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Discussion Starter #1
I'm going to dyno my car and tune my SAFC today at 6pm. The dyno said they can stick a probe up my exhaust without welding it in and get a A/F reading. Is this true? I've always heard of people getting something bungwelded so the probe could go in the DP. I want my reading to be as accurate as possible. What should I do? Also, any tips on tuning the SAFC are wanted also. I already have all the points set, and know how to add and take away fuel, anything else I should know?
 

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Supra OG
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Putting the probe in the exhaust tip vs the downpipe delays the reading by ~300RPM.. meaning that the AF you see on the graph at 4500RPM actually happened at 4200RPM, etc. I prefer to have the probe in the downpipe for a quicker response and more accurate reading.

Leave 1000RPM->3500RPM at zero. Try to tune 4000RPM on up to get a flat 11.5:1 A/F. Make sure to run race gas as knock retard from subsequent pulls can skew your readings. Don't reset the ECU at the dyno.... reset the ECU a few hours before and let the ECU learn your MAF/etc on the drive there.

Regards,
Andi
 
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Discussion Starter #3
I went to dyno. All I could muster was a 379.8rwhp/386 rwtq. Was on pump gas at 19psi. I could not get the SAFC to lean out the fuel curve :( at 6000rpms I was at 11:1, 6500rpms 10:1, 6900rpms 9:1 :( I'm straight BPU other the the SAFC that I could not get to work!
 

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Supra OG
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l 94SupraTT l said:
I went to dyno. All I could muster was a 379.8rwhp/386 rwtq. Was on pump gas at 19psi. I could not get the SAFC to lean out the fuel curve :( at 6000rpms I was at 11:1, 6500rpms 10:1, 6900rpms 9:1 :( I'm straight BPU other the the SAFC that I could not get to work!
1) you should tune on race gas as I said before... race gas doesn't change your AF, it just keeps you from getting knock retard.

2) you probably have a boost leak causing your MAF equipped system to go extremely rich.

3) I'm assuming the AFC is installed correctly... this is a safe assumption correct? Recheck all the wiring to be sure... and maybe play with the SAFC at idle and see if you can cause the engine to almost die by leaning it out, just to make sure it's working......

Andi
 
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Discussion Starter #5
I appreciate the help, I'm going to try and solve the problem. I'll be going back next month once I get my FMIC, and cam gears. thanks again for the info.
 
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