Adam
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Registered: 1st May 01
Location: Hurstbourne Tarrant
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this might help you matt
http://www.lextreme.com/Turbo.htm
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Adam
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Registered: 1st May 01
Location: Hurstbourne Tarrant
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Krisk, you got a pic of his engine?
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MattyB
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Registered: 13th Nov 01
Location: 118.5bhp :D
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quote: Originally posted by Kris TD
quote: Originally posted by MattyB
quote: Originally posted by Kris TD
erm, the air get used to combust the fuel.
So what your saying is, even without a D/V, the boost would all be released.
I know that with my D/V turned off, boost levels drop pretty rapidly anyway. So - Basically whether i have a dump valve or not, you are saying that the engine will release boost, there fore increasing lag.
Some people are also saying that ALL turbo petrols have a Dump valve as standard OR need one, but they cant explain why???
sorry but i really dont have a clue what you are asking.
the air will combust with the fuel in the engine, it doesnt just dissappear. the reason it stops boosting is because there is not as much fuel pumped into the engine, hence less air is combusted, hence less exhaust gas, hence the turbo doesnt spool.
dump valves on petrols are there to prolong turbo life and reduce stalling of the turbo.
Just to clear this up for myself more than anything.
On a petrol model, when throttle is released, butterfly closes, causing boost to store up (leads to turbo stall etc). So, is this now a sealed system? If so, how does engine get air to idle?
On a diesel engine, there is no butterfly. Instead, what, the injection pump just increases amount of diesel vapour once throttle is increased? Meaning no vacuum inside inlet manifold? If so, how come boost can still build up initially?
Matt
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Adam-D
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Registered: 11th May 02
Location: Cheshire
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i think when at idle the exhaust pressure isnt great enuff to create boost
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MattyB
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Registered: 13th Nov 01
Location: 118.5bhp :D
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yes - but where does the engine get air from to idle, if the throttle flap is closed (causing a sealed system behind it)
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Adam-D
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Registered: 11th May 02
Location: Cheshire
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the air filter?
?too simple?
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MattyB
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Registered: 13th Nov 01
Location: 118.5bhp :D
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nah - it cant, coz the butterfly is closed? But i would have thought it is still partially open, but in that case, surely boost must escape???
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Adam-D
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Registered: 11th May 02
Location: Cheshire
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perhaps it draws air from somwhere else?
the breathers in the engine maybee
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MattyB
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Registered: 13th Nov 01
Location: 118.5bhp :D
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no i doubt think - it would only ever feed in clear fresh air! Well that would make sense.
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Adam-D
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Registered: 11th May 02
Location: Cheshire
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on my petrol corsa there are two breather pipes coming from the rocker cover and they feed into the inlet manifold
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Adam
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Registered: 1st May 01
Location: Hurstbourne Tarrant
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http://auto.howstuffworks.com/engine.htm
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vibrio
Banned
Registered: 28th Feb 01
Location: POAH
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quote: Originally posted by MattyB
quote: Originally posted by Tam the diesel man
matty b what you done to get 118bhp?? you still got the standard i/c?
Fuelling and boost reset/adjusted by a derv specialist. Runs 1.1bar boost. Torque also up to 174lb/torque from 144lb/torque.
Results from stage 1 tune vary massively between engines, seen one get 121bhp on rollers, but had viper kit as well. Where as others (usually older ones), only had 114-115bhp (all on same rollers).
I've also fitted a little cheapo raid induction kit. Doubt its increased power on the rollers, but it does seem to rev a lot free-er and drive bit smoother.
Matt
closed induction kits restrict boost
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MattyB
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Registered: 13th Nov 01
Location: 118.5bhp :D
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quote: Originally posted by vibrio
quote: Originally posted by MattyB
quote: Originally posted by Tam the diesel man
matty b what you done to get 118bhp?? you still got the standard i/c?
Fuelling and boost reset/adjusted by a derv specialist. Runs 1.1bar boost. Torque also up to 174lb/torque from 144lb/torque.
Results from stage 1 tune vary massively between engines, seen one get 121bhp on rollers, but had viper kit as well. Where as others (usually older ones), only had 114-115bhp (all on same rollers).
I've also fitted a little cheapo raid induction kit. Doubt its increased power on the rollers, but it does seem to rev a lot free-er and drive bit smoother.
Matt
closed induction kits restrict boost
nope - it didnt vibs made a lovely noise (for TD) as well.
He did have the end of the pipe pulled out towards the fan (summat the rest of us cudnt do)
[Edited on 08-12-2003 by MattyB]
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vibrio
Banned
Registered: 28th Feb 01
Location: POAH
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quote: Originally posted by MattyB
quote: Originally posted by vibrio
quote: Originally posted by MattyB
quote: Originally posted by Tam the diesel man
matty b what you done to get 118bhp?? you still got the standard i/c?
Fuelling and boost reset/adjusted by a derv specialist. Runs 1.1bar boost. Torque also up to 174lb/torque from 144lb/torque.
Results from stage 1 tune vary massively between engines, seen one get 121bhp on rollers, but had viper kit as well. Where as others (usually older ones), only had 114-115bhp (all on same rollers).
I've also fitted a little cheapo raid induction kit. Doubt its increased power on the rollers, but it does seem to rev a lot free-er and drive bit smoother.
Matt
closed induction kits restrict boost
nope - it didnt vibs made a lovely noise (for TD) as well.
He did have the end of the pipe pulled out towards the fan (summat the rest of us cudnt do)
[Edited on 08-12-2003 by MattyB]
a closed induction kit restricts boost.
this is without filter
this is with an enclosed filter
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MattyB
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Registered: 13th Nov 01
Location: 118.5bhp :D
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Is that a graph for a D Turbo? In fact the one i'm talking bout? - nope
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M4rk P
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Registered: 22nd Jan 03
Location: Herts, Car:1.5tds
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quote: Originally posted by Adam
Krisk, you got a pic of his engine?
ill take a few pics tomorrow. also we looked on the inside of the manifold and there isnt a overboost valve in there either? very odd.
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vibrio
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Registered: 28th Feb 01
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no it is a pic of a turbo car and it shows whar happens when you stick one of these filters on. trust me the restrict boost
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M4rk P
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Registered: 22nd Jan 03
Location: Herts, Car:1.5tds
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quote: Originally posted by M4rk P
quote: Originally posted by Adam
Krisk, you got a pic of his engine?
ill take a few pics tomorrow. also we looked on the inside of the manifold and there isnt a overboost valve in there either? very odd.
http://groups.msn.com/markpringle/carmods.msnw?action=ShowPhoto&PhotoID=72
http://groups.msn.com/markpringle/carmods.msnw?action=ShowPhoto&PhotoID=73
http://groups.msn.com/markpringle/carmods.msnw?action=ShowPhoto&PhotoID=74
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M4rk P
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Registered: 22nd Jan 03
Location: Herts, Car:1.5tds
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sod it im gunna fit a d/v anyway. dont care if it makes the car a bit slower, ill just get a turbo back system, fit my intercooler and run higher boost . so what d/v do i need? i dont thing i need a twin cylinder one coz deisels dont run as high pressure as petrols. so a single chamber one will be ok? not getting a blow off valve coz they are £300!
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MattyB
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Registered: 13th Nov 01
Location: 118.5bhp :D
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quote: Originally posted by M4rk P
i dont thing i need a twin cylinder one coz deisels dont run as high pressure as petrols
I run 1.1 bar, which in january will be 1.3bar. They do run high boost pressures Especially once tuned
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M4rk P
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Registered: 22nd Jan 03
Location: Herts, Car:1.5tds
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so you think i will need one with 2 chambers? the bloke in the shop said if the single one is gash then i change it for the other. trial and error i spose.
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Adam
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Registered: 1st May 01
Location: Hurstbourne Tarrant
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mine runs 1.1 bar or so hapily withour need for a dv
Mark - Was that car a TD from the factory? cos the bottom 1/2 of the plenum chamber is the same as a non Turbo one
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M4rk P
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Registered: 22nd Jan 03
Location: Herts, Car:1.5tds
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it says its a td in the log book?
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Adam
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Registered: 1st May 01
Location: Hurstbourne Tarrant
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here's my safety
http://www.adampetherick.co.uk/images/Parts/Head/head5.jpg
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M4rk P
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Registered: 22nd Jan 03
Location: Herts, Car:1.5tds
User status: Offline
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is that inside the manifold
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