Converting MAP tune to Alpha-N

[HuxRacing]

 Car was fully tuned on MAP using a plenum style intake and TB. I now have ITBS and made the recommended tune changes.....I think...lol. Load to BAP and Fuel Y axis to TPS. I have a high and low cam fuel table. About to throw on the Dyno and want to avoid making a major tune setup error and then needing to retune.  Modded tune attached.  Much Thanks

AlphaN start.pclr

[Vaughan]

Only had a quick look:

• Make sure your MAP is hooked up to your balance bar so that your differential fuel pressure is correct.
• Might want to consider changing AFR/Lambda target table, ignition tables, charge temp table and VVT target y axes to TPS. Knock tables are also still in MGP.

[Adamw]

Yeah your basic set up looks fine.  One problem that needs fixing is the Y axis on your fuel tables is referencing the AN input voltage (it will only go to about 4.5V), you should be using the parameter "TP (Main)".   

I would also say you can likely make the fuel tables a little more simple than they are. I start with the bare minimum and only add extra rows/columns if I find when tuning interpolation between two cells isnt keeping things in control - then I will only add an extra row or column where it is needed.  With no MAP reference you will probably find VE numbers around idle area much smaller - I often see around 30-40%.

I also find charge temp approximation will be lower than a typical plenum type manifold.  

I have attached an example fuel table and charge temp table from the last ITB engine I done in modelled mode just for your interest.

  

      

Charge Temp Approximation.lte ITB Fuel Table BAP load.lte

[HuxRacing]

1 hour ago, Vaughan said:

Only had a quick look:

• Make sure your MAP is hooked up to your balance bar so that your differential fuel pressure is correct.
• Might want to consider changing AFR/Lambda target table, ignition tables, charge temp table and VVT target y axes to TPS. Knock tables are also still in MGP.

Thanks for the info. I have a rail under the runners tied to a map cannister. I'm hoping to not need to change AFR target and ignition tables. Not using knock and luckily vvt is pretty much a fixed angle versus rpm, I will watch the low rpm stuff. 

1 hour ago, Adamw said:

Yeah your basic set up looks fine.  One problem that needs fixing is the Y axis on your fuel tables is referencing the AN input voltage (it will only go to about 4.5V), you should be using the parameter "TP (Main)".   

I would also say you can likely make the fuel tables a little more simple than they are. I start with the bare minimum and only add extra rows/columns if I find when tuning interpolation between two cells isnt keeping things in control - then I will only add an extra row or column where it is needed.  With no MAP reference you will probably find VE numbers around idle area much smaller - I often see around 30-40%.

I also find charge temp approximation will be lower than a typical plenum type manifold.  

I have attached an example fuel table and charge temp table from the last ITB engine I done in modelled mode just for your interest.

  

      

Charge Temp Approximation.lte 423 B · 0 downloads ITB Fuel Table BAP load.lte 1.18 kB · 0 downloads

Much thanks for the tables. I just noticed there were 2 separate tp main selections, one under an volt. I will make the changes you noted and get this thing on dyno. I will share with you guys how this is progressing. 

[HuxRacing]

Loaded image of the current setup.

[HuxRacing]

I attempted to tune on Sunday but ran into an issue where the Throttle position is dropping after 9k. I can find nothing tune related as it worked fine earlier. Possibly failing DBW actuator. My tps sensor is on the throttle shaft not the actuator so  the tp-main report is correct.  I have attached the tune file and the log. I was only concerned with WOT as I wanted to confirm all was good before spending any more time on it. The ITBS picked up considerably where the DBW was not failing. 

drf14.pclr drf14.llg

[Vaughan]

From the log you can see it sitting on it's max DC clamp, this may be one of those reasonably rare cases where the vibrations from the engine can cause the brushes in the throttle motor to bounce off the motor shaft. How is the throttle motor mounted?

[Adamw]

Yep I'm with Vaughan, I have seen this on a few K hondas now, in my case only with stock single throttle though, so im surprised to see it on yours.  In my case it was bang on 8400RPM.  I discovered this was the problem by putting a scope on the throttle measuring both voltage and current, at 8400 you would see the voltage stay constant (ie ecu is still sending out full power) but the current suddenly drop (motor winding is disconnected).  On one it had an aftermarket bottom pulley, so fitting a proper damper fixed it.  On the other from memory is still had the stock front pulley but we put a brace under the manifold and that allowed it to work.  So they must have a real harsh resonance around that RPM.  

I know the R35 GTR suffers from the same problem and on those the common fix is they fit a rubber spacer under the throttle body.  So you might be able to cushion your motor mount somehow or if if doesnt have a harmonic damper I would look at that - it cant be good for the crankshaft at the same time.   

[HuxRacing]

Thanks guys at that is exactly what I was fearing. I am on the crank pulley recommended by the motor builder. I braced the DBW actuator to the block. No doubt this thing has vibration above 9k. I put the plenum setup back on for now. Will revisit the ITB later, most likely with a cable throttle.

[Adamw]

For my own curiosity, what does it have for a crank pulley - is it a damper or just a billet pulley?

[HuxRacing]

It has an OEM damper. I was advised that my issue might be the control amperage necessary for the s54 actuator. 

[Adamw]

3 hours ago, HuxRacing said:

I was advised that my issue might be the control amperage necessary for the s54 actuator.

They pull lots of current when driving the stock S54 ITBs- but it is their very odd design with the off-centre butterfly shafts that causes that - the vacuum pulls the butterflies shut very tight so it takes a lot of grunt to open them from idle position. 

On any other ITB application they dont pull especially high current - and certainly not just to hold WOT, current usually only maxes out for short periods of hard transients. The ecu will fault with an error if the throttle is pulling too much current.  

[Sainty]

On 5/10/2022 at 7:13 AM, Adamw said:

Yeah your basic set up looks fine.  One problem that needs fixing is the Y axis on your fuel tables is referencing the AN input voltage (it will only go to about 4.5V), you should be using the parameter "TP (Main)".   

I would also say you can likely make the fuel tables a little more simple than they are. I start with the bare minimum and only add extra rows/columns if I find when tuning interpolation between two cells isnt keeping things in control - then I will only add an extra row or column where it is needed.  With no MAP reference you will probably find VE numbers around idle area much smaller - I often see around 30-40%.

I also find charge temp approximation will be lower than a typical plenum type manifold.  

I have attached an example fuel table and charge temp table from the last ITB engine I done in modelled mode just for your interest.

  

      

Charge Temp Approximation.lteUnavailable ITB Fuel Table BAP load.lteUnavailable

Hi Adam, 

I have a blacktop 3sge beams with 4age 20v ITBs and need a ignition and fuel map to make it drivable to get it to a tuner. Do you have anything that can help? Even some example tables would be a great help.

[Adamw]

On 11/30/2022 at 2:28 PM, Sainty said:

Hi Adam, 

I have a blacktop 3sge beams with 4age 20v ITBs and need a ignition and fuel map to make it drivable to get it to a tuner. Do you have anything that can help? Even some example tables would be a great help.

I dont have anything, but I would probably start with the altezza base map and change the fuel & ign tables to suit.  I can knock something up when I get my server at home working again, might be a couple of days.  Remind me if I dont reply within 2 days

[Sainty]

2 hours ago, Adamw said:

I dont have anything, but I would probably start with the altezza base map and change the fuel & ign tables to suit.  I can knock something up when I get my server at home working again, might be a couple of days.  Remind me if I dont reply within 2 days

No Problem, thanks Adam. Any help is appreciated. I'm running the G4X and 1250cc injectors