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bs0u0155 · 09-07-2010, 02:22 PM

Don
I was thinking exactly that this morning.
I was also wondering about the best location for the catalytic converter (if fitted). One assumes that turbocharger turbine stages work best with the best pressure/temperature gradient across them. So the quieting effect of the turbo allowing the removal/simplification of the muffler setup is very handy. In addition, you may be able to loose some of the weight gained in the turbo.

Perhaps adding a catalytic converter ahead of the turbo would place it in a high temperature/high pressure environment created by the turbocharger's back pressure therefore speeding up warm-up time and increasing efficiency with regard to the pressure. Also loosing the cat from behind the turbo may give some gains.

Perhaps the biggest problem to overcome is the ducting. Getting a large duct from the engine bay to a situation where it can deliver air in a large car-rear-sized square isn't going to be particularly easy. In my car there is certainly space to run it under the dashboard, around the gear lever and around the handbrake. Then it would have to go up over the fuel tank through the back seat and across the boot floor to the hatch back. Then some form of sealed duct built into the hatch which would interface with the boot floor duct. All quite difficult and a potentially tortuous air path, and to be usefully non-draggy, the duct has to be quite big.... 3" diameter?

An alternative would be to simply vent the turbo into the car interior, then create "exit" holes around the hatch perimeter. Simple, but how would the interior react to having a lot of air vented into it which may be hot from compression or cold from a cold exterior.

Another alternative, which is quite simple would be to only address the bottom of the car, simply run a duct paralell to the exhaust and have (both?) feed a lower trailing edge extension. Sort of a "blown diffuser" if there are any F1 fans in.

A simple experiment could be to build the rear perimeter ducts and have them open to the interior then simply give the heater fan everything and look for small changes. An electrical load control would be needed of course, but probably easily achievable with combinations of non-fan interior devices.

I wonder if the many interior channels of coroplast make it the ideal material to go around the perimeter? :-)

With regard to the "STS" remote turbos, they gain points for not having any specific manifold/header modifications but loose them for efficiency and they retain the ducting problem, just on the suction side.

09-07-2010, 02:22 PM	#10 (permalink)
bs0u0155 EcoModding Lurker Join Date: Apr 2010 Location: Liverpool, UK Posts: 16 Thanks: 0 Thanked 0 Times in 0 Posts	Don I was thinking exactly that this morning. I was also wondering about the best location for the catalytic converter (if fitted). One assumes that turbocharger turbine stages work best with the best pressure/temperature gradient across them. So the quieting effect of the turbo allowing the removal/simplification of the muffler setup is very handy. In addition, you may be able to loose some of the weight gained in the turbo. Perhaps adding a catalytic converter ahead of the turbo would place it in a high temperature/high pressure environment created by the turbocharger's back pressure therefore speeding up warm-up time and increasing efficiency with regard to the pressure. Also loosing the cat from behind the turbo may give some gains. Perhaps the biggest problem to overcome is the ducting. Getting a large duct from the engine bay to a situation where it can deliver air in a large car-rear-sized square isn't going to be particularly easy. In my car there is certainly space to run it under the dashboard, around the gear lever and around the handbrake. Then it would have to go up over the fuel tank through the back seat and across the boot floor to the hatch back. Then some form of sealed duct built into the hatch which would interface with the boot floor duct. All quite difficult and a potentially tortuous air path, and to be usefully non-draggy, the duct has to be quite big.... 3" diameter? An alternative would be to simply vent the turbo into the car interior, then create "exit" holes around the hatch perimeter. Simple, but how would the interior react to having a lot of air vented into it which may be hot from compression or cold from a cold exterior. Another alternative, which is quite simple would be to only address the bottom of the car, simply run a duct paralell to the exhaust and have (both?) feed a lower trailing edge extension. Sort of a "blown diffuser" if there are any F1 fans in. A simple experiment could be to build the rear perimeter ducts and have them open to the interior then simply give the heater fan everything and look for small changes. An electrical load control would be needed of course, but probably easily achievable with combinations of non-fan interior devices. I wonder if the many interior channels of coroplast make it the ideal material to go around the perimeter? :-) With regard to the "STS" remote turbos, they gain points for not having any specific manifold/header modifications but loose them for efficiency and they retain the ducting problem, just on the suction side.