Bluetooth O2 sensor and a carb

[AcampoDave]

Today I went ahead and treated myself to this: https://pe-ltd.com/product/wideband/

I intend to use it on my 283 with an Edelbrock 500 cfm carb. The rest of the engine has the usual old school stuff....RV cam, ramhrons w/ duals, Performer EPS, HEI type distributor, and it's got a pair of ported/polished 416 heads from the (ahem) "mighty" 305 H.O.

As I write this, gasoline is around $6.50/gallon in the "Golden State" and so even adding 1 or 2 MPG'S would be worth it to me as this truck does go places. I don't use a speedometer so I have no odometer, but have used the internet to calculate miles on a route and my truck seems to get about 15mpg on the open road. The arrival of this sensor should correspond with the return of my ramhorns from Jet-hot and if it intrests you guys, I'll return to this post and update things as I go. This is my first go-round on seriously tuning a carb so naturally, suggestions along the way are always welcome.

Here's to 17 mpg on the open road......

[bhap]

I’m running a Quadrajet with an L31 and even with a 3.38 rear axle, I’m in the low teens for mpg. Curious to hear “before and after” air fuel ratios.
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[cwcarpenter98]

I would love to hear your experience with this! I'm all about squeezing as much MPGs out of the old rigs as possible while still staying on a carb diet

[AcampoDave]

Ok, when the sensor gets here, I'll unpack it and we'll see how it looks. My truck has a 4 speed and a 3.08 rear and my carb is presently tuned to #11 in the manual. Edelbrock says the 1404 came factory tuned for performance on 305 and smaller engines or for dual quad applications on larger engines. That's why I have mine leaned out some already.

I also ordered a second weld on bung for my mainly stock longbed with hopes of refining my ol' 2-jet as well. That is one of the things I like about this product. Since my phone is my "guage" all I need to do is move the electronics and the O2 sensor to the other truck and connect two wires.

Now I gotta find something to secure my big and heavy Motorola smartphone to my dash...anyone have a recommendation for that?

[Braunschweiger]

Do it, it's a fantastic thing.
I used an AFR gauge to reduce consumption on my '68 Mustang by tuning the 600 Summit Carburetor to an average of 12 liters per 100km/19.6MPG.
The 289 Engine is similar to a K-Code/Boss with 277hp on a dyno, 5 Gear and 3.55 differential
With a light gas foot, even less is possible. I hope that I can set the C10 with SB 350/350 to 15 liters per 100km / approx. 15MPG, the lambda connection is already set.

[cwcarpenter98]

I bought a $6 phone mount from Walmart a couple years ago. It was in the electronics section, not the automotive section. Works good enough for me and it was cheap enough for me to put one in the 63 and one in the Dakota so I don't have to use one for both trucks. Biggest thing is making sure the window is clean before you install it.
Is it the perfect mount? Nope, but it's cheap and hasn't broken in over 2 years of sitting outside all the time. It works great for google maps as well. I don't have to pull my eyes off the road much to check the directions

[Steeveedee]

OK, I'm pretty old school, having been a mechanic back in the '60s-'80s. A vacuum gauge and attention to detail will achieve as much as that oxygen sensor. I personally consider that, without a control system and feedback to the carburetor to be a solution looking for a problem. I hope that it works for you!

[AcampoDave]

Solution looking for a problem is very similar to boredom looking for a project...but thanks for the good wishes. And CW...I will drop into the Wally World electronics dept on Monday. A suction cup to the windshield for a mount should be fine I suppose, and yeah, easier to see the road at the same time for sure thanks.

[Braunschweiger]

It is only for Adjusting in the Car, it allows good conclusions to be drawn about how the Carburetor works. Transitioning from the idle system, to the main jet, with the accelerator pump and at Holley also the PV valve working in these Areas, can put you on the wrong track, without the experience of an Old Mechanic. It helped me, a lot to understand my carburettors and adjust them properly. The AFR is not permanently in the car, it always went to the one who just wanted to tune his carburetor.

[AcampoDave]

0The PE Wideband is here but the manifolds are still at Jet-Hot (they said Oct 30th for those). Here's a look though at the sensor and related stuff...
The electronic box is not waterproof but it is very sturdy. The o2 sensor has a 16" lead which snaps into a 12" lead off the box so I should be able to get it all placed without the purchase of an extension. There is a red power wire (ign. hot) a black ground and an optional pink for 0-5v output (not sure what 0-5v output is for...anybody?...) in a harness of about 36" and 2 short aux leads for CAN input and output. (I dont have that I guess. Could anybody tell me what those are for?) The directions are fine for the basic wiring, but lack any real detail on the optional wiring. Here are pics...

[AcampoDave]

It also came with the weld on mild steel exhaust bung and I bought a couple more along with a plug.

[Arne]

The 0-5v output is probably so you can connect it to engine management computer (which you ain't got). The CAN ports are to connect into very modern computerized engine management, which again, you don't have.

[AcampoDave]

Originally Posted by Arne

The 0-5v output is probably so you can connect it to engine management computer (which you ain't got). The CAN ports are to connect into very modern computerized engine management, which again, you don't have.

Thanks, that's pretty much what I thought. I may go ahead and get this thing installed on my stock long bed and check it out while I'm waiting for Jet-Hot to do the manifolds for the shortbed. If so I'll post an update. The phone holder arrives from Amazon tomorrow. It looks just like CWCarpenter's. I went to Wally World like he suggested but they were all locked up behind glass and nobody was around to open the case. Too bad

[Braunschweiger]

Actually, these are self-sufficient displays, screw in the lambda probe and attach the display, connect to 12V and calibrate and off you go.
I know these systems.

https://www.rsr-performance-parts.de/de/

What system do you have?

[jjzepplin]

I am in. I have always wanted to do this on my 406. Should help with jet changes etc.

[Cohi]

Did the same with a hardwired procomp wideband AFR gauge when i was running a carb. I'd thought of installing a sensor on both banks and using a switch to flip back and forth for guage readings (or just run two independent guages) but didn't go that far.

AFR guage surely helped me jetting and monitoring changes for sure in the mile high city.

[theastronaut]

I had a wideband in my '64 VW and used it to keep an eye on the twin Dellorto two barrels. Very handy tool to know exactly how lean or rich it is at various engine speeds and loads.

A big key to tuning AFR is also being able to adjust timing to suit. The leaner mixtures you'll be after at light throttle burn slower so you'll need to add in more ignition timing under those circumstances to pick up as much mpg as possible. As lean as 16-17:1 is perfectly fine under light load situations as long as you have a way to add ignition timing to start the slower burn sooner. 12.75:1 is ideal for heavy/full throttle.


This thread on the VW forum has been the biggest help for me to understand tuning carbs for the AFR targets you want under different loads. The tuning info is for Weber/Dellorto style carbs but the principles are the same no matter what carb or engine you have. Pay particular attention to the posts from john@aircooled, he is super sharp on tuning for the most mpg, cool cruise temps, drivability, and power at WOT.

https://www.thesamba.com/vw/forum/vi...c.php?t=293837

[Cohi]

Originally Posted by theastronaut

I had a wideband in my '64 VW and used it to keep an eye on the twin Dellorto two barrels. Very handy tool to know exactly how lean or rich it is at various engine speeds and loads.

A big key to tuning AFR is also being able to adjust timing to suit. The leaner mixtures you'll be after at light throttle burn slower so you'll need to add in more ignition timing under those circumstances to pick up as much mpg as possible. As lean as 16-17:1 is perfectly fine under light load situations as long as you have a way to add ignition timing to start the slower burn sooner. 12.75:1 is ideal for heavy/full throttle.


This thread on the VW forum has been the biggest help for me to understand tuning carbs for the AFR targets you want under different loads. The tuning info is for Weber/Dellorto style carbs but the principles are the same no matter what carb or engine you have. Pay particular attention to the posts from john@aircooled, he is super sharp on tuning for the most mpg, cool cruise temps, drivability, and power at WOT.

https://www.thesamba.com/vw/forum/vi...c.php?t=293837

Nice

[AcampoDave]

Mr. Astronaut, thank you for that. I have not had a chance to read that thread yet, but hope to after dinner. My manifolds are supposed arrive today on the big brown truck (that's what they say anyhow but it's getting late) so pretty soon here I should have some progress.

[AcampoDave]

Finally have some work done. In order to weld that bung on the pipe I did a little homework and watched this first https://youtu.be/1kPJ03FGYMY I learned a bit with that . Since the bung I have wasn't curved to match the pipe like he recommended, I contoured it myself on the bench grinder. Then I drilled the proper sized hole with a step bit and clamped it on the pipe with a big hose clamp. After finally getting a leak free weld, (I like to cap of the pipe with my hand and fill it with water to look for seepage) I thought I was good to go but noooooo..... Too bad the pipe mounting flange for the manifold was on the wrong side of my work and there was no way it was sliding over that bung to go back up the pipe where it belongs. So... I split the flange open with a Sawzall, spread a bit and slipped it past my work then welded it back together again. That was a rookie movie for sure. One thing I did that was smart however, was to buy a threaded plug for that bung to use a heatsink during welding and for protecting the threads during mockup.

Anyhow once I mocked it up on the truck the location was just where I wanted it so I quit for today. I'm going to pull the pipe off the truck once more and use my Dremmel to grind off a tad of the pipe inside the bung as I was just a wee bit off center when I welded. The sensor just drags on the overage slightly causing it to not want to thread right in by hand. Then I'll paint the welds with cold galvanizing compound and I'll be back here.

[Steeveedee]

Nice work! Every man needs two trucks parked in the garage!

[AcampoDave]

Thanks, it's a nice job until I show off my welding I shouldn't have ditched metal shop so much in school. I only have a little Harbor Frieght Flux wire mig which works pretty well, but getting that thing welded on there "leak free" required a few attempts at getting it right. Yep, nothing like using 10 feet of wire to do 3 feet worth of work.

[Steeveedee]

Hah! I have one of those, and resorted to only using my oxyacetylene rig, anymore. I should just sell that wire feed critter.

[AcampoDave]

Today I got it up and running. It works exactly as advertised. My steady cruise is solidly in the 14's. It's hard to be exact at any given moment because after the decimal, the AFR is bouncing around quite a bit. I saw it bounce occasionally into the low 15's as well as the high 13's but as an average the engine was cruising at about 14.5 or so. Foot to the floor got me to high 11's and my idle was rich, in the 10's. I adjusted the mixture screws and got that into the 14's with a few bounces to the 15's upon deceleration.

What do you guys think? It seems to me like I am well within the ballpark. I suppose seeing things more into the 15's at a steady cruise wouldn't hurt but going up one rod size on the primarys may just be too much. I dunno. I'll get some more behind the wheel time with it to get a better idea over a wider range of conditions. Could I also anticipate it leaning or enriching itself as air temps change. Today it was mid 70's outside

[AcampoDave]

Here's a couple of pics. The first one shows the mounting of the electronic box on the inner fender with the o2 sensor lurking below on the pipe by the starter.

The second is a shot of my virtual guage on my phone while the truck is at idle. The rich lean parameters around the circle of the guage are adjustable so you can narrow the scope of the linear reading below. I found that when I did that, the new narrower range showed on the dial and the color changes from green to yellow to red adjusted to suit the new parameters. For example if my lean limit was set at 17 then 15 was getting into the orange territory. Leaving a wider range kept 15 AFR in the pale green territory. Notice how the linear graph is tracking the last 20 seconds of run time. That is adjustable as well, but since I have no device to log a greater time span, I just left it at the factory setting.