Fuel Compensations Query

Give input on tuning as well as any tips and tricks you may have. Also feel free to share base mapping files for various engine types.
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proutyc
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Joined: Sun Sep 04, 2011 6:59 pm

Fuel Compensations Query

Post by proutyc »

Morbning gents.

Quick little question. We talking to my tuner about how he'll set up the fuel compensation tables and wanted to check something with you all. I'm assuming that the DTA doesnt have a built in ideal gas law which is why there is a default button in the compensation tables for it?

Also if this is the case if I want the 80kpa to be 1 lamada and 100kpa to be .95 lamada do I actually need to have 5% and not zero in the 100kpa column?

As another example if I wanted 130kpa to be .85 lamada the default would be +30% but due to wanting the run the car at a richer lamada does this actually need to be +47%

Lastly 160kpa I want it to be .8 lamada so so using the logic I have mention above should this be +85 instead of the default +60??

Thanks in advance
stevieturbo
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Re: Fuel Compensations Query

Post by stevieturbo »

Has your "tuner" actually ever tuned any ecu before ?

And no, making percentage adjustments like that will not work.

Your tuner needs to...well tune/map the ecu himself.

And I think either you or him is really confusing the whole thing beyond belief, when the tuning process is relatively simple.
proutyc
Posts: 104
Joined: Sun Sep 04, 2011 6:59 pm

Re: Fuel Compensations Query

Post by proutyc »

Thanks Steveie.

It is now tuned and no they havent done a DTA with a turbo before, they predominately doing links and motecs ecu. As they do a number of these ecu that want to replicate a particular setup (tps/rpm for fuel and MAP/RPM for advance. This is why I asked the last few questions.

This question is only here as his preference to adjust target lamada for different boost setting in general is to adjust this compensation table. As I'm not 100% comfortable with what he's doing I'm asking the forum as there are a number of higher skilled souls on here.

Where I live this is the only dyno operator as such and the closest DTA person is a 5 hour drive away. That will be where the car goes next but that's a hell of a trip for a shakedown when I dont know if we have any bug (Its a new car and we did end up with a slipping clutch which cant be fixed from 5 hours away)

Thanks again\Chris
Rob Stevens
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Re: Fuel Compensations Query

Post by Rob Stevens »

To do what you want can be done as follows.
Leave the pressure compensation set to standard.
Use TPS Vs RPM for main map, just map as normal, ignore pressure compensations.
You need to ensure that in
Other map settings/ Lambda Functions / parameters / Use MAP for Lambda / set to 'map'
Then
Other map settings/ Lambda Function / target map - now you can set lambda target per engine pressure.

However as with any system you must get the fueling somewhere close, you can't expect the ecu to tune its self if its barley running, this is universal regardless of ecu type.

Just make sure you have the lambda fitted and working nicely.
proutyc
Posts: 104
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Re: Fuel Compensations Query

Post by proutyc »

Many Thanks Rob

Was trying to avoid closed loop at higher rpm levels.

Wasnt sure if I had other options to perform the same funstions.

Thanks again
Roverdose
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Re: Fuel Compensations Query

Post by Roverdose »

you can turn off lambda above xx throttle and revs.

Drew
proutyc
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Re: Fuel Compensations Query

Post by proutyc »

Thanks Drew. That was the plan.

That's why wanted to use maths not closed loop to adjust the target lamada by MAP.

Thanks all
Chris
stevieturbo
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Re: Fuel Compensations Query

Post by stevieturbo »

Roverdose wrote:you can turn off lambda above xx throttle and revs.

Drew
AFAIK That is only for narrowband, not wideband.

Wideband is either off or on.

Depending on wideband used, I would also limit control +/-, and ensure that under any fault condition, it reverts to a voltage below 100mV so that you can have DTA disable closed loop operation.

If you cannot do this, tune the main fuel map open loop very close to where you want it, and limit any fuel removal from the wideband, so should a fault occur with the wideband, it could never do any harm.

And if the tuner has used Motec or Link etc, then tuning fuel tables on the DTA should be an absolute doddle. It's very basic and easily laid out compared to a Motec for example.

Any tuner with experience would be able to do a pull, review logs and make adjustments based on experience to get very close to ideal, very quickly.

Plus the fuel correction or lambda logging on the DTA can be useful too, but certainly not essential.
Roverdose
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Re: Fuel Compensations Query

Post by Roverdose »

haven't driven mine for a while, but i thought mine turned off?
ill have to look at that again.

Drew
stevieturbo
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Re: Fuel Compensations Query

Post by stevieturbo »

Roverdose wrote:haven't driven mine for a while, but i thought mine turned off?
ill have to look at that again.

Drew

I'm 99% sure, but I guess not something I played with that much.

One thing I have noticed and thought very odd. Go over 80% IDC and closed loop seems to turn off.
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