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Discussion Starter #1
Hi everyone,

I'm curious about the feasibility of the following products, and if such statements make sense.

As far as the flow of air, and exhaust gasses, I'm curious as to if an engine (petrol or diesel) would actually, feasibly, benifit from having less back pressure, or not, and if the following system, coupled with tuning/replacement cat etc, would actually perform like they claim?

Vortex Exhausts

Does anyone have any good/professional knowledge that could enlighten me, or is it all just a con and marketing?
 

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Revolution Member
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I saw the episode of wheelers and dealers where they put that vortex exhaust on the car...forgot what car it was. I always wondered if it was marketing b.s. or legit.
bump for an answer.
 

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Discussion Starter #3
I've just spoken to a chap at work, in his words, "back pressure is more work for the engine, so any decrease in back pressure is a good thing" That's all well and good, I'd still love to hear some more opinions!
 

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Aspiring Mad Scientist
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Backpressure is never good, but the need for flow velocity at low RPMs drives the need for smaller tubing that necessarily creates some backpressure. So for our NA motors we tend to keep the same piping diameter but reduce the number of turns and bends to improve backpressure and flow velocity in one move.
 

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Discussion Starter #5
How about on turbo engines, or more specifically the twin turbo diesel 3 2014?
 

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My recollection has always been that a car with some exhaust piping will generate more HP than running off straight headers. That's based on v8 engines, where having an H pipe to balance the back pressure between each side of the engine is important. With these little 4 bangers I'm not 100% sure. Would love to hear from someone with some dyno experiences...
 

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Revolution Member
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Backpressure is never good, but the need for flow velocity at low RPMs drives the need for smaller tubing that necessarily creates some backpressure. So for our NA motors we tend to keep the same piping diameter but reduce the number of turns and bends to improve backpressure and flow velocity in one move.
I remember my friend saying try blowing through different straws...to small and the force is little. To big of a straw and its also meek. A medium size straw is just optimal and the flow/force is good. Not the best description but I think I got what he mean. If I ran 1 pinch piping thats to small and car would be choked up...4 inch is overkill and the car would be laggy....2.5 inches might be just the ticket.
 

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Discussion Starter #8
After having a read around thanks to some Google results, it seems Turbo Diesel engines specifically, don't need any back pressure at all, so the whole 'vortex exhaust - sucking the gasses out' idea has some logic to it. However apparently the same can't be said for N/A petrols as they apparently 'prefer' to have 'some' back pressure.

I'd still like to hear other opinions, all input is welcome.
 

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I remember my friend saying try blowing through different straws...to small and the force is little. To big of a straw and its also meek. A medium size straw is just optimal and the flow/force is good. Not the best description but I think I got what he mean. If I ran 1 pinch piping thats to small and car would be choked up...4 inch is overkill and the car would be laggy....2.5 inches might be just the ticket.
This is the exact analogy I use. Take a coffee stir stick & a paper towel roll. Too restrictive (no flow) vs too open (still no flow). Take a regular drink straw, or one of those tapioca drink straws & you get much higher velocity.
 

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I thought I read these skyactive engines used headers to lessen backpressure and make them more efficient.
 
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