Hey guys,
does anybody have the dimensions of the EGR bung handy? For a 1978? I'm talking about the thread size of where it goes into the exhaust manifold.
Why, you ask? Well, today I discovered that the wideband 02 sensor harness on my VW is gigantic, like 10'. And the sensor easily plugged into my other car, allowing me to fine tune the mixture on that bad boy. Now I would like to do the same on the Fiat, but it is most likely a different thread size so I would need to buy/build an adapter.
Cheers
Steiny
EGR Valve Thread
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SteinOnkel
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- Your car is a: 1978 124 Spider 1800
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Nut124
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- Your car is a: 1978 124 Spider 1800
Re: EGR Valve Thread
?? What do you do? Drive the two cars side by side at WOT with a cable in between?
I would look into this:
Innovate Motorsports 3918 MTX Series MTX-L Plus Wideband Gauge, sensor. $177.
I would look into this:
Innovate Motorsports 3918 MTX Series MTX-L Plus Wideband Gauge, sensor. $177.
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SteinOnkel
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- Your car is a: 1978 124 Spider 1800
Re: EGR Valve Thread
The Innovate is the worst wideband on the market. And I already have one.Nut124 wrote:?? What do you do? Drive the two cars side by side at WOT with a cable in between?
I would look into this:
Innovate Motorsports 3918 MTX Series MTX-L Plus Wideband Gauge, sensor. $177.
No, not at WOT. Obviously can only tune idle.
Here, have a look.
Wideband from blue car gets plugged into white car, because the cable is long enough.
With 6 cars, $200 per wideband is a lot of money...1978 Fiat doesn't have a an 02 sensor bung, but I can make or buy an adapter for the egr connector.
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Nut124
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Re: EGR Valve Thread
OK. Got it.
What is wrong with the Innovate wideband? Is your concern based on personal bad experience?
Which one do you recommend? They all seem to use the same Bosch sensor.
You could buy one system and not mount it permanently, move from car to car as needed.
What is wrong with the Innovate wideband? Is your concern based on personal bad experience?
Which one do you recommend? They all seem to use the same Bosch sensor.
You could buy one system and not mount it permanently, move from car to car as needed.
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SteinOnkel
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- Your car is a: 1978 124 Spider 1800
Re: EGR Valve Thread
Not directly personal, but in my circle of friends, and especially in the pits at various racing events. They just start to go intermittently off the charts. On my brother's Porsche, the thing will suddenly jump to full lean or rich, even though literally nothing on the ecu has changed. Then it ping-pongs back and forth (car starts to buck, as it runs closed-loop) and you need to power cycle the unit for it to figure it out. Things like that, it just seems unreliable.Nut124 wrote:OK. Got it.
What is wrong with the Innovate wideband? Is your concern based on personal bad experience?
That is the $64,000 question and I don't have a good answer for you. I use the PLX unit. It's accurate and reliable, but I hate the connectors they use with a passion. They are just not automotive grade (3.5mm audio cables wtf). Just screams "We couldn't source the proper things, so you get the cheap junk". You are correct, they all use a Bosch LSU 4.9 which is the gold standard of 02 sensors. It's all the stuff upstream from it that gives you headaches.
Which one do you recommend? They all seem to use the same Bosch sensor.
This has also crossed my mind. Put a nice 12v battery on it, place the whole thing on a wooden board. Would make my life easier for use. Just pop them in before a smog check and see what's what.
You could buy one system and not mount it permanently, move from car to car as needed.
Cheers
Steiny
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Nut124
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- Your car is a: 1978 124 Spider 1800
Re: EGR Valve Thread
Hello Steiny, Thanks for the tip. I wish I hade seen it a few weeks ago.
I actually installed the Innovate Plus in my car a few days ago. I'm holding my judgement until further testing but I kinda like it so far. I had an old narrow band system for 20 years, which was good. Now I have the narrow band in a single exhaust primary and the Innovate in the collector.
I wish the Innovate gauge was slimmer for "surface" mount. Yours look slimmer. But has a box to mount.
At idle or low speed cruising the Innovate AFR reading is a bit unsteady. At load I find it pretty steady. The reading could be unsteady because at idle my big carbs are not perfectly tuned. Then again I care about WOT top RPM AFR and to lesser extent steady HWY cruising AFR.
As to your brother's troubles with closed loop control, I can sympathize. I am a controls engineer by trade and education and can see how closed loop control could go badly wrong.
Not sure how he is doing it but here's what I would try:
- Any attempt to adjust the fuel delivery based on instantaneous AFR reading alone will fail.
- It must be assumed that the ideal fuel curve is constant and good once dialed in and only need tweaking over time.
- For closed loop control, any AFR readings need to be tabulated by RPM and load for purposes of adjusting the curve.
- The closed loop control should only ever adjust the curve slightly at specific rpm/load based on multiple readings at that rpm/load and only if the proposed adjustment is within expected worst case limits for that rpm/load.
I actually installed the Innovate Plus in my car a few days ago. I'm holding my judgement until further testing but I kinda like it so far. I had an old narrow band system for 20 years, which was good. Now I have the narrow band in a single exhaust primary and the Innovate in the collector.
I wish the Innovate gauge was slimmer for "surface" mount. Yours look slimmer. But has a box to mount.
At idle or low speed cruising the Innovate AFR reading is a bit unsteady. At load I find it pretty steady. The reading could be unsteady because at idle my big carbs are not perfectly tuned. Then again I care about WOT top RPM AFR and to lesser extent steady HWY cruising AFR.
As to your brother's troubles with closed loop control, I can sympathize. I am a controls engineer by trade and education and can see how closed loop control could go badly wrong.
Not sure how he is doing it but here's what I would try:
- Any attempt to adjust the fuel delivery based on instantaneous AFR reading alone will fail.
- It must be assumed that the ideal fuel curve is constant and good once dialed in and only need tweaking over time.
- For closed loop control, any AFR readings need to be tabulated by RPM and load for purposes of adjusting the curve.
- The closed loop control should only ever adjust the curve slightly at specific rpm/load based on multiple readings at that rpm/load and only if the proposed adjustment is within expected worst case limits for that rpm/load.
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SteinOnkel
- Posts: 1000
- Joined: Tue Feb 19, 2019 9:31 pm
- Your car is a: 1978 124 Spider 1800
Re: EGR Valve Thread
His car is an air-cooled boxer 4 banger with racing spec components. Who knows what in God's name is going on in that thing 
It's running megasquirt (as is my other car) and you can tune all the curves you described to your heart's content. I've got the closed-loop feedback on my car set to a healthy 20% +/- maximum change in commanded fuel. Once you have the response time of your sensor from datalogs, you are good to go. My VE table alone can usually nail the afr targets with only minimal correction, but it's good to have the closed-loop algorithm as a backup. That's how most OEM ecus work as well. You can dyno tune all you want, but out there in the real world, things can happen that require a 20% change in fueling on the fly. That number can decrease the more fine tuned your tables are, but it's served me well so far.
My new engine I'm building (mmmh forged internals) I think I will actually spend the $1000 to have the dyno guy give my street tune a good once over. It'll be interesting to see how little afr correction I can get away with then. The setup does have ITBs though and with those, anything goes.
Oh, and by the way, the white car in the picture has a narrowband 02 that's supposed to do...something. It's a brand new sensor, and unless you blip the throttle to 50% load, the voltage output barely changes. I tried to tune it with that first, no dice. It's far too static of a signal. And yes, I used an oscilloscope, not a dmm.
Way back when I got my first wideband, I think I had carbs too. Some dual barrel downdraft or something. I never got them to 14.7 at idle, 14.7 at cruising and 13.0 wide open. That's what started the long journey of programmable efi, because I'm a bit of a perfectionist when it comes to afr. I want fuel mileage and maximum power. Hence, my disdain for carbs.
It's running megasquirt (as is my other car) and you can tune all the curves you described to your heart's content. I've got the closed-loop feedback on my car set to a healthy 20% +/- maximum change in commanded fuel. Once you have the response time of your sensor from datalogs, you are good to go. My VE table alone can usually nail the afr targets with only minimal correction, but it's good to have the closed-loop algorithm as a backup. That's how most OEM ecus work as well. You can dyno tune all you want, but out there in the real world, things can happen that require a 20% change in fueling on the fly. That number can decrease the more fine tuned your tables are, but it's served me well so far.
My new engine I'm building (mmmh forged internals) I think I will actually spend the $1000 to have the dyno guy give my street tune a good once over. It'll be interesting to see how little afr correction I can get away with then. The setup does have ITBs though and with those, anything goes.
Oh, and by the way, the white car in the picture has a narrowband 02 that's supposed to do...something. It's a brand new sensor, and unless you blip the throttle to 50% load, the voltage output barely changes. I tried to tune it with that first, no dice. It's far too static of a signal. And yes, I used an oscilloscope, not a dmm.
Way back when I got my first wideband, I think I had carbs too. Some dual barrel downdraft or something. I never got them to 14.7 at idle, 14.7 at cruising and 13.0 wide open. That's what started the long journey of programmable efi, because I'm a bit of a perfectionist when it comes to afr. I want fuel mileage and maximum power. Hence, my disdain for carbs.