Bambam7

Well, Obviously the EGT gauge makes a better safety precaution, but for tuning the A/F mixture, and seeing if you are running lean or rich, which one is better?

Scott 89t2

air fuel gauge is almost usless, you need a wide band one which are around $1000 if you want it to be good enough for tunning. you are better off with EGT.

Evil Aviator

I disagree. IMO a narrow-band works fine. However, if you really like the features of a wideband O2 sensor, then I think that the Haltech E6K is the best way to spend your money.

I think that the need for an EGT gauge (aka thermocouple) would depend on what you are tuning. I have had good results tuning aircraft engines with EGT and CHT gauges.

BTW, both the O2 and EGT gauges make for a good saftey precaution.

Scott 89t2

ya I have both but I never look at the A/F. you can't tune with a EGT since it's to slow, but it's better to tell if you're running lean at WOT. and if you want to tune it you should really use a wide band. A local shop should have one you can use for pretty cheap. probably on their dyno.

Evil Aviator

What kind of thermocouple are you using? The EGT gauge should react even faster than the O2 sensor unless you have the display dampened.

OK, nobody has been able to explain this to me. What in the heck is so great about a wideband O2 sensor?

pp13bnos

iTrader: (1)

For light throttle, i'd use the mixture meter. For full throttle stuff, i'd use a egt gauge. Under full throttle in 3rd or 4th gear, idealy you want to see 1850*f. This is what type of exaust temps that Rob at Pineapple shoots for. He's tuned everything from my 13B street port, to my 13B injected peripheral engine, so he knows what he's doing. CJ

Scott 89t2

the wide band is just way more acurrate. there is a reason why they run $700-$2000+ for a kit. at WOT on a standard 02, the difference between rich and lean is so small, a cheap gauge like an autometer won't even pick it up, as the voltage for rich and lean will still be on the same light. they are only any good for tuning normal crusing. the other thing about wide band is it knows the exhaust temp and changes itself. where as a normal 02 will give different readings if the sensor is a different temp.

I'm not telling everyone to go and buy one. just find some one who has one and use there's. there is a local guy with a motec one which is over $2000 I think, as it comes with an exhaust probe you stick in the tip as well. my friend got some haltech tuning done a couple weeks ago. the guy sat in the pass seat and drove around with him for 30 mins and tunned his haltech and charged him $50cnd (30usd). now that is way cheaper then a cheap a/f gauge, and a lot better! as you don't really need the gauge to be permanent anyways.

fcturbo2

how are the 52mm Greddy EGT gauge??Are they accurate?

Crusader_9x

i ordered the haltech and will be getting the 4wore o2 sensor with it. what gauge shoulf i get to be the most accurate? the gredy guage? also what do yall recommend for the egt guage? who sohuld i go with?
thanx

BlackFC_NYC

I bought a autometer air/fuel gauge which im going to install soon in my pod. i hope i didnt waste money on this thing.
how will this work with a stock o2 sensor?

also, in the other pod opening im throwing in a Autometer Temp gauge.

are these good choices?
i already have a boost gauge mounted on my column.

Evil Aviator

The display resolution has nothing to do with the sensor, as I have seen narrowband AFR gauges read out to 3 decimal places. OK, the wideband measures the AFR off a direct relationship to a modulated spectrum, as opposed to the narrowband which relies on indirect point-voltage crosscounts... blah, blah, blah, and various other technostuff. Basically, it comes down to the fact that the continuous progression of the wideband is better for operating an engine when compared to the chaotic binary switching of the narrowband. However, why does this make any difference when the AFR is only used as a reference for tuning or as a safety feature while driving? Does anybody actually tune a sportscar solely to a static AFR rather than dyno or track performance?

Sorry, I haven't used enough current automotive AFR or EGT gauges to give you guys any recommendations. Whenever buying an Autometer gauge, be sure to stick with the "Pro-Comp" series (ie Pro-Comp, Ultra-Lite, and Carbon Fiber), as the other lines like "Sport-Comp" are not made as well. A friend of mine tuned a popular racer's car which had an Autometer AFR installed, and he tuned it just fine although it took him a while to get used to the "backwards" display. I will be using a SPA Boost/EGT gauge for tuning my 20B (probably in February) so I can let you know how I like it once I get a chance to use it.
http://www.spatechnique.com/index3.html

Here is an AFR meter comparison that I borrowed from the Celica folks:
http://www.alltrac.net/tuning/afgauge.html

BTW, here's an interesting link from the Tightwad land of OZ:
http://www.techedge.com.au/vehicle/wbo2/default.htm

BLUE TII

iTrader: (9)

If you are running lots of boost on stock TII turbo and I/C mabye a EGT meter would be better since you could get terribly overheated intake charge which would raise risk of detonation but not lean out mixture and this would show up as increased exhaust temps?

Bambam7

Well, the exact purpose I will be using it for will be to tune for the perfect A/F mixture from 5000 to 8000 RPMs. Since I will be running bigger injectors all around, a turbo, and I have a ported engine, I wouldn't trust the stock ECU to **** itself. For this purpose I have gotten the general opinion an EGT is better- shooting for 1850 degrees?
Where is that thermocoulple located on the exhaust? Is that themp for turbo or N/A? (Wouldn't turbo be higher because of higher intake temps and radiant heat from the turbo, falsifying the reading?)


The A/F meter (narrow band) I am assuming is still good for idle to 3/4 throttle under 4000 rpms or so to tunre for torque and miliage for city driving??

Maybe I should get both.
Happy Holidays

pp13bnos

iTrader: (1)

A turbo car should run no different tempature than a n/a engine, as the air/fuel mixture ratio should still be pretty close. The ideal setup is to have (on a n/a engine) the coupler 6" away from the exaust flange, on the inside radius. I've probably just lost ya. But anyways, the farther away from the motor, the cooler the temp. After you get it to 1850f, at 6" away from the flange, you can then put the exuast probes anouther 6" back, for a total of 12". This way it will lengthen the life of the probes. If you do buy a guage, buy something with a dual sweep. This way you can monitor bolth the front rotor, and rear. Hope this helps, CJ

surfpac

The wide band O2 sensor should be used when tuning along with the EGt gauge. After that you should just monitor with an over the counter air/fuel gauge like the AutoMeter, Haltech or this one I saw on Ebay. They all use pretty much the same components inside, which is just a fancy voltmeter.
http://cgi.ebay.com/ebaymotors/aw-cg...635586&r=0&t=0

sublime5254

hey i have a question for you guys. i hope to be running catback (racing beat one on there when i bought it), downpipe, air box w/ k&n air filter, air inlet duct (racing beat one on there when i bought it), stock cat, and ecu upgrade. i know that i am going to get a boost guage but don't know if i should get a/f guage or EGT guage. i will not be racing on the track ever and most of the time be driving pretty normally, just every now and then drive it hard. which guage is best for me? thanks alot for you help and time.

setzep

I think it's because the resolution is so much better. 0-5v vs. the 0-1v of a norowband. The narowband is very acurate around 14.7 afr. Have you ever seen a chart for a narowband? It's not linear at all like a wideband. 300mv's-700mv's is right around 14.7 to give you a idea how well it reads 14.7 (kinda takes up a lot of that 0-1v you have to work with) The narow bands are great for closed loop operation or tring to acheve fuel economy but under heavy load/boost they don't read out 11.5 afr very well.

Felix Wankel

My narrowband went to **** once I modded my car out. I think the 02 sensor took a ****

Evil Aviator

Actually, I think that the wideband is much better for closed loop operation, but who on this forum actually runs their EMS in closed loop mode? A narrow band sensor can be calibrated in several different ways, to include the 11.5 afr range if needed:
http://www.alltrac.net/tuning/afgauge.html

The only advantage that I have found so far in a wideband is that it can maintain accuracy throughout temperature changes. I guess that those who tune solely from the O2 sensor would like a finer digital readout, but I think that most serious tuners only use the O2 and dyno for a base setup, and do the final tuning on the track.

patman

iTrader: (3)

actually, the output for a narrowband sensor is a step function. 14.7 takes up a tiny fraction of the output range, because that is what the computer looks for, are the values on either side of the vertical step at 14.7. basically, the output of an o2 sensor looks something like this: (dots are just to hold it in place..damn auto format.)
--------------------|
.........................|
.........................|
.........................|-------------------------------

with the vertical line at 1.0 lambda, adn then a relatively wide range of values on either side. unfortunately, i dont really know what is different from this in a wideband, but i would like to...

pat

patman

iTrader: (3)

heh...2 1/2 years old....sorry

gsracer

http://www.plxdevices.com/Installati...ay_Install.pdf

Look on page 3 of the pdf file. Notice how for the narrowband, 90 percent of the available voltage is dedicated to the air/fuel ratio's betwen 14.4-15.1 area. This means less than .1volts is available for all other air/fuel ranges. As the a/f ratio creeps further away from stoich, the narrowband becomes even more innacurate.

midnightride42

ok i have a autometer EGt guage and let me tell you if im not mistaken, im at work right now so i cant look at it, but it read t only 1600F so when im on the highway cruising say 55 65 im already at about 1200f so at full throttle there really is no way to tell how hot im getting cause the needle goess al the way to the end.

if you can find a nice guage that goess higher than get it. or move the probe further back. i made a hole i the exhaust pipe in the down pipe.