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Howdy,
Can someone enlighten me as to why some exhaust experts recommend an amount of backpressure in an exhaust? I've got a 186 (3spd manual) which I have the option of plumbing into my existing twin 2 inch system, or just 1 side, to make a single 2 inch. Which will be most efficient (economical) for my daily driver...? Ta.
The Beige Hornet.
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If you look at your cam shaft timing you will see that there is a period of time that both the exhaust and inlet are open at the same time. This is so that the incoming clean air helps expell the last of the burnt air.
Without back pressure too much of
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Thats an interesting thery Warren. I wouldn't like to argue the point on that.
I've always run nice free flowing exhaust looking for HP, although I'm always seaching for the best comprimise for HP with accectable fuel economy.
The Lobe Centre Angles are
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Don't do twin 2" pipes on a 186...there won't be enough backpressure and you'll lose torque (as explained by Warren above) and, on the street, torque is KING.
Cheers...Dave
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If you are serious about getting the best possible exhaust system then take the time to study exhaust design. There are plenty of books on the subject plus a lot of information on the net.
It is not just a simple matter of getting a certain size pipe
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To answer this question in a simple manner...
1. If the motor is stock then you'll be happy with either a single 2" or 2 1/4" pipe as backpressure and flow will be at optimum (the latter producing more horsepower but similar torque).
2. If the mot
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I hate the term back pressure...gets bandied around too much.
Pressure = resistance to flow.
An exhaust is more than just a pipe to get exhaust gas to the back of the car...It aids in scavenging (dreawing the fresh air into the cylinder on overlap)
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This article is about motor bikes but it is basicaly the same for cars Understanding Exhaust:
The How & Why
No exhaust system is ideal for all applications. Depending on their design and purpose,
all exhaust systems compromise something to achieve s
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Wow, Paul...that's a great read. Thanks
Cheers...Dave
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I think the last sentence of that explanation sums it up nicely which is why I suggested he study exhaust systems first if he wants to get the best out of them. The same thing applies to any other part of a car if you want to modify it.
For every goo
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As Brian said there is a lot too the right system. You even have to consider what the enigne is doing right from the intake and match from there if you are going to get the maximum effect.
Warren
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The main thing I always wanted from my exhaust was the right note to be coming out the back at all revs and an easy way to get the front pipes off and out of the way at the drags. Maybe Im just a **** but it always gave me great pleasure at the drags or t Edited by user Monday, 25 December 2006 1:23:43 AM(UTC)
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I read a book power and economy (what) Any way it said about the wave that goes down the exhaust and over the balance pipe and up the other pipe. If it arrived as the exhaust valve opened it would cause a low pressure area to which the exhaust would come |
If its not broke it will be soon |
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As always a wealth of knowledge guys. I know I could get more with more research but I've got a brand new twin 2" system under the car, so I guess I'll just use one side. It's only a stock motor & a daily driver, & using that system is cheaper than the di
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