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Thinking about adding twin electric cutouts to the QV, what size are the factory exhaust pipes?
 

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👎 seriously doubt its less than 2", lol
Anyway... I was referring to the Exhaust tips which are 48mm, main piping is 67mm from memory.

I am sure you can get under the car and measure, then head to your local pepboys for the cutouts. ;)
 

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There piping is 2.5 inches I believe and I think the tips are 3 inches
 

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The pipe into the exhaust tip end (2 each side) is 48mm not referring to the end pipe diameter which is 3" yes.
 

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I'm pretty sure factory exhaust is 2.5 inches.

Most aftermarket seems to be 2.75 inches.

A few are 3 inches.
 

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I'm pretty sure factory exhaust is 2.5 inches.

Most aftermarket seems to be 2.75 inches.

A few are 3 inches.
Supersprint is same size as stock, anything larger and it becomes inefficient.
 

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No I don't. We are all learning these cars since they are so new.

Usually becomes inefficient this is why Supersprint has stated to me that they have not gone larger on the Quad exhaust. There is possible improvement with tuning of exhaust and engine but for me that's a different subject. Just throwing on a larger diameter exhaust can be inefficient unless there is extensive tuning of that exhaust involved but it makes no sense to go larger on stock. Anyway. different post I think. ;)

You know more than I do but IIRC Eurocompulsion picked up ~15hp on their tuned car by going to a 3" Centerline exhaust.
 

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Changing exhaust pipe diameter will have an effect on torque, especially lower down detriment when going larger diameter without compensating with an ECU tune. Without tune the ECU will self adjust to a degree within parameters for an upgraded air intake or an exhaust. There are lots of people who say going free flow larger diameter is the best for a turbo car but my own personal experience suggests otherwise at least in the low rpm region before the turbo has started working in the envelope of power. In terms of efficiency you will be better of sticking with factory size pipe diameter or slighlty larger if there is no choice and then removing some of the restrictons,for example a more free flowing rear silencer. Exhaust tuning is an art which can produce variable results dependant on the experience and science backed skill of the designer.
 
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