Power FC What AFR to target?
09-27-03, 12:01 PM
#1
What AFR to target?
All,
I've recently installed an TechEdge WBo2 v2.0 in my FD and I am starting to tune. What I really need is a map of target AFRs to tune against. For instance, I know under boost that I should be at around 11:1. What I don't know is:
1) what should the AFR be at idle?
2) at crusing?
3) when coming off throttle (P01-P04 at higher revs)?
4) at zero vacuum/partial throttle?
I've got all this great equipment, but I don't know what to do with it!
What I would love to see is some datalogit logs of your tuning so I can just play it back and see what AFR values are typical of a well-tuned FD.
For reference, I have stock turbos/motor with upgraded intake, I/C, and exhaust.
Any help would be greatly appreciated! Thanks,
-ch
I've recently installed an TechEdge WBo2 v2.0 in my FD and I am starting to tune. What I really need is a map of target AFRs to tune against. For instance, I know under boost that I should be at around 11:1. What I don't know is:
1) what should the AFR be at idle?
2) at crusing?
3) when coming off throttle (P01-P04 at higher revs)?
4) at zero vacuum/partial throttle?
I've got all this great equipment, but I don't know what to do with it!
What I would love to see is some datalogit logs of your tuning so I can just play it back and see what AFR values are typical of a well-tuned FD.
For reference, I have stock turbos/motor with upgraded intake, I/C, and exhaust.
Any help would be greatly appreciated! Thanks,
-ch
09-27-03, 09:22 PM
#2
Rotary Freak
^
I could use answers to these very questions also...
I found this thread on basic engine tuning http://www.nopistons.com/forums/inde...howtopic=25103
I could use answers to these very questions also...I found this thread on basic engine tuning http://www.nopistons.com/forums/inde...howtopic=25103
09-27-03, 09:38 PM
#3
actually, you can actually safely (depends on your car of course and the knock your car experiences) go up to around 11.5 after peak torque. Some will say you can go a tad leaner and some will say richer. My car's feels great at 11.5 to 1 after about 5600 to redline with a very low knock number.
Chuck has done a lot of logging with his wideband and has his and Rick's car running nicely. He might be able to chime in on a few pointers. I really don't care about part throttle/cruising applications since the PFC is in O2 feedback (if you have it on) and is in lean run mode and will cycle from rich to lean anyway. If your worried about gas mileage, well, don't, it won't get better than 20 mpg. I can roughly avg about 19 to 20 per gallon.
Tim
Chuck has done a lot of logging with his wideband and has his and Rick's car running nicely. He might be able to chime in on a few pointers. I really don't care about part throttle/cruising applications since the PFC is in O2 feedback (if you have it on) and is in lean run mode and will cycle from rich to lean anyway. If your worried about gas mileage, well, don't, it won't get better than 20 mpg. I can roughly avg about 19 to 20 per gallon.
Tim
09-27-03, 10:21 PM
#4
Yeah, I would love to see some of Chuck's A/F logs! PLEASE! 
Right now I am not running with the O2 as it makes tuning the lower cells problematic. I'll add it back in once I've got everything dialed in.
Please, all supertuners, we'd love to hear you thoughts on this! Thanks,
-ch
Right now I am not running with the O2 as it makes tuning the lower cells problematic. I'll add it back in once I've got everything dialed in.
Please, all supertuners, we'd love to hear you thoughts on this! Thanks,
-ch
09-30-03, 03:34 AM
#5
Not trying to be an *** but this has been discussed to death. Try searching the single turbo forum, there are several great threads on afr and timing.
What you will find is a bunch of different advice based on everything from experience to heresay. Here's a basic rundown from my experience.
Idle; lean out the idle until it goes unstable and then add a couple of percent back until you are happy with it. W/o air pump I run 12.8-13+:1 afr at idle.
Cruise; you can lean out cruise vacuum conditions to ~15 afr. If you get bucking you have gone too far. I run high 14, low 15 afr at cruise. You may have to adjust the accel table to prevent lean condition stumble when you accelerate from cruise.
WOT; gotta be confident that you can afford to replace a motor and turbo, tuning can be expensive. Anywhere from 10 to about 12 afr is feasible with stock motor/turbos below 15 psi. 10 afr may be too rich for your ignition, may get misfire. 12 afr may be too lean for your total ignition advance and you may get detonation. Start rich and lean out to your comfort zone. This is where timing and split really matter.
I tune to personal targets based on my mods and boost level and then adjust timing to my personal knock limits. Not perfect but it works for me.
What you will find is a bunch of different advice based on everything from experience to heresay. Here's a basic rundown from my experience.
Idle; lean out the idle until it goes unstable and then add a couple of percent back until you are happy with it. W/o air pump I run 12.8-13+:1 afr at idle.
Cruise; you can lean out cruise vacuum conditions to ~15 afr. If you get bucking you have gone too far. I run high 14, low 15 afr at cruise. You may have to adjust the accel table to prevent lean condition stumble when you accelerate from cruise.
WOT; gotta be confident that you can afford to replace a motor and turbo, tuning can be expensive. Anywhere from 10 to about 12 afr is feasible with stock motor/turbos below 15 psi. 10 afr may be too rich for your ignition, may get misfire. 12 afr may be too lean for your total ignition advance and you may get detonation. Start rich and lean out to your comfort zone. This is where timing and split really matter.
I tune to personal targets based on my mods and boost level and then adjust timing to my personal knock limits. Not perfect but it works for me.
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