PowerFC: Ran out of Load Points.

[Cubes]

I've dropped Tim a message at Tilbrooks. No doubt he will know as he has always been on the ball so to speak.

Hopefully I can grab a hold of him before he heads overseas again.

[Chris32]

Maybe even see if Simon/Martin (if he's still there) at Morpowa know. Shaun knows Martin quite well, maybe get him to give him a buzz and see what he thinks

[Cubes]

Speaking to Tilbrooks, they said Martin and Tim tune there.

[Chris32]

Martin would know about it for sure I reckon, as they have the FC-logit software and they use that quite a bit. Grepin's car was tuned via FC-logit at Tilbrooks

[Bl4cK32]

dunno if i wanna pay $600 for a tune....if the datalogit solves our problem, id rather buy it myself, and let Shaun have a play

[Sydneykid]

Hi guys, on the Datalogit Settings, Page 3 there is configurable table for the 20 map reference points for RPM and the 20 map reference points for Airflow.

The default RPM reference points are in 400 rpm increments from 400 rpm to 8,000 rpm.

The default Airflow reference points are 1446 (load point 2) increasing by 482 up to load point 10 then 964 from load point 10 to load point 15 then 1928 from load point 15 to load point 20. This is determined by the Air Flow Curves (AFM voltage ramp table) which is also on Settings Page 3

Hope that was of some help

[JaFF]

how much it cost you guys in general to go to a rb30det?

say if you already have a rb25det, were happy to keep the rb25det turbo for a while, how much would the upgrade cost?

[Dr_Drift]

sydneykid - Looking at the screenshot are all the white cells user definable? If they are then it certainly looks like fc-datalogit might be the only way around it??

[Sydneykid]

sydneykid - Looking at the screenshot are all the white cells user definable? If they are then it certainly looks like fc-datalogit might be the only way around it??

Yep, the whites are input cells.

[Cubes]

Once again....

Thanks SK.

[Bl4cK32]

cheers for that SK.

Datalogit time....

[Chris32]

Hi guys, on the Datalogit Settings, Page 3 there is configurable table for the 20 map reference points for RPM and the 20 map reference points for Airflow.

The default RPM reference points are in 400 rpm increments from 400 rpm to 8,000 rpm.

The default Airflow reference points are 1446 (load point 2) increasing by 482 up to load point 10 then 964 from load point 10 to load point 15 then 1928 from load point 15 to load point 20.  This is determined by the Air Flow Curves (AFM voltage ramp table) which is also on Settings Page 3

Hope that was of some help

That looks interesting, SK, so to get more load points out of the PFC, which values need to be changed?

[Oosh]

That looks interesting, SK, so to get more load points out of the PFC, which values need to be changed?

I don't believe it's a matter of getting more load points, but taking the 20 you have and "stretching" them out, by increasing the "distance" between points on the AFM axis of your map.

I doubt you need to alter all of them, perhaps the top 5, obviously once something as fundamental the "scale" on you map changes the associated fueling values will need to change also.

I hope i made some sense there, if not, ignore me and wait for SK to ride to the rescue!

[Cubes]

Hi SK,

After a little investigating it appears the rb20's airflow value at load point 20 is roughly the same as the rb25's airflow value at load point 15.

Oosh, You are spot on, all it does is reduce the resolution, the rb20 map reference with the rb30 is fairly usless as to use load points 5-12 you really have to concentrate to only ever so slightly touch the accelerator.

Bigger motor drawing more air the 2.5ltr reference map suits it much better.

[Cubes]

I've stumbled upon an interestering airflow vs horsepower relation.

After using the rb25det reference map, the airflow required to make ~200rwkw now uses load point 15-16, previously with the rb20det reference map it was maxing out at load point 20 to make the same power.

Calcs.. It appears that the rb25det reference map has been scaled enough to support ~325rwkw of power on the same dyno and peak RPM as I and Bl4ck32 use.

I find it interesting that I am making ~176rwkw and using load points 18-19, both Bl4ck32's and my power figure is supported by the calc. :lock:

Obviously an rb20det, rb25det or rb26dett may make use of the air supplied a little better or worse, the power figure as a result 'should' vary with different motors and RPM!

Now to find some one that knows the power they make at approx 5000rpm with a PowerFC and see if the calc can 'predict' the load point they will use.

If it appears to be fairly accurate, we will be able to weed out those bodged dyno power figures.

I haven't really thought about rpm at this stage, I have no idea how it scales its airflow/loadpoints as rpm increases, or if it does at all.

My map trace is horizontal, from 2000rpm it drops to load point 18-19 then sits there all the way to peak power.

As an engine increases RPM its supposed to increases its airflow requirement. :confused:

[Cubes]

Just to note, I noticed for example.

A load is placed upon the motor that is inbetween two airflow values. The PFC will do a linear (I assume) calc and determine the value to use for that load.

So providing airflow and ignition timing required is linear between the two load points the pfc will do a pretty damn good job working out the optimal value.

It will only do this where ignition timing or fuel has different values between load point cells.

Hope that makes sense.

[discopotato03]

Cubes , have been very interested in this topic . Is there an Apexi PFC for the VG30DET or VG30DETT ? If so it would be interesting to know their reference tables particularly as the airflow would be based around 3 litres .

Also probably impossible but are Z32 ECU's electrically similar to R32's ?

Cheers Adrian .

[Sydneykid]

I've stumbled upon an interestering airflow vs horsepower relation.

 

After using the rb25det reference map, the airflow required to make ~200rwkw now uses load point 15-16, previously with the rb20det reference map it was maxing out at load point 20 to make the same power.

 

Calcs.. It appears that the rb25det reference map has been scaled enough to support ~325rwkw of power on the same dyno and peak RPM as I and Bl4ck32 use.

 

I find it interesting that I am making ~176rwkw and using load points 18-19, both Bl4ck32's and my power figure is supported by the calc. :lock:  

 

Obviously an rb20det, rb25det or rb26dett may make use of the air supplied a little better or worse, the power figure as a result 'should' vary with different motors and RPM!

 

Now to find some one that knows the power they make at approx 5000rpm with a PowerFC and see if the calc can 'predict' the load point they will use.

If it appears to be fairly accurate, we will be able to weed out those bodged dyno power figures.

 

I haven't really thought about rpm at this stage, I have no idea how it scales its airflow/loadpoints as rpm increases, or if it does at all.

My map trace is horizontal, from 2000rpm it drops to load point 18-19 then sits there all the way to peak power.

As an engine increases RPM its supposed to increases its airflow requirement. :confused:

Interesting, ultimately the engines power would depend on its VE at the various airlfow rates. That can vary by 15% or so at numerous RPM's.

One thing I would add is that the RB25DET AFM (PFC default) is set for 5.1 volts at 10860, which is around 170 rwkw. Yet the load point mapping goes to 21213, this means 5.1 volts (the AFM maximum) of 10860 is around load point 14/15. So a standard RB25DET AFM could never show more than load point 14/15.

You are at load point 18/19, but I can't remember what AFM you have?

[Cubes]

Sounds fairly spot on SK, I was very close to 5v on the std RB20DET afm (which actually was a R33 S1 AFM) before the tune so obviously a few more rev's I may have seen it hitting 5v or slightly over.

I made sure before the tune I wired in the Z32 AFM, it has hit a highest of 4.1v on Load point 18/19.

Where did you grab the R33's Airflow airflow value at 5.1v?

Going by the table below (taken from FC_Pro Apexi Software) R32/R33 at 5.1v has an airflow value of 4423.

It doesn't make sense. Especially when you look the Z32 apparently has a higher airflow per voltage than the VH41?!?!

Discopotato,

The airflow reference map from a VG30 would be very interestering to see.

It appears the FC-Logit doesn't do one for the VG30 nor does the Apexi FC Pro Software.

Both softwares do one for the 2JZGTE, might see if I can grab it from the FC Pro Software.