| View previous topic :: View next topic |
| Author |
Message |
Techsalvager
Joined: 21 Jun 2011
Posts: 140
|
 Posted: Wed Mar 28, 2012 6:03 pm Post subject: tuning fuel\map based on calc engine load |
 |
|
Hi I'm back, 
Under SD setup I wouldn't pull fueling until after a few psi, I would leave it at stoich at 100kpa. Is this commonly done or do people start pulling fuel sooner.
I say this because if I do pull fuel then I would get worse gas mileage as I commonly go into a small amount of boost between shifts just getting up to speed.
Right now at 80% calc load under maf fueling I start going to 13.5 then to 11 at 90%, learning how to tune this in.
Also currently I have spark table using map sensor. I plan to change it to be based on calc engine load from maf sensor. Is there any good guides to look at to see how others normal setup this table? |
|
| Back to top |
|
 |
hezsmurf
Joined: 17 Nov 2005
Posts: 101
Location: The Netherlands
|
| Posted: Thu Mar 29, 2012 12:16 am Post subject: |
|
|
TurboIvo will answer all your questions and solve all your problems.
Last edited by hezsmurf on Thu Mar 29, 2012 11:36 pm; edited 1 time in total |
|
| Back to top |
|
|
Turboivo
Joined: 09 Mar 2006
Posts: 671
Location: Bulgaria
|
| Posted: Thu Mar 29, 2012 5:35 am Post subject: |
|
|
| hezsmurf wrote: | When you use load or the airmass meter you get the same load for low boost + low temperature and a bit higher boost + high temperature.
|
That's not qiute correct when using MAF imho. Higher boost means more measured air mass for same engine rpms/flow. |
|
| Back to top |
|
|
hezsmurf
Joined: 17 Nov 2005
Posts: 101
Location: The Netherlands
|
| Posted: Thu Mar 29, 2012 7:10 am Post subject: |
|
|
| Turboivo wrote: |
Higher boost means more measured air mass for same engine rpms/flow. |
Realy? Except when the air is a lot hotter. |
|
| Back to top |
|
|
Turboivo
Joined: 09 Mar 2006
Posts: 671
Location: Bulgaria
|
| Posted: Thu Mar 29, 2012 1:54 pm Post subject: |
|
|
What's so surprising? To have higher IAT you have to rise the boost. Before that your compressor have to suck more air through the MAF. Higher MAF reading/value = more load for the engine. So a bit higher boost means higher load, not the same load.
Remember the first VAG 1.8T 20V engines (AEB code)? They have no MAP sensor, just MAF + IAT sensor, EU2/D3/TLEV emissions. Does that mean bad load estimation? |
|
| Back to top |
|
|
hezsmurf
Joined: 17 Nov 2005
Posts: 101
Location: The Netherlands
|
| Posted: Thu Mar 29, 2012 11:35 pm Post subject: |
|
|
| Turboivo wrote: | | To have higher IAT you have to rise the boost. ? |
Realy? Ever heard of weather? -30 or more degrees in Siberia or Finland.
+40 in Spain or Cyprus and anything in between. |
|
| Back to top |
|
|
Turboivo
Joined: 09 Mar 2006
Posts: 671
Location: Bulgaria
|
| Posted: Fri Mar 30, 2012 12:00 am Post subject: |
|
|
| Hez, this is MAF sensor. The turbo inlet temp(ambient) is already compensated in the MAF readings. |
|
| Back to top |
|
|
baldur
Joined: 12 Oct 2007
Posts: 430
|
| Posted: Fri Mar 30, 2012 3:49 am Post subject: |
|
|
| Turboivo wrote: | | Hez, this is MAF sensor. The turbo inlet temp(ambient) is already compensated in the MAF readings. |
That's the point he's trying to make clear.
The same MAF reading can be had with 10psi and -20°C air or 15psi and 100°C air. Those two conditions call for different amounts of spark timing even if the amount of oxygen ingested per cycle is the same. |
|
| Back to top |
|
|
Techsalvager
Joined: 21 Jun 2011
Posts: 140
|
| Posted: Fri Mar 30, 2012 5:42 am Post subject: |
|
|
| well that would be why there is IAT fuel compenstation. |
|
| Back to top |
|
|
Techsalvager
Joined: 21 Jun 2011
Posts: 140
|
| Posted: Fri Mar 30, 2012 5:56 am Post subject: |
|
|
Here is what I'm seeing so far
 |
|
| Back to top |
|
|
Turboivo
Joined: 09 Mar 2006
Posts: 671
Location: Bulgaria
|
| Posted: Fri Mar 30, 2012 6:51 am Post subject: |
|
|
I'm sorry Techsalvager. That's last off topic.
Baldur, Hezsmurf, thanks! I understand that but could that be possible at the same engine rpm? I mean if MAF is the same but at different rpms that means different ign.table cells so different advance values? If MAF and rpms are the same then engine IAT or throttle pos. should be different. How's that arranged in mentined VAG MAPless engine? |
|
| Back to top |
|
|
Techsalvager
Joined: 21 Jun 2011
Posts: 140
|
| Posted: Fri Mar 30, 2012 7:07 am Post subject: |
|
|
| Turboivo wrote: | I'm sorry Techsalvager. That's last off topic.
Baldur, Hezsmurf, thanks! I understand that but could that be possible at the same engine rpm? I mean if MAF is the same but at different rpms that means different ign.table cells so different advance values? If MAF and rpms are the same then engine IAT or throttle pos. should be different. How's that arranged in mentined VAG MAPless engine? |
Thats fine Turboivo I don't mind using this thread as an informative Q\A since its all being asked on the same stuff I'm trying to find out.
I meant earlier thats why there is probably IAT based spark correction\fuel correction. |
|
| Back to top |
|
|
Techsalvager
Joined: 21 Jun 2011
Posts: 140
|
| Posted: Sat Mar 31, 2012 6:55 pm Post subject: |
|
|
| Turboivo wrote: | I'm sorry Techsalvager. That's last off topic.
Baldur, Hezsmurf, thanks! I understand that but could that be possible at the same engine rpm? I mean if MAF is the same but at different rpms that means different ign.table cells so different advance values? If MAF and rpms are the same then engine IAT or throttle pos. should be different. How's that arranged in mentined VAG MAPless engine? |
I think I just bounced into this issue Turboivo. The date of this posting I had driven on the highway and while going under load I was seeing leaner then usual I believe, positive pressure vs load. I will have to check my datalogs but I know that at the time my IAT sensor which is mounted in the airfilter\cone filter was reading around 63F intake temps.
I'm gonna go over the data to figure out if was just because I couldn't make the engine go to a higher load point of possible an area I haven't seen before that I put as leaner then should be. |
|
| Back to top |
|
|
Techsalvager
Joined: 21 Jun 2011
Posts: 140
|
| Posted: Tue Apr 03, 2012 7:45 pm Post subject: |
|
|
With the transition into boost how much timing should I be taken out at 13.9:1 - 14.1:1 AFR
1-2psi
timing is around 30 degrees around this area
Should I look at taken out more timing?
rpm around 2500-4000 area
Just mild acceleration or when up to speed used with mild pedal effort to pass people |
|
| Back to top |
|
|
|
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
