AFRs and Timing advance/retard
#16
Nordschleife Master
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I'm seeing knock in 5th on pulls from 2K.. I plan to retune tomorrow morning to lean the mixture up top and retard timing a little bit above 3K in the partial throttle maps and accross the board on the WOT map and see how she runs, other than that she is running like a raped ape... Drove almost 200 miles tonight, logged 8 knock events durring highway driving at 75MPH+ and she runs like a bat out of hades...
eventualy I will need dyno time to finalize, but I'm verry impressed with the MaxTune functionality..
Spencer,
NOPE, no messing with hex code allowed in the PRO version (need upgrade for full tuning to allow HEX editing directly in the proggie..) Base setup allows editing of the fuel values and timing values in a very easy to understand interface...
PMs are fine, e-mail is probably better, but PMs work IF more in depth assistance is needed I can also send you my cell number, but I screen calls so the first call or 2 might just get you voicemail...
AND I am planning a full rebuild with machine work, new turbo, full exhaust this winter, so even were I to grenade my motor, it can get fixed.. and is the plan and budget (pending contract negotiations in September)... I'm actually considering joining the 3L and up club, but the additional cost of the 3L crank is holding me back right now... I can get HP out of this motor, but would love the 3L low end torque...maybe I'll end up at 101mm bore with my 87 951 crank... and see how much I like the setup... If I still need more get ahold of a 3L motor and build it up to swap in at a later date... who knows
eventualy I will need dyno time to finalize, but I'm verry impressed with the MaxTune functionality..
Spencer,
NOPE, no messing with hex code allowed in the PRO version (need upgrade for full tuning to allow HEX editing directly in the proggie..) Base setup allows editing of the fuel values and timing values in a very easy to understand interface...
PMs are fine, e-mail is probably better, but PMs work IF more in depth assistance is needed I can also send you my cell number, but I screen calls so the first call or 2 might just get you voicemail...
AND I am planning a full rebuild with machine work, new turbo, full exhaust this winter, so even were I to grenade my motor, it can get fixed.. and is the plan and budget (pending contract negotiations in September)... I'm actually considering joining the 3L and up club, but the additional cost of the 3L crank is holding me back right now... I can get HP out of this motor, but would love the 3L low end torque...maybe I'll end up at 101mm bore with my 87 951 crank... and see how much I like the setup... If I still need more get ahold of a 3L motor and build it up to swap in at a later date... who knows
#18
Rainman
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too much timing you think?
john, you will definitely hear from me via one of those channels lol.
see if you can hit the timing so aggressive that the exhaust comes out as blue flames like an F430 on full race mode
john, you will definitely hear from me via one of those channels lol.
see if you can hit the timing so aggressive that the exhaust comes out as blue flames like an F430 on full race mode
#19
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Yup. Add to that the fact that the turbo is leaking a little oil – oil contamination in the fuel lowers the functional octane quite a bit…
Actually it you run in rich and retarded you can make lots of flames…and lots of heat in the turbo.
Actually it you run in rich and retarded you can make lots of flames…and lots of heat in the turbo.
#20
Nordschleife Master
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2 changes this morning to each fuel and timing, here is where I stopped due to time constraints...
retarded teh timing some, leaned the fuel some at WOT...
AFRs now go as low as 12:1 above 4K WOT
are above 12:1 part throttle application
turned boost back to 13PSI.. and am planning on replacing leaky turbo no later than next weekend...
Last set of data shows AFRs holding where you guys have said they should be, and only 1 knock event recorded on a 1-2 shift (5300RPM shift)
![](http://www.renntube.com/addons/albums/images/411372948.jpeg)
retarded teh timing some, leaned the fuel some at WOT...
AFRs now go as low as 12:1 above 4K WOT
are above 12:1 part throttle application
turned boost back to 13PSI.. and am planning on replacing leaky turbo no later than next weekend...
Last set of data shows AFRs holding where you guys have said they should be, and only 1 knock event recorded on a 1-2 shift (5300RPM shift)
![](http://www.renntube.com/addons/albums/images/411372948.jpeg)
![](http://www.renntube.com/addons/albums/images/410312585.jpeg)
#21
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AND just so I understand your point of view, if you are rich and retarded you are flaming... but with a hot blower?
#23
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Well, my but dyno hasn't been calibrated in a while, but feels same as before... mixture and timing changes weren't HUGE, so no noticeable difference was felt... I am sure a true spin on a dyno could help fine tune it, but as of right now I'm going off of data logs and feel...
800-5400 rpm maybe a 1 or 2 data point change in the log (log being recorded at 33hz) so 1-2 33nds of a second difference, but ambient air temp could account for that by itself... a dyno run would be the only real way to track changes in HP of less than 15-20 HP I believe...
800-5400 rpm maybe a 1 or 2 data point change in the log (log being recorded at 33hz) so 1-2 33nds of a second difference, but ambient air temp could account for that by itself... a dyno run would be the only real way to track changes in HP of less than 15-20 HP I believe...
#24
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I think I have the mixtures about where they need to be, I'll back down timing this afternoon (unless it is raining) until I see an appreciable drop in performance and then go back a little bit from where It drops off...
#25
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I doubt you will see a significant power increase anyway......however that is really the point . Why run on such a ragged edge? With no additional power??
Unless you are John Force who likes to burn em down every run
Unless you are John Force who likes to burn em down every run
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#26
Nordschleife Master
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Yeah you know, I'm also going to start off my afternoon by pulling the plugs, reading them, cleaning them, and then back off the timing some more like above...
#27
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The problem that you may run into is that the point of detonation changes (a lot) with use. For the occasional blast of power you can get away with more ignition advance but if you start having more fun and beating it harder you will get into the detonation zone…hot days will do the same thing…as will ‘not great’ gas. So even though your set up is not hard into detonation today you are right on the edge, one small change in the picture and poof!!!
#28
Three Wheelin'
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Can someone explain what kind of timing values we should be looking for with these engines?
Low, mid and high, I thought 32 34 degrees at wot w/ no knock is ok.
Is that off?
Low, mid and high, I thought 32 34 degrees at wot w/ no knock is ok.
Is that off?
#29
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Proper timing values depends on a lot of factors... IAT, RPM, Load/boost, Coolant Temp, Baro, Humidity, fuel octane & type, ect.
One can have too much timing advance, without knock.
Ideally, peak cylinder pressure will be ~15ATDC.
-Rogue
One can have too much timing advance, without knock.
Ideally, peak cylinder pressure will be ~15ATDC.
-Rogue
#30
Three Wheelin'
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Hmmm, well I was looking for general numbers... Stock Turbo S, 70 degree day 3rd gear pull,pump gas, 15 pounds boost ? Not my set up but just looking for general numbers.
Rogue_Ant, saw your build I like the MAF T Pro, what kind of timing are you running?
Rogue_Ant, saw your build I like the MAF T Pro, what kind of timing are you running?