Help with turbo base tune

[Leiden]

Hey,

I've just finished installing a turbo onto my RS200 Altezza (build in members projects) and I'm looking for a few guru's to help me with a base tune. I'm using a emanage base tune from a KA24DE+T with a T25 turbo which seems to run fine but would rather something more specific...

I've got the ignition sorted so its not knocking. I've removed 1 degree per psi of boost, bit crappy in lower rev's but still pulls hard when turbo kicks in.

I've read a little about how the MAF setup works and I'm a little confused about a few things regarding that,

The maf sensor reads the amount of airflow and density via the temp sensor and the ecu adjusts the amount of fuel based on airflow, density, load, and o2 feedback (in closed loop). Probably a few other things but trying to keep it to the basics.

With a turbo setup there would be more airflow thus the ecu would adjust fuel based on the extra airflow pulled and compressed by the turbo up to a certain point where it becomes maxed out.

I'm confused on why I would need to tune the fuel map when the ecu would adjust fuel according to the maf feedback, I understand its necessary for when the sensor maxes out to prevent lean out, but while its under its limit shouldnt it cope with the turbo setup?

Fuel mixtures probably wouldnt be ideal with the factory ecu keeping fueling more for N/A but would it cope with the extra airflow?

Here are my current fuel/ignition maps. Fuel is in % over stock fueling and timing is in degrees over stock timing.



And here is a log with the maf sensor maxed out and ignition and fuel adjustment correction for boost:



If there are any guru's out there who know a bit more about tuning a N/A to F/I setup or any information on the general amount of extra fuel / timing needed I would be stoaked,

I'm a DIY person and love working on my car so any help would be appreciated

Thanks in advance guys,

[Lith]

I'm confused on why I would need to tune the fuel map when the ecu would adjust fuel according to the maf feedback, I understand its necessary for when the sensor maxes out to prevent lean out, but while its under its limit shouldnt it cope with the turbo setup?

Fuel mixtures probably wouldnt be ideal with the factory ecu keeping fueling more for N/A but would it cope with the extra airflow?

I assume you have a o2 sensor setup of some sort to check the resulting AFRs? Do you have any form of det detection?

If I understand your question correctly, you are saying that you're not sure why you'd have to adjust the fuelling as the ECU should already know? The ECU even though it uses a MAF setup doesn't do a special calculation to determine how much fuel it would need for that amount of airflow at those revs, there will be a premade map loaded into it which will suit the stock engine with a bit of a margain of error which would normally suit different atmospheric conditions/modifications etc.

A turbo effectively changes the VE of the engine quite substantially and therefore has a big effect how much timing and fuel it needs, even for a given reading from the MAF. There are lots of things which can alter how much fuel/whatever an engine needs to be happy which is why we need aftermarket tuneable ECUs when we do things like change cams/turbos etc. I'm not sure if I quite read your question right but answered based on how I interpreted, just in case

[barryogen]

why not take up xnickx with his offer of giving you his tune from his turbo'd altezza with emanage blue and take it from there, it'll be remarkably closer being at least the same engine.

[Leiden]

I would take up his offer but he couldnt manage to get it connected just yet but hopefully He'll be able to sort something out for me,

Really keen on using the MAP sensor for something more than just ignition retard, but I guess a proper dyno shop could do more than I could with it. Just getting to one without a license and 200KM's away from where I am.

I would be keen for a dyno and a/f readout with nicks map and then could go from there and adjust as needed.

Thanks Lith you made things alot clearer!

Assuming basics, is there a way to work out the difference in stock CFM vs turbo CFM and use the difference as fuel correction in the emanage?

[Lith]

Assuming basics, is there a way to work out the difference in stock CFM vs turbo CFM and use the difference as fuel correction in the emanage?

I would love to know about it if there is but nothing I know of, far too many variables at play for that - guess it would make tuners a bit redundant if you could make that accurate estimates of what the engine wants

Good luck with.

[tsoob]

I would take up his offer but he couldnt manage to get it connected just yet but hopefully He'll be able to sort something out for me,

Really keen on using the MAP sensor for something more than just ignition retard, but I guess a proper dyno shop could do more than I could with it. Just getting to one without a license and 200KM's away from where I am.

I would be keen for a dyno and a/f readout with nicks map and then could go from there and adjust as needed.

Thanks Lith you made things alot clearer!

Assuming basics, is there a way to work out the difference in stock CFM vs turbo CFM and use the difference as fuel correction in the emanage?

where are you? did you get it done at all?

[Leiden]

Nah,

Cars still sitting on the lawn at the moment, am going to take it for a grandma run to the beach on sunday with a laptop and log the trip and find out what its doing, see if theres any knock,

If there isnt knock is it safe to assume the engine will be ok until I get a proper tune?