I got the megasquirt up and running on my 1600 xflow with honda CBR throttle bodies.. however it idles at 60Kpa... I have a 244 cam, is this normal?

Yes.

Use alpha_n for your load sensing and not speed_density because you have long duration cams. Otherwise you wont get a good smooth map.

Change the fuelling algorithm in configurator and in the basic engine settings.

You then need to go to tools and calibrate TPS. Note down the figures for closed and open throttle. Then fill in your VE and spark tables with those values for closed and WOT then spread the intermediate values between them. Concentrate on the crusiing areas and use maybe the last 4 lines for the last 2/3rds of the throttle travel.

This will make sure you get a nice smooth map.

ETA you'll need to reset all your table values as well to suit, but better to do it now rather than have to start again once you have it all mapped.

[Edited on 18/1/10 by flak monkey]

thanks, will give it a go.

quote:

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Originally posted by thepest
thanks, will give it a go.

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erm where exactly in the configurator? '


EDIT: Nevermind... found it

[Edited on 18/1/10 by thepest]

Open megatune, click file then configurator.

Click the plus sign next to your project file (usually car1 or similar) then open it out as far as it goes. Then there is a fuelling algorithm option in the list. Change it in the drop down to be alpha_n

The click file, save then file, lauch megatune. Load your map file and then in the engine constants settings change the alogirthm to alpha_n too.

Like I say then all you need to do is change your VE and spark Y axis values to suit.

I'm a little baffled, I did all that however I had to reduce the Req_fuel by almost 1/2!! is there any difference to how the fuel is sent with TPS as opposed to map?

Keepin the same VE bins on idle of course. I'm only running idle right now

Its probably something to do with your VE table bins then.

I would generally expect, from past experience anyway, to run VE table values from around 20 at idle to 120 at WOT, depending on your req_fuel settings

Your req fuel will also depend on whether you have set alternating or simultaneous and 1 squirt or 2 in your engine settings.

thats the strange part, I'm using about 32 VE bin at idle.
If its KPa then I need a req fuel of around 19
If its Alpha N then I need around 10!

simultaneous injection is set too. Once I set Alpha N can I do away with the ecu map sensor?
IE should I block it off?

You can either disconnect it, or you could leave it connected and that will give you the option to use either TPS or MAP for acceleration enrichment.

The difference could just be in the maths, I dont really know.

I would set it up to be alternating injection if you can as then the pressure drop in the rail is less. So set 2 squirts alternating rather than 1 squirt simulataneous. Wont make any difference to your other numbers though.

With GSXR throttle bodies I ran a req fuel of about 11.5 and a VE bin value of abour 20 for idle on my pinto.

Req fuel of 10 is more like it anyway, 19 is very high.

Thanks, I'll experiment some more...