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Discussion Starter #1
ok, I know I am running rich, cause I can smell the fumes, how can I tune the fule controller without using a dyno?

or can I not.. i'm looking at the apex afc
 

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supraron said:
ok, I know I am running rich, cause I can smell the fumes, how can I tune the fule controller without using a dyno?

or can I not.. i'm looking at the apex afc
I wouldnt suggest doing it without a dyno. If you have an EGT guage you can use the temps to tune. If your temps are high you need to richen up, if they are low you can lean the mixture a bit. I best way is the dyno though.
 

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aAD

just an fyi...using the egt to tune is dangerous unless you have had the car dyno tuned before and you know what temp is optimal for your setup and where your egt probe is mounted...so if you get your car dyno tuned and at WOT and a/f at 11:1 your egt is say 700, you know that is the highest you should ever hit and could possibly tune accordingly but its still not safe
 

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Discussion Starter #4
Re: aAD

tks guys--
how is the dyno used for tuning? what are the steps? is it trial and error? I dont want soneome who owns a dyno to tune my supra if they dont know how to tune a fuel controller

agggg
Its hard to trust anyone with your precious supra

:)
 

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Get on a Dyno with a shop that has a Wideband O2....if they have the wideband O2, then they should know how to tune. Ask if they know about Supras...also post about a tuner in your area.
 

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Spool said:
Get on a Dyno with a shop that has a Wideband O2....if they have the wideband O2, then they should know how to tune. Ask if they know about Supras...also post about a tuner in your area.
Try to tune to 11.25:1 AF between 4000RPM and redline. Don't touch the AF below 4000RPM.

Andi
 

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I may be wrong, but I try to tune for about 12.8:1 at about 5,000 rpm and then slowly richen the mixture to about 11.8:1 by redline. I run this everyday including my time on the roadcourses. I might tune a little richer when I install my SP63. Probably 12.5:1 at 5,000 rpm richening to 11.5:1 at redline.

Later, Steve
 

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If you want to tune accurately, you MUST have a wideband O2 monitor. (Actually, you could install a pressure transducer in each cylinder, but I doubt that any of us are going to do that. :) ) Realistically speaking, you can NOT accurately determine the A/F ratio based upon EGT readings using the GReddy, HKS, Apex type gauge with their slow-ass, inaccurate thermocouples. NO WAY.

With all else being equal (engine load, throttle position, boost pressure, ignition timing, etc), there is only 35 C EGT difference in one full A/F point. For example, there is only 35 C difference between 12:1 and 13:1. Ever try to determine the actual EGT at 5500 RPM on a pull through 4th gear? There's no way in hell you can get within 200 C of it using a conventional thermocouple type gauge -- the gauge is just way too slow reacting. BTW, I have an elaborate, $1750 EGT monitoring system that exposes how slow and inaccurate the GReddy/HKS/Apex type gauges are. (I also have a GReddy 60 mm Peak/Hold guage.)

What you CAN do is to tune with a wideband on a Dynojet and try to guess what A/F you should set it at on the Dynojet so that the AFR will be close to what you want on the street or track. The Dynojet doesn't load the engine the same way the engine is loaded on the road, so you may not get the same results on the road that you got on the Dynojet. For example, I know of a couple of 700-900 RWHP Supras which are tuned on a Dynojet and wideband, then the cars won't run smoothly (stumble, hesitation, sputtering) on the street until they are leaned out a few clicks. (Those results are contrary to conventional wisdom that says the car will run leaner on the street than it does on the Dynojet, but that's what these owners have reported to have to do on a routine basis to get the cars running strong on the street.)

OR you can install a portable wideband and tune on the fly with the engine seeing its real-world load.

I'm doing a group buy on an accurate, affordable wideband that offers data-logging and can be built into your car so that you'll always know what you have in terms of AFR. $665. I have the system built into my T-64 car and it works perfectly (I actually have the earlier version that does not offer data-logging capability). If interested, send me an e-mail at [email protected].

Steve
 
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