Having trouble with dyno tuned FP Green on STi

nathansvt · 11-25-2005, 10:34 PM

A a professional tuner dyno tune my car and it runs great at full throttle or highway driving < 25% throttle. But anything between that and It's very uncooperative.

I've got an 04 STi with internally gated FP green and supporting mods. I have a dyno-tuned map on my street tuner.

The car runs great at full throttle. My 1/4 mi mph is around 109 with piss-poor driving. So that part seems fine.

What bugs me is that the drives like crap at part-throttle. Highway cruise is fine, but any kind of acceleration less than about 90% results in one of two scenarios:

1) car bucks and shudders until revs get above 3500, then takes off.

2) car builds full boost (18-20psi) and the turbo makes lots of noise, but the car goes nowhere for 4-5 seconds then takes off.

This only happens at roll-on from 3rd gear or better. Launch from 1st or roll-on in 2nd runs great all the way through the gears, I suspect because I'm going strong from the start rather than trying to pull from a highly-loaded state in a relatively high gear.

I posted logs over on nabisco

http://forums.nasioc.com/forums/show...7#post11788237

Or you can grab the .zip file from here:

Helpme.zip

I'm new to tuning and don't feel comfortable overly second-guessing an otherwise reputable tuner. But my car runs like crap and I'm afraid something bad (TM) is gonna happen if I keep driving it as-is.

WolfPlayer · 11-26-2005, 10:19 AM

I have an '05 so I can't open these files. I'd love to take a look though so if anyone with '04 StreetTUNER could maybe get some screenshots ... or maybe anyone with ProTUNER could save for an '05?

I took a look at the logs you posted and your 'engine load' doesn't even look close to correct. Now, engine load is just engine load. It is a variable calculated off of MAF,RPM,Boost, etc. Are you running a large MAF tube? If so - cool. If not, then something is causing the engine load to be way below normal. Please list all your mods.

I'd like to see a FULL scan. Drive the car around until it gets up to temperature. Start recording. Reproduce some problem areas, and do some true WOT (2000rpms to 6500rpms). Make sure to collect Abs Pressure, Baro Pressure, Engine Load, Dyn Advance, Ign. Advance, Knock Activity, Wastegate, Throttle position, AFR, RPM, Injector Pulse Width, Coolant Temp, and Intake Air temp. Put your scanning on 5 records per second .... nothing more. Don't try to start and stop the logs to catch something specific. Just put it all in one log and capture as much stuff as you can in that one log. If you want, open that log up in excel and highlight areas and make comments next to those areas. But, I'd like to see everything in order to put everything in context.

Before doing the above, do an ECU reset and drive around for a day and do a few WOT pulls. THEN get the logs.

t

nathansvt · 11-26-2005, 11:28 AM

Quote:

Originally Posted by WolfPlayer

I have an '05 so I can't open these files. I'd love to take a look though so if anyone with '04 StreetTUNER could maybe get some screenshots ... or maybe anyone with ProTUNER could save for an '05?

Actually, the files I posted are not the maps. They're just the logs. Grab the .zip file and you'll find the logs in both .csv and .xls (excel) format. Any decent spreadsheet should be able to open them. I guess the cobb logviewer can even open the .csv files.

Quote:

I took a look at the logs you posted and your 'engine load' doesn't even look close to correct. Now, engine load is just engine load. It is a variable calculated off of MAF,RPM,Boost, etc. Are you running a large MAF tube? If so - cool. If not, then something is causing the engine load to be way below normal. Please list all your mods.

oops. should have been more specific. I do have a Perrin BigMAF.

Perrin bigMAF
Perrin FMIC
FP Green (2.4" inlet)
Perrin modded injectors
StreetTuner
TXS catted stealthback
stock plugs

Quote:

I'd like to see a FULL scan. Drive the car around until it gets up to temperature. Start recording. Reproduce some problem areas, and do some true WOT (2000rpms to 6500rpms). Make sure to collect Abs Pressure, Baro Pressure, Engine Load, Dyn Advance, Ign. Advance, Knock Activity, Wastegate, Throttle position, AFR, RPM, Injector Pulse Width, Coolant Temp, and Intake Air temp. Put your scanning on 5 records per second .... nothing more. Don't try to start and stop the logs to catch something specific. Just put it all in one log and capture as much stuff as you can in that one log. If you want, open that log up in excel and highlight areas and make comments next to those areas. But, I'd like to see everything in order to put everything in context.
Before doing the above, do an ECU reset and drive around for a day and do a few WOT pulls. THEN get the logs.

These logs were taken within 48 hours of an ECU reset, although the earlier logs in the zip file had about a week and a half run time since reset. To avoid clogging up the forum, I posted edited logs, but the ones in the zip file are full pulls, and the xls versions have color highlights in what I think are the problem areas.

The tune is by a 'reputable' professional tuning shop who will remain nameless for now. It was a pro-tune that was then exported to streettuner format.

WolfPlayer · 11-26-2005, 11:47 AM

I grabbed the zip file and the zip file contains the actual maps. High, low, Torco, and the base map. There are no logs in that ZIP file.

t

nathansvt · 11-26-2005, 07:03 PM

Quote:

Originally Posted by WolfPlayer

I grabbed the zip file and the zip file contains the actual maps. High, low, Torco, and the base map. There are no logs in that ZIP file.

t

oops. link is now fixed.

WolfPlayer · 11-28-2005, 06:24 PM

Nathan,

Nothing in the logs looks that awkward to me. However, I am not familiar with optimal timing for an FP Green so I can't say that the timing is OK. What did find very interesting is that you are getting over 18.5lbs of boost by 3000 rpms. On an FP Green? If so - WOW. I don't think I have ever heard of an FP Green spooling that fast. Some people can't even get their VF39's to spool that quickly. I feel weird asking you if you are sure it is an FP green but I must ... are you sure it's an FP Green? If so ... double wow on the incredible spoolup you are getting.

The biggest piece of data that is missing here is Wideband O2 data. I have a feeling the car is running too rich in that 3000-3500 region and you are getting the bucking/stuttering you mention. I am guessing a tip-in enrichment problem since you are fine when you start out in first or second. However, we can't really know for sure unless you have some logs with wideband data. The stock factory O2 is useless at this point because it is bottomed out.

t

***MidlifeCrisis*** · 11-28-2005, 08:16 PM

Nathan, I have a fairly similar setup to yours in my 04. My TD06H 50-Trim is quite close to an FP Green from what I understand, and my supporting mods are relatively the same (see the link in my signature). I am, however, using a Typhoon (integrated MAF housing) and not a big MAF housing. I'm not at a primo state of tune yet, but I'm getting there and the car is quite streetable, very fast, and I am not experiencing the driveability problems you are.

So, perhaps I can help some with comparative analysis. I would expect that my logs and yours should be similar, notwithstanding the 5000 foot difference in elevation. If it becomes useful, I can open your map files with my version of ST and put up relevant tables as .gif or .jpg for analysis by others (Wolf).

In looking at some of the logs in the .zip file, the first thing I see is that the Engine Load values are WAY low for the inputs you are giving the car. This smacks of a completely improper intake calibration.

I notice that its taking 1.0 seconds from the time you punch it until it goes into open loop, based on the A/F Trim Immed. value. When the ECU goes into open loop, it will put 0.39 there for the duration. For an STi, the Closed Loop Delay table should be all 0s and the Closed Loop TPS table should be somewhere around 40% up to around 4k RPM or so and then 0 from there on up.

With your FP Green turbo, you need to log Abs. Pres. and Baro. Pres. and forget about Rel. Pres. For some reason Rel. Pres. maxes out at 18.42, but you can calculate the actual real boost pressure by subtracting Baro. from Abs. in the spreadsheet. Works for me running boost in the low 20s. From the logs I looked at I can't tell where your boost is really going. In some of the logs WGDC values do not look like mine, they're wierd. Need to see the real boost values.

Without a wideband, it is challenging to tell how rich you are really going. Part of the problem could be that you are going seriously too rich in this RPM range. If that is the case, a solution may be to fix an improper intake calibration in that area. Perhaps your tuner didn't touch this area, focusing only on the WOT areas instead. The Big MAF would have made a mess of this area if it weren't addressed.

What Injector Scale value are you running for the Perrin modified injectors? 3286 seems to be about the right place for my PE850s. This was chosen based on an actual flow test of my stock 04 injectors showing them to flow at 520, not 480 as Christian had assumed.

The above assumes no mechanical or installation problems, air leaks in particular. Be sure all your plumbing is where it is supposed to be and all clamps are tight. Have you modified your boost control solenoid system at all or added springs, etc. to the wastegate actuator? Is the air restrictor pill still installed in the boost control lines? Too much to speculate about, hope it is all properly installed.

I can post log snippets of my car attempting similar pulls for you if that would help for comparison. Here is one from today logging a short mid-RPM high gear WOT pull up a hill at about 6000 ft elev. and I am running 91 oct winter crap fuel we get here (w/10% MTBE, stoich 11.7) I had just reset the ECU:

You'll notice:

1. Boost spike - I'm currently playing with aggressive WGDC values and Turbo Dynamics. Boost targets in this map are 2600-15.0, 3200-18.0, 3600-19.01, 4000-19.99.

2. Too rich at tip-in - I have not messed with fuel much yet, just keeping it safely rich for now.

3. Engine Load in the low 3s - I would expect to see this on your car. I have hit 3.9 in some instances.

4. Goes into open loop instantly based on A/F Trim Immed. values

I don't know if this comparison helps, but it feels good writing it.

I'll defer to Wolf, Christian, Scott, and others for the deep stuff and help if I can.

-Bruce

WolfPlayer · 11-29-2005, 04:03 AM

Quote:

Originally Posted by MidlifeCrisis

In looking at some of the logs in the .zip file, the first thing I see is that the Engine Load values are WAY low for the inputs you are giving the car. This smacks of a completely improper intake calibration.

Bruce,

That was the first thing that I noticed too. However, if he has a big MAF installed - which he does - then those load values can be AOK. In fact, that's the entire purpose of a big MAF. A big MAF will basically result in a reduction of load values. For a given MAF voltage the big MAF will be taking in a lot more air. Working in reverse, this means that the SAME amount of air will come at the result of less MAF voltage. This makes sense when you think about the whole reason of installing a big MAF is to get around the issue of the MAF maxing out. Thus, with lower MAF voltages, the overall load will be lower.

t

***MidlifeCrisis*** · 11-29-2005, 07:05 AM

Not sure I agree, and here's why. A big MAF housing will reduce the velocity of air passing by the MAF sensor for a given total mass of air, thus reducing the cooling effect, therefore lower voltage for the air mass rate. This allows more air to be passed before the sensor VOLTAGE maxes out. I believe we agree so far. The intake calibration table converts the voltage to air mass. In ordrer for the car to run right, the intake cal table has to be massaged (increase air mass for a given voltage roughly as much as the area increase between the housings as a starting point) and then tuned just like any other intake changes would need to be. In the end, for a given MAF voltage, a higher air mass value will be taken by the ECU to use in subsequent calculations.

I contend that it is the AIR MASS, NOT the VOLTAGE that is used in the load calculations. This should not change how the car runs if it is tuned properly. It will simply allow a larger mass of air to be measured before the sensor saturates. So, even though the actual sensor voltage is lower, the calculations should be based on the *real* air mass and thus the loads should be the same as any properly calibrated car.

Right? Help me if I'm all wrong here.

Christian. · 11-29-2005, 03:40 PM

I am willing to help out...I would like to see some datalogs that show MAF Voltage, Engine Load, Ignition Timing, DA, Relative Pressure, & TPS (some datalogs had them, some did not) added if possible. If the datalogs could be from 2k to 5 or 6k at 100% TPS that would be helpful for analyzing the WOT tune. Otherwise, just let me what row # you would like me to look at for a particular datalog. The highlighting you did worked as well. Analysis would be easier (more simple if you labeled the .csv or .xls files something like Datalog A, Datalog B, etc.) I think this would be more benficial if we could just focus on one datalog at a time then have a group discussion about that particular event in that one datalog. I am at PRI this week so my responses may be a little slow.

I am not bashing...but I can almost guarantee you the great majority of any drivability/tuning issue is created by the improperly designed intake system. I know this from experience. That particular intake system will fluctuate MAF voltage at two points along your run. These points will not be RPM, load, gear, boost, etc. dependent; thus impossible to properly tune. I can further explain once I have some additional data to demonstrate what I am talking about.

If I do not get back to this thread by Wednesday of next week please PM me.

Take care,
Christian.

Adam · 11-29-2005, 05:29 PM

Curious about the discussion:

Adam

WolfPlayer · 11-29-2005, 06:40 PM

Bruce,

I'm going to rattle on to see where I go with this - even I don't know yet, lol. The entire point of a big MAF is so that you don't hit the upper limit of the MAF. This is accomplished by rescaling the MAF table to indicate that a given MAF voltage equals more Oxygen entering the engine. Thus, 4v on a big MAF equals a lot more air than 4v on a stock MAF. Engine load is based on RPMs and MAF. Yea - I see what you are saying ... and it totally makes sense. Actual g/s and not MAF voltage. In fact, this is how load (LV8) is calculated in Domestic applications. I must have had a brain fart above? Not sure. I hope it is done via actual g/s and not voltage. Somebody should paruse NABISCO and search down a log from a big MAF setup just to make sure.

t

***MidlifeCrisis*** · 11-29-2005, 07:25 PM

Perusing.........

{edit} Perused. Nada.

-B

nathansvt · 11-29-2005, 08:02 PM

thanks for the input guys. I'm going to try to get a wideband in the car ASAP so I can see what's really going on with the A/F. I didn't know the Cobb is bugged with the rel. pressure setting so I'll go back to using ABS pressure and doing the conversion in excel.

Adam · 11-29-2005, 09:10 PM

My input is this (take it for what its worth):

Your car was tuned on ST, something the turners were not real familar with, regardless of experence its not what they use on a daily basis.

Also, the use of torco on your tune has obvously messed things up. I understand the senario as it unfolded but it is not going to provide a reliable tune on normal gas, even if they detune the setup for wot, your pt and daily driving is inherintly off.

Knowing your problems are all over the place not sure you can pin it to just a MAF issue. My car with exact mods (i have tgv's deleted) has tunred out well with only minor issues, none so as you have run into. This leads me to think the MAF maybe an issue, but is not THE issue as my car is relatively well off with this piece of hardware.

You are going to have to use a wideband and log the hell out of the car documenting the exact time of your issues. I am sure the said tuner will work it out, even though I also have the same experence regarding "send them an email and they will respond asap"..... Still, 2 months later I am waiting to have the TGV cel's turned off as promissed on the day of our tune, and a week later when I called, and 10 days ago some 45 days after the tune when I asked again, all 3 or 4 times was asked to send an email which gets lost in the cyber sea of x's and o's with no decipher of any one reading it on the other side... Let alone any thought of a reply....

I know your car is fast, in some cases faster then my car with a larger inlet and tgv's removed... But your not at my 12.3 1/4 at 112 yet. I WILL HIT 11's this winter some time!!

Give me a call soon if you want, I can get you some logs if you are seeking compairsons, however I use the TARI logging software so I am not sure if the values will align?

Adam

11-25-2005, 10:34 PM	#1
nathansvt Junior STI Driver Posts: 128 Join Date: Sep 2003 Trader Rating: (0)	Having trouble with dyno tuned FP Green on STi A a professional tuner dyno tune my car and it runs great at full throttle or highway driving < 25% throttle. But anything between that and It's very uncooperative. I've got an 04 STi with internally gated FP green and supporting mods. I have a dyno-tuned map on my street tuner. The car runs great at full throttle. My 1/4 mi mph is around 109 with piss-poor driving. So that part seems fine. What bugs me is that the drives like crap at part-throttle. Highway cruise is fine, but any kind of acceleration less than about 90% results in one of two scenarios: 1) car bucks and shudders until revs get above 3500, then takes off. 2) car builds full boost (18-20psi) and the turbo makes lots of noise, but the car goes nowhere for 4-5 seconds then takes off. This only happens at roll-on from 3rd gear or better. Launch from 1st or roll-on in 2nd runs great all the way through the gears, I suspect because I'm going strong from the start rather than trying to pull from a highly-loaded state in a relatively high gear. I posted logs over on nabisco http://forums.nasioc.com/forums/show...7#post11788237 Or you can grab the .zip file from here: Helpme.zip I'm new to tuning and don't feel comfortable overly second-guessing an otherwise reputable tuner. But my car runs like crap and I'm afraid something bad (TM) is gonna happen if I keep driving it as-is. This ad is not endorsed by this member. Please register or login to hide this ad.

11-28-2005, 06:24 PM	#6
WolfPlayer Moderator & ECU Tech Car: 05 CGM STI Fav Mod: mo boostaz Location: Fredneck, MD Posts: 3,620 Join Date: Jun 2004 Trader Rating: (6)	Nathan, Nothing in the logs looks that awkward to me. However, I am not familiar with optimal timing for an FP Green so I can't say that the timing is OK. What did find very interesting is that you are getting over 18.5lbs of boost by 3000 rpms. On an FP Green? If so - WOW. I don't think I have ever heard of an FP Green spooling that fast. Some people can't even get their VF39's to spool that quickly. I feel weird asking you if you are sure it is an FP green but I must ... are you sure it's an FP Green? If so ... double wow on the incredible spoolup you are getting. The biggest piece of data that is missing here is Wideband O2 data. I have a feeling the car is running too rich in that 3000-3500 region and you are getting the bucking/stuttering you mention. I am guessing a tip-in enrichment problem since you are fine when you start out in first or second. However, we can't really know for sure unless you have some logs with wideband data. The stock factory O2 is useless at this point because it is bottomed out. t Last edited by WolfPlayer : 11-28-2005 at 06:28 PM.

11-29-2005, 03:40 PM	#10
Christian. STI Driver Car: 01 Subaru WRX STi Sp Fav Mod: Coming Soon Posts: 262 Join Date: Aug 2005 Trader Rating: (0)	I am willing to help out...I would like to see some datalogs that show MAF Voltage, Engine Load, Ignition Timing, DA, Relative Pressure, & TPS (some datalogs had them, some did not) added if possible. If the datalogs could be from 2k to 5 or 6k at 100% TPS that would be helpful for analyzing the WOT tune. Otherwise, just let me what row # you would like me to look at for a particular datalog. The highlighting you did worked as well. Analysis would be easier (more simple if you labeled the .csv or .xls files something like Datalog A, Datalog B, etc.) I think this would be more benficial if we could just focus on one datalog at a time then have a group discussion about that particular event in that one datalog. I am at PRI this week so my responses may be a little slow. I am not bashing...but I can almost guarantee you the great majority of any drivability/tuning issue is created by the improperly designed intake system. I know this from experience. That particular intake system will fluctuate MAF voltage at two points along your run. These points will not be RPM, load, gear, boost, etc. dependent; thus impossible to properly tune. I can further explain once I have some additional data to demonstrate what I am talking about. If I do not get back to this thread by Wednesday of next week please PM me. Take care, Christian. Last edited by Christian. : 11-30-2005 at 08:15 AM.

11-29-2005, 07:25 PM	#13
*MidlifeCrisis* Platinum Member Car: WRB 04 WRX STi+++ Fav Mod: Tech Exec Location: Golden, Colorado Posts: 153 Join Date: Jul 2004 Trader Rating: (0)	Perusing......... {edit} Perused. Nada. -B Last edited by MidlifeCrisis : 11-29-2005 at 07:30 PM.

11-29-2005, 09:10 PM	#15
Adam Junior STI Driver Posts: 122 Join Date: Mar 2005 Trader Rating: (0)	My input is this (take it for what its worth): Your car was tuned on ST, something the turners were not real familar with, regardless of experence its not what they use on a daily basis. Also, the use of torco on your tune has obvously messed things up. I understand the senario as it unfolded but it is not going to provide a reliable tune on normal gas, even if they detune the setup for wot, your pt and daily driving is inherintly off. Knowing your problems are all over the place not sure you can pin it to just a MAF issue. My car with exact mods (i have tgv's deleted) has tunred out well with only minor issues, none so as you have run into. This leads me to think the MAF maybe an issue, but is not THE issue as my car is relatively well off with this piece of hardware. You are going to have to use a wideband and log the hell out of the car documenting the exact time of your issues. I am sure the said tuner will work it out, even though I also have the same experence regarding "send them an email and they will respond asap"..... Still, 2 months later I am waiting to have the TGV cel's turned off as promissed on the day of our tune, and a week later when I called, and 10 days ago some 45 days after the tune when I asked again, all 3 or 4 times was asked to send an email which gets lost in the cyber sea of x's and o's with no decipher of any one reading it on the other side... Let alone any thought of a reply.... I know your car is fast, in some cases faster then my car with a larger inlet and tgv's removed... But your not at my 12.3 1/4 at 112 yet. I WILL HIT 11's this winter some time!! Give me a call soon if you want, I can get you some logs if you are seeking compairsons, however I use the TARI logging software so I am not sure if the values will align? Adam This ad is not endorsed by this member. Please register or login to hide this ad.

11-26-2005, 10:19 AM	#2
WolfPlayer Moderator & ECU Tech Car: 05 CGM STI Fav Mod: mo boostaz Location: Fredneck, MD Posts: 3,620 Join Date: Jun 2004 Trader Rating: (6)	I have an '05 so I can't open these files. I'd love to take a look though so if anyone with '04 StreetTUNER could maybe get some screenshots ... or maybe anyone with ProTUNER could save for an '05? I took a look at the logs you posted and your 'engine load' doesn't even look close to correct. Now, engine load is just engine load. It is a variable calculated off of MAF,RPM,Boost, etc. Are you running a large MAF tube? If so - cool. If not, then something is causing the engine load to be way below normal. Please list all your mods. I'd like to see a FULL scan. Drive the car around until it gets up to temperature. Start recording. Reproduce some problem areas, and do some true WOT (2000rpms to 6500rpms). Make sure to collect Abs Pressure, Baro Pressure, Engine Load, Dyn Advance, Ign. Advance, Knock Activity, Wastegate, Throttle position, AFR, RPM, Injector Pulse Width, Coolant Temp, and Intake Air temp. Put your scanning on 5 records per second .... nothing more. Don't try to start and stop the logs to catch something specific. Just put it all in one log and capture as much stuff as you can in that one log. If you want, open that log up in excel and highlight areas and make comments next to those areas. But, I'd like to see everything in order to put everything in context. Before doing the above, do an ECU reset and drive around for a day and do a few WOT pulls. THEN get the logs. t

11-26-2005, 11:47 AM	#4
WolfPlayer Moderator & ECU Tech Car: 05 CGM STI Fav Mod: mo boostaz Location: Fredneck, MD Posts: 3,620 Join Date: Jun 2004 Trader Rating: (6)	I grabbed the zip file and the zip file contains the actual maps. High, low, Torco, and the base map. There are no logs in that ZIP file. t

11-28-2005, 08:16 PM	#7
*MidlifeCrisis* Platinum Member Car: WRB 04 WRX STi+++ Fav Mod: Tech Exec Location: Golden, Colorado Posts: 153 Join Date: Jul 2004 Trader Rating: (0)	Nathan, I have a fairly similar setup to yours in my 04. My TD06H 50-Trim is quite close to an FP Green from what I understand, and my supporting mods are relatively the same (see the link in my signature). I am, however, using a Typhoon (integrated MAF housing) and not a big MAF housing. I'm not at a primo state of tune yet, but I'm getting there and the car is quite streetable, very fast, and I am not experiencing the driveability problems you are. So, perhaps I can help some with comparative analysis. I would expect that my logs and yours should be similar, notwithstanding the 5000 foot difference in elevation. If it becomes useful, I can open your map files with my version of ST and put up relevant tables as .gif or .jpg for analysis by others (Wolf). In looking at some of the logs in the .zip file, the first thing I see is that the Engine Load values are WAY low for the inputs you are giving the car. This smacks of a completely improper intake calibration. I notice that its taking 1.0 seconds from the time you punch it until it goes into open loop, based on the A/F Trim Immed. value. When the ECU goes into open loop, it will put 0.39 there for the duration. For an STi, the Closed Loop Delay table should be all 0s and the Closed Loop TPS table should be somewhere around 40% up to around 4k RPM or so and then 0 from there on up. With your FP Green turbo, you need to log Abs. Pres. and Baro. Pres. and forget about Rel. Pres. For some reason Rel. Pres. maxes out at 18.42, but you can calculate the actual real boost pressure by subtracting Baro. from Abs. in the spreadsheet. Works for me running boost in the low 20s. From the logs I looked at I can't tell where your boost is really going. In some of the logs WGDC values do not look like mine, they're wierd. Need to see the real boost values. Without a wideband, it is challenging to tell how rich you are really going. Part of the problem could be that you are going seriously too rich in this RPM range. If that is the case, a solution may be to fix an improper intake calibration in that area. Perhaps your tuner didn't touch this area, focusing only on the WOT areas instead. The Big MAF would have made a mess of this area if it weren't addressed. What Injector Scale value are you running for the Perrin modified injectors? 3286 seems to be about the right place for my PE850s. This was chosen based on an actual flow test of my stock 04 injectors showing them to flow at 520, not 480 as Christian had assumed. The above assumes no mechanical or installation problems, air leaks in particular. Be sure all your plumbing is where it is supposed to be and all clamps are tight. Have you modified your boost control solenoid system at all or added springs, etc. to the wastegate actuator? Is the air restrictor pill still installed in the boost control lines? Too much to speculate about, hope it is all properly installed. I can post log snippets of my car attempting similar pulls for you if that would help for comparison. Here is one from today logging a short mid-RPM high gear WOT pull up a hill at about 6000 ft elev. and I am running 91 oct winter crap fuel we get here (w/10% MTBE, stoich 11.7) I had just reset the ECU: You'll notice: 1. Boost spike - I'm currently playing with aggressive WGDC values and Turbo Dynamics. Boost targets in this map are 2600-15.0, 3200-18.0, 3600-19.01, 4000-19.99. 2. Too rich at tip-in - I have not messed with fuel much yet, just keeping it safely rich for now. 3. Engine Load in the low 3s - I would expect to see this on your car. I have hit 3.9 in some instances. 4. Goes into open loop instantly based on A/F Trim Immed. values I don't know if this comparison helps, but it feels good writing it. I'll defer to Wolf, Christian, Scott, and others for the deep stuff and help if I can. -Bruce

11-29-2005, 07:05 AM	#9
*MidlifeCrisis* Platinum Member Car: WRB 04 WRX STi+++ Fav Mod: Tech Exec Location: Golden, Colorado Posts: 153 Join Date: Jul 2004 Trader Rating: (0)	Not sure I agree, and here's why. A big MAF housing will reduce the velocity of air passing by the MAF sensor for a given total mass of air, thus reducing the cooling effect, therefore lower voltage for the air mass rate. This allows more air to be passed before the sensor VOLTAGE maxes out. I believe we agree so far. The intake calibration table converts the voltage to air mass. In ordrer for the car to run right, the intake cal table has to be massaged (increase air mass for a given voltage roughly as much as the area increase between the housings as a starting point) and then tuned just like any other intake changes would need to be. In the end, for a given MAF voltage, a higher air mass value will be taken by the ECU to use in subsequent calculations. I contend that it is the AIR MASS, NOT the VOLTAGE that is used in the load calculations. This should not change how the car runs if it is tuned properly. It will simply allow a larger mass of air to be measured before the sensor saturates. So, even though the actual sensor voltage is lower, the calculations should be based on the real air mass and thus the loads should be the same as any properly calibrated car. Right? Help me if I'm all wrong here.

11-29-2005, 05:29 PM	#11
Adam Junior STI Driver Posts: 122 Join Date: Mar 2005 Trader Rating: (0)	Curious about the discussion: Adam

11-29-2005, 06:40 PM	#12
WolfPlayer Moderator & ECU Tech Car: 05 CGM STI Fav Mod: mo boostaz Location: Fredneck, MD Posts: 3,620 Join Date: Jun 2004 Trader Rating: (6)	Bruce, I'm going to rattle on to see where I go with this - even I don't know yet, lol. The entire point of a big MAF is so that you don't hit the upper limit of the MAF. This is accomplished by rescaling the MAF table to indicate that a given MAF voltage equals more Oxygen entering the engine. Thus, 4v on a big MAF equals a lot more air than 4v on a stock MAF. Engine load is based on RPMs and MAF. Yea - I see what you are saying ... and it totally makes sense. Actual g/s and not MAF voltage. In fact, this is how load (LV8) is calculated in Domestic applications. I must have had a brain fart above? Not sure. I hope it is done via actual g/s and not voltage. Somebody should paruse NABISCO and search down a log from a big MAF setup just to make sure. t

11-29-2005, 08:02 PM	#14
nathansvt Junior STI Driver Posts: 128 Join Date: Sep 2003 Trader Rating: (0)	thanks for the input guys. I'm going to try to get a wideband in the car ASAP so I can see what's really going on with the A/F. I didn't know the Cobb is bugged with the rel. pressure setting so I'll go back to using ABS pressure and doing the conversion in excel.