How many run without EGR?

[jdub]

never mind, you'll get better soon, oh and take some pills for that headache :biglaugh:

c-ya

You guys really can't do any better than that...innuendo, sarcasm, the "duck & cover", that's it. No facts...just belief.

BTW - mechanics are some of the world's worse when it comes to belief. If you press for an answer why, they will come up with some conjecture like the "EGR cooler theory"...that can't be proved. You should hear the ones on motor oil...it's incredible what people will believe.

 

[figgie]

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

NOPE.

EGT measured in the Combustion Chamber hover around 800c degrees. At that point the heat transfer from the hot gases to the head is at it's greatest. Exhaust valves and surrounding port also see around 700c degree at that point. Back of EGR cooler is seeing at MOST 400c and I am going to go out on a limb and say not even close to that temprature.

You logic is flawed anyway as the highest tempratures AND pressure are within the combustion chamber. No where else, to include the EGR cooler, sees "pressure" of that magnitude.

So care to grab another straw?

ROFLMAO indeed.

 

[HommerSimpson]

no need to.... you are wrong if you think that area in the back of the head that the exh goes threw to the egr valve is same temp or even close to same temp as reast of head...

 

[figgie]

no need to.... you are wrong if you think that area in the back of the head that the exh goes threw to the egr valve is same temp or even close to same temp as reast of head...

Actually they are not. The EGR cooler temps are NO WHERE NEAR what the head is seeing CONSTANTLY. For you to think otherwise is short of ignorant.

So keep grabbing, they are still plenty of other straws to grab.

 

[Zumtizzle]

hommer stop while you're behind.

figgie is the godfather to the E85 Supra, and wiring.

So i take: he knows a thing or two.

 

[Poodles]

The back of the head IS hotter, but NOT because of the EGR. It's the farthest from the heat exchanger (radiator), nothing more.

This is why companies in Japan made coolant bypasses to the back of the block to keep it cool back there. Why would they do that if it was the EGR? Oh wait...they didn't have EGR!

 

[BillyM]

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".

...but the questions comes down to this:

Is it better for the VPC setup to feed an incorrectly RICH reading to the ecu when the EGR is open than to do without EGR all together?

--billyM

 

[IJ.]

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..

And what have you done to combat the Light throttle light load Lean condition that happens when the US ECU thinks the EGR system is in place?

Yet again you have "modded" your car in the belief that Toyota got it wrong and you're right.

Now you have people that actually understand how the system works and why it works telling you it's a bad idea but you're arguing because you "know".

Last time this happened and I gave you a week off you swore that you were never going to post on SM again and went off to SF and bad mouthed SM to anyone stupid enough to listen to you.

You lasted a week there before they nailed you and then tore you to pieces in Off Topic about your butchered dash, you come back here post a couple of feelers then when you think you're secure you start the shit again.

Do us a favour and just SHUT THE FUCK UP I won't let you derail another thread.

EVERYONE ELSE: Keep it civil this is no idle threat.

 

[figgie]

...but the questions comes down to this:

Is it better for the VPC setup to feed an incorrectly RICH reading to the ecu when the EGR is open than to do without EGR all together?

--billyM

well it depends.

The richness will take care of the NOx production and as such lower cylinder temps BUT that will also deviate the CO and HC production. The issue in the end though is that at first it will be rich until the TCCS adjust. Once it adjust it will be back at square one. Now keep in mind that the VPC is sending a signal to the TCCS and as such the TCCS is adjusting to that signal.

 

[HommerSimpson]

And what have you done to combat the Light throttle light load Lean condition that happens when the US ECU thinks the EGR system is in place?

Yet again you have "modded" your car in the belief that Toyota got it wrong and you're right.

Now you have people that actually understand how the system works and why it works telling you it's a bad idea but you're arguing because you "know".

Last time this happened and I gave you a week off you swore that you were never going to post on SM again and went off to SF and bad mouthed SM to anyone stupid enough to listen to you.

You lasted a week there before they nailed you and then tore you to pieces in Off Topic about your butchered dash, you come back here post a couple of feelers then when you think you're secure you start the shit again.

Do us a favour and just SHUT THE FUCK UP I won't let you derail another thread.

EVERYONE ELSE: Keep it civil this is no idle threat.

no problem Dude.....

 

[Poodles]

Bypass kit I was speaking about...

 

[figgie]

The back of the head IS hotter, but NOT because of the EGR. It's the farthest from the heat exchanger (radiator), nothing more.

This is why companies in Japan made coolant bypasses to the back of the block to keep it cool back there. Why would they do that if it was the EGR? Oh wait...they didn't have EGR!

btw. It was never that straight

They blocked the front thermostat housing port that comes from the head and ran the pipe from the back to the radiator. The area in the back of the head is a high pressure area (water is moving) and when you block the exit up front then you are forcing all the coolant out that 24mm opening (that happens to T off into the Heater).

BTW this verision I am talking about is based on the Group A supra (yes the racing version).

 

[black89t]

this one got intense. :rofl:

 

[BillyM]

well it depends.

The richness will take care of the NOx production and as such lower cylinder temps BUT that will also deviate the CO and HC production. The issue in the end though is that at first it will be rich until the TCCS adjust. Once it adjust it will be back at square one. Now keep in mind that the VPC is sending a signal to the TCCS and as such the TCCS is adjusting to that signal.

I know full-well how the VPC operates and how and what it feeds the TCCS, so lets drop that. My can runs VERY well, I see exceptional mileage, and the ecu has to do minimal correction to maintain closed-loop operation. I run with an innovate wideband and datalog rpm, AFM signal, map, and throttle position at all times.

I don't have any figures on egr flow (do any of you?), but imagining it is cranking out 33% of the air flow into the cylinders when enabled, my car would exceed the TCCS correction and run like a friggin' dog. I would be forced to pull 33% fuel to match the higher MAP readings that the EGR caused, at which case it would run 33% lean when at higher load without EGR (which I don't ever want).

It has been said time and time again that the TCCS is fuel-map tuned for EGR operation. ...I highly doubt that. I bet $$$ the ECU relies solely on the AFM, RPM, and IAT (and ofcourse 02 in closed-loop) to judge fuel load and the EGR being operational or not makes zero difference on fuel adjustment.

Simply said, in my experience I have found the VPC (and imagine any other map-based piggyback) to react very oddly to EGR operation, AFR swings, hesitation, and general TCCS confusion... Never say "Never", because there are times when removal is the lesser evil.

-Do any of you have figures on the ammount of timing advance you gain at different driving conditions when running EGR vs not?

-How about flame-front speed difference between 100% air/fuel vs 70% air/fuel to 30% egr? I don't know those calculations and would be interested in the results if one of you did.

--BillyM

 

[figgie]

33% EGR?

no way.

Not even the Honda insight does that much EGR %. They do 30% and is one of the very very few cars with that much EGR%.


Doubt all you want. Ther TCCS is infact tuned for EGR in the us. That like taking whatever favorite standalone and tuning the engine with the EGR in place. Since the EGR is inert (like Argon or Helium) you get nothing but a reduction in the displacement of the engine. The issue still remains, the standalone was tuned with EGR included (All do Alpha-n blending) so take EGR out and just by that one "mod" you now have increased pumping losses, increased the displacement at any given time in the same load cell but yet have not corrected for the increase by adding fuel. That means lean condition at the same load cell.

A 4 gas analyzer shows that as removing the EGR increases all by products but more so the NOx production at the SAME EXACT load points as with the EGR connected. Toyota (and Honda for that matter) is pretty damn brilliant.

Also remember, regardless of the piggy back in question. All the piggyback is doing is feeding the TCCS a shovel of shit. The TCCS of course does not know this and does what it was programmed to do.

 

[BillyM]

33% EGR?

no way.

Not even the Honda insight does that much EGR %. They do 30% and is one of the very very few cars with that much EGR%.


Doubt all you want. Ther TCCS is infact tuned for EGR in the us. That like taking whatever favorite standalone and tuning the engine with the EGR in place. Since the EGR is inert (like Argon or Helium) you get nothing but a reduction in the displacement of the engine. The issue still remains, the standalone was tuned with EGR included (All do Alpha-n blending) so take EGR out and just by that one "mod" you now have increased pumping losses, increased the displacement at any given time in the same load cell but yet have not corrected for the increase by adding fuel. That means lean condition at the same load cell.

A 4 gas analyzer shows blah blah blah (we're not talking emissions here).

Also remember, regardless of the piggy back in question. All the piggyback is doing is feeding the TCCS a shovel of shit. The TCCS of course does not know this and does what it was programmed to do.

TCCS is tuned for EGR operation: YES, I agree with you. ...but I doubt EGR operation changes ANYTHING on the fuel mapping, flowing or not, just on the simple fact of how the system meters air. Got proof otherwise? Datalogs? Bin dumps?

All the piggyback does is...: Again, I realize what the piggyback does, thank you. My goal is to make sure this "shovel of shit" my VPC outputs is as close as possible as possible to the "shovel of shit" the ECU gets from the AFM under all operating conditions.

...a VPC car is a whore to tune in when you have EGR stepping in and fucking up the MAP readings. You're little story about the standalone car is exactly what those of us who've converted to map-based piggybacks feeding the TCCS run into, in reverse. I'm simply pointing out that there are cases where it is easier to remove the EGR than tune around its damned affect on the manifold pressures. ...you said so yourself.

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".

That said, lets get into "HOW" bad it is to disable EGR. I can't run with it, sorry, it makes AFR tuning too difficult and the TCCS responds poorly to it. ...lets touch on how much timing must be pulled in the operating instances where EGR would normally flow? Lets get back to my questions in the last post, do we know or can we find out, the flow % of EGR vs fresh? ...do we know the ammount of timing that we need to pull in those instances to make it safe to run sans-egr?

We all agree that EGR allows you to run advanced timing, it's a simple fact, and we all know TCCS is (timing) mapped around that, again, simple fact. But to what extent? Some of us choose to or are forced to run without EGR, so lets figure out what it takes to make it safe for everyone. (Solonoid powered off the EGR VSV that rotates the cps 5deg forwards?)

--BillyM

 

[figgie]

TCCS is tuned for EGR operation: YES, I agree with you. ...but I doubt EGR operation changes ANYTHING on the fuel mapping, flowing or not, just on the simple fact of how the system meters air. Got proof otherwise? Datalogs? Bin dumps?

All the piggyback does is...: Again, I realize what the piggyback does, thank you. My goal is to make sure this "shovel of shit" my VPC outputs is as close as possible as possible to the "shovel of shit" the ECU gets from the AFM under all operating conditions.

...a VPC car is a whore to tune in when you have EGR stepping in and fucking up the MAP readings. You're little story about the standalone car is exactly what those of us who've converted to map-based piggybacks feeding the TCCS run into, in reverse. I'm simply pointing out that there are cases where it is easier to remove the EGR than tune around its damned affect on the manifold pressures. ...you said so yourself.



That said, lets get into "HOW" bad it is to disable EGR. I can't run with it, sorry, it makes AFR tuning too difficult and the TCCS responds poorly to it. ...lets touch on how much timing must be pulled in the operating instances where EGR would normally flow? Lets get back to my questions in the last post, do we know or can we find out, the flow % of EGR vs fresh? ...do we know the ammount of timing that we need to pull in those instances to make it safe to run sans-egr?

We all agree that EGR allows you to run advanced timing, it's a simple fact, and we all know TCCS is (timing) mapped around that, again, simple fact. But to what extent? Some of us choose to or are forced to run without EGR, so lets figure out what it takes to make it safe for everyone. (Solonoid powered off the EGR VSV that rotates the cps 5deg back?)

--BillyM

AFR tuning difficult?

On a piggy back? Unless you have the complete HKS gizmo list (VPC, FCON, GCC) I am going to say that tuning in closed loop is not really tuning, as the TCCS will take control of all the nice stuff you tried to do. On the WOT side. EGR is disabled. So what tuning are you refering to (for clarification purposes)?

Timing is not the main contributor to det at those point unless Toyota was crazy to run that much advance down there.

Also doesn't the VPC just TAP into the AFM signal but not intercept it (according the wiring diagrams I see for the 87-88 supra)?

EGR contributes exactly 0 to the O2. So that does not affect AFR in anyway. EGR will increases pressure in the intake by the introducing EG (one of the benifits of EGR being reducined pumping losses or the "engine brakeing feeling). I am curious as to what trouble you are having and specifically what RPM. The other reason I doubt is the EGR is because the VPC needs to scale down the signal for a given load to run 550's. That means that at the low cruise condition the VPC will be telling the TCCS that is would be in a lower load cell and in turn would be to low to enable the EGR.

Now with that said, I had to dig the VPC wiring diagrams out. I swear that I thought it had a TPS input and the MAP input also.

Removing the EGR might solve the issue IF HKS accounted for it and richened the fuel curve up by sending a higher signal than needed for the RPM but that is a HUGE if.

Also. The HKS instruction manual never mention anything about removing the EGR system. Are you sure your MAP sensor is good?

 

[BillyM]

Also doesn't the VPC just TAP into the AFM signal but not intercept it (according the wiring diagrams I see for the 87-88 supra)?

It is painfully obvious to me that you have no idea how the VPC works or what it does... (You show me how the VPC can tap an AFM signal with no AFM, and I'll give you $50.) Sadly, it negatively affects your entire approach to the problem.

EGR contributes exactly 0 to the O2. So that does not affect AFR in anyway.

When you alter the manifold pressure on a VPC converted car, you alter the AFM signal!

EGR will increases pressure in the intake by the introducing EG (one of the benifits of EGR being reducined pumping losses or the "engine brakeing feeling).

Yes we understand the theoretical aspects of EGR, but do you have any idea as to what extent?

I am curious as to what trouble you are having and specifically what RPM. The other reason I doubt is the EGR is because the VPC needs to scale down the signal for a given load to run 550's. That means that at the low cruise condition the VPC will be telling the TCCS that is would be in a lower load cell and in turn would be to low to enable the EGR.

...stock injectors, 440 eprom, tuned at low-loads to zero-out the fuel trim signal. My AFR's are perfect and my car runs great. It did NOT play nice when EGR was fuggin' up the MAP reading... Please don't confuse this for asking you for help as I'm telling you why I was forced to remove my EGR, nothing else.

Now with that said, I had to dig the VPC wiring diagrams out. I swear that I thought it had a TPS input and the MAP input also.

RPM in
MAP in
IAT in
-------
AFM out

Removing the EGR might solve the issue IF HKS accounted for it and richened the fuel curve up by sending a higher signal than needed for the RPM but that is a HUGE if.

...pretty advanced speculation there, might want to reaffirm how the vpc even works before making that one. Keep in mind it was manufactured and tuned in Japan, and I bet you $$$ they didn't import an EGR'd car to build the 7mgte 440cc chip curves.

Also. The HKS instruction manual never mention anything about removing the EGR system. Are you sure your MAP sensor is good?

My AFR's are solid under all circumstances, fuel trim voltage out is nearly zeroed at all times, my car runs fantastic, makes great power, and returns awesome mileage. ...I'm pretty sure the map sensor is O.K... My VPC outputs a better AFM signal than the AFM did...

What I AM trying to point out, is that telling multiple people with map-based ECU's or piggy-back systems to simply toss an EGR valve in the mix without warning them of the hundreds upon hundreds of dollars it will cost them to have it tuned in around the effective changes in manifold pressure, or the pain-in-the-ass side effects they will see if it isn't re-tuned for it is not cool.

...I bet you'd have a hard time even finding a tuner who would touch it...

--billyM

 

[Sar-Supra]

Cool down, guys. There´s no need for a forum-war only because of that EGR-U.F.O...

 

[BillyM]

"Uh-oh guys, someone pointed out a well-written, researched, and data-backed exception to our egr rule." SHHHHHHH, maybe we can still be right in our suggestion that everyone use EGR (even that those with map-based standalones and piggybacks) if we just stay quiet till he leaves. Lets go post the same stuff in the other EGR thread instead! Quickly now, to the EGR-mobile!"

Mr "SWD Fredster", post 26, has already blown $380 buying brand new EGR components and plans to toss it on his previously-tuned AEM on your suggestions. I will keep an eye out for the "Help, my car is running 11:1 AFR's at cruise since I installed my $380 egr and now I fail emissions worse than ever!" thread...

Just keep in mind for your future "EGRants", that suggesting an EGR setup to someone who's converted to map-based air metering, you could cause them plenty of hassle, waste their money, and make their car run poorly, so be careful with it unless you have absolute first-hand experience.

--BillyM