quick 3bar SD OS, PE and boost PE enrichment table question

[denmah]

ok, just a quick one, as i understand from reading the directions, i just wanna make sure i got this strait


i can setup the PE EQ for 12.20 afr, then as the boost comes up to 160kpa say 11.50

then as i hit around 200KPA i can hit 11.0...

the boost EQ table takes over, and does not add to the PE table already in place correct?

say i flatline the PE EQ to 1.20
then low boost i set the boost enrich table to 1.28 at low boost and then 1.33 for higher boost say over 14psi...

the richest EQ ratio will take over, no matter what table i am using or have filled out correct?

they are not adding into each other say 1.20 then in boost its adding another 1.28 or 1.33 on top?

just wanted to make sure

thanks !

[MunsonAuto]

That's the way I understand it. I'm still new to this as well, but the way I read/understand it is as follows: The PE is for WOT below your set BE enable kPa, then once the set BE enable kPa is hit the BE table takes over. Both tables are working off the Stoich ratio. BE is enabled as long as the enable kPa is met, doesn't matter whether full throttle or not.

Pro's please correct me if I'm wrong!

Your PE is currently set for command/create 12.03afr, not 12.20 like you stated above, just a heads up. BE table is set to command ratio's that you stated in your post though.

[sarg]

I was curious about this as well and the answers I got were a bit conflicting. Some said that BE has a good bit of a delay to it and if you rely completely on it you will likely go lean and toast the motor. Others said it worked fine. I guess it was somewhat dependant on the ecu being used. What I have done so far with my tune is figure the rpm the car will come up on full boost and starting at 105 kps set you boost enrichment to desired final level then blend you PE table down to that level as rpms rise to where you think it will hit say 7 psi.

[denmah]

ah i gotcha, well i noticed in my friends car i thought they might blend together like other settings in hpt.

and i commanded a 11.0 right away and throwing the fuel around like that was a bit shakey commanded for whatever reason, but commanding a 12.5 worked great. stabs right to 12.5

then i set the boost enrich to like 1.10 because i figured it added anther multi on top of the regular pe,

and i noticed in datalogs it says commanded 12.25. so it wasnt commanding lower like i thought it would blend together, so after carefully reading those things, (im glad you guys were conflicted and unsure also makes me feel better haha..)
anyway i will try this and make sure it says commanded 11.5 or better, when i re-datalog my friends car.

he has a 2002 firebird we turbod, and i have a twin turbo silverado i am just finishing up and i wanna get this stuff right for best performance.

blending the PE table down is a great idea also! just to make sure

[sarg]

Yup, been following the build on tech. Just makes me sick how fast you get stuff done!

[denmah]

haha i guess i will see how this goes with my truck and if it sees any lean spikes, over 3000 ill shoot for 11.50 air fuel commanded, and see how it does when i roll into it and the low boost PE table takes effect once its tuned in nice maybe ill command a 10.50 at low boost in the PE table and see how much faster it clicks to that vs the 11.80 EQ table..

[denmah]

since for some people it seems to work and others its "slow" and causes lean conditions

[sarg]

No I am right there with ya. I am just waiting on some fitting and line and I should be able to start my junk for the first time. I have been reading up and pouring over this crap in hopes that I will have the tune mostly sorted when I go to start it the first time.

My thought was have the BE activation point at 105 hpa and instantly command around 11.0 on boost. Since I am pretty sure my turbo will not spool til around 4000 rpms, I plan to ramp my PE down to 11.5 by 4000 rpms and then have it flat at 11.0 from there on out. That way if BE is slow to react then it will still reference PE and still hit 11.0. I just don't feel like swapping this motor out after my first pull in boost, lol.

[mxguy1286]

Hate to jump in here and derail but why not just flatten out both p.e. and b.e and tune straight off the ve table. Tune it like a stand alone, every load and rpm make it the afr that you want that way? I did that with a car that I did and it worked great. I was trying to use the b.e. and p.e and got annoyed with it and just flat lined it and used just the ve table and things went much easier after that. I am new to hp tuners interface so that may be out of the box thinking or whatever you want to call it but it worked fine for me.

[Ben Charles]

Hate to jump in here and derail but why not just flatten out both p.e. and b.e and tune straight off the ve table.

B/C PE and BE are the reference point for commanded Fuel.



denmah, they won't add on each other, like you mentioned the computer will take the richer of the 2 values. It would also look at the OFLA table as well, if your colum at 100 is richer, it would take that.
BE can be a little slow on certain 0s's so its best just to use PE and use BE as a back up. You can try it and put a richer value in BE and see how fast it reacts.

What build is yours on LS1tech?

[denmah]

twin turbo 2500

i also tuned my friends single turbo 2002 TA with speed density 3 bar os

commanded 11.0 with the PE EQ table, trimmed everything with the AFR error, then changed it to 12.5 PE EQ, so when you stab it it hits 12.5 but its still 11s in boost since its also open loop.

much snappier on motor hitting the 12.50 PE when you stab it vs the doggy 11.0 haha