This is topic Crazy ass Air Fuel Ratio????????? in forum Tech Talk at Northern California Ford Owners  .


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Posted by 4RS FED (Member # 2067) on :
 
i am using a pms to tune my twin turbo car

i have no idea about it... i have a tune in it that a guy put in, seemed to work fine, now i have changed the intake and the roller rockers, and installed a boost controller in it.... i want to get your opinions on it........

here is the tune

Year model: 1991 mustang
Engine cubic inch: 306
Power Adder/NA: twin turbo
Amount of boost/nitrous: 8 psi
Intake: gt-40
Throttle Body: 75mm
Mass Air Meter: 3.5 Univ blow thru
Intake Piping:3 inch after intercooler
Cylinder Head & rockers: 351 gt-40 heads with O-rings 1.7 roller rockers
Camshaft profile: f 303 cam
Injector Size: motorsport 42#
FMU type:none
Header size/type: 1 5/8-1 3/4
Fuel Pump(s):Aeromotive A1000
Rails: 1/2 inch
Supply/Return Line size:supply -8 return -6
Fuel type: pump gas 91 octane

IDLE Control On/Off: ON
fuel:
timing: +15*
start-up fuel: -40%
idle air adjuster: 63%
Low Load (Fuel first & Timing second)
2200rpm: 0/0
4000rpm: 0/0
6000rpm: 0/0
7800rpm: 0/0
Medium Load (Fuel first & Timing second)
2200rpm: 0/0
4000rpm: 0/0
6000rpm: 0/0
7800rpm: 0/0
High Load (Fuel first & Timing second)
2200rpm: 0/ +12*
4000rpm: 0/ +10*
6000rpm: 0/ +8*
7800rpm: 0/ +6*
WOT (Fuel first & Timing second)
2200rpm: +12% / +12*
4000rpm: +10%/ +0*
6000rpm: +8%/ +0*
7800rpm: +6%/ +0*
Boost or Tables: (Fuel first & Timing second)
Max Boost setting: 15
@1 psi
2200rpm: +0 /-7*
4000rpm: +0 /-7*
6000rpm: +0/ -7*
7800rpm: +0/ -7*
@Max Boost
2200rpm: +14% / -18*
4000rpm: +12% / -15*
6000rpm: +12% / -15*
7800rpm: +12% / -15*
Standalone On/Off: ON
Rev Limiter: 7000

all pulls were with 8 psi of boost

anyhow.. here is the A/F graph

it is using a wideband that was installed in the drivers side down pipe about 24 inches from the outlet of the turbo....



looks crazy!!!!!!


here is the horsepower graph.....




here is the torque graph.......


 

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Posted by mtbaughs (Member # 4052) on :
 
Yikes that thing runs way to lean from 2100 to 5000 rpms. I'm a little suprised they didn't wave the run off. It's fat at the very top where you would be making your peak numbers. When I worked next to the dyno ideal was an air/fuel which followed a pretty consistant path of 12.0:1 to 12.5:1 for forced induction. Your AFR is all over the map. I don't know a whole lot about PMS but I have seen people tune it well. From what I've seen with it it's about making minor adjustments and than doing a run and so on till you achieve the results.
 

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Posted by 66 AC COBRA (Member # 904) on :
 
get on stang tuning, there are a ton of pms tuners on there
 

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Posted by mtbaughs (Member # 4052) on :
 
WOT (Fuel first & Timing second)
2200rpm: +12% / +12*
4000rpm: +10%/ +0*
6000rpm: +8%/ +0*
7800rpm: +6%/ +0*


I'd start by increasing fuel from 2200 up to 5000 but remember I am no expert with this system. It's just what I would do based on other tuning methods I have seen. Make small changes and the thing that sucks is you'll be renting the dyno for at least 1-2 hours to properly do it
 

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Posted by mtbaughs (Member # 4052) on :
 
And theres the reason why you most likely lifted your head gasket. Same car right?
 

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Posted by Black94 5.0 (Member # 655) on :
 
What happens at 3,100rpm?...It's obvious thats when things start to happen....When do you see full boost?....

I wish I could help you more....
 

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Posted by DropTopFox (Member # 1689) on :
 
The circle is still my favorite part. WHat the hell was that all about
 

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Posted by John91coupe (Member # 18) on :
 
I know this is going to sound crazy but here's what I would do at this point. Contact Byron Reynolds and arrange to get a custom chip and some dyno time. You would have a really good chance at getting that screwy A/F ratio in line through the chip work and then use the PMS for fine tuning for weather conditions, fuel octane, etc. You would most likely need to set your PMS fuel settings to neutral/zero and the timing to something conservative to start with and let the custom chip do the heavy work. Just a suggestion.
 

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Posted by mustanggt5091 (Member # 444) on :
 
I would start by adding fuel in the medium throttle maps, you dont have any thing added for fuel If the tune sheldon did is on set 1 for instance, save al your data to set 2 and that way you can toggle back and forth to see the differences to make sure you are going in the right direction! I am still learning the PMS system myself, lots of shit you can do!!!!!!!!!!

[ March 15, 2004, 09:22 AM: Message edited by: mustanggt5091 ]
 

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Posted by Jeff S (Member # 371) on :
 
There is NOT A SERIOUS PROBLEM with your AF ratio. There only appears to be a problem with your car being lean do to the fact the dyno operator is pressing the button to start recording info before you are going to WOT. As you can see in the RWHP graph you do not actually go WOT until ~3650rpm(which seems to be the case since you are only making 50hp and 75ft#'s at 3500rpm) at which point your car is running ~15:1 AF like it should be at part throttle.

You need to go WOT around 2000-2500rpm and have the dyno operator not start recording data until you are WOT.

After you go WOT the fuel curves could be flattened out with some timing of the fuel tables. The "spike" at 4500rpms is a flaw of the PMS's stand alone feature kicking in.
 

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Posted by Jeff S (Member # 371) on :
 
I'm also confused by the "High Load" timing settings and the -7* being pulled at 1psi boost seems odd as well.
 

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Posted by DropTopFox (Member # 1689) on :
 

quote:

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Originally posted by John91coupe:
I know this is going to sound crazy but here's what I would do at this point. Contact Byron Reynolds and arrange to get a custom chip and some dyno time. You would have a really good chance at getting that screwy A/F ratio in line through the chip work and then use the PMS for fine tuning for weather conditions, fuel octane, etc. You would most likely need to set your PMS fuel settings to neutral/zero and the timing to something conservative to start with and let the custom chip do the heavy work. Just a suggestion.

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Like I said Rob, have Byron do a flip chip, one side for the 5 psi tune and one side for the 16 psi tune
 

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Posted by Jeff S (Member # 371) on :
 

quote:

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Originally posted by DropTopFox:

quote:

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Originally posted by John91coupe:
I know this is going to sound crazy but here's what I would do at this point. Contact Byron Reynolds and arrange to get a custom chip and some dyno time. You would have a really good chance at getting that screwy A/F ratio in line through the chip work and then use the PMS for fine tuning for weather conditions, fuel octane, etc. You would most likely need to set your PMS fuel settings to neutral/zero and the timing to something conservative to start with and let the custom chip do the heavy work. Just a suggestion.

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Like I said Rob, have Byron do a flip chip, one side for the 5 psi tune and one side for the 16 psi tune

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quote:

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Originally posted by Jeff S:

quote:

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Originally posted by DropTopFox:

quote:

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Originally posted by John91coupe:
I know this is going to sound crazy but here's what I would do at this point. Contact Byron Reynolds and arrange to get a custom chip and some dyno time. You would have a really good chance at getting that screwy A/F ratio in line through the chip work and then use the PMS for fine tuning for weather conditions, fuel octane, etc. You would most likely need to set your PMS fuel settings to neutral/zero and the timing to something conservative to start with and let the custom chip do the heavy work. Just a suggestion.

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Like I said Rob, have Byron do a flip chip, one side for the 5 psi tune and one side for the 16 psi tune

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Do you guys really think that a autologic chip is better than a PMS? Or is it that you think the person doing the tuning is the problem?

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Idon't think rob nor anyone he's had on the PMS knows the system well enough to tune Rob's car. I'm sure the PMS is great if you know how to use it to your advantage, but it doesn't seem like Rob does at this point so why not have Byron do a quick fix on it until Rob learn's the PMS system inside and out
 

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Posted by 87 Saleen (Member # 1549) on :
 
What's up with the first graph?! That's not a function. Not a function at all!!
 

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Posted by jmcclesk (Member # 1355) on :
 
I have been throught the eectuner and the tweeker rt and finaly the epec. the BEST thing i ever did to figure out the systems was to buy a wide ban o2 sensor that data logged. It also logged rpm's and one 5 volt sensor. that was i could make small changes and see the AFR change. once i did that it was VERY easy to nail down the afr. just my two cents worth.

[ March 17, 2004, 10:36 PM: Message edited by: jmcclesk ]
 

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Posted by mustanggt5091 (Member # 444) on :
 

quote:

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Originally posted by jmcclesk:
I have been throught the eectuner and the tweeker rt and finaly the epec. the BEST thing i ever did to figure out the systems was to buy a wide ban o2 sensor that data logged. It also logged rpm's and one 5 volt sensor. that was i could make small changes and see the AFR change. once i did that it was VERY easy to nail down the afr. just my two cents worth.

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Thats exactly what I just did, I just purchased a LM-1 o2 sensor to aid in tuning my car with my PMS
 

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