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Carburetor gas milage - wideband tuning idle and primary main jets

Is there a market for wideband tuning for gas MPG?

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  • Poll closed .
rcamacho

rcamacho

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Given the number of carbureted vehicles out there, I'm wondering if there is much of a market out there for custom tuning services locally. Innovate, PLX, etc seem to be doing very well selling wideband rigs to the import tuner and nostalgia markets.

Having just tuned the heck out of my Holley carb, it seems to me there should be some market out there for those looking to save some gas while not making a $300-500 investment in a wide band rig. I've been able to take 20% of the idle fuel circuit out without benefit of a wideband (idle fuel restrictions) and can probably go farther with one.
 
I never tuned mine with a wideband (I put a cheap O2 sensor in the exhaust and used a voltmeter) but the wideband tuning is worth it.

I wish I had done it before but its not worth it to me now that my rig is pretty much trail only.
 
I started looking at the widebands a bit recently, and stumbled upon this: http://www.moates.net/product_info.php?cPath=57&products_id=142

I knew Craig had this sort of thing for a long while, hadn't realized they had come down so much in price.

I agree, a lot of money to dump into something you will probably use at best once every five years, but it wouldn't be a bad thing to share cost on. It's too bad it's impossible to trust everyone, "rental" of something like this would be handy, even if you were talking about mailing it.

Carbureted or not really doesn't matter. There are a few on here (myself I'm sure) that would be more than moderately surprised at how well or poorly their injected vehicle is running.
 
Finally got a hold of a wide-band monitor after all these years. I'll be diving into it over the weekend.
 
Wideband

Im gonna be purchaseing a wideband for my truck aswell i daily drive the beast. im a bit more lucky i got a dyno i can use whenever for free so when it comes down to it i will beable to give some numbers. but in all reality this is a good idea not only for mileage but power aswell. should be interesting and fun regardless.

Dirk
 
Well I finally picked up an LC-1. Here are my cruise specs at various RPM with the 0.016 wire in 0.033 IJ. Looks about a point leaner than I would like and not entirely linear. The primary main start up appears to be somewhere north of 3000 RPM as the PV shows no effect regardless of vacuum/load below 3000. The mixture screws are pretty far out to get to 13.8 at idle. Any leaner and it rattles a bit.
RPM AFR
1500 16
2000 15.5
2500 15
800 13.8 (Idle)

Here are the primary specs:
IFR:0.033
PIAB:0.078
PVCR 0.059
PV: 10.5"Hg
PMJ:72
PMAB:0.025
Orange cam on #2
0.035 shooters
 
I have done all my tuning with a wideband, so I'm no expert on doing it without. If you are looking for near-stoich mixes on a NA motor, you can probably get by with a narrowband. They are pretty good within about a point of stoich. If you need super rich (i.e. Turbo) mixes or are pushing the limits of lean-burn it is a very valuable tool. You just can't trust the O2 too much. Basic feedback from the engine is still more valuable. For example, the O2 gives you no good information on your mixture when you are misfiring. For idle, it's more important to listen to the engine and see what it likes best than to target a certain AFR. Plus, the wideband needs periodic calibration, which means pulling it out of the bung.

For tuning a carb, you might want to go to a datalogging system so that you can see the transient response and record the AFRs under different conditions. Reading a physical gauge as you drive is really only useful for steady dyno runs, not actual street driving. To me, that would be more valuable than having the WBO2 over the NBO2. Heck, except for the times I'm tuning or datalogging, all my WB does is EMULATE a NB to drive my AFR gauge. For that function, the $35 NB would do the same job.

EDIT: Of course the datalogging only helps you if you put some extra sensors in, like a TPS and/or MAP. You have to know which circuit(s) of the carb you are using when you log an AFR you want to adjust. If you want to read steady state AFRs over much of the operating range (Vac/RPM), then you need a dyno anyway and most dyno shops have WBO2 setups they can use.
 
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