Lagging a downpipe whilst still fitted to your car?
20 June 2002, 06:28 PM
#1
20 June 2002, 06:35 PM
#2
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egt wont increase.. may make the exhaust warmer further down though... you dont use repair bandage...
I would like to know the cheapest places as it seems to be about £100... also anybody know where to get the turbo wraps from cheap?
David
I would like to know the cheapest places as it seems to be about £100... also anybody know where to get the turbo wraps from cheap?
David
20 June 2002, 09:47 PM
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Cheers Guy 
Steve, its not that its cos its starting to affect my clutch resovoir so rather than rip my heatshield to bits im going to lag me pipe instead, just ordered my lagging material so hopefully will be here in a few days (saturday will be nice so i can try to fit it!)
Tony
Steve, its not that its cos its starting to affect my clutch resovoir so rather than rip my heatshield to bits im going to lag me pipe instead, just ordered my lagging material so hopefully will be here in a few days (saturday will be nice so i can try to fit it!)
Tony
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20 June 2002, 10:20 PM
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Tony,
Guy's right. I lagged mine while it was still on the car. Usual thing, seems straight forward enough but ended up being a complete pain in the ar$e to get it done.
I took the heatshield off and started the wrapping from the top. I think I jacked the car up just enough so I could slide under. I then had somebody pass the wrap down one side of the downpipe and I passed it back up the other side. It was awkward as it kept slipping about. I tied it at either end with some wire.
Later that night I could feel all my face burning as I had been lying directly beneath the wrap and I was in such a tight space I could not avoid the wrap dropping onto my face when it was passed down. LOL!!!
I can understand wrapping the downpipe as from what I have read this retains more heat in the downpipe and so allows exhaust gases to exit faster. Is this the same reason for doing the manifold? If so what are it's effects?
Damian.
Guy's right. I lagged mine while it was still on the car. Usual thing, seems straight forward enough but ended up being a complete pain in the ar$e to get it done.
I took the heatshield off and started the wrapping from the top. I think I jacked the car up just enough so I could slide under. I then had somebody pass the wrap down one side of the downpipe and I passed it back up the other side. It was awkward as it kept slipping about. I tied it at either end with some wire.
Later that night I could feel all my face burning as I had been lying directly beneath the wrap and I was in such a tight space I could not avoid the wrap dropping onto my face when it was passed down. LOL!!!
I can understand wrapping the downpipe as from what I have read this retains more heat in the downpipe and so allows exhaust gases to exit faster. Is this the same reason for doing the manifold? If so what are it's effects?
Damian.
20 June 2002, 10:33 PM
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What utter twaddle!
Surely the reason for lagging the headers and the downpipe is primarily to keep heat in the engine bay down!! so that you dont get the usual power sapping heat so soon........ and the other 0.01% is to protect certain things like the clutch reservior and the turbo, etc
As I now have an FMIC I wont be lagging my downpipe at all, as I'd be wasting monies
Surely the reason for lagging the headers and the downpipe is primarily to keep heat in the engine bay down!! so that you dont get the usual power sapping heat so soon........ and the other 0.01% is to protect certain things like the clutch reservior and the turbo, etc
As I now have an FMIC I wont be lagging my downpipe at all, as I'd be wasting monies
20 June 2002, 11:05 PM
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John
That maybe so - but thats not why people lag the exhaust and other bits in reality
Well know-one I ever knew that did it...
(You had to lag the RS Turbo as the exhaust went directly next to the starter motor and it fried it.... but many kev boy racers thought it was too much money to do this and preferred to jump start their cars....)
That maybe so - but thats not why people lag the exhaust and other bits in reality
Well know-one I ever knew that did it...
(You had to lag the RS Turbo as the exhaust went directly next to the starter motor and it fried it.... but many kev boy racers thought it was too much money to do this and preferred to jump start their cars....)
20 June 2002, 11:05 PM
#15
\m/ ^_^ \m/
20 June 2002, 11:08 PM
#16
\m/ ^_^ \m/
also you'll notice the wrc car's exhaust system is white, that'll be ceramic coating (rich man's exhaust wrap 
)
kev
)kev
20 June 2002, 11:13 PM
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If Corky Bell says it and it makes sense it is good enough for me.
"Performance of the turbine is in part determined by the temperature of the exhaust gases. It is reasonable to expend some effort toward getting the exhaust gas from the combustion chamber to the turbine with the least possible temperature loss." "....the objective is to keep heat inside the manifold...."
[Edited by john banks - 6/20/2002 11:22:37 PM]
"Performance of the turbine is in part determined by the temperature of the exhaust gases. It is reasonable to expend some effort toward getting the exhaust gas from the combustion chamber to the turbine with the least possible temperature loss." "....the objective is to keep heat inside the manifold...."
[Edited by john banks - 6/20/2002 11:22:37 PM]
20 June 2002, 11:49 PM
#19
\m/ ^_^ \m/
exhaust gas is hot. And we'd like to keep it hot throughout the exhaust system. Why? The answer is simple. Cold air is dense air, and dense air is heavy air. We don't want our engine to be pushing a heavy mass of exhaust gas out of the tailpipe
kev
21 June 2002, 08:35 AM
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OK most people lag their downpipes to reduce under bonnet temperatures but lagging the exhaust also increase the thermal retention within the exhaust pipes and subsequently expediates exhaust gas flow at a higher velocity, which increases horsepower. Albeit by a negligible amount, you would really need replacement headers (also wrapped) and the turbo thermally wrapped to see any gains.
£100 for exhaust wrap
you only need enough to do the downpipe not the whole system
£100 for exhaust wrap
you only need enough to do the downpipe not the whole system
21 June 2002, 09:26 AM
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Except replacement headers as well, or I think the lower plasticy thingy under the engine might start to sag a little. And the oil feed lines above the header melt, or at least add quite a bit of unwanted heat to the oil
I think lagging's worth it 'cos it helps keep the things that should be hot, hot, and the things that should be cold, cold (or cooler, anyway. Who knows - maybe if more pipes were lagged there'd be less engine popping going on.
I think lagging's worth it 'cos it helps keep the things that should be hot, hot, and the things that should be cold, cold (or cooler, anyway
. Who knows - maybe if more pipes were lagged there'd be less engine popping going on.
21 June 2002, 10:51 PM
#23
\m/ ^_^ \m/
i'm not expecting a massive gain, some performance would be a bonus but if you saw the state of my heatshields you'll know the main reason why i've lagged all my pipes
although less heat in the engine bay will lower intake temps, intercooler temps etc. and it all adds up
kev
although less heat in the engine bay will lower intake temps, intercooler temps etc. and it all adds up
kev
25 June 2002, 09:06 PM
#26
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I love those negligible gains me
Headers wrapped, uppipe wrapped, downpipe wrapped, turbo blanket, turbo inlet radiused, downpipe internals radiused, intercooler pipework ported and radiused, inlet manifold ceramic spacers, throttle body radiused, turbo exhaust matched to uppipe, cold air duct to air filter etc etc....
All negligible until added together........ RESULT !!
Headers wrapped, uppipe wrapped, downpipe wrapped, turbo blanket, turbo inlet radiused, downpipe internals radiused, intercooler pipework ported and radiused, inlet manifold ceramic spacers, throttle body radiused, turbo exhaust matched to uppipe, cold air duct to air filter etc etc....
All negligible until added together........ RESULT !!
26 June 2002, 02:52 PM
#30
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John Banks,
I am suprised that you neglected to quote Corky Bell thus:
"Reducing the amount of ambient air flowing around the exhaust manifold and turbocharger will further reduce heat loss from the system. It is generally not feasible to directly wrap the exhaust manifold with an insulating material as the manifold itself will overheat to the point of structural failure" (Chapter 10 Page 119 Psalm "Thermal Characteristics" ).
Mind you, didn't stop me wrapping my headers, but I expect the free flow of ambient air around them should help cool them sufficiently not to be too worried by the structural failure bit.
Steve Mc.,
You really do have a way with words!
Moray
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I am suprised that you neglected to quote Corky Bell thus:
"Reducing the amount of ambient air flowing around the exhaust manifold and turbocharger will further reduce heat loss from the system. It is generally not feasible to directly wrap the exhaust manifold with an insulating material as the manifold itself will overheat to the point of structural failure" (Chapter 10 Page 119 Psalm "Thermal Characteristics"
).Mind you, didn't stop me wrapping my headers, but I expect the free flow of ambient air around them should help cool them sufficiently not to be too worried by the structural failure bit.
Steve Mc.,
You really do have a way with words!
Moray
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