Changing map for bigger injectors

Hodge
Posts: 27
Joined: Thu Feb 17, 2011 12:34 am
Location: Consett

Changing map for bigger injectors

Post by Hodge »

Morning all
I've got a supra here with an S6 running BPU with 440cc injectors, now I've changed the injectors for 1000cc and fitted a single turbo. The map needs the fueling adjusted for the bigger injectors so I can get the car running. Is there an injector size option in the menus the I can adjust to just get the car started and leak check it etc.

Cheers
John
TimH
JT Innovations
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Re: Changing map for bigger injectors

Post by TimH »

There's a "global multiplier" under Run-Mode Fuelling then Corrections. You could probably set that to around 0.4 or 0.5 to get it to run. Would be worth checking the lambda once warmed up and tweaking the multiplier to get it nearer right.
stevieturbo
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Joined: Sun Dec 07, 2008 2:04 pm

Re: Changing map for bigger injectors

Post by stevieturbo »

Or just whack the entire fuel map in half and leave the global at 1.

And change whatever injector latency/dead times values you are using as required too.
Hodge
Posts: 27
Joined: Thu Feb 17, 2011 12:34 am
Location: Consett

Re: Changing map for bigger injectors

Post by Hodge »

That's a bit beyond me Steve at the moment. I've tried what Tim suggested and it's worked perfectly. I reduced the global to 0.6 and the car runs nicely at 14.8-15-0 AFR.
TimH
JT Innovations
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Re: Changing map for bigger injectors

Post by TimH »

Glad it worked for you :) I think it's a great way to basically get a car running when changes to fuelling have been made, prior to a proper map.
stevieturbo
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Re: Changing map for bigger injectors

Post by stevieturbo »

it's simple....select all the cells in the relevant fuel table, either via mouse or keyboard.

Select "Math" then either multiply by 0.5, or divide by 2.

It really doesnt get any easier, and means the numbers in the fuel map are still more akin to the actual injector pulse widths in operation.

Whereas using the global they can be vastly different from the IJPW values in the table.
TimH
JT Innovations
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Re: Changing map for bigger injectors

Post by TimH »

Surely the result is the same!!?? (I am not a mapper LOL).

For different injectors the pulse width needed is never going to be a straight multiple of the original (when mapped).
stevieturbo
Posts: 1321
Joined: Sun Dec 07, 2008 2:04 pm

Re: Changing map for bigger injectors

Post by stevieturbo »

TimH wrote:Surely the result is the same!!?? (I am not a mapper LOL).

For different injectors the pulse width needed is never going to be a straight multiple of the original (when mapped).
End result at the injector yes....

But you could end up with poor resolution, or just strange numbers in the fuel map is the global is far from 1.0

It's just nice to have values in tables that make sense to the end result you're trying to achieve.

In the same way I could calibrate say a TPS from 0-50, or 50-100, or 20-80...but wouldnt it make more sense to calibrate it 0-100 ?

For injectors, If I was expecting injectors to max out at at say 20ms at 6000rpm ( ie 100% duty ) yet the numbers in my fuel table were only 10ms...I'd think something strange was going on.....which there would be. Either a fault, or some eejit changed the global to 0.5 so there are other huge calcs going on in the background.

it's just nicer to have the global at 1.0, or close to it given the values in the main fuel tables are supposed to be time based, ie ms.
TimH
JT Innovations
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Re: Changing map for bigger injectors

Post by TimH »

Agreed - but this is a quick fix to get the car running,
Hodge
Posts: 27
Joined: Thu Feb 17, 2011 12:34 am
Location: Consett

Re: Changing map for bigger injectors

Post by Hodge »

So if I have the global at 0.6 I'm guessing if I was to adjust the entire fuel table instead I'd reduce it. How much would you recommend Steve?
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