Hi, can anyone help with a little experiment? Mainly for people who have deleted their EGR valve, removed it and still have it sat on a shelf gathering dust.
Research shows that deletion of the EGR, while cleaning up the engines combustion cycle, causes raised EGT's. In the 1kz surf anyway.
This is due to the restriction caused by the big butterfly in the throttle body.
It is there to provide a safety shut off in the case of runaway but also to give some vacuum for the EGR to suck in from the exhaust. (The EGR port sits just below the butterfly).
The engine expects to see a certain amount (volume) of mixed air and exhaust gasses for the combustion cycle. By blanking the intake side of the EGR and not removing the butterfly you are preventing the correct volume of gasses entering the chamber. There is oxygen to burn in the exhaust gasses going in after all and the engine has no way to feed back this kind of unbalance because there is no O2 sensor in the system. No negative feedback at all in fact.
Problem with deleting the EGR is that this butterfly is then still causing a restriction in the intake. Causing a vacuum for a system no longer active. Result seems to be raised EGT's due to a lower volume of air/gasses available to the combustion cycle.
Thats the known effect people speak about. You can extrapolate other negative effects from that like engine wear, hot spots on pistons and reduced efficiency.
My thought is this:
Rather than delete the EGR valve with a couple of plates and a ballbearing why not reroute it and feed it cold air? Blank the exhaust side and either plumb the EGR pipe into the airbox or stick a decent breather filter on the end of it? This is just an idea I want some opinion on. Not something I know has or can be done..
Prospective result? Engine gets the volume of air it expects to get, the restriction of the butterfly is negated and your combustion cycle is now cleaner and fully loaded with air.
Result of that? Throttle response increased, lower EGT's and possibly better mpg?
So. I deleted mine ages ago and chucked the bits.... Since then I have an EGT gauge fitted and fancy testing this hypothesis out.
With real world readings I can see if its a valid modification or not.
I need the EGR bits from a factory intercooled 1KZ, or any 1KZ to bolt back on and feed cold air instead of exhaust gasses. I will then compare readings from the EGT gauge and maybe a couple of dyno runs as I live two miniutes away from powerstation in tewkes.
Now normally I would say deleting the EGR was enough. Stop at that point. But the surf engine has two sides to the EGR and without addressing the side effects caused by ignoring the other side I think we might be suffering for it.
Anyone got an EGR for scooby snacks and thanks so I can test this idea out?
And does anyone have an opinion on this? Is it sound or am I barking?
Research shows that deletion of the EGR, while cleaning up the engines combustion cycle, causes raised EGT's. In the 1kz surf anyway.
This is due to the restriction caused by the big butterfly in the throttle body.
It is there to provide a safety shut off in the case of runaway but also to give some vacuum for the EGR to suck in from the exhaust. (The EGR port sits just below the butterfly).
The engine expects to see a certain amount (volume) of mixed air and exhaust gasses for the combustion cycle. By blanking the intake side of the EGR and not removing the butterfly you are preventing the correct volume of gasses entering the chamber. There is oxygen to burn in the exhaust gasses going in after all and the engine has no way to feed back this kind of unbalance because there is no O2 sensor in the system. No negative feedback at all in fact.
Problem with deleting the EGR is that this butterfly is then still causing a restriction in the intake. Causing a vacuum for a system no longer active. Result seems to be raised EGT's due to a lower volume of air/gasses available to the combustion cycle.
Thats the known effect people speak about. You can extrapolate other negative effects from that like engine wear, hot spots on pistons and reduced efficiency.
My thought is this:
Rather than delete the EGR valve with a couple of plates and a ballbearing why not reroute it and feed it cold air? Blank the exhaust side and either plumb the EGR pipe into the airbox or stick a decent breather filter on the end of it? This is just an idea I want some opinion on. Not something I know has or can be done..
Prospective result? Engine gets the volume of air it expects to get, the restriction of the butterfly is negated and your combustion cycle is now cleaner and fully loaded with air.
Result of that? Throttle response increased, lower EGT's and possibly better mpg?
So. I deleted mine ages ago and chucked the bits.... Since then I have an EGT gauge fitted and fancy testing this hypothesis out.
With real world readings I can see if its a valid modification or not.
I need the EGR bits from a factory intercooled 1KZ, or any 1KZ to bolt back on and feed cold air instead of exhaust gasses. I will then compare readings from the EGT gauge and maybe a couple of dyno runs as I live two miniutes away from powerstation in tewkes.
Now normally I would say deleting the EGR was enough. Stop at that point. But the surf engine has two sides to the EGR and without addressing the side effects caused by ignoring the other side I think we might be suffering for it.
Anyone got an EGR for scooby snacks and thanks so I can test this idea out?
And does anyone have an opinion on this? Is it sound or am I barking?
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