Saint.V8 said:
I am not gonna enter the argument (this has been through the ringer a number of times previous) - I just want to check something.....

You said the Recirc. air goes through the intercooler.....I thought the charged air goes through the intercooler first, then picks up the recirc air from the EGR then into the manifold...???

Or am I wrong and the charge air goes throught the EGR first then into the intercooler before being inducted through the manifold..!!??
Click to expand...

That was not what i was saying. The air goes through the EGR valve after it has been through the intercooler. What i was saying is that the airflow restriction of a blocked off EGR valve makes little or no difference to the amount of air entering the engine. So buying a £50.00 bypass unit is a waste of money.
 
Not you Tony - it was a response to Paul D, he said (subsequently he corrected himself) that the charge air is fed to the EGR before the intercooler.....I was questioning that statement, not yours..!!:)
 
Saint.V8 said:
Not you Tony - it was a response to Paul D, he said (subsequently he corrected himself) that the charge air is fed to the EGR before the intercooler.....I was questioning that statement, not yours..!!:)
Click to expand...

Ok Ant i was replying to the post before mine. About removing restriction. The restriction left after blocking an EGR valve is neither here nor there on a turbo charged engine. The manifold will always be pressured the main restriction to air flow is then the inlet tract and the inlet valve itself. The EGR valve internals unless clogged with **** pose no real airflow restriction. Not one that will cause any performance increase by removing it. So those who pay silly money for an EGR block and bypass unit do so for naught. They read (and believe) to many adverts basically.
 
wammers said:
The restriction value of the EGR valve is much over stated unless it is clogged solid. The only time removal of restriction would have much effect is at low RPM when turbo pressure is low. At all other times air is being blown into the engine and providing the intercooler is clear the engine will never lack air.
Click to expand...

Not totally true! Traditional tuning techniques still apply to turbo charged engines ie. gas flowing heads and manifolds, free flowing exhausts etc. so removing any restriction is likely to improve air flow, even pressurised. To increase cylinder charge.
 
When I blanked my 300tdi it made bugger all difference! When I did my td5 the turbo seemed to spin up a smidge quicker but it was very minimal! It also seemed a bit more willing to rev at the top end, again minimal. Over all benefit not a lot but I'd say more than on a 300tdi on which there is no restriction.
 
Diesel Do said:
Not totally true! Traditional tuning techniques still apply to turbo charged engines ie. gas flowing heads and manifolds, free flowing exhausts etc. so removing any restriction is likely to improve air flow, even pressurised. To increase cylinder charge.
Click to expand...

We are not talking race tuning here, we are talking a road going diesel engine. Removing whats left of the EGR valve will do diddly squat for the engine performance.
 
Diesel Do said:
When I blanked my 300tdi it made bugger all difference! When I did my td5 the turbo seemed to spin up a smidge quicker but it was very minimal! It also seemed a bit more willing to rev at the top end, again minimal. Over all benefit not a lot but I'd say more than on a 300tdi on which there is no restriction.
Click to expand...

The turbo will spin up quicker because removing the EGR gas allows more Oxygenated air in, bigger bang, more exhaust gas to spin turbo. The idea of an EGR valve is to reduce the oxygen content of the charge therefore reducing the burn temperature and cutting down the production of NOX.
 
.. and I'll get the route wrong and ask for a map .. ;)
 
wammers said:
The turbo will spin up quicker because removing the EGR gas allows more Oxygenated air in, bigger bang, more exhaust gas to spin turbo. The idea of an EGR valve is to reduce the oxygen content of the charge therefore reducing the burn temperature and cutting down the production of NOX.
Click to expand...

Possibly when cruising at a constant throttle then accelerating but at most other times the egr should be closed!
 
Diesel Do said:
Possibly when cruising at a constant throttle then accelerating but at most other times the egr should be closed!
Click to expand...

It will spin quicker at all times when the EGR valve would normally be open. With the EGR open less exhaust gas is produced.
 
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