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Stainless steel exhaust front box removal  Rating:  Rating
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 Posted: 08-15-2014 10:05 am
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roland11a
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Hi, at present I'm looking to refit the stainless steel exhaust system to my JH. Unfortunately the front box after the manifold is damaged due to it grounding out on the road. Therefore I'm considering removing the front box completely and replacing it with a straight pipe. This will give the car a couple of inches increased ground clearance in the middle of the car, as we need all the ground clearance we can get over here in the UK due to the terrible state of our roads and the over use of traffic calming measures such as speed bumps.


Removing the front box can be done easily by a specialist exhaust specialists for just a few pounds, however I was wondering what effect  removing it would have on the characteristics of the whole system. I know there is more to the design of an exhaust system than meets the eye and getting it wrong can greatly effect the performance of the engine.


Any thoughts would be greatly appreciated.

Thanks Roland

Thanks Roland




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 Posted: 08-15-2014 10:18 am
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subwoofer
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On Ms Jensen there is a smallish resonator around where I would have expected a front muffler to be. As I understand it, in terms of exhaust manifold tuning you need an open volume in that spot since it effectively terminates the tuned transmission line from the head through to the rest of the exhaust system. With the resonator the only requirement for the rest of the exhaust from there and rearwards is to be low back pressure - without it the exhaust pipe all the way back to the back box becomes part of the manifold tuning system and may impact performance.

Caveat Emptor: I am no expert on exhaust systems, but knowing a little bit about transmission lines for RF the above explanation makes sense.

--
Joachim

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 Posted: 08-15-2014 03:08 pm
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Jensen Healey
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I just read an article on the subject:

http://www.popularhotrodding.com/enginemasters/articles/hardcore/0505em_exh/

The collector after the 4 into one connection is critical to maximizing performance. A resonator can be part of the collector, or, as Joachim stated, a termination box to isolate the tuned length of the collector.

Enjoy the article!

Kurt

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 Posted: 08-16-2014 11:29 pm
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roland11a
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Hi All
Thanks for the reply's. it seems that I'm destined to keep the first box after all.

A good friend in the uk sent me this article to read, so if anyone is following this thread, have a read
http://sideways-technologies.co.uk/forums/index.php/topic/1395-exhaust-tuning-theory-and-system-design/

I must admit I've learned a lot in the past couple of days!!

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