hi, does anybody know how to change the megasquirt 1 so that it can be mapped via the throttle position sensor rather than just the map sensor. my stock c20xe on gsxr tb's made 181 but the mapper said he could tune it more accurately if the ecu would allow him to tune from the tps????
any help or advice would be greatly appreciated

[Edited on 16/10/18 by Stedow]

[Edited on 16/10/18 by Stedow]

Hi there! When you say "gsxr barbs" I take it you mean gsxr carbs so the Megasquirt is only controlling ignition?

Or are you using GSXR throttle bodies?

sorry, I meant to write throttle bodies.

You need to change it from speed density to alhpa N in general and ignition settings and calibrate TPS
I have the megasquirt 3 if mine was set to speed density and I only had TPS connected with no MAP sensor I don't think my engine would run

[Edited on 16/10/18 by chris]

[Edited on 16/10/18 by chris]

I used MS 1 a while back.
I had GSXR600 bodies on a RF900 bike engine.
I ended up using the MS Extra code with the hybrid option. This use both the TPS ans MAP sensor together.

Before changing ANYTHING always "save" the tune so you can go back if necessary.

Answers can usually be found by consulting the manual but casting my memory back...

You select the PRIMARY ALGORITHM on the CONSTANTS page. You will be selecting AlphaN. I think you have to make a similar selection under
PROJECT PROPERTIES.

Make sure your TPS calibration is spot on. Burn these changes to the ECU and restart Tunerstudio.

Your VE table should now show TPS as load up the left hand side. Most, if not all of the values in the table will now be wrong.

When using AlphaN it is usual to have closer spaced load bins in the lower part of the table and wider spaced ones higher up.

My load axis values when I was on MS1 AlphaN, on a similar 2 litre 16v engine, were something like...

100
80
65
50
38
30
24
18
13
8
3
1



The load bins on your ignition table should be similar. From here on it will be over to your tuner chappie to retune the tables.
Or you can use VE Analyze Live feature which will get your VE table very close if used correctly.

When you first make these changes your car may run horribly.

You may consider upgrading to MS2 which has a dedicated ITB mode. That's what I did.

Don't forget that you need to "burn" changes to the ecu to make them permanent.