Seeking feedback and recommendations from Wide Band 02 users

I had the bungs installed and then while the car was on the chassis dyno and the guy was tuning the carb we installed the sensors so every thing was being pulled up on his computer screen. One in each pipe before the mufflers. Once the session was complete the bung bolts/caps were reinstalled and left. Very unnoticeable and yes I would recommend for tuning.

Why attempt to rebuild for the second time a 25 year old carb?  O2 sensors aside, I would buy a new carb first.  The QuickFuel units are very nice and tune very easily.

My opinion is that a wide and O2 sensor can be useful, but are more valuable on a dyno, than on the street.

I had imagined I would be able to get a nice straight line at the stoichiometric mixture on the display, but while you are driving a car, there are so many variables changing that it is  really difficult to judge exactly what is happening at any given time.

IF you have additional information - like you would get with a Fuel Injection setup - you could correlate your O2 ratio to throttle position, gear, RPM, vacuum, etc.  Just looking at a graph of O2 ratio, you don’t have all that other context.

On a dyno, you will have a constant load, controllable RPM, no unexpected accelerator pump shots, constant vacuum, etc.

If you look on my 5357 thread, I had a wide and O2 sensor, and posted some plots up.  I got helpful feedback, but….  I found the plots to be less instructive than I had hoped.

Obviously, if you have a lot of experience evaluating this kind of data, it would be much more helpful!

But it is easy to put bungs in!  You should do it!

Rocky

The carb on there was hardly used and the 4160s are not bad carbs. Only rebuilding it for potential gasket leaks.

Once I get the car up and running and solve any radiator, cooling system, clutch, fuel pump (they get old), electrical glitches, new tires etc., I might consider a new carb. Regarding carbs (not fuel injection) Edelbrock's new redesigned version of the Holley looks pretty interesting. I think that tuning any fuel system seems to be much easier with a wide band 02?

I've used a wide band to tune carburetors, not on a Pantera but whatever, and agree with what's already been said, very useful on a Dyno but off a dyno, aside for idle, it is absolutely necessary to know the position of the accelerator and to be able to make simultaneous recordings of rpm, AFR and alpha (position of the accelerator) otherwise it is unusable. It is therefore necessary to plan to install a potentiometer somewhere on the throttle control.

The type of chassis dyno I was on was a Mustang dyno (nothing to do with the Ford Mustang) and did as many real driving scenarios as possible. The O2 sensors were essential for this.  We looked at how the motor was behaving, air fuel ratios, etc, while going through gears not wide open runs. The Mustang dyno is much better for this than a Dyno jet. Your peak numbers at wide open with a load  will be lower than the guys quoting numbers off a Dyno jet, but it will be more realistic and some will argue more accurate numbers.

If you can find a shop willing to do this, I reccomend it. I got to be right in the shop with the car and it was a fun experience. We did quite a few carb adjustments and played with the distributor too. We didn't get it perfect and to do so I was told the Quickfuel carb would need some off the car further adjustments. I did, however leave the day getting more usable power while burning less fuel.

The shop guys loved learning about the Pantera, while at the same time hated having to contort their bodies for distributor and carb adjustments. Changing a spring in the distributor while the decklid is still attached is not easy.😀

Consider a professional / custom rebuild on the carb or a new carb. Bob at Competition Carburetion will build and jet a carburetor based on your personal engine specs and it will work straight out the box!

Most people have a tendency to put too much carburetor on these engines.

Chuck Nuytten is also an excellent resource for high performance Holley carbs.

@otis posted:

The type of chassis dyno I was on was a Mustang dyno (nothing to do with the Ford Mustang) and did as many real driving scenarios as possible. The O2 sensors were essential for this.  We looked at how the motor was behaving, air fuel ratios, etc, while going through gears not wide open runs. The Mustang dyno is much better for this than a Dyno jet. Your peak numbers at wide open with a load  will be lower than the guys quoting numbers off a Dyno jet, but it will be more realistic and some will argue more accurate numbers.

If you can find a shop willing to do this, I reccomend it. I got to be right in the shop with the car and it was a fun experience. We did quite a few carb adjustments and played with the distributor too. We didn't get it perfect and to do so I was told the Quickfuel carb would need some off the car further adjustments. I did, however leave the day getting more usable power while burning less fuel.

The shop guys loved learning about the Pantera, while at the same time hated having to contort their bodies for distributor and carb adjustments. Changing a spring in the distributor while the decklid is still attached is not easy.😀

Thanks for the informative post. I've often wondered how much easier things would be if the glass between engine compartment and the passenger compartment were easily removable...

I installed wide band O2 sensors and it was a godsend in tuning my Panteras and race car.  I could see the effect of the pump shot on acceleration for tuning and optimizing A/F ratio when driving a constant speed on the highway. (Hard to replicate on a dyno) Also facilitated getting the proper tune at idle.  These are just quick thoughts.  Go for it.  I tried to tune my carb correctly for decades and never got them optimized.  Once I shifted to O2 sensors, it has become a quick process based on facts verses hypothesis.  I install them on all my carb cars. 

JT

@joules posted:

Consider a professional / custom rebuild on the carb or a new carb. Bob at Competition Carburetion will build and jet a carburetor based on your personal engine specs and it will work straight out the box!

Ditto on Bob Oliver

I sent him a new in the box 670 avenger with all of my 404-C stroker engine and car specifications. Blue printed everything and final flow of 710.

when setting up for FWHP dyno, my tuner saw the Holley and complained that he did not like them because they never seem to be responsive to his tuning attempts.

after several runs and several jet changes he admittedly ate his words, at least on my Bob Oliver Holley. 😉

Larry

and if you have to ask how much it costs  (I really don’t remember),  please just look at it as a very small expense when building a new engine, and also a very small expense to maximize performance on an existing or newly installed manifold/carb upgrade.

Larry

@jtpantera posted:

I installed wide band O2 sensors and it was a godsend in tuning my Panteras and race car.  I could see the effect of the pump shot on acceleration for tuning and optimizing A/F ratio when driving a constant speed on the highway. (Hard to replicate on a dyno) Also facilitated getting the proper tune at idle.  These are just quick thoughts.  Go for it.  I tried to tune my carb correctly for decades and never got them optimized.  Once I shifted to O2 sensors, it has become a quick process based on facts verses hypothesis.  I install them on all my carb cars.

JT

JT: Could you tell me what brand of 02 sensors you have used how they worked out  and what you might recommend? I see a lot of them advertised and used on Youtube etc., but there seems to be a lot of discussions about the durability of the sensors. Budget is a concern. Thanks