Jump to content


Photo
- - - - -

Air fuel ratio gauge to achieve the correct fuel mixture at idle


  • Please log in to reply
22 replies to this topic

#1 jalexquijano

jalexquijano

    Advanced Member

  • Members
  • PipPipPip
  • 85 posts
  • Location:Panama
  • Cars:1972 240z

Posted 07 December 2017 - 03:36 PM

Which air fuel ratio gauge is recommended to get the precise mixture on my 240z? Innovate??? Which model and brand?

#2 G-Duax

G-Duax

    prickly in San Antonio

  • Senior Member
  • PipPipPipPip
  • 872 posts
  • Location:San Antonio, The Republic of Texas
  • Cars:73 620 & 90 Toyota Cressida

Posted 07 December 2017 - 03:58 PM

That's what I run on my 3-liter Toyota, with their option to record it on my lap-top.

The ability to keep both eyes on the road during hard runs through the gears is especially valuable at high speeds.

But on my old 620, I just run a an almost as old Tomei narrow band, as it tops out about where the 3--liter does when it's only in 3rd (of 6).



#3 Crashtd420

Crashtd420

    Senior Member

  • Senior Member
  • PipPipPipPip
  • 1,691 posts
  • Location:Massachusetts
  • Cars:1972 Datsun 521

Posted 07 December 2017 - 04:09 PM

Are you carberated and looking for a gauge so you can tune?

That's what I bought one for to monitor and tune my L16....I have the innovative brand and love it....
As a monitor it's real responsive and the o2 sensor is heated so it's quick to start giving readings...

It has the ability to data log by plugging into Laptop or tablet and can feed info to an ecu if neccessary....
So even if you were adding it to a fuel injection system it's the one I would recommend..... need to go to garage and I'll post the model

#4 Crashtd420

Crashtd420

    Senior Member

  • Senior Member
  • PipPipPipPip
  • 1,691 posts
  • Location:Massachusetts
  • Cars:1972 Datsun 521

Posted 07 December 2017 - 04:24 PM

So the one I bought was model number...
3844
Seems that has been recently upgraded... innovative motorsports 3918....

#5 distributorguy

distributorguy

    Senior Member

  • Senior Member
  • PipPipPipPip
  • 1,135 posts
  • Location:Metropolis, MN
  • Cars:77 Datsun 620, 73 Datsun 620

Posted 08 December 2017 - 06:09 AM

The new innovate MTX-series is listed as the world's fastest, and still way under $200 if I remember correctly.  We have one in the race truck.  They flake out when you get outside the parameters they are designed for, but always restart and work on the next cycle of your ignition key.  I think that "glitch" is designed to help preserve the O2 in bad conditions.  



#6 Crashtd420

Crashtd420

    Senior Member

  • Senior Member
  • PipPipPipPip
  • 1,691 posts
  • Location:Massachusetts
  • Cars:1972 Datsun 521

Posted 08 December 2017 - 07:01 AM

I was seeing them for around 175....
Of course I bought the other one just before they changed it....
Either way great products....
Also read directions before installing, they have procedures for first time use to set up the o2 properly....

#7 datzenmike

datzenmike

    KING RAT

  • User Administrator
  • 70,286 posts
  • Location:Vancouver Island
  • Cars:'74 710 sedan, '76 710. prevoius... '78 620, '71 521, '68 510 new '76 B-210

Posted 08 December 2017 - 07:35 AM

What stores sells them in the States?


Posted Image

#8 G-Duax

G-Duax

    prickly in San Antonio

  • Senior Member
  • PipPipPipPip
  • 872 posts
  • Location:San Antonio, The Republic of Texas
  • Cars:73 620 & 90 Toyota Cressida

Posted 08 December 2017 - 08:09 AM

Mike, you can go to Innovate's web site. What ever it is.

 

Funny, how many fast bikes, snowmobiles, karts, and cars I've built, and tuned fuel delivery by just reading the plugs, or watching for the first sign of soot out the back of the car.

Now everyone needs the latest & greatest high $$ gauge.

Even then, some people still can't get it right.



#9 racerx

racerx

    Senior Member

  • Senior Member
  • PipPipPipPipPip
  • 4,426 posts
  • Location:NorCal
  • Cars:71 Datsun 510 and 65 Mustang Fastback

Posted 08 December 2017 - 08:12 AM

Yep..so this af is more of a want not a need? I just check my spark plugs, vacuum gauge, smell and listen.

#10 datzenmike

datzenmike

    KING RAT

  • User Administrator
  • 70,286 posts
  • Location:Vancouver Island
  • Cars:'74 710 sedan, '76 710. prevoius... '78 620, '71 521, '68 510 new '76 B-210

Posted 08 December 2017 - 10:13 AM

The gauge is almost like cheating isn't it? You can set timing be 'ear' too but a timing light is so much more easier and accurate. In a generation no one will know how to read plugs except on You Tube. I guess it's the lazy man's way but it will show possible dips in the ratio you may not see or feel. I would love to have one just the same. I would like to run R-1 carbs and it would be invaluable for that.


Posted Image

#11 distributorguy

distributorguy

    Senior Member

  • Senior Member
  • PipPipPipPip
  • 1,135 posts
  • Location:Metropolis, MN
  • Cars:77 Datsun 620, 73 Datsun 620

Posted 08 December 2017 - 11:08 AM

Whenever you're only a little bit out of tune, its difficult for most people to tell if you're rich or lean.  The gauge only lies in certain circumstances - usually at idle (reversion) and when you're grossly out of tune, when common sense has to weigh in and start making big tuning adjustments.  The gauges are a way to get that last 5% that most people leave on the table.  

 

Dash mounted gauges are ok for basic tuning.  Very distracting for the driver however.  An LM-1 or LM-2 is invaluable for data logging so you can record and watch a playback.  Its almost like having your own mobile dyno.



#12 Spiff

Spiff

    Advanced Member

  • Members
  • PipPipPip
  • 200 posts
  • Location:Norge
  • Cars:720, mazda b2200, merc s320

Posted 08 December 2017 - 12:50 PM

I have the innovate dual gauge in my z32 and a plx sm-afr in my 720, between those too I feel the innovate is the better. The plx kit looks antiquated with the aluminium control box and in my case the plug for the power connector cracked and plastic bits went flying when I plugged it in :/ Not confidence inspiring, also in the 1.5years I've had it installed the sensor or the controller stopped working for a month , then suddenly started working again and if you jiggle the  connector for the gauge it stops displaying, not good. Then again I've heard people talk crap about innovate as well but for me that kit was just heaps better, sealed control box, clearly marked wires and connectors and good instructions. I was shopping for a gauge for my oil temp and pressure now and wanted some dual gauge of some sorts, choice was between plx and the new innovate mtx-d line, the plx again; old type analog sensors and again that big ugly control box and all in all more expensive than the innovate dual gauge...

 

If you want a low cost option for datalogging then check out the spartan wideband. 



#13 wayno

wayno

    Datsunahaulic

  • Senior Member
  • PipPipPipPipPipPipPipPipPipPip
  • 12,982 posts

Posted 08 December 2017 - 05:20 PM

I have a feeling this is still about the exhaust popping.


 

 


#14 NC280z

NC280z

    Advanced Member

  • Members
  • PipPipPip
  • 141 posts
  • Location:Havelock,NC
  • Cars:1975 280z, 1987 300zx *sold*

Posted 08 December 2017 - 06:47 PM

I highly recommend the Innovate series of gauges/sensors. I have the base model analog wideband gauge (no laptop hookup or software), and it fit perfectly in the same spot as the old clock on my 280z. I can't tell you how easy it made tuning and troubleshooting my Z. I've used it for everything from troubleshooting small vacuum leaks to adjusting the AFM spring tension to compensate for mods and/or AFR differences between pure gas and the ethanol-laden mess we have here in VA. 

 

Most will tell you that plug reading is the way to go, but a wideband 02 gauge cuts out a good deal of guesswork and leaves you with more time to drive and enjoy your Z. 



#15 racerx

racerx

    Senior Member

  • Senior Member
  • PipPipPipPipPip
  • 4,426 posts
  • Location:NorCal
  • Cars:71 Datsun 510 and 65 Mustang Fastback

Posted 08 December 2017 - 07:00 PM

Nah...no guess work, takes a few minutes to read plugs. Another 10 seconds to connect vacuum gauge.

#16 G-Duax

G-Duax

    prickly in San Antonio

  • Senior Member
  • PipPipPipPip
  • 872 posts
  • Location:San Antonio, The Republic of Texas
  • Cars:73 620 & 90 Toyota Cressida

Posted 09 December 2017 - 07:26 AM

 to get the precise mixture on my 240z?

 

So, I just have to ask, do you know what a precise mixture even is ?



#17 NC280z

NC280z

    Advanced Member

  • Members
  • PipPipPip
  • 141 posts
  • Location:Havelock,NC
  • Cars:1975 280z, 1987 300zx *sold*

Posted 09 December 2017 - 06:08 PM

Datzenmike, I agree that a wideband 02 gauge is going to show the dips in your AFR that you'd normally not notice (I got my gauge from JEGS). I also understand where racerx and G-duax are coming from. Plug reading is an invaluable skill to hone, and a vacuum gauge is a must-have for any shadetree mechanic. That being said, an wideband 02 gauge is not so expensive as to be out of the reach of the average joe, and I don't find mine distracting while I drive (otherwise all guages would be!). For complex multi-carb setups and EFI setups a wideband can give you accurate readings throughout the engine's operating range that a normal plug reading would not. I can literally see how many points too high or too low I am AFR-wise, and then adjust the teeth in my AFM to correct. Could this be done though the tried-and-true plug method? Sure, but it would take more time and likely be less accurate. It's like comparing a slide ruler and a calculator. 

 

jalexquijano, your best bet is to practice the plug reading skills that racerx and G-duax are recommending, and then resort to a wideband AFR if you believe you need a higher degree of accuracy. A normal wideband gauge would only be able to be used on one vehicle, the LM-1/2 series can be used on multiple vehicles if you have more than just your 240z. I'll finish by saying that the wideband I have was probably the best investment I've made in a tool throughout the life of my Z.  



#18 racerx

racerx

    Senior Member

  • Senior Member
  • PipPipPipPipPip
  • 4,426 posts
  • Location:NorCal
  • Cars:71 Datsun 510 and 65 Mustang Fastback

Posted 09 December 2017 - 11:46 PM

/\...don't knock out slide rulers, they used that to help build rockets and land on the moon and I'm fairly sure other engineering projects benefited from slide rules. What about the Greek guy who figured out the circumference of the earth by using a stick and it's shadow? No calculators and no fast computers.

#19 datzenmike

datzenmike

    KING RAT

  • User Administrator
  • 70,286 posts
  • Location:Vancouver Island
  • Cars:'74 710 sedan, '76 710. prevoius... '78 620, '71 521, '68 510 new '76 B-210

Posted 10 December 2017 - 07:37 AM

Abacus.
Posted Image

#20 NC280z

NC280z

    Advanced Member

  • Members
  • PipPipPip
  • 141 posts
  • Location:Havelock,NC
  • Cars:1975 280z, 1987 300zx *sold*

Posted 10 December 2017 - 10:38 AM

Wasn't knocking on slide rules, I'm just making a comparison between the accuracy of the two tools. Yes, slide rules were used in a great many projects prior to the advent of modern calculators, but they don't have the degree of accuracy that modern tech has. Just as I said, plug reading has worked for generations and will continue to, but it's not going to be as accurate as a wideband. It's important to have the understanding that comes with the tools and skills of prior generations (such as plug reading), but if newer technology exists why not take advantage of it? Had wideband 02 sensors existed in the 50's and 60's in abundance I'm very certain that the hot-rodders and gearheads of that generation would've used them to their advantage, just as they used Hilborn injection and other tech that may have been viewed as unnecessary by some.