AFR gauge

[John B]

After holing a piston in our first engine, and breaking a crank in our second, I want to take really good care of engine #3. To that end, I've opted for an AFR gauge to monitor the Air/Fuel ratio.  I figure a quick peek at the end of the straight while still WOT will help me keep an eye on things and give me an extra layer of comfort. I went with an analog gauge rather than LED's as it fits in better with the old school nature of the panel, and also LED's can be hard to distinguish in bright sunlight. 

It's an Innovate MXT - AL. I swapped in where the Fuel Gauge was and moved the fuel gage further off to the right.  Temp, Pressure, AFR...

https://www.innovatemotorsports.com/products/MTXA.php#3855

 

 

Edited August 4, 2022 by John B
update

[KnifeySpoony]

What is involved in running a wideband AFR gauge on a duratec with stock ECU? Is it even possible?

[Vovchandr]

1 hour ago, KnifeySpoony said:

What is involved in running a wideband AFR gauge on a duratec with stock ECU? Is it even possible?

 

Shouldn't be a problem at all as long as you run it in parallel. If you're  trying to replace your primary o2 with a wideband for whatever reason, that would certainly complicate things however. 

 

For parallel you can either install it post the cat into the likely existing bung of your downstream, which is what I did. You can also get a new bung installed pre cat as an alternative. 

 

@John Bthat's a clean install! Mine is nowhere near as neat and I had no idea you can have a mechanical wideband. 

[KnifeySpoony]

I don't have a cat but I have the OEM O2 sensor in the bypass pipe. So I just have a new bung welded on the pipe and the sensor runs right to the wideband gauge? (excuse my ignorance)

[Vovchandr]

Just now, KnifeySpoony said:

I don't have a cat but I have the OEM O2 sensor in the bypass pipe. So I just have a new bung welded on the pipe and the sensor runs right to the wideband gauge? (excuse my ignorance)

 

Yes, the standard package of the unit is completely standalone. There are some rules as to how to install the bung in regards to height and angle etc but it's pretty direct. 

 

Sensors is 6 wire if I recall and goes to the guage and you give the gauge power. Depending on which ones you get they have different capabilities. I suggest something with dataloging capability. 

 

Feeding widebands into ecus actually gets a little more complicated and right now Im actually at this crossroads for that. 

[Croc]

17 hours ago, John B said:

After holing a piston in our first engine, and breaking a crank in our second, I want to take really good care of engine #3.

 

John - How much was leaning out the cause of #1 and #2 engines breaking?  Are you really that close to the wire on the tune and does it make sense to just up the octane for a track day to provide some safety instead trying to run standard pump gas?

 

 

[NSXguy]

I have an AEM wideband i'll be using and likely permanently installing in my dash. Helps with dialing/verifying carbs tuning and also keeping an eye on things. 

[John B]

Croc, Engine #1 was as installed in the car when I bought it and we never messed with it. It was a 220 hp 2.3L Duratec. The prior owner set it up himself on a dyno and only drove it on the street. It holed a piston at NJMP. We never dyno tuned it, but I suspect it was lean. After that failure we sent the engine to our race engine builder, Paul Hasselgren with instructions to build a kick ass motor out of it, "And by the way it doesn't have to stay 2.3L". Paul builds lots of 2.3L Duratec race engines for Swift 016 Formula Atlantic race cars, but they all have to remain 2.3L. I wasn't really clear with him at the time, but I was thinking increased bore, not stroke. He put in a 2.5L Stroker crank from a Ford Ranger which are cast, not forged. I wasn't too pleased either the stroker or cast idea. It made 270 hp. We broke the crank and holed the block at NJMP. Not much was useable from that engine except the barrel throttle. That failure was not due to a lean condition though. On engine #3 I was very specific on what I wanted this time, preferring a bigger bore, shorter stroke, higher revving configuration.  It's a 2.5L MZR block and head with bigger valves and a shorter stroke billet crank from a 2.3L. It displaces 2.4L. It's also modified with a belt drive for the cams instead of the chain drive. it made a rather surprising 327 hp on a fairly conservative tune. The reason for the AFR gauge now is purely for driver peace of mind, it's not for a closed loop ecu system. My car doesn't have a cat and didn't even have a lambda sensor previously. The engine is tuned to run on 93 octane, but we've always used the 100 octane unleaded available when at the track and use 93 on the street. Last time at NJMP we broke a chunk out of the bell housing and also had a coil wire break. The coil wire has been re-pinned and a new bellhousing from Bruce at Beachman Racing is being installed at the moment. I'm crossing my fingers and looking forward to the USA7's event in September.

 

 

[KnifeySpoony]

Out of curiosity, was it your #4 coil wire?

[GTIspirit]

On 8/4/2022 at 6:41 PM, Vovchandr said:

 

Shouldn't be a problem at all as long as you run it in parallel. If you're  trying to replace your primary o2 with a wideband for whatever reason, that would certainly complicate things however. 

 

For parallel you can either install it post the cat into the likely existing bung of your downstream, which is what I did. You can also get a new bung installed pre cat as an alternative. 

 

@John Bthat's a clean install! Mine is nowhere near as neat and I had no idea you can have a mechanical wideband. 

No need to run it in parallel if the aftermarket wideband controller outputs a simulated binary/narrowband/switching sensor signal.  The Innovate Motorsports LC-1 did this.  So then you just had to connect that simulated narrowband signal to the factory ECU.  The cool thing about that is the ability to bias that simulated signal to say lambda 0.9.  The factory ECU would then closed loop control to that switching point, and cause your fuel consumption to increase from running at 13.2 AFR. 

[Croc]

@John B  Thanks for clarifying.  Purely precautionary gauge then and not part of a broader pattern driving concerns.  Good to hear you sorted out what happened that day at NJMP - coil wire explains why it was not as sweet at the end of the day.  

[ProfGriff]

This looks like a good idea. I have no idea of how the D'Ellorto 48's are set up on my 7, other than that they seem to work great. This would give me half a clue, and I like that you can data log too. I'm sure they're set up pretty fat, as my fuel mileage is horrendous for such a tiny car.

 

Cheers

 

Phil

[IamScotticus]

@John B

The website doesn't give the guage housing diameter. 

Did you have to enlarge the dash hole?

[MV8]

On 1/2/2023 at 8:48 PM, ProfGriff said:

This looks like a good idea. I have no idea of how the D'Ellorto 48's are set up on my 7, other than that they seem to work great. This would give me half a clue, and I like that you can data log too. I'm sure they're set up pretty fat, as my fuel mileage is horrendous for such a tiny car.

 

Cheers

 

Phil

I saw the listing for your car. You have plenty of vertical room under the bonnet for a 38 weber or 350cfm holley two barrel and intake. Should be night and day difference in response off idle and mpg, as well as last (less) ring wear.

Edited January 4, 2023 by MV8
Spelling

[ProfGriff]

Thanks. I'm sure that's possible, but I'll put up with the mileage penalty for the D'Ellortos. There's nothing quite like the sound of one barrel per cylinder, and once the RPMs hit about 3K, It pulls HARD to 7-7.5K. My Westie is mostly a track and auto-x car, but I do drive it on the street some. I have a great twisty, smoothly paved road near my place, so that's where I go for "testing".  It sure freaks out the ol' boys when I show up for a local cars 'n coffee too.

I think I am going to do an AFR guage. I do really like the look of the Innovate one, although it does look slightly bigger than the std. 2-1/8 dia. I have to learn how to tune these carbs at some point, so the AFR guage should help.

[MV8]

I noticed the cam range was from 2750rpm. May not want to lean much. The extra richness is probably helping to prevent a lower rpm bog from the 48s due to lower port velocity. I think dellorto made a 38 dhla but I'm not sure. A race cam combined with big carbs is tough on low rev driveability. If you consider a carb swap later on, cv carbs (such as a set from a liter bike) are more flexible.

[John B]

On 1/3/2023 at 4:38 PM, IamScotticus said:

@John B

The website doesn't give the gauge housing diameter. 

Did you have to enlarge the dash hole?

No, it was the same size as the other gauges. I think 2 3/4"

[1turbofocus]

You want to shoot for 12.8 WOT A/F , what are you seeing ? Do you have a knock sensor ?

 

Tom