guttng cats on V12V
#17
All of this begs the question of course that if it was this straightforward to achieve these gains, why hasn't Aston just done it themselves? The obvious potential answers might be noise, consumption or emissions regulations but still, makes one wonder.
#18
Cost and emissions. Headers like the ones we're building with proper merge collectors and long-branch primaries cost a lot to build compared to what AM is fitting as standard. The removal of 4 primary catalysts in order to achieve the gains would also not come anywhere near to passing emissions. The V12V for example is borderline on emissions as-is and that is with 6 catalysts present!
#19
If this is the case, I am very interested for my DBS!! Lets hit 599 territory!
#22
Noise and emissions are always the big problem for manufacturers. With the engineering required to design a modern car, I'm sure they are well aware of what the power limits would be. In fact, the initial V12V was designed as a 600 hp car. The One77 showcases just a few of the possibilities. Realistically 510 hp out of a 5.9l engine would have been unheard of 10 years ago.
#23
Cost and emissions. Headers like the ones we're building with proper merge collectors and long-branch primaries cost a lot to build compared to what AM is fitting as standard. The removal of 4 primary catalysts in order to achieve the gains would also not come anywhere near to passing emissions. The V12V for example is borderline on emissions as-is and that is with 6 catalysts present!
Consider me in line!
#24
The V12V..or even the V12 VH platform engines(same cat locations) can have the downstream can completely removed and not cause any issues other than a lounder exhaust tone..it's been done..IT'S F*CKING LOUD!!!!!!! LOL
The cats downstream are to be fitted for again..like I've talked about on other post..the wonderful C.A.R.B law..noise pollution and emissions are the only reason they are fitted in place..but because they are so far downstream and have no solo air pump to heat them up fast at startup, they are not monitored for the results would not be steady..so the upstream cats (dude there are 4 upstream!!) are the only ones monitored.
The cats downstream are to be fitted for again..like I've talked about on other post..the wonderful C.A.R.B law..noise pollution and emissions are the only reason they are fitted in place..but because they are so far downstream and have no solo air pump to heat them up fast at startup, they are not monitored for the results would not be steady..so the upstream cats (dude there are 4 upstream!!) are the only ones monitored.
__________________
__________________
Technical Director
Christopher Edgett
Velocity Automotive Performance Limited
214 Maple Ave.
Oliver, B.C
Canada V0H 1T9
Office: (1)250-485-5126
Email: Tuning@VelocityAP.com
www.velocityap.com
__________________
Technical Director
Christopher Edgett
Velocity Automotive Performance Limited
214 Maple Ave.
Oliver, B.C
Canada V0H 1T9
Office: (1)250-485-5126
Email: Tuning@VelocityAP.com
www.velocityap.com
#25
The RSC design is way better on those V12 headers compared to the Bamford rose ones. The primaries are much longer. Even though both are Tri-Y setups (you can't really have a 6-1 header so it's by default), the RSC should provide better midrange torque with those extra long primaries, plus the packaging looks nicer as well.
If you get the V12 headers, keep the stock rear secondary cats and stock exhaust in place, you will need them to quiet things down and prevent exhaust from smelling bad.
It's interesting, the V8 headers look like a much better stock design than the V12 stock headers, they must have put the cats so far up close to the heads to heat the cats up FAST for emissions testing, then secondaries to scrub for even cleaner emissions.
You can code out the rear 02 sensors so no check engine light comes on with a performance ECU upgrade (some code them out, others don't). But sometimes some emissions shops check to see of rear 02 are live and ready, if not you will still fail the test, just FYI. At least no annoying CEL on the dash though
If you get the V12 headers, keep the stock rear secondary cats and stock exhaust in place, you will need them to quiet things down and prevent exhaust from smelling bad.
It's interesting, the V8 headers look like a much better stock design than the V12 stock headers, they must have put the cats so far up close to the heads to heat the cats up FAST for emissions testing, then secondaries to scrub for even cleaner emissions.
You can code out the rear 02 sensors so no check engine light comes on with a performance ECU upgrade (some code them out, others don't). But sometimes some emissions shops check to see of rear 02 are live and ready, if not you will still fail the test, just FYI. At least no annoying CEL on the dash though
Last edited by 007 Vantage; 10-05-2012 at 03:00 PM.
#26
The RSC design is way better on those V12 headers compared to the Bamford rose ones. The primaries are much longer. Even though both are Tri-Y setups (you can't really have a 6-1 header so it's by default), the RSC should provide better midrange torque with those extra long primaries, plus the packaging looks nicer as well.
If you get the V12 headers, keep the stock rear secondary cats and stock exhaust in place, you will need them to quiet things down and prevent exhaust from smelling bad.
It's interesting, the V8 headers look like a much better stock design than the V12 stock headers, they must have put the cats so far up close to the heads to heat the cats up FAST for emissions testing, then secondaries to scrub for even cleaner emissions.
You can code out the rear 02 sensors so no check engine light comes on with a performance ECU upgrade (some code them out, others don't). But sometimes some emissions shops check to see of rear 02 are live and ready, if not you will still fail the test, just FYI. At least no annoying CEL on the dash though
If you get the V12 headers, keep the stock rear secondary cats and stock exhaust in place, you will need them to quiet things down and prevent exhaust from smelling bad.
It's interesting, the V8 headers look like a much better stock design than the V12 stock headers, they must have put the cats so far up close to the heads to heat the cats up FAST for emissions testing, then secondaries to scrub for even cleaner emissions.
You can code out the rear 02 sensors so no check engine light comes on with a performance ECU upgrade (some code them out, others don't). But sometimes some emissions shops check to see of rear 02 are live and ready, if not you will still fail the test, just FYI. At least no annoying CEL on the dash though
I have heard from a number of sources, (including an Aston factory rep) that the only reason for the exhaust manifold design on the V12V was for quicker pre-heat of the cats for emisssions testing.
I have also learned that there is no need for any ECU tuning, as the V12V ECU is highly adaptive and will compensate for the removed cats.
Obviously the car would still fail an emissions test, but that isn't a concern here in Alberta (at the moment anyway).
I will probably try the headers without changing the factory cats & muffler system initially, just to see what decibels and sound I will initially have (I'll make some recordings for the other owners out there), and then change the cats and mufflers just to see what a full hardcore system will produce.
I've always enjoyed the initial test & tune portion of ownership on all my performance vehicles!
#28
We at Velocity are in possession of some OEM headers and will be jigging and testing very soon!
__________________
Stuart Dickinson
Managing Director
Velocity Automotive Performance Limited
206 Maple Avenue
Oliver, BC
Canada V2A 4W6
Office: (1)250-485-5126
www.velocityap.com
Stuart Dickinson
Managing Director
Velocity Automotive Performance Limited
206 Maple Avenue
Oliver, BC
Canada V2A 4W6
Office: (1)250-485-5126
www.velocityap.com