tunes for E37, i has them (w/ screenshots)
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lol good catch...I didn't even notice that
gotta get back to reading my tuning book
I see what he did though, he put 14.7 first when dividing thats where he got the 1.15 value
gotta get back to reading my tuning book
I see what he did though, he put 14.7 first when dividing thats where he got the 1.15 value
Last edited by IonNinja; Apr 15, 2008 at 12:35 PM.
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To the OP, Jperris:
I am not sure if you discovered this on your own yet or not, but the lambda value you used to achieve a PE a/f-r of 12.8:1 is incorrect, in a big way.
A Lambda value of 1.15 is equivalent to an a/f-r of 16.9:1!!!!!!
In order to run a 12.8:1 a/f-r, you need to insert a lambda value of .87
Remember lambda equates to a/f in a linear way. 1=14.7, higher than 1 =higher than 14.7, lower than 1 = lower than 14.7. Low=FAT large=LEAN
Take the a/f you want and divide it by 14.7, this gives you youre lambda: 12.8/14.7= ~.87 14.7/14.7=1
If you need to convert lambda to a/f you MULTIPLY the lambda value by stoich(14.7)
.87*14.7=12.789 1.15*14.7=16.905
If you felt a difference with your current settings, try the proper lambda value!
I am not sure if you discovered this on your own yet or not, but the lambda value you used to achieve a PE a/f-r of 12.8:1 is incorrect, in a big way.
A Lambda value of 1.15 is equivalent to an a/f-r of 16.9:1!!!!!!
In order to run a 12.8:1 a/f-r, you need to insert a lambda value of .87
Remember lambda equates to a/f in a linear way. 1=14.7, higher than 1 =higher than 14.7, lower than 1 = lower than 14.7. Low=FAT large=LEAN
Take the a/f you want and divide it by 14.7, this gives you youre lambda: 12.8/14.7= ~.87 14.7/14.7=1
If you need to convert lambda to a/f you MULTIPLY the lambda value by stoich(14.7)
.87*14.7=12.789 1.15*14.7=16.905
If you felt a difference with your current settings, try the proper lambda value!
The PE ratio doesn't work like you would typically think about lambda values. Yes, conventionally Lambda < 1 = Rich; Lambda > 1 = Lean; but that's not how it works here.
The values in the PE table are NOT Lambda values.
Let's see if can get some info to back me up here.........
First, I did a quick google search and found this. It's a quote from the HPTuners online help page talking about PE vs. RPM:
"The values in this table are Equivalence Ratio's (Fuel/Air multipliers or AFR divisors) ie. values greater than one are richer, values less than one are leaner. The values relate directly to the Stoich AFR and the resulting commanded AFR is Stoich divided by this PE equivalence ratio. Eg. if the multiplier is 1.1 then the commanded AFR will be 14.7/1.1 or 13.36."
quite the opposite of what you said, no?
Secondly, according to your formula, the factory tune is commanding an AFR of 17.2:1 from 4500rpm upwards, since the values show 1.17 in that entire range. I don't think that is even remotely plausible.
when you are tuning for afr you take the stoich number which is usually set at 14.7. the number is represented as a 1 in lambda table. to richen up your tune you would divide. ie if you were looking for an afr of 11.7 for your typical forced induction application you would divide by 1.25 to achieve the correct value. therefore the value you would put into the table for a richer than stoich tune would be anything higher than 1.0
1=14.7 afr
1.25=11.75 afr
EDIT: effective communication through typing>me
1=14.7 afr
1.25=11.75 afr
EDIT: effective communication through typing>me
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when you are tuning for afr you take the stoich number which is usually set at 14.7. the number is represented as a 1 in lambda table. to richen up your tune you would divide. ie if you were looking for an afr of 11.7 for your typical forced induction application you would divide by 1.25 to achieve the correct value. therefore the value you would put into the table for a richer than stoich tune would be anything higher than 1.0
1=14.7 afr
1.25=11.75 afr
EDIT: effective communication through typing>me
1=14.7 afr
1.25=11.75 afr
EDIT: effective communication through typing>me
when you are tuning for afr you take the stoich number which is usually set at 14.7. the number is represented as a 1 in lambda table. to richen up your tune you would divide. ie if you were looking for an afr of 11.7 for your typical forced induction application you would divide by 1.25 to achieve the correct value. therefore the value you would put into the table for a richer than stoich tune would be anything higher than 1.0
1=14.7 afr
1.25=11.75 afr
1=14.7 afr
1.25=11.75 afr
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Thread Starter
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"The values in this table are Equivalence Ratio's (Fuel/Air multipliers or AFR divisors) ie. values greater than one are richer, values less than one are leaner. The values relate directly to the Stoich AFR and the resulting commanded AFR is Stoich divided by this PE equivalence ratio. Eg. if the multiplier is 1.1 then the commanded AFR will be 14.7/1.1 or 13.36."
atleast i had my math right
post up a screen of the PE table
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just a sec... at the coffee shop with my tuning laptop, need to download ftp client so can upload pics....
.... ok got it, here's the stock PE table, had to take two screenshots to get most of the RPM range. It goes up to 8k, but stays at 1.17 from 4500 on up.
.... ok got it, here's the stock PE table, had to take two screenshots to get most of the RPM range. It goes up to 8k, but stays at 1.17 from 4500 on up.
Last edited by jperris; Apr 16, 2008 at 02:45 PM. Reason: added screenshots
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yes, it seems to be as simple as that for tuning WOT afrs, just monitor your afrs at WOT and adjust accordingly.
as for the interface, yes, you're adjusting the same values in the same way as you would with HPTuners, if they supported the E37, which i think they probably will eventually.
so, if you have the need to see pretty colors while tuning, you can hold out for HPT.
as for the interface, yes, you're adjusting the same values in the same way as you would with HPTuners, if they supported the E37, which i think they probably will eventually.
so, if you have the need to see pretty colors while tuning, you can hold out for HPT.
no money for dyno time at the moment.
also, still looking for a solution for our intake cams.
i called comp cams' tech line, i asked if they could regrind a stock cam on a smaller base circle, and the guy told me that was a no-go, he mumbled something about hardness and heat-treating, and didn't really have any suggestions to offer. The guy was actually pretty rude about it and finally he hung up on me without any kind of "goodbye" or "have a nice day". So much for southern hospitality, I buy a set of cams from these people and they won't hardly give me the time of day. Another large performance parts company gone bad, I guess.
also, still looking for a solution for our intake cams.
i called comp cams' tech line, i asked if they could regrind a stock cam on a smaller base circle, and the guy told me that was a no-go, he mumbled something about hardness and heat-treating, and didn't really have any suggestions to offer. The guy was actually pretty rude about it and finally he hung up on me without any kind of "goodbye" or "have a nice day". So much for southern hospitality, I buy a set of cams from these people and they won't hardly give me the time of day. Another large performance parts company gone bad, I guess.
The guy told me there nuthing he could do and to send them back..he was rude as ****...i was like thanx for the help ******* and he hungup...i was like WTF?
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