet the same emissions targets I believe, hence why bikes need retuning. Carbs were still common on bikes not long ago!!
With a closed loop system with lambda feedback I would have expected the ECU to self adjust in the same way it does for barometric pressure and fuel.
Bikes don't have such sophisticated closed loop feedback systems as they don't have to meet the same emissions targets I believe, hence why bikes need retuning. Carbs were still common on bikes not long ago!!
To echo what the OP is saying throughout this thread, after market exhausts are usually worse for performance. The BMW example is a good one, I always found it amusing that some people though that BMW spent millions on their drivetrain package, only for a small company to improve on this with a simple exhaust....
Anyway, exhaust design is incredibly complex, especially with emission and noise requirements these days. A 'free flowing' exhaust is not the be all and end all of modifications, rarely will a better flow rate be the sole factor in improvement on an engine.
Chris
Anyway, exhaust design is incredibly complex, especially with emission and noise requirements these days. A 'free flowing' exhaust is not the be all and end all of modifications, rarely will a better flow rate be the sole factor in improvement on an engine.
Chris
Interesting topic and will follow this one!
However, I'm also not sure that simply driving 25km will optimise the timing/ fuelling etc.
It would probably be better to reset the ECU and do a baseline run(s) on the standard exhaust and then reset the ECU before each exhaust change and dyno run.
Even if the base map it reverts to is not optimal, it's the only way to ensure a level playing field for each exhaust to check gains.
Manufacturers tune for a lot of parameters (including noise and driveability) and that doesn't always mean you have the best exhaust for your application.
A racer might be willing to give away some power lower in the rev range for more at the top end etc. You just have to choose the right aftermarket exhaust for your application. Even if they lose power everywhere, it may be the owner doesn't miss 20bhp through the rev range (for example) in return for an exhaust note they find much more pleasing!
However, I'm also not sure that simply driving 25km will optimise the timing/ fuelling etc.
It would probably be better to reset the ECU and do a baseline run(s) on the standard exhaust and then reset the ECU before each exhaust change and dyno run.
Even if the base map it reverts to is not optimal, it's the only way to ensure a level playing field for each exhaust to check gains.
Manufacturers tune for a lot of parameters (including noise and driveability) and that doesn't always mean you have the best exhaust for your application.
A racer might be willing to give away some power lower in the rev range for more at the top end etc. You just have to choose the right aftermarket exhaust for your application. Even if they lose power everywhere, it may be the owner doesn't miss 20bhp through the rev range (for example) in return for an exhaust note they find much more pleasing!
dom9 said:
Interesting topic and will follow this one!
However, I'm also not sure that simply driving 25km will optimise the timing/ fuelling etc.
It would probably be better to reset the ECU and do a baseline run(s) on the standard exhaust and then reset the ECU before each exhaust change and dyno run.
Even if the base map it reverts to is not optimal, it's the only way to ensure a level playing field for each exhaust to check gains.
Manufacturers tune for a lot of parameters (including noise and driveability) and that doesn't always mean you have the best exhaust for your application.
A racer might be willing to give away some power lower in the rev range for more at the top end etc. You just have to choose the right aftermarket exhaust for your application. Even if they lose power everywhere, it may be the owner doesn't miss 20bhp through the rev range (for example) in return for an exhaust note they find much more pleasing!
I write code for a living so will be monitoring adaption and fuelling and making sure all tests are as close as can be outside of the testing facility.However, I'm also not sure that simply driving 25km will optimise the timing/ fuelling etc.
It would probably be better to reset the ECU and do a baseline run(s) on the standard exhaust and then reset the ECU before each exhaust change and dyno run.
Even if the base map it reverts to is not optimal, it's the only way to ensure a level playing field for each exhaust to check gains.
Manufacturers tune for a lot of parameters (including noise and driveability) and that doesn't always mean you have the best exhaust for your application.
A racer might be willing to give away some power lower in the rev range for more at the top end etc. You just have to choose the right aftermarket exhaust for your application. Even if they lose power everywhere, it may be the owner doesn't miss 20bhp through the rev range (for example) in return for an exhaust note they find much more pleasing!
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