follow ft86club on our blog, twitter or facebook.
FT86CLUB
Ft86Club
FT86 Motorsports
Register Garage Members List Calendar Search Today's Posts Mark Forums Read

Go Back   Scion FR-S Forum | Subaru BRZ Forum | Toyota 86 GT 86 Forum | AS1 Forum - FT86CLUB > Technical Topics > Software Tuning

Software Tuning Discuss all software tuning topics.


User Tag List
steve99

Reply
 
Thread Tools Search this Thread
Old 07-16-2014, 09:04 PM   #197
jamesm
Banned
 
Join Date: Mar 2013
Drives: 2013 FR-S
Location: Orlando, FL
Posts: 2,929
Thanks: 1,166
Thanked 2,284 Times in 1,177 Posts
Mentioned: 313 Post(s)
Tagged: 4 Thread(s)
Quote:
Originally Posted by Turdinator View Post
Thank you for your input guys. I was trying to do similar to what Jamesm was talking about as far as getting a good known maf scale on the DI to then scale the PI against. My car is pretty much stock so what I am doing is overkill but I figured it was a good way to learn more tuning etc.


I deliberately didn't change the cold port injection ratio table as I didn't want to mess with the normal warm up procedure.
Whenever i change the port ratios i just change all 3 tables at once. I've found that always running the minimum amount of port ratio necessary for a given setup will allow for significant gains in terms of knock suppression on pump gas.

I essentially monitor Direct Injection Time Final and/or DI requested volume (the latter of which is only available in an unreleased RaceRom beta, so not much use to most folks). I'll then gradually bring down the PI ratio until i'm ~10-20% under what i consider to be a safe limit (1ml or 6.5ms depending on the param that i have access to).

I used this technique on an NA tune last night and was able to make considerable horsepower up top in the most knock-proned area of the curve. With stock port ratios knock up there was an issue @ ~15-17whp over stock (can't remember the actual timing or AFR values, i'd have to look), and by the time i brought down the port ratio and added a couple other tricks we were at 29whp over stock with no knock in sight.

something to consider trying if you're fighting knock above 6500rpm or so. On an NA car you'll never get close to any limitation, even with 0% port ratio across the board.

Last edited by jamesm; 07-16-2014 at 09:15 PM.
jamesm is offline   Reply With Quote
The Following 2 Users Say Thank You to jamesm For This Useful Post:
solidONE (07-17-2014), Turdinator (07-16-2014)
Old 07-17-2014, 03:46 AM   #198
Kodename47
Senior Member
 
Kodename47's Avatar
 
Join Date: Oct 2012
Drives: UK GT86
Location: UK
Posts: 2,691
Thanks: 171
Thanked 1,377 Times in 948 Posts
Mentioned: 131 Post(s)
Tagged: 1 Thread(s)
Quote:
Originally Posted by jamesm View Post
Something to consider trying if you're fighting knock above 6500rpm or so. On an NA car you'll never get close to any limitation, even with 0% port ratio across the board.
I'm sure I was once told that having more PI at the top end was beneficial as it allows for more aggressive timing, something to do with the DI firing angles/time being an issue.
__________________
.: Stealth 86 :.
Abbey Motorsport/K47 Tuned Sprintex 210 Supercharger

Litchfield Springs / Abbey MS Geo
Kodename47 is offline   Reply With Quote
Old 07-17-2014, 10:04 AM   #199
wparsons
Senior Member
 
wparsons's Avatar
 
Join Date: Jul 2012
Drives: 2013 Asphalt FR-S Manual
Location: Whitby, ON, Canada
Posts: 6,028
Thanks: 6,206
Thanked 2,867 Times in 1,840 Posts
Mentioned: 89 Post(s)
Tagged: 1 Thread(s)
Garage
DI gives WAY more charge cooling though, which also lets you run more timing. I imagine that in knock prone areas a colder charge is way more beneficial.
__________________
Light travels faster than sound, so people may appear to be bright until you hear them speak...
flickr
wparsons is offline   Reply With Quote
Old 07-17-2014, 11:15 AM   #200
jamesm
Banned
 
Join Date: Mar 2013
Drives: 2013 FR-S
Location: Orlando, FL
Posts: 2,929
Thanks: 1,166
Thanked 2,284 Times in 1,177 Posts
Mentioned: 313 Post(s)
Tagged: 4 Thread(s)
^ yep. i believe it's the charge cooling doing the trick, but it's definitely an observable phenomenon lol.
jamesm is offline   Reply With Quote
Old 07-17-2014, 11:46 AM   #201
solidONE
Senior Member
 
solidONE's Avatar
 
Join Date: Dec 2012
Drives: FR-S Whiteout
Location: California
Posts: 2,393
Thanks: 1,473
Thanked 634 Times in 488 Posts
Mentioned: 36 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by jamesm View Post
Whenever i change the port ratios i just change all 3 tables at once. I've found that always running the minimum amount of port ratio necessary for a given setup will allow for significant gains in terms of knock suppression on pump gas.

I essentially monitor Direct Injection Time Final and/or DI requested volume (the latter of which is only available in an unreleased RaceRom beta, so not much use to most folks). I'll then gradually bring down the PI ratio until i'm ~10-20% under what i consider to be a safe limit (1ml or 6.5ms depending on the param that i have access to).

I used this technique on an NA tune last night and was able to make considerable horsepower up top in the most knock-proned area of the curve. With stock port ratios knock up there was an issue @ ~15-17whp over stock (can't remember the actual timing or AFR values, i'd have to look), and by the time i brought down the port ratio and added a couple other tricks we were at 29whp over stock with no knock in sight.

something to consider trying if you're fighting knock above 6500rpm or so. On an NA car you'll never get close to any limitation, even with 0% port ratio across the board.
Might be a stupid question, but how do you figure the amount of ignition advance you can add safely besides the absence of knock detected? Or do you have to add advance incrementally until knock or the lack of power increase is detected then pull back timing?
solidONE is offline   Reply With Quote
Old 07-17-2014, 12:03 PM   #202
jamesm
Banned
 
Join Date: Mar 2013
Drives: 2013 FR-S
Location: Orlando, FL
Posts: 2,929
Thanks: 1,166
Thanked 2,284 Times in 1,177 Posts
Mentioned: 313 Post(s)
Tagged: 4 Thread(s)
Quote:
Originally Posted by solidONE View Post
Might be a stupid question, but how do you figure the amount of ignition advance you can add safely besides the absence of knock detected? Or do you have to add advance incrementally until knock or the lack of power increase is detected then pull back timing?
You won't reach MBT on pump gas... you'll always hit knock first. But yeah, you basically got the idea.
jamesm is offline   Reply With Quote
The Following User Says Thank You to jamesm For This Useful Post:
solidONE (07-17-2014)
Old 07-17-2014, 12:14 PM   #203
arghx7
Senior Member
 
Join Date: Nov 2011
Drives: car
Location: cold
Posts: 599
Thanks: 72
Thanked 596 Times in 185 Posts
Mentioned: 33 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by jamesm View Post
Whenever i change the port ratios i just change all 3 tables at once. I've found that always running the minimum amount of port ratio necessary for a given setup will allow for significant gains in terms of knock suppression on pump gas.

I essentially monitor Direct Injection Time Final and/or DI requested volume (the latter of which is only available in an unreleased RaceRom beta, so not much use to most folks). I'll then gradually bring down the PI ratio until i'm ~10-20% under what i consider to be a safe limit (1ml or 6.5ms depending on the param that i have access to).

I used this technique on an NA tune last night and was able to make considerable horsepower up top in the most knock-proned area of the curve. With stock port ratios knock up there was an issue @ ~15-17whp over stock (can't remember the actual timing or AFR values, i'd have to look), and by the time i brought down the port ratio and added a couple other tricks we were at 29whp over stock with no knock in sight.

something to consider trying if you're fighting knock above 6500rpm or so. On an NA car you'll never get close to any limitation, even with 0% port ratio across the board.
The stock port ratios are constrained by smoke/particulate emission and fuel impingement on the cylinder wall and piston. When you don't have that as a concern, you can run a lot more DI.
arghx7 is offline   Reply With Quote
Old 07-17-2014, 12:35 PM   #204
jamesm
Banned
 
Join Date: Mar 2013
Drives: 2013 FR-S
Location: Orlando, FL
Posts: 2,929
Thanks: 1,166
Thanked 2,284 Times in 1,177 Posts
Mentioned: 313 Post(s)
Tagged: 4 Thread(s)
Quote:
Originally Posted by arghx7 View Post
The stock port ratios are constrained by smoke/particulate emission and fuel impingement on the cylinder wall and piston. When you don't have that as a concern, you can run a lot more DI.
I'd rather knock less. Plants wither when i drive by anyway lol.
jamesm is offline   Reply With Quote
Old 07-19-2014, 06:33 PM   #205
solidONE
Senior Member
 
solidONE's Avatar
 
Join Date: Dec 2012
Drives: FR-S Whiteout
Location: California
Posts: 2,393
Thanks: 1,473
Thanked 634 Times in 488 Posts
Mentioned: 36 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by jamesm View Post
You won't reach MBT on pump gas... you'll always hit knock first. But yeah, you basically got the idea.
Are these the tables that control the PI to DI ratios? Looks like it only goes up to 5200rpm.


I'm still getting a bit of knock past 6300rpm with no modification to the Port to DI ratios. And my MAF scale with modified temp compensation runs really rich with cool IAT's and closer to 12.5:1 when IAT get hotter, in case you were wondering why it's so rich. I modified the MAF temp compensation to run with low amount of correction from 68f to 130+f IAT's in closed loop (1.1v ~ 2.8V maf volts). Open loop (2.8v ~ 4.2v)is not so ideal.

http://datazap.me/u/solidone/maf68-1...-1036&mark=971
solidONE is offline   Reply With Quote
The Following User Says Thank You to solidONE For This Useful Post:
steve99 (07-19-2014)
Old 07-19-2014, 07:11 PM   #206
sluflyer06
Senior Member
 
Join Date: Jun 2014
Drives: 2014 BRZ Ltd - DGM
Location: Saint Louis
Posts: 200
Thanks: 2
Thanked 70 Times in 51 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Well this thread answered my curiosity if Subaru still uses closed loop & open loop strategy. My last car was closed loop all the time.
__________________
2014 BRZ Ltd. - DGM
E30 318is trackday funday car
E46 323ci vert
sluflyer06 is offline   Reply With Quote
Old 07-19-2014, 07:41 PM   #207
jamesm
Banned
 
Join Date: Mar 2013
Drives: 2013 FR-S
Location: Orlando, FL
Posts: 2,929
Thanks: 1,166
Thanked 2,284 Times in 1,177 Posts
Mentioned: 313 Post(s)
Tagged: 4 Thread(s)
Quote:
Originally Posted by solidONE View Post
Are these the tables that control the PI to DI ratios? Looks like it only goes up to 5200rpm.


I'm still getting a bit of knock past 6300rpm with no modification to the Port to DI ratios. And my MAF scale with modified temp compensation runs really rich with cool IAT's and closer to 12.5:1 when IAT get hotter, in case you were wondering why it's so rich. I modified the MAF temp compensation to run with low amount of correction from 68f to 130+f IAT's in closed loop (1.1v ~ 2.8V maf volts). Open loop (2.8v ~ 4.2v)is not so ideal.

http://datazap.me/u/solidone/maf68-1...-1036&mark=971
Like all maps... the highest value is applied for any higher input value on each axis. i.e. '5200rpm' means '5200rpm or greater'. also of course you can rescale any way you wish.

Temperature compensations are one of the many things that subaru engineers probably did better than we can. They just shouldn't need to be messed with IMHO, and i've never been in a situation where i had to.
jamesm is offline   Reply With Quote
The Following User Says Thank You to jamesm For This Useful Post:
solidONE (07-19-2014)
Old 07-19-2014, 08:06 PM   #208
solidONE
Senior Member
 
solidONE's Avatar
 
Join Date: Dec 2012
Drives: FR-S Whiteout
Location: California
Posts: 2,393
Thanks: 1,473
Thanked 634 Times in 488 Posts
Mentioned: 36 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by jamesm View Post
Like all maps... the highest value is applied for any higher input value on each axis. i.e. '5200rpm' means '5200rpm or greater'. also of course you can rescale any way you wish.

Temperature compensations are one of the many things that subaru engineers probably did better than we can. They just shouldn't need to be messed with IMHO, and i've never been in a situation where i had to.
So values of 0.000 would be 100% DI, right?

Well, using the stock compensation table there was at least a +- 4~5% fuel trim variation in closed loop due to temperature in lower intake volume closed loop operation. I dialed in a maf scale at approximately 66~72f IAT's. When ran within that temp range fuel trim were below 2% in closed loop. Once the temperature gets higher the the fuel trim would change pretty proportionately to the amount of IAT increase leading me to believe the temp compensation needed to be adjusted.
solidONE is offline   Reply With Quote
Old 07-19-2014, 08:30 PM   #209
jamesm
Banned
 
Join Date: Mar 2013
Drives: 2013 FR-S
Location: Orlando, FL
Posts: 2,929
Thanks: 1,166
Thanked 2,284 Times in 1,177 Posts
Mentioned: 313 Post(s)
Tagged: 4 Thread(s)
Quote:
Originally Posted by solidONE View Post
So values of 0.000 would be 100% DI, right?

Well, using the stock compensation table there was at least a +- 4~5% fuel trim variation in closed loop due to temperature in lower intake volume closed loop operation. I dialed in a maf scale at approximately 66~72f IAT's. When ran within that temp range fuel trim were below 2% in closed loop. Once the temperature gets higher the the fuel trim would change pretty proportionately to the amount of IAT increase leading me to believe the temp compensation needed to be adjusted.
Yes 0.000 is 0% port, or 100% di.

As for the temperature comp, I suppose you could split hairs trying to adjust comps beyond their factory effectiveness at every possible temperature range, but it'd be a lot of work for little to no material benefit. I've never found a need to do any of that, and my customers don't have temperature-related drivability issues that I'm aware of.

Principle of least intrusion is important. You'll save yourself a lot of trouble by minimizing the amount of opportunities you give it to arise. Only solve identifiable problems after they've been identified, in other words. The goal is better-than-stock drivability, not an arbitrary fueling error number. Just my .02.
jamesm is offline   Reply With Quote
The Following 3 Users Say Thank You to jamesm For This Useful Post:
arghx7 (07-20-2014), solidONE (07-19-2014), steve99 (07-19-2014)
Old 07-21-2014, 09:29 AM   #210
Grip Ronin
The Mechanic
 
Grip Ronin's Avatar
 
Join Date: Mar 2012
Drives: Civic Turbo,FR-S
Location: NJ
Posts: 928
Thanks: 130
Thanked 171 Times in 119 Posts
Mentioned: 2 Post(s)
Tagged: 1 Thread(s)
wondering does this maf scaling technique work for a blow thru FI like the JR kit?
__________________
IG-Joey_Soul
Progress Thread Ported billet 20G
Grip Ronin is offline   Reply With Quote
 
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
AFR in Closed Loop Toyota John Software Tuning 12 12-14-2015 04:53 AM
BRZedit Fuel Trims, Closed to Open loop transiton mad_sb Engine, Exhaust, Transmission 32 08-06-2015 03:14 AM
Notes on injector / maf scalining using full time open loop mad_sb Software Tuning 40 03-03-2014 06:49 PM
Screencast: closed loop boost control with RaceRom jamesm Software Tuning 2 02-10-2014 03:23 PM
Screencast: experimenting with full-time closed loop fueling jamesm Software Tuning 2 12-27-2013 11:19 AM


All times are GMT -4. The time now is 07:35 PM.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Garage vBulletin Plugins by Drive Thru Online, Inc.