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datalogit apexi rb25det spec 1

General Tuning Discussion

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hi i was thinking of giving tuning a try or actually start learning by trying.. i have my friends car a skyline spec 1 rb25det with custom intakemanifold, bigger turbo 63mm exducer, spitfire coils, walbro 255 fuelpump and oem injectors,

my tought was to start with this map that i found on the datalogit forum that is from a spec 2 engine, i think it will be a good starting point becouse it has almost verything that is mounted on my friends skyline beside a z32 maf and bigger injectors.. i have looked over the map and it seems good but you never now... is there anybody here that can take a look at it and give me some judgement on it ?

i could email it to you becouse i couldent upload it here..

and also how do i set the injector size on the datalogit ?

thanks for the support and sorry for my english!

If you are wanting to learn to tune then start with the original map with little or no boost and tune it from there, then increment it up. Remember and monitor AFR's and listen for knock, don't rely on the PFC telling you it's knocking.

Injector scaling is on the last tab, standard it will be 100 as in 100%, you need to work out the multiplication factor needed for you replacement injectors:

If we say standard injectors are 100cc and you are fitting 200cc



So you would put 50 in each of the injector channels

Thank you for The answer chris!

Since my friend has bought a secondhand apexi, where can i find a complete start/base map? Do you have one that you could email me?

[email protected]


I agree with Chris, you are almost certainly going to be better off starting with a stock map and tuning from there to suit your modifications. I've seen too many situations where a map from someone else that 'should' have been perfectly suited to a particular combo included some strange alterations to a map that weren't immediately obvious. This can have you chasing your tail for ages, causing a lot of frustration and wasted time.

If you choose 'initialise', this will revert all the maps to stock.

thanks for the answer andre

your course on road tuning have helpt me alot, do you maybe have a short command list or something like that for the apexi fc datalogit ?

i have googled it preety much but couldt find something that sums them all up..

Sorry I don't. I've tuned plenty of Power FC over the years but more recently we haven't seen many. It seems like their popularity has maybe fallen off a little which is a shame since they are a very capable ECU.

If you want to post up what you're having trouble with and I'll do my best to help you out.

no worries ! im trying to get it running but im having a problem getting the stuppid "watches" to work, i have added watches ,knock,water,lambda/afr and so on but i dont get no numbers at all, i can se where the engine is in the map with the "ghost" function but i cant read any lambda so that makes is cind of difficult hehe

i seem to got one of the watches to work now, but ran in to another problem.. i got a innovattiv mtx-L and when i start the car the didgets seems to be so far away from real life.. it reads 18.>> Lambda and from what i have heard the car wouldt even run with 18 lambda..

when i enter the inj map on the fc edit and add max fuel ( i heald the + key in ) it wont even go lower then 14,9 lambda wich is still to Lean..

i mean the injector ( stock) cant be maxed out on 14.9 lambda.. i have tried recalculated the sensor again but reads to lean still

whould apreciate if someone could help me :)

You need to start logging to get the 'Watch' or the Monitor screen to start populating with numbers. F1 will start this and F2 will stop it.

One thing to watch with the aux inputs is that you are using the correct output from the MTX-L. One is a wideband output and the other is a simulated narrow band (0-1V). Other than that it's just a case of matching the voltage input to an AFR value in the auxiliary setup section.

Go by what the MTX-L is showing on the gauge or you can do what I do. Download Innovate Logworks, use the serial output on the gauge and if you dont have a serial port on your laptop since most recent ones dont, use a USB to Serial adapter. In the Logworks software set up a gauge and you can have an on screen gauge window you can see in real time. Advantage of this is that you are seeing a true digital signal and you dont have to worry about ground loops and such when you wire in the 0-5v output into the ecu. So in other words you will see the true A/F reading. Ive never used Datalogit for Power FC so can comment on setting up the Wideband offset or voltage curve in the software.

thank you andree and tommy ! i maneged to get it to work, we changed the lambda ground so that it hade it's own ground source and then calibrated the lambda to times and then i used the logworks software and saw that it was on afr insted of lambda -.- so stupid rockie mistake hehe, thank you alot for all the help !

is there some way to get the number that the lambdas are going to give ? since i hade the instruction manual to the innovative gauge it gave me direct number, like 0v = .. .. and 5v = .. .. how can you calculate the numbers if you dont have the insturction manual for exempel ?

thanks you again !

@ Leoadler you can download all of the manuals for Innovate products from their website

thanks for the tip michael !

but how do you calculate what numbers it gives between a sertain voltage ? :)

I'm not too sure what you're asking @leoadler?

With the innovate product you can program the output to be any lambda value you like at any voltage. You can then program the FC Datalogit to match these values.

@andre simons

ahaa okey so if i want i can set the wideband to for example 5v= 14.7 and 0v = 0,50 lambda ?

is there anyway that yo can change the fuelmap in the apexi in % ? like adding a surtain % to a row ?

yes you can program it to be whatever you want however it sounds like you just specified both AFR units and lambda in one go? It doesn't really matter what units you use of what your span is as long as it matches in the datalogit software. One tip I have is to make sure you have good resolution across the range of AFR you expect to actually use. For example there isn't much point spanning AFR from 5:1 @ 0V through to 20:1 at 5 volts. This will simply reduce the useful range of voltage you are actually working across and amplify any errors.