I recently rebuilt the motor in my STI and installed a lightweight flywheel in the process. Upon putting it back together and driving it around I feel at certain times when i punch the throttle there is some lag. Now that i went from 110 feet above sea level to 5000 feet above sea level it feels even worse. I have a little bit of experience tweaking the map in my vehicle using the tactrix cable and romraider so as long as i can get some guidance in which parameters to change that would be excellent. thanks...
lightweight flywheel+elevation drivability
- Thread starter fuji_production
- Start date
what do you mean? So far i have done all the tuning on my car myself. self tuned stage 2 at 21.5 psi
im just looking for the specific parameters that need to be changed that affect the drivability of both due to the flywheel and higher elevation.
Okie dokie. We will get that for you.
HolyCrapItsFast
Drinks beer!
Is there hesitation or it just feels like it is lacking in power. That is actually expected when changing altitude. I kinda doubt it has to do with the flywheel. Usually that effects missfire counts and I don't believe those tables are available in RomRaider that I can find.
Some tables you can look at to improve your power at different elevations are Target Boost, Target Boost Compensation Multiplier and offset, Waste Gate Duty, Initial Waste Gate Duty compensation (ATM Pressure), Engine Load Compensation (MP), Timing compensation (MRP). All of these are closely related to altitude and you may or may not have to touch them.
Essentially you will need to tune specifically for the elevation you are at because the stock values in these tables are either geared toward emissions and safety or are not very well defined from the factory. You should also have a clear understanding of what your turbo likes to see so you need to become very familiar with the compressor map to determine the most ideal target boost for the elevation you are at. It may be quite a bit lower than you would think.
The good news is you don't have to do much fuel tuning provided you are properly tuned to begin with. If yours is a MAF based tune then the altitude is inherently compensated for automatically. :tup:
Some tables you can look at to improve your power at different elevations are Target Boost, Target Boost Compensation Multiplier and offset, Waste Gate Duty, Initial Waste Gate Duty compensation (ATM Pressure), Engine Load Compensation (MP), Timing compensation (MRP). All of these are closely related to altitude and you may or may not have to touch them.
Essentially you will need to tune specifically for the elevation you are at because the stock values in these tables are either geared toward emissions and safety or are not very well defined from the factory. You should also have a clear understanding of what your turbo likes to see so you need to become very familiar with the compressor map to determine the most ideal target boost for the elevation you are at. It may be quite a bit lower than you would think.
The good news is you don't have to do much fuel tuning provided you are properly tuned to begin with. If yours is a MAF based tune then the altitude is inherently compensated for automatically. :tup:
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the lack of power is expected of course. the issue is sometimes when i peg the throttle at idle it doesnt rap right up or have that crisp throttle response. or when you push the pedal in the lower rpm's there is just a large lack of torque...its been like this since ive owned it for the past coupld of years. its a 2005 sti. ive tried getting the open/closed loop within good ranges as well as getting all the boost/wastegate tables on point but havent touched tip in, timing, or any other tables...
HolyCrapItsFast
Drinks beer!
Gotcha... Timing is probably the most important parameter for drivability. :tup: I would suggest looking at the areas of the base timing tables while you drive and see where you could use improvement. To many times will I see people remove timing across the whole table because they feel it would be safer but really our cars like to see quite a bit of timing in the lower and mid load regions of the map. The other tables you might want to look at are the drive by wire tables for requested torque and throttle plate position. These will give you back some crisp response but I would look at timing first.
If you can would you post a log just driving around? I would like to see if I can pick anything out particularly. I'm interested in timing and fueling parameters mostly. Also do you have larger than stock injectors installed? That can often have a profound effect on drivability when at altitude because of the lower duty cycles. The effects can be tuned out in most cases but it is not easy because you have to do a tremendous amount of logging and much of the solution is intuition.
If you can would you post a log just driving around? I would like to see if I can pick anything out particularly. I'm interested in timing and fueling parameters mostly. Also do you have larger than stock injectors installed? That can often have a profound effect on drivability when at altitude because of the lower duty cycles. The effects can be tuned out in most cases but it is not easy because you have to do a tremendous amount of logging and much of the solution is intuition.
I can def post some logs up. I have stock injectors so im still running all the stock values in the appropriate tables...I keep thinking that tip in needs to be altered. Is my belief behind tip in wrong? I just feel like when i give the throttle a quick tap there should be some quick, crisp, throttle response in there...
HolyCrapItsFast
Drinks beer!
Oh yes Tip-in can most definitely be a factor. 
And you will notice the effects even more at altitude because the tip-in fueling isn't compensated by the MAF routines. But usually you will notice tip-in symptoms like a stumble or a dead spot just as you give it some gas. From what you describe it sounds to me that you are just lacking response and/or power which doesn't really sound like tip_in to me, but you never really know until you start playing around with it.
Do you have a wide band AFR gauge at you disposal? You can see tip-in problems right away on the wide band by observing a lean spike as you quickly apply the gas. Then you will know, with great certainty, that you will need to tune your tip-in :tup:
So yeah, go ahead and give me a log just driving around normally. I'm interested only in the following parameters and use the fast poll feature in RR logger...
? Engine Speed (RPM)
? Engine Load
? IAM
? A/F Correction #1
? A/F Learning #1
? A/F Sensor #1
? CL/OL Status
? Feedback Knock Correction (FBCK)
? Fine Learning Knock Correction (FLKC)
? Ignition Base Timing
? Ignition Total Timing
? Knock Correction Advance
? Mass Air Flow Sensor Voltage
? Throttle Opening Angle
? Manifold Relative Pressure
? Primary Waste Gate Duty Cycle
? Injector Duty Cycle
? Intake Air Temp
George.
And you will notice the effects even more at altitude because the tip-in fueling isn't compensated by the MAF routines. But usually you will notice tip-in symptoms like a stumble or a dead spot just as you give it some gas. From what you describe it sounds to me that you are just lacking response and/or power which doesn't really sound like tip_in to me, but you never really know until you start playing around with it.Do you have a wide band AFR gauge at you disposal? You can see tip-in problems right away on the wide band by observing a lean spike as you quickly apply the gas. Then you will know, with great certainty, that you will need to tune your tip-in :tup:
So yeah, go ahead and give me a log just driving around normally. I'm interested only in the following parameters and use the fast poll feature in RR logger...
? Engine Speed (RPM)
? Engine Load
? IAM
? A/F Correction #1
? A/F Learning #1
? A/F Sensor #1
? CL/OL Status
? Feedback Knock Correction (FBCK)
? Fine Learning Knock Correction (FLKC)
? Ignition Base Timing
? Ignition Total Timing
? Knock Correction Advance
? Mass Air Flow Sensor Voltage
? Throttle Opening Angle
? Manifold Relative Pressure
? Primary Waste Gate Duty Cycle
? Injector Duty Cycle
? Intake Air Temp
George.
fast poll feature? i'm not familiar with that...
oh and yes i have a wideband at my disposal. Ive been working on tuning my own vehicle for the past few months...
HolyCrapItsFast
Drinks beer!
It's really cool... the latest version of RomRaider has a fast poll feature that allows you to log twice the amount of data in the same amount of time so you can really capture alot of data that otherwise you might miss. In the logger if you look up toward the top you will see a check box option for it. I do believe that it is available for all 32bit ecu's
thats awesome...i really need to experiment more with the software to show my gratitue toward the software developers of the open source rhealm(sp?)
would you like me to reset the ecu as well?
HolyCrapItsFast
Drinks beer!
Good call! Maybe take a quick log just to capture the conditions as they are and then another after reset so we are not looking at learned data :tup:
When you do log maybe you could give the throttle a couple of quick stabs just to see what tip-in is doing and the rest of the time you can drive normally
When you do log maybe you could give the throttle a couple of quick stabs just to see what tip-in is doing and the rest of the time you can drive normally
Alright, i know im a little behind but im having a hard time getting the logger to work. It keeps cutting out while i try to log so i cannot gather any data at all. I get an interference error or something like that...so i need to troubleshoot that. i did pull a learning view and i have an error of -15 in the first box for fuel trims so i think that is where my problem is at. Any input?
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