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DaNnY_LaD's HTA-Gt2868R Big turbo Build(Now @ AKS Tuning)

IbizaAlex said:
The maf and injectors is what myself and Revo worked out to be correct. On the cars I've run the setup its been perfect on cruising and on power with the fuel trims being damn good too.
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You've always said to me that an S4 MAF is whats used, and what you used on your car mate.

http://www.seatcupra.net/forums/showpost.php?p=3340154&postcount=30

RS4 is a MASSIVE MAF and the calcs dont add up to me.

The only way i can see it working if you max out the 2.5bar MAP sensor so your ECU thinks at 2550mbar your MAF readings are really high but you'd have to run a lot of boost for this.

The ecu expects to see certain airflow at a certain boost and if it doesnt it will add fuel in and your trims will raise to accomodate. This is why you used a 3 bar map sensor, as it drops the read boost pressure by ~500mbar making the MAF reading vs. boost closer to what it should be.


For example:

If on a 2.5bar map maxed out (vag com reading of 2550mbar) you would see say 220g/s max but the ECU expects to see 250g/s at this boost level you would see your LTFT rise to about +15%.


Now on the same boost level but with a 3 bar map (ecu now reads ~500mbar lower but the car delivers the same boost) you would see the same g/s but your fuel trims would drop as the car is seeing more air flow for a reported lower boost.
 
PhilW said:
You've always said to me that an S4 MAF is whats used, and what you used on your car mate.

http://www.seatcupra.net/forums/showpost.php?p=3340154&postcount=30

RS4 is a MASSIVE MAF and the calcs dont add up to me.

The only way i can see it working if you max out the 2.5bar MAP sensor so your ECU thinks at 2550mbar your MAF readings are really high but you'd have to run a lot of boost for this.

The ecu expects to see certain airflow at a certain boost and if it doesnt it will add fuel in and your trims will raise to accomodate. This is why you used a 3 bar map sensor, as it drops the read boost pressure by ~500mbar making the MAF reading vs. boost closer to what it should be.


For example:

If on a 2.5bar map maxed out (vag com reading of 2550mbar) you would see say 220g/s max but the ECU expects to see 250g/s at this boost level you would see your LTFT rise to about +15%.


Now on the same boost level but with a 3 bar map (ecu now reads ~500mbar lower but the car delivers the same boost) you would see the same g/s but your fuel trims would drop as the car is seeing more air flow for a reported lower boost.
Click to expand...

I understand what you are saying.

The map on my car was tweeked by revo to get the maf, injectors and map sensor working properly together. Without the map tweek the trims were miles off when cruising and on boost. The tweeks brought the trims to within +/-5%.

It was Adams (buch's) leon that the rs4 maf was first tried and the trims were +/-10% iirc and with a wideband lambda its not as important as the ibiza's and you could even do a maf delete with no real bother inlike the ibiza's.
 
Ahh, wideband setup. Might along with maxing out the map mean it would be ok.

What kind of boost was you running on it Alex? More than 1.5bar?

Thanks for chipping in tho, appreciate it.
 
Gave her a Clean today first time in months was a Brief one at that due to the weather...think i need to get her on the road asap...

319194_10150355405149537_510819536_8478165_758825260_n.jpg
 
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