shaun byrne Posted December 15, 2009 Report Share Posted December 15, 2009 hi all, getting a g4 fitted in my skyline in january, i know there is an option for a variable switch for say 4 boost settings on the ecu. i assume its would need to be a potentiometer type switch, has anyone fitted a dash switch that has say 2-4 boost options, if so what type of switch would i need?. 4 postion toggle or riostat type. does the g4 work on voltage to control the boost?. sorry for a long winded question straight off. bernie Quote Link to comment Share on other sites More sharing options...
Phil Williams Posted December 16, 2009 Report Share Posted December 16, 2009 Hi Shaun, You have two main option; either an Analogue Potentiometer, or a two position switch. The analogue potentiometer would allow you to adjust the boost over the range you configure. The switch allows you to select between two boost settings. Regards,Phil Quote Link to comment Share on other sites More sharing options...
shaun byrne Posted December 16, 2009 Author Report Share Posted December 16, 2009 cheers Phil. was thinking of something like this http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item;=310171519712&ssPageName;=STRK:MEWAX:IT#ht_1584wt_1051 so zero would be wastegate spring pressure, say 1.0 bar then have number 1 as 1.4 bar ans number 2 as 1.8 bar. would that work or would i need something like this?. http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item;=260520203483&ssPageName;=STRK:MEWAX:IT#ht_2107wt_960 cheers bernie Quote Link to comment Share on other sites More sharing options...
Phil Williams Posted December 16, 2009 Report Share Posted December 16, 2009 The first switch would be ideal, only disadvantage I can see is that it would consume two digital inputs. If you are running a Storm you only have four in total. The other more complicated option is to wire the switch to an analogue channel with a special arrangement of resistors around the switch. Then setup two vitual aux channels to determine the state of the switch, and then trigger the boost tables off the virtual aux states. If you want to go down this path, please let me know and ill provide you with the information to set this up. Quote Link to comment Share on other sites More sharing options...
shaun byrne Posted December 16, 2009 Author Report Share Posted December 16, 2009 cheers phil. not sure which model of g4 mgt are fitting, but i know its a pcb that goes in the original ecu and uses the original ecu plug..if that helps. i like the first switch, simple. so if i used that what number of variable boost settings would i infact be abble to have 2?. say 1.4 and 1.8 bar? would the number 0 be redundant? cheers bernie Quote Link to comment Share on other sites More sharing options...
Phil Williams Posted December 16, 2009 Report Share Posted December 16, 2009 http://www.linkecu.com/support/documentation/g4-engine-management-documentation/NissanGTS is the installation manual for the ECU you will most likely recieve. Section 4.3.1 Nissan Skyline GTS/GTR of the manual shows the expansion connector. There are two avaliable DIs and these can be used with the additional purchase of an expansion loom. Looking again at that switch, I cant tell you exactly how it works as there is no datasheet for it on the web address you gave me. I'd assume it would work if there are three pins on the back of it. Otherwise your local electronics store will sell something that will work. This does confirm that you will be able to run three seperate boost maps. Quote Link to comment Share on other sites More sharing options...
shaun byrne Posted December 17, 2009 Author Report Share Posted December 17, 2009 cheers phil. thanks for your help again bernie Quote Link to comment Share on other sites More sharing options...
Matt Dunn Posted December 17, 2009 Report Share Posted December 17, 2009 Hi, I run this in my car, but I run an 11 position switch to have 11 different boost settings. If you have a little bit of electrical knowledge it is no hard to do, and only requires 1 input. Here's how I did it. I used a Rotary switch that clicks into positions, I think it was up to 12 positions, with a locking tab so you could make it any number up to 12, and so that was how I got 11 positions. It has one common terminal and connects to each other pin one at a time. I soldered 10 resistors from output 1 to output 2, output 2 to output 3, output 3 to output 4, etc etc. All resistors must be the same value and from memory were .5K ohm, so in total the resistance from output 1 to output 11 was 5K ohm. Then feed a 5V feed into output 1, and and earth onto output 11. and an analogue input channel to the common wire. This will put out 0.0V at position 1 0.5v at position 2 1.0 at position 3, etc etc, Set up the boost control as though you are going to use an analogue potentiometer, and so each position it lines up exactly with one of the rows in the table, meaning that you know by which position the switch is in, what row in the table it is in. using an analogue potentiometer would be just as good and have the same outcome, only thing different is the system I use clicks. I actually fitted the system quite a while ago, but have only recently been using the link for my boost control and this system works great. Quote Link to comment Share on other sites More sharing options...
shaun byrne Posted December 17, 2009 Author Report Share Posted December 17, 2009 cheer matt. so if i only want say 3 boost settings, a potentiometer with 3 postions and a centre contact would do it?.bernie Quote Link to comment Share on other sites More sharing options...
Phil Williams Posted December 17, 2009 Report Share Posted December 17, 2009 A Potentiometer generally refers to a dial with an analogue voltage output. A 3 position rotary switch can be wired with resistors to an analoge channel just how Matt has done. The G4 has configurable axis so it doesnt matter how many switch positions you have. Quote Link to comment Share on other sites More sharing options...
shaun byrne Posted December 22, 2009 Author Report Share Posted December 22, 2009 cheers guys, have bought both the above switches to experiment, probably try to use the top one of those two, the 3 postions one.i can only find resistors of 1.5k ohm,s?. will these be ok if they are all the same rating and does it matter what wattage they are?. thanks again bernie Quote Link to comment Share on other sites More sharing options...
shaun byrne Posted January 1, 2010 Author Report Share Posted January 1, 2010 att. phil & matt. hi guys happy new year. below is the switch i have got, its a 2 pole 5 postion, i only really need 3 boost settings. i have marked the terminals, can you advice wher they should go. i presume pin 5 is 5v ecu output, pin 6 is ecu input, and pins 4,3,2,1 are the variable settings?. but M att mentions and earth?. any help is appreciated guys,just trying to get the switch fitted and wiring down to the ecu piont so the guys fitting/mapping the ecu can then just solder my harness to the ecu ..bernie Quote Link to comment Share on other sites More sharing options...
shaun byrne Posted January 1, 2010 Author Report Share Posted January 1, 2010 quick note , the resistors are 1k 25w. i only have a multimeter, but when i put 2.5v to pin 5 2.5v came out of pin 6. as i turned the switch the readings were pin 4 .6v pin 3 .9v pin 2 1.2v pin 1 1.4v not sure if this helps..lol bernie Quote Link to comment Share on other sites More sharing options...
martin battye Posted January 7, 2010 Report Share Posted January 7, 2010 pin 6 should be v output.. then you connect your 5v bench supply to the pot at the connection 1 and 5.. Quote Link to comment Share on other sites More sharing options...
shaun byrne Posted January 7, 2010 Author Report Share Posted January 7, 2010 cheers martin. so pin 6 goes to analogue input on the ecu the 5v output from the ecu is then split in two and fed to terminals 1 and 5 correct?. i understand the terminal 5 theory as that is what i was going to do, how does powering terminal 1 work?. is there not a direct 5v feed then going to terminal 1 so when in this position 5v goes straight to the ecu, or is that the plan?.sorry for being a pain bernie Quote Link to comment Share on other sites More sharing options...
martin battye Posted January 8, 2010 Report Share Posted January 8, 2010 hi.. you need to take a sensor gnd and 5v to the sw... then the switch works like a potential divider.. Quote Link to comment Share on other sites More sharing options...
shaun byrne Posted January 11, 2010 Author Report Share Posted January 11, 2010 final update, think i am finally sorted. i rigged up a 5.6v feed and this is how i wired it. and the results. pin 1 was earthed pin 5 was fed 5.6v pin 6 is ecu input now when the switch is on pin 1 voltage out of pin 6 is zero, so this i presume could be used as wastegate spring pressure in my case 17psi. when switched to pin 2 voltage at pin 6 was 1.2 v when switched to pin 3 voltage at pin 6 was 2.4 v when switched to pin 4 voltage at pin 6 was 4.5 v when switched to pin 5 voltage at pin 6 was 5.6 v so hopefully these voltage variations can be used for various boost maps within the g4.. cheers guys for all the help..it was needed..lol bernie Quote Link to comment Share on other sites More sharing options...
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