How many run without EGR?

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supramad77

supramad
Feb 5, 2006
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Ok my first HG failed on mine at 24k. The car was totaly stock and fully maintained by Toyota. So why did my HG fail? The car could not even handle stock boost with all the parts fitted that it left the factory with.
 

jdub

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john93t;1136520 said:
If you guy's want/need EGR's why not ask on www.mkiiisupra.net (uk supra site)..i think i might have a couple laying around,

How about facts vs comment like this?
You're whole argument is based on speculation.

john93t said:
we removed them because ....(a) we don't need them, and it's an ugly critter to have under the hood..(b) because the passage for the exhaust gas from number 6 cylinder run's around the back of the head to the egr unit (this is direct heat to the rear of the head, not radiant heat)..and there were alot of bhg on number 6 cylinder..

More of the same...figgie covered it quite nicely.

john93t said:
i think one of you guy's asked if uk supras had egr's fitted as "standard"?..yes they were, toyota also supplied our supra's with the head torqued to 55ft/lb as "standard"...this was no good either:biglaugh:

This comment is absurd...you're trying to correlate head bolt torque to the EGR.
What I was getting at is UK Supra's have the same ECU as USDM. It's tuned for the EGR, both fuel and timing...the EGR also causes air to be displaced in the cylinders, which means more O2 in the combustion chamber if it's removed.

supramad77;1136530 said:
So why did my HG fail? The car could not even handle stock boost with all the parts fitted that it left the factory with. So I took the EGR off to make sure it will happen again.

Fixed that for ya ;)


Your UK gang can believe whatever you want...personally, I'm tired of repeating myself. So, take your car over to Dover and make a statement by driving it off a cliff for all that I care. I'm done dealing with the hearsay and "common knowledge" that keeps getting spewed around the bar like so much bad beer.
 

supramad77

supramad
Feb 5, 2006
331
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Dartmouth, Devon, UK
jdub;1136538 said:
How about facts vs comment like this?
You're whole argument is based on speculation.



More of the same...figgie covered it quite nicely.



This comment is absurd...you're trying to correlate head bolt torque to the EGR.
What I was getting at is UK Supra's have the same ECU as USDM. It's tuned for the EGR, both fuel and timing...the EGR also causes air to be displaced in the cylinders, which means more O2 in the combustion chamber if it's removed.



Fixed that for ya ;)


Your UK gang can believe whatever you want...personally, I'm tired of repeating myself. So, take your car over to Dover and make a statement by driving it off a cliff for all that I care. I'm done dealing with the hearsay and "common knowledge" that keeps getting spewed around the bar like so much bad beer.


No need to be an ass about it. For your info i never removed it. It was taken of by people who know a hell of a lot more about enigines that i ever will.

Still does not explain why it went the first time so no need to try a make me look a twat.
 

BillyM

MK2 + 7M = FUN
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Ok ok, lets get this thread back on track...

Figgie, Jdub, Jetjock, you guys know the mk3 ecu's far better than I, but look over this and tell me what you think...

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Q: What is a situation where the stock ECU were retained, but EGR should be removed or disabled.
A: When converting your car to a map-based airflow calculating piggyback.

It is likely the ECU relies simply on the AFM to dictate changes to the fueling and timing during EGR use. A MAP-based system will have no way of differentiating between air flow and EGR flow.

I will lay out a couple of scenarios:

Scenario 1: Cruising down road at a constant speed, no EGR
Stock AFM - 10inches of vacuum (manifold pressure), 50hz AFM frequency to ecu
HKS VPC - 10inches of vacuum, the vpc is outputting 50hz AFM frequency to ecu

Scenario 2: Cruising down road at the same speed, but with EGR full open...
Stock AFM - 7 inches of vacuum (manifold pressure), 50hz AFM frequency to ecu
HKS VPC - 7 inches of vacuum, the vpc is now outputting 75hz AFM frequency to ecu

In both scenarios the engine is taking in the same ammount of oxygen, the stock AFM'd car is able to realize the actual FRESH airflow and differentiate between the volume (and its resulting affect on manifold pressure) with and without EGR, whereas the map-based system simply sees the manifold pressure change. It (and thusly the ECU) has no way of knowing the EGR valve is supplying non-oxygenated air volume and will thusly run rich and possibly advance timing.

----------------------------------------------------------------------------------------------------------------------

...just brainstorming, but I respect your guys' input and experience, let it hang out.

--billyM
('84 Supra, FFIM, VPC, NoEGR, 23-25mpg mixed-driving, 26-27 all highway average, on 4.30 rear end)
 
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figgie

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supramad77;1136562 said:
...It was taken of by people who know a hell of a lot more about enigines that i ever will.

Apparently not by much. They might know "engines" but they do not know the 7m well, otherwise they would know NOT to remove the egr system ;)
 

jdub

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supramad77;1136562 said:
No need to be an ass about it. For your info i never removed it. It was taken of by people who know a hell of a lot more about enigines that i ever will.

Still does not explain why it went the first time so no need to try a make me look a twat.

So, I'm an ass because I'm sick and tired of all the crap people like you post as "facts". I can't help that you (and your buddies) choose to live in ignorance. I guess that's why you have to call people names that point it out to you.

Don't have to make you look like anything...you're doing a fine job of that all by yourself.
 

figgie

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BillyM;1136565 said:
Ok ok, lets get this thread back on track...

Figgie, Jdub, Jetjock, you guys know the mk3 ecu's far better than I, but look over this and tell me what you think...

Q: What is a situation where the stock ECU were retained, but EGR should be removed or disabled.
A: When converting your car to a map-based airflow calculating piggyback.

It is likely the ECU relies simply on the AFM to dictate changes to the fueling and timing during EGR use. A MAP-based system will have no way of differentiating between air flow and EGR flow.

I will lay out a couple of scenarios:

Scenario 1: Cruising down road at a constant speed, no EGR
Stock AFM - 10inches of vacuum (manifold pressure), 50hz AFM frequency to ecu
HKS VPC - 10inches of vacuum, the vpc is outputting 50hz AFM frequency to ecu

Scenario 2: Cruising down road at the same speed, but with EGR full open...
Stock AFM - 7 inches of vacuum (manifold pressure), 50hz AFM frequency to ecu
HKS VPC - 7 inches of vacuum, the vpc is not outputting 75hz AFM frequency to ecu

In both scenarios, the stock AFM'd car is able to realize the actual FRESH airflow and differentiate between the volume (and its resulting affect on manifold pressure) with and without EGR, whereas the map-based system simply sees the manifold pressure change. It (and thusly the ECU) has no way of knowing the EGR valve is supplying non-oxygenated air volume and will thusly run rich and possibly advance timing.

...just brainstorming.

--billyM
('84 Supra, FFIM, VPC, NoEGR, 23-25mpg at each mixed-driving, and 26-27 at each highway fill-up, with 4.30 out back...)

Nope.

The reason. The "piggy backs" regardless of manufacture or load sensing type (MAF, MAP, AFM) rely on the stock TCCS for the closed loop portions. Anytime a piggy back attempts to adjust the closed loop mapping. The TCCS comes back in and readjust everything to match what it was programmed with. It is really an excersice in futility to try to adjust any of the close loop portion of the TCCS.

The low load portion lands squarely on the closed loop portion of the TCCS. So that means how every you try to adjust it, the TCCS is STILL expecting the EGR to be there. So that statement with what we know now a days, is FALSE. Also as you have concluded, MAP based system sense pressure, EGR being injected into the manifold will increase pressure, on a MAP based system it will think that load is increasing when it is not :) The final result will be the engine running rich because of the "infered load increase".
 

jdub

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frontierguy - If you run an AEM EMS, you have control over timing and fuel. You do not have to install an EGR unless you want to help the gas mileage.

Billy - The piggyback fuel/MAP computers do not allow timing to be changed. You will be forced to run rich to get the same effect as the EGR.
 

supramad77

supramad
Feb 5, 2006
331
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Dartmouth, Devon, UK
jdub;1136568 said:
So, I'm an ass because I'm sick and tired of all the crap people like you post as "facts". I can't help that you (and your buddies) choose to live in ignorance. I guess that's why you have to call people names that point it out to you.

Don't have to make you look like anything...you're doing a fine job of that all by yourself.

Whatever dude i guess we just don't agree. No point in slagging each other of. It's just a discussion at the end of the day and we all have different opinions. Right or wrong.
 

figgie

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supramad77;1136578 said:
Whatever dude i guess we just don't agree. No point in slagging each other of. It's just a discussion at the end of the day and we all have different opinions. Right or wrong.


In this case it will be wrong on your part, but hey. It is your belief (like my previous pixie dust comments) and in the end, it is your car to do as you please.
 

jdub

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I'm still thinking a trip to Dover. It would be a spectacular video with the White Cliffs in the background :evil2:
 

supramad77

supramad
Feb 5, 2006
331
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Dartmouth, Devon, UK
figgie;1136592 said:
In this case it will be wrong on your part, but hey. It is your belief and your car to do as you please.

No not really my belief, the belief of the guys who did the work. I am a house builder at the end of the day i have little knowledge of engine building.
Just seems strange that we have such different ideas on what is right or wrong between the two clubs.
 

figgie

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supramad77;1136599 said:
No not really my belief, the belief of the guys who did the work. I am a house builder at the end of the day i have little knowledge of engine building.
Just seems strange that we have such different ideas on what is right or wrong between the two clubs.

In that case.

Touche!

Now. Our facts are based on the TCCS itself. See 3p's reverse engineer of the TCCS for that which is located inside the build sub-forum. Those are facts not beliefs ;)

Anything that deviates from how the TCCS was programmed is nothing but an fairy tales and since the TCCS was not programmed that way, makes it for a very suspect opinion. :)

Computers are really straight forward.

They either do something or not. No inbetween and definetly no room for "interpretation". :)
 

HommerSimpson

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my block was dead ass strait... sept for #6 cly around the back...

I would think the gasses passing threw the back of the head makeing the head and block hotter in that area is why...

Seams lota people think on that line to...

on a bone stock car... no matter what car... I would leave it on and working as it was desigend to do...

once the factory aircleaner and rest of polution stuf gone. aka the cat...

I dont see a need for it at all..

But hey thats just my Opinun..
 

figgie

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HommerSimpson;1136611 said:
I would think the gasses passing threw the back of the head makeing the head and block hotter in that area is why...

Seams lota people think on that line to...

So what makes the Exhaust gas back there any different or HOTTER than what the physical exhaust port or combustion chamber is actually seeing?

The answer. It is not. It is a belief and nothing else. The cooling capacity of the OEM system is more than adequate in cooling the EGR.

btw. People are stupid. They tend to do the monkey see monkey do without questioning it. There is proof of that in this thread. ;)
 

HommerSimpson

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figgie;1136621 said:
So what makes the Exhaust gas back there any different or HOTTER than what the physical exhaust port or combustion chamber is actually seeing?

The answer. It is not. It is a belief and nothing else. The cooling capacity of the OEM system is more than adequate in cooling the EGR.

btw. People are stupid. They tend to do the monkey see monkey do without questioning it. There is proof of that in this thread. ;)



so you are saying that it does not run hotter around the back of #6 cly ?

ROFLMAO

ok try taking a temp gun to it... commen sence would tell you that it does...mater fact any car on any intake on any head... that cly always runs hotter...

go pop hood on a brand new car...

look at egr... look at intake... notice a color diferance ? thats called HEAT
 
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