alternative to oem Cats on a 3R Sandard Exhaust ?
Discussion
I have recently had my OEM exhaust replaced.
In the process of discussing what to do with the old exhaust Dave @ BCS said that the original cats could be cut out and easily replaced with higher flowing ones, so maybe thats an option for you to consider.
If you want a spare OEM exhaust system to have altered so you can swap them over with minimal downtime i'll sell mine. I think the rear cat on my exhaust is in marginal condition but the rest is ok.
Thanks
Matt
In the process of discussing what to do with the old exhaust Dave @ BCS said that the original cats could be cut out and easily replaced with higher flowing ones, so maybe thats an option for you to consider.
If you want a spare OEM exhaust system to have altered so you can swap them over with minimal downtime i'll sell mine. I think the rear cat on my exhaust is in marginal condition but the rest is ok.
Thanks
Matt
StreetDragster said:
I have recently had my OEM exhaust replaced.
In the process of discussing what to do with the old exhaust Dave @ BCS said that the original cats could be cut out and easily replaced with higher flowing ones, so maybe thats an option for you to consider.
If you want a spare OEM exhaust system to have altered so you can swap them over with minimal downtime i'll sell mine. I think the rear cat on my exhaust is in marginal condition but the rest is ok.
Thanks
Matt
hi mattIn the process of discussing what to do with the old exhaust Dave @ BCS said that the original cats could be cut out and easily replaced with higher flowing ones, so maybe thats an option for you to consider.
If you want a spare OEM exhaust system to have altered so you can swap them over with minimal downtime i'll sell mine. I think the rear cat on my exhaust is in marginal condition but the rest is ok.
Thanks
Matt
thanks for that . I will have mine checked out and if they are knackered I might just get them taken out and remain catless for a while. (The noble cats in total are just over a grand with the gaskets.)
What's the bcs exhaust like ? and who fitted yours ?
cheers
stefano
BCS fitted mine 
Its the prototype of their active version. I've not tested it yet as the car is having some work done at another garage.
Hopefully it'll be back soon.
From dealing with BCS and viewing their work and other projects i have absolutely no hesitation in recommending them
Matt
Its the prototype of their active version. I've not tested it yet as the car is having some work done at another garage.
Hopefully it'll be back soon.
From dealing with BCS and viewing their work and other projects i have absolutely no hesitation in recommending them
Matt
StreetDragster said:
BCS fitted mine
Its the prototype of their active version. I've not tested it yet as the car is having some work done at another garage.
Hopefully it'll be back soon.
From dealing with BCS and viewing their work and other projects i have absolutely no hesitation in recommending them
Matt
Active version?Its the prototype of their active version. I've not tested it yet as the car is having some work done at another garage.
Hopefully it'll be back soon.
From dealing with BCS and viewing their work and other projects i have absolutely no hesitation in recommending them
Matt
Do tell!
https://m.facebook.com/bcsnigel.leeming/albums/101...
Will give more detail when I have the car back
Matt
Will give more detail when I have the car back
Matt
StreetDragster said:
https://m.facebook.com/bcsnigel.leeming/albums/101...
Will give more detail when I have the car back
Matt
Bugga, I'm not a Facebooker!Will give more detail when I have the car back
Matt
StreetDragster said:
https://m.facebook.com/bcsnigel.leeming/albums/101...
Will give more detail when I have the car back
Matt
Wow! Truly, wow! Work of art and a great idea, can it be controlled from the cabin too?Will give more detail when I have the car back
Matt
Its hard to describe, but its goes from being a very nice sporty but quiet sound, you can easily hold a conversation in the car, and i would even say that the off boost sound in cabin is actually slightly quieter than stock.
When it comes on boost and opens the diverter valves, its not the volume of the exhaust that changes too much in the cabin, but the tone, it goes to a very deep thudding sound that you feel more than you hear. Its not the F1 screaming type sounds of yesteryear F1, but does sound similar to this years F1 cars.
However, this is all based on one drive, with only two actuatations onto boost with me in the car, so i'll give a thorough report when i get back, i'll try and get some video two to capture the noise both inside and outside the car.
BCS did take pictures and video as well before i got the car back, i expect they will be putting them on their site too at some point.
I was certainly impressed with the system and glad i had it fitted, its the best of both worlds. If on a track day, you can disconnect the valves and retian silencing all the way through the boost range. I am considering fitting a 2-port boost solenoid so that this on/off activation can be performed from the cabin.
Hope that helps
Matt
When it comes on boost and opens the diverter valves, its not the volume of the exhaust that changes too much in the cabin, but the tone, it goes to a very deep thudding sound that you feel more than you hear. Its not the F1 screaming type sounds of yesteryear F1, but does sound similar to this years F1 cars.
However, this is all based on one drive, with only two actuatations onto boost with me in the car, so i'll give a thorough report when i get back, i'll try and get some video two to capture the noise both inside and outside the car.
BCS did take pictures and video as well before i got the car back, i expect they will be putting them on their site too at some point.
I was certainly impressed with the system and glad i had it fitted, its the best of both worlds. If on a track day, you can disconnect the valves and retian silencing all the way through the boost range. I am considering fitting a 2-port boost solenoid so that this on/off activation can be performed from the cabin.
Hope that helps
Matt
I was looking at the BCS system also but was a little concerned about how the ECU will cope with what is effectively 2 different exhaust systems. Obviously when the car is re-mapped in full "Open" un-silenced state everything will be fine but what if you run a track day with the system "Closed" in silenced mode then the breathing will be different to the "Open" map and the AFM could get screwed up?
It's probably not a big deal but thought it worth mentioning?
Thoughts anyone?
It's probably not a big deal but thought it worth mentioning?
Thoughts anyone?
I'm sure someone more knowledgable will reply.
In my mind as i understand it-
People worry about mapping after the fitment of a free flow exhaust because removing some restriction after the turbo effectively raises the boost pressure.
As its pressure dropped across the turbo which counts, so either raise the intake pressure, or drop the exhaust restriction will both give an increase in 'boost' pressure.
So if the fuelling is not matched to the new slightly raised boost pressure (more 'air' if you will) then the car may run slightly leaner, as its open loop when at WOT, and the lambda sensor is not activated to compensate. Whether this is enough to cause damage though is open to speculation. It can't be a huge effect.
Comparing a car which has been refined to run a free flow exhaust, but then has a restrictive one added, the boost pressure is effectively dropped, less air for the same amount of fuel, it'll probably run slightly richer at WOT, and as i understand it that gives reduced cylinder temperatures. How much difference this makes as a percentage though must be pretty low and within some sort of margin. After all track day silencers are added to cars at trackdays to get the noise down, with seemingly not effect on how the cars runs, just a slight reduction in performance.
Therefore in my mind, and this may not be correct and i'm happy to be corrected, there shouldn't be a problem running an 'active' car in deactivated mode at all.
Matt
In my mind as i understand it-
People worry about mapping after the fitment of a free flow exhaust because removing some restriction after the turbo effectively raises the boost pressure.
As its pressure dropped across the turbo which counts, so either raise the intake pressure, or drop the exhaust restriction will both give an increase in 'boost' pressure.
So if the fuelling is not matched to the new slightly raised boost pressure (more 'air' if you will) then the car may run slightly leaner, as its open loop when at WOT, and the lambda sensor is not activated to compensate. Whether this is enough to cause damage though is open to speculation. It can't be a huge effect.
Comparing a car which has been refined to run a free flow exhaust, but then has a restrictive one added, the boost pressure is effectively dropped, less air for the same amount of fuel, it'll probably run slightly richer at WOT, and as i understand it that gives reduced cylinder temperatures. How much difference this makes as a percentage though must be pretty low and within some sort of margin. After all track day silencers are added to cars at trackdays to get the noise down, with seemingly not effect on how the cars runs, just a slight reduction in performance.
Therefore in my mind, and this may not be correct and i'm happy to be corrected, there shouldn't be a problem running an 'active' car in deactivated mode at all.
Matt
Edited by StreetDragster on Wednesday 30th April 16:53
V1DL3R said:
Can i just clarify, is the valved opened at a certain rev range or do you have an amazing button in the cabin which opens the valve?
As Blue3R said, they open under boost pressure. However a 2 port boost solenoid, such as found on early imprezas, can be used to make it electronically activated from the cockpit active/deactivated.Matt
StreetDragster said:
This evening, i'll repeat the facebook pictures here, its too much faff trying to do it on my phone
Matt
The Facebook photos below-Matt
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