Efficiency Table change UP?

Hey there!

Jack, from Boston Mass here. I was wondering if I could get your gentleman's and/or Ladies' input for this situation. I have a Motec M130 ECU on a supercharged (Non Intercooled) 2004 Hayabusa. I bought the M130 with a drag package. I had a preliminary dyno tune done on my bike based on doing LSR (Land Speed Racing). After watching this course, I have decided to make this bike more street drivable. The initial package came with a Volumetric table based on throttle position. My questions are:

1. Should I change the table to be based off of inlet manifold pressure instead of throttle position?

2. How do I go about doing this in a systematic way?

2. Because this is a custom manifold, how do I insure my manifold pressure sensor is properly placed to read a reliable and viable pressure for all cylinders? What is the basic idea behind how and where to position the Pressure sensor?

3. How do I calibrate this sensor for accurate pressure data?

4. Is there a way to program the M130 to switch back to the original data table with reference to throttle position for a limp home mode should the manifold pressure sensor ever fail or some other method to get the bike home?

Thanks for taking to time to read this post!

May the speed be with you!

Jack

Hi Jack,

I am resuming that this Hayabusa engine has been converted to having a single throttle body, rather than the ITB's that are found on the standard engine.

There are a number of different Drag Packages available, as this is on a Hayabusa in the US, I am going to presume that you are using the MoTeC USA Suzuki Hayabusa Package in the M130, having a look at this Package there has been a number of functions removed from it that are standard in the MoTeC GP Packages that are used with ITB's to ease the tuning of them.

If you are running a common plenum with a MAP Sensor, then Inlet Manifold Pressure is the recommended tuning option, the Throttle Position tuning method is recommended for ITB's where it is extremely difficult to get a consistent MAP signal.

MoTeC M1 ITB Tuning guide

If you go to the Initial Setup | Engine Details worksheet in your Package, in the notes on the bottom of the left hand side of the worksheet you will see the recommended settings for the Engine Details parameters for each tuning method, start with these settings.

Without doing a fluid dynamics analysis of the inlet plenum, the correct location for the MAP sensor is a guesstimate, usually a location that is central to the manifold is used to try and give the best average of conditions in the plenum.

There are a number of calibrations available in the Inlet Manifold Pressure Sensor Resource drop down list that will cover a lot of commonly used sensors, you can also organise to have a sensor that is not in the list calibrated by MoTeC through an approved MoTeC Dealer.

In the standard GP Packages there are some fall over settings to handle a failed Inlet Manifold Pressure sensor, but this is not always available in the Custom Packages.

Hey Stephen,

Thank You for reply. Unfortunately, this is an ITB setup. I knew that there was a reason for the throttle position axis but couldn't remember why. I guess I am not understanding the actual mechanics of the error that would be induced using manifold inlet pressure. I am a novice at this stuff, so I do like to have a understanding of the how these things work. I am wondering, does any body use multiple sensors and average the output to correct for error? Also, how is throttle position calibrated for non-linear airflow actualization?

Thank you again for your time,

Jack

Hi Jack,

The issues that come from using ITB's with a MAP sensor are that the signal gets very noisy as there is minimal pulsation dampening between each of the inlet runners which makes it difficult to get a smooth idle and transient response, and when the throttle is opened, the pressure in the trumpets rapidly rises, so you can have the same MAP values at 30% throttle and 100% throttle, but not the same air mass/flow rate going into the engine so the fueling is not consistent.

The usual practice to get a MAP reading from an ITB setup is to have each of the runners tapped between the throttle plate and inlet valves, and then a hose is run from each of the tapped ports to a common manifold that has a MAP sensor installed in it. This will also provide some pulsation dampening and smoothing of the signal.

The non linear airflow is compensated for in the fuel mapping, with an ITB setup you may find that you have to have some areas of the map that are closer together to accommodate for the rapid change in the airflow at certain throttle openings/engine speeds, and more open in other areas.