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I am installing on a R32 GTR a Link G4+ plug n play ECU . The Link comes with a 4bar map sensor which from my understanding I can use that instead of the MAF sensors that the oem set up uses (I will be taking them off completely). My question is do I need to to any adjustment to the ecu menu or anything else extra to the wiring besides using a vacuum line to the map sensor ?
Implementing the onboard MAP sensor for primary load calculations means that you will be using speed density calculations for measuring air mass, this would mean that you're also going to have to install an intake air temperature sensor. Rather than run a new harness for this going right back to your plugin ECU, I think that you should be okay to utilize wires within the MAF sensor harness which already go all the way back to the plugin ECU.
Long story short, you can remove the stock MAF sensors as they will no longer be used. Using the MAP sensor means that you're going to have to use an intake air temp sensor. There are instances where some MAF sensors have intake air temp sensors built into the factory MAF, if so then these may be utilized. However, while calibrating the engine you have to be mindful of the mounting position of the intake air temperature sensor within the MAF. This isn't the ideal, you have to remember that you are trying to measure the mass of the air that makes it to the engine. That means that it's going to be ideal for the sensor to be mounted very close to the intake plenum, very similar to where the vacuum port being used to sample the manifold pressure being used by the onboard MAP sensor.
Much of what I have explained should be in your quick start guide which would have been shipped with your plugin ECU, your dealer can also explain this at length for you. If you have any follow up questions or curiosities please feemfeee to follow up at your convenience.
Yes, the MAP sensor just replaces the two MAF sensors. From memory you will need to wire the MAP sensor into one of the MAF sensor plugs - You'll need a 5V, sensor ground and an analogue voltage input.
There's an IAT sensor factory fitted to the plenum but I've found it to be effected dramatically by heat soak. I usually add a sensor in the I/C pipe pre-plenum. If you haven't tuned a multi throttle turbo engine already then there are some big differences compared to a single throttle / plenum. Check out this webinar which explains the situation - https://www.hpacademy.com/previous-webinars/4d-tuning-link-g4-plus/
To Add to what Andre said, the GTR Plug n play actually has an on board MAP sensor so no wiring required.
These come pre configured in the ECU Map under AN Volt 1. So really all that is needed is a vacuum line run to the map sensor in the ecu.
Also as mentioned the factory IAT in the plenum suffers from a lot of heat soak, fitting a sensor pre plenum and use the original IAT wiring and just change the calibration under the AN Temp to the sensor you're using.
Also a tip, some people leave the MAF sensors in place and plugged in to keep the factory look. If the sensors are plugged in it will cause a back feed on the 5v and cause tuning issues with your other 5V sensors like MAP and TP
Thank you for the input . So I should install the IAT sensor on the piping prior to the throttle body and extend a little bit the wire of the stock IAT .
Would like to ask the following , I will be installing a atmo/plump bov which will be on the upper pipping prior to the throttle body so the owner can use it as he wises . Will that although affect the reading to my IAT ? I do understand that it will be measuring the air temp but because they will be on the same pipping , most likely on a different angle .
Thank you again .
A pleasant good day to you.
The understanding for the intake air temperature sensor is sound, and although it should be perfectly okay to extend the existing harness for the stock intake air temperature, I would actually advise that a fresh harness be run as the data the sensor is transmitting is sensitive to changes in circuit resistance. Once again, this is just based on a best practice approach. With regards to the atmospheric blow off valve, I would advise that the plumbing for the blow off valve be maybe 6 to 8 inches away from the intake air temperature sensor, leaving the intake air temperature sensor closer to the Throttle body while the blow off valve will be furthest away; distance between both being 6 to 8 inches. Just as I noted previously this advisory is based on a best practice approach.
I'm certain that the more senior members will comment further with a more comprehensive explanation in their response, thereby offering a much more insightful response which might be more pragmatic and equally insightful.
Please feel free to follow up with any further questions at your convenience so that we may better assist.
and try to go with an intercooler kit, that provides you with qualitiy alum. piping ... I've tuned an R34 GTR with a knock off greddy IC kit and even with the IAT sensor relocated to that hideous thick cast piping, it still suffered from heat soak.
I want to set up 2 different tunes for 2 different boost pressures . If I am correct I will have to go to the boost control menu -> mutliple tables -> ON selecting the input . My question is can I use the same input example DI 6 for the 2nd boost map as well as the secondary fuel/ignition table ?
Also as I have seen in the menu I can have up to 3 different boost tables but only 2 fuel and ignition tables . If that is true and if I wanted how would I be able to have those extra maps ?
Personally I don't use different fuel or ignition maps unless I am using different fuels, I usually map for the highest boost setting and this will cover you for the lower setting as well.
But in answer, yes you can use the same DI for switching boost and fuel/ignition tables together
There's really no need to use different fuel/ign tables for different boost levels. Particularly with the ignition table you will simply be operating in a different row of the table as you change boost so all your tuning can be done here.
With the fuel tuning on the GTR this is a little different because of the ITB configuration. Your main fuel table will be configured with TPS as the load axis. This means you're operating in the same cells at wastegate boost pressure as well as maximum boost. Generally the fuel model will track your target lambda quite nicely until you start really pushing the turbos hard and the efficiency drops off. Here you'll find that the AFR starts to move rich at high boost and high rpm. I deal with this by using a 4D overlay table as required. This is all covered quite nicely in the webinar I linked to in my earlier reply.
Thank you for the info . I was under the impression that I would have to have different maps but what you are saying makes sense .
But if I do not use a different fuel map , wouldn't I be running too rich on low boost ? Of course I mean if we go at high rpm's on low boost . I mean if low boost would be let's say 1bar (14psi) and then go to 2bar (29psi) .
This is what the 4D overlay that Andre mentions covers, if you watch the webinar you'll get it explained better