Decatting a sport
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Decatting a sport
I don't want any of the don't bother buy a turbo comments...
Dose anyone know of any potential problems with starting my exhausts mods from the front of the car and working back.
I have been offered a front decat pipe for a swap with a front cat.
Will this do anything for my car as the rest of the exhaust system is completely standard? It is the correct pipe for a sport and so should just bolt on in place of the front cat. I am not expecting huge power gains of mass amounts of exhaust noise. But as this is a swap, I felt it was not worth missing the opertunity of starting my exhaust upgrades. In the long run I will probably do the back box, and if I can stand the nise will do the second decat pipe.
All I want to know really is, am I going to do any damage by replacing the front cat Prioir to doing the rest of the exhaust?
Dose anyone know of any potential problems with starting my exhausts mods from the front of the car and working back.
I have been offered a front decat pipe for a swap with a front cat.
Will this do anything for my car as the rest of the exhaust system is completely standard? It is the correct pipe for a sport and so should just bolt on in place of the front cat. I am not expecting huge power gains of mass amounts of exhaust noise. But as this is a swap, I felt it was not worth missing the opertunity of starting my exhaust upgrades. In the long run I will probably do the back box, and if I can stand the nise will do the second decat pipe.
All I want to know really is, am I going to do any damage by replacing the front cat Prioir to doing the rest of the exhaust?
Whilst I have no specific experience of decating a sport:
Exhaust tuning on any N/A is a slightly different kettle of fish from a forced induction item.
It is possible to actually reduce your max power output by installing a completely free flow system. This is oftendue to the original item having the ability to reflect pressure waves back to the head and produce a small pressure charge like effect at the cylinders.
Having said this the result will depend on many factors, not least of which is the quality of the original design. If the original design is merely restictive alone you are likely to increase max power, however even in this situation you may find that it is at the expence of bottom end torque due to the reduced back pressure.
The short answer to your question specifically is, no there is no real reason AKAIK why you should start at the cat and work back as long as the replacement part still has the lambda sensor in the same place etc etc. Your real issue comes with what exactly you are trying to achieve and how much good the original design is.
It's for these reason that replacing the backbox is such a winner. Yuo can be reasonably sure your going to get a nicer sounding note, reduced restriction overall (so potentially higher bhp) but not at the expense on any exhaust tuning designed in by the manufacturer which is generally done nearer the head.
Exhaust tuning on any N/A is a slightly different kettle of fish from a forced induction item.
It is possible to actually reduce your max power output by installing a completely free flow system. This is oftendue to the original item having the ability to reflect pressure waves back to the head and produce a small pressure charge like effect at the cylinders.
Having said this the result will depend on many factors, not least of which is the quality of the original design. If the original design is merely restictive alone you are likely to increase max power, however even in this situation you may find that it is at the expence of bottom end torque due to the reduced back pressure.
The short answer to your question specifically is, no there is no real reason AKAIK why you should start at the cat and work back as long as the replacement part still has the lambda sensor in the same place etc etc. Your real issue comes with what exactly you are trying to achieve and how much good the original design is.
It's for these reason that replacing the backbox is such a winner. Yuo can be reasonably sure your going to get a nicer sounding note, reduced restriction overall (so potentially higher bhp) but not at the expense on any exhaust tuning designed in by the manufacturer which is generally done nearer the head.
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I took part in a sport rolling road day a couple of months ago, and it did seam that the cars with full decats were putting out the most power. (Except mine which is an automatic and so seamed to confuse the rollers and came out with a staggering 135.5BHP with just a green cotton air filter on the engine mods side. Only beaten by 139BHP from a MY00 phase2 engine, with full decat, magnex back box, and K&N induction kit)
It also showed that improving the air filter side of things gives a better gain than just doing a back box but both together, gave good improvement. I believe that there is enough back pressure produced by the headers alone to keep the engine relatively happy, so it was more a case of "Could damage be caused by doing a front decat before the 2nd?" Just it seams that everyone starts at the rear of the exhaust system and works forward .
It also showed that improving the air filter side of things gives a better gain than just doing a back box but both together, gave good improvement. I believe that there is enough back pressure produced by the headers alone to keep the engine relatively happy, so it was more a case of "Could damage be caused by doing a front decat before the 2nd?" Just it seams that everyone starts at the rear of the exhaust system and works forward .
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Can you have the motor chipped to run with 1 or no cats...I don't know of a chip for the Sport, but one could be available. Getting the car to run perfectly on fuel mix is key with your setup of filter and cats removal. I would expect more fuel is required due to the free flowing changes.
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I know someone has had a chip fitted to a MY00? Sports special edition. Don't think it did much for the power output, and not sure what exhaust/induction setup they were running. But I think it had a good effect on the fuel consuption particuallry at the top end of the rev range where Subaru tend to overfuel but quite a high degree.
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