PSpirine
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| posted on 30/7/10 at 08:38 PM |
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Exhaust-less?
As the plan is still hopefully to use a turbocharged engine (TBC) in my locost build, I was wondering what the IVA outlook is on having a car with no
silencer.
I've worked on a couple of turbo (jap) cars that basically had an exhaust downpipe, approx 3" diameter and only long enough to expel
outside the nearest point of bodywork (so we're talking less than 2 foot long here), and the turbo did a bloody good job of silencing the engine
to the point that it was quieter than some NA's running with free-flowing cans...
Even my 1.9td wasn't very loud when the exhaust fell off on the motorway!
Is it a problem for Mr. SVA man, other than the db noise limit which hopefully will be containable?
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Davey D
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| posted on 30/7/10 at 08:44 PM |
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you will need a cat fitted unless your engine is old enough to not need one, and you can prove the age
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speedyxjs
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| posted on 31/7/10 at 08:11 AM |
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Your engine may not run very well without sufficient back pressure.
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Benzine
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| posted on 31/7/10 at 09:26 AM |
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quote:
Originally posted by speedyxjs
Your engine may not run very well without sufficient back pressure.
84(l< P12355l_l123
The mental gymnastics a landlord will employ to justify immoral actions is clinically fascinating. Just because something is legal doesn't make
it moral.
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smart51
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| posted on 31/7/10 at 09:31 AM |
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quote:
Originally posted by speedyxjs
Your engine may not run very well without sufficient back pressure.
F1 engines seem to manage.
I know a guy with a turbo diesel kit car (I know!) without a silencer. It is surprisingly quiet. My cappuccino came with a tiny after market
straight through silencer and it was about the same level of loudness as the kit car. I believe IVA requires you to have a silencer. You could
either try to persuade the inspector that the tubo satisfied this requirement or you could fit the smallest one you can find.
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Strontium Dog
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| posted on 31/7/10 at 11:46 AM |
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You don't need back pressure to run your engine but you might need some to prevent your turbo from over spooling! A very good waist gate to a
screamer pipe might do it though!
Mr. IVA man won't like the screamer though I suspect
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PSpirine
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| posted on 1/8/10 at 08:44 PM |
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Re back pressure, turbo engines don't need any back pressure from the exhaust system, the turbo itself creates all the backpressure into the
exhaust manifold and back to the cylinders!
Didn't realise IVA *required* a silencer to be present.. technically the turbocharger is arguably a silencer (a device which reduces the
loudness of the exhaust/engine noise?)
The wastegate is a problem indeed, but running it with an underspecced turbo for the IVA should work (won't spool up to full boost till quite
high up the rev range so hopefully not too much will be going out the waste). Having said that even if you had a full silenced exhaust system and had
an external waste gate it would still cause the same problem!
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pdm
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| posted on 1/8/10 at 08:47 PM |
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Try daz-davies at 22b.com - he's got similar thing on his subaru, under Projects.
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