Topic: Correct Air Fuel Ratio For 22r?

[Yotaoverland]

I have a Weber carb on my truck and I'm considering getting an Innovate Motorsports air/fuel ratio gauge. I'm hoping to find out the
correct air/fuel ratio, otherwise the gauge is kind of useless. Has anyone used one on their truck? Is this a dumb idea on my part?
I just want to be able to monitor how the truck runs with a little more detail.

[Gnarly4X]

I have a Weber carb on my truck and I'm considering getting an Innovate Motorsports air/fuel ratio gauge. I'm hoping to find out the
correct air/fuel ratio, otherwise the gauge is kind of useless. Has anyone used one on their truck? Is this a dumb idea on my part?
I just want to be able to monitor how the truck runs with a little more detail.

Hey Yotaoverland,

I think there are two basic paths for enjoying an AFR gauge:

One – buy one and have fun reading it.  Or Two – buy a high quality instrument and do some fine tuning.

A wide band AFR gauge is nice instrument and can really provide detailed information on what your engine wants and how it’s breathing.

I love gauges and have always installed aftermarket gauges in most of my vehicles to monitor basic readings – RPMs, oil pressure, engine temp, and amps. I’ve never installed an AFR gauge.  I’ve always tuned-by-ear and spark plug color, then by butt-dyno.

Innovate makes some really nice instruments. Before I jumped into an AFR gauge I’d do some research.  I’d talk to Innovate and find out a much as I could from the Weber experts.

I ran Webers on my sand rails for about 8 years – they require pure air, are picky to tune, very versatile, and performance enhancing.  And of course, a very popular Toyota 22R modification.

Jim at 22RE Performance does some serious carb/intake manifold design and might share some hot tips.  H8PVMNT has done lots of Weber tuning and shares much of his experiences and knowledge.

Tuning for best AFR starts with a very healthy and well-tuned engine.

I ran Holley carbs on both my 327-powered Corvettes and did minor jet tuning back in the day.  My 85 22R had a stock Toyota carb and did not work well on very steep inclines while rock crawling, but I got 19 to 20 MPG here in the Phoenix, AZ area.

If you are really interested in getting serious about carb tuning and an AFR gauge, this is THE best article I’ve ever read!  It’s written for tuning Holley carbs but absolutely provides some incredible insight into the art and science of tuning a carb that can be applied to a Weber carb.

http://members.tccoa.com/392bird/tuning.htm

I’m looking forward to your report on what you experience if you decide to go with an Innovate gauge.

Gnarls.

[Yotaoverland [OP]]

Hey Yotaoverland,

I think there are two basic paths for enjoying an AFR gauge:

One – buy one and have fun reading it.  Or Two – buy a high quality instrument and do some fine tuning.

A wide band AFR gauge is nice instrument and can really provide detailed information on what your engine wants and how it’s breathing.

I love gauges and have always installed aftermarket gauges in most of my vehicles to monitor basic readings – RPMs, oil pressure, engine temp, and amps. I’ve never installed an AFR gauge.  I’ve always tuned-by-ear and spark plug color, then by butt-dyno.

Innovate makes some really nice instruments. Before I jumped into an AFR gauge I’d do some research.  I’d talk to Innovate and find out a much as I could from the Weber experts.

I ran Webers on my sand rails for about 8 years – they require pure air, are picky to tune, very versatile, and performance enhancing.  And of course, a very popular Toyota 22R modification.

Jim at 22RE Performance does some serious carb/intake manifold design and might share some hot tips.  H8PVMNT has done lots of Weber tuning and shares much of his experiences and knowledge.

Tuning for best AFR starts with a very healthy and well-tuned engine.

I ran Holley carbs on both my 327-powered Corvettes and did minor jet tuning back in the day.  My 85 22R had a stock Toyota carb and did not work well on very steep inclines while rock crawling, but I got 19 to 20 MPG here in the Phoenix, AZ area.

If you are really interested in getting serious about carb tuning and an AFR gauge, this is THE best article I’ve ever read!  It’s written for tuning Holley carbs but absolutely provides some incredible insight into the art and science of tuning a carb that can be applied to a Weber carb.

http://members.tccoa.com/392bird/tuning.htm

I’m looking forward to your report on what you experience if you decide to go with an Innovate gauge.

Gnarls.

Thank you for the response and info!
I do have a stage 1 22reperformance 22r engine and I want to protect my investment by keeping the engine tuned happily.
I did email them with a similar question as the one in this post, I hope to hear back.
I'll definitely check out that article. I was watching Roadkill Garage when they had that black '65 F250 and they tuned the carb along a roadtrip,
it gave me some ideas.

[Gillesdetrail]

A wideband a/f gauge is the most usefuel carb tuning tool, keeps you from guessing.

Do not tune the idle with a/f ratio, tune it for smoothest idle/maximum vacuum reading. On mine that is around 13.1-13.3:1.

Full throttle on any naturally aspirated engine sould be aproximately 12.5:1. My 22r runs very good at a steady 12.8:1 full throttle. They say lean is mean but 12:1 is considered rich and above 13:1, lean (full throttle).

Part throttle can read very lean, close to or above 16:1 sometimes for best fuel economy and that is ok.

In my experience on my 38/38, part throttle cruising is controlled by the main jets, so is full throttle below 4000rpms. Above 4k you tune with the air correctors. The idle mixture and idle jets control nothing but idle.

Have fun, tune to what the engine likes best and don't go looking for that stoichiometric 14.7:1 a/f ratio.

[Yotaoverland [OP]]

A wideband a/f gauge is the most usefuel carb tuning tool, keeps you from guessing.

Do not tune the idle with a/f ratio, tune it for smoothest idle/maximum vacuum reading. On mine that is around 13.1-13.3:1.

Full throttle on any naturally aspirated engine sould be aproximately 12.5:1. My 22r runs very good at a steady 12.8:1 full throttle. They say lean is mean but 12:1 is considered rich and above 13:1, lean (full throttle).

Part throttle can read very lean, close to or above 16:1 sometimes for best fuel economy and that is ok.

In my experience on my 38/38, part throttle cruising is controlled by the main jets, so is full throttle below 4000rpms. Above 4k you tune with the air correctors. The idle mixture and idle jets control nothing but idle.

Have fun, tune to what the engine likes best and don't go looking for that stoichiometric 14.7:1 a/f ratio.

Got it.
Thank you!

[Gnarly4X]

Hey Yotaoverland,

“Have fun, tune to what the engine likes best and don't go looking for that stoichiometric 14.7:1 a/f ratio.”

That is excellent advice. 

Clipped for a Hot Rod article… 

https://www.hotrod.com/articles/hrdp-0406-density-altitude-tuning/

“Reality Check -Theory aside, there is still no substitute for analyzing how the car actually runs. If the car surges or hesitates, chances are it's too lean. If black smoke comes out of the exhaust, it's too rich. Always be extremely careful before making a change. Make sure you know what you're doing before you do it. It is always safer to be 5 percent rich than 1 percent lean!”

There are reams of paper and 10’s of 1000’s of hours spent on engine tuning research for the AFR.  Similar to exhaust theory - "Density Altitude Tuning" is what I call a “super-science”.  It gets extremely complex.

If you are in Dallas, depending on your weather - ambient air temp, RH, air density - your readings and ultimate tuning changes can be very different. Obviously barometric pressure and fuel blend can make a difference.

The average annual percentage of humidity in Dallas Texas is: 66.0%  In Phoenix, AZ my average annual percentage of humidity is: 17.0%.  With similar elevations.

On thing I really enjoyed about my 1985 22R 3200 lb. shortbed was being able to sense (by butt dyno) the changes in performance by very minor changes in tuning – including ignition, gasoline, header/exhaust, intake air flow, and especially weather and elevation. 

I had no clue what my actual AFR was reading.

Gnarls.