RB25DET 240SX MS1 Extra All stock sensors and coilpacks

Nissan, Infiniti, Datsun
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beav
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RB25DET 240SX MS1 Extra All stock sensors and coilpacks

Post by beav » Mon Apr 12, 2010 8:44 pm

This is a MS1 extra setup I just helped my friend with in his RB25DET swapped 240sx. We got it running and idling smooth this weekend but have not driven it yet, still need to get the driveshaft remade since he swapped trannys and it needs the downpipe and charge piping fabbed still. The motor was freshly rebuilt with built bottom end, Precsion turbo, greddy intake manifold, q45 throttle body, 300zx transmission, top feed fuel rail with modified WRX injectors etc...

We went out of our way to use everything stock as possible with the ecu setup. I used the stock coolant temp, stock 360 tooth cas wheel, stock coil packs with built in ignitors. The stock IAC is setup for PWM and there is another automatic fast idle valve that is hooked up. The VCT solenoid is setup using Nitrous control so it can be activated in the proper RPM window at heavier engine load. The only thing changed is we used a GM IAT sensor since there is no stock IAT, just the MAF which was obviously ditched.

I programmed a PIC16F628 microcontroller running at 20mhz to decode the 360 tooth wheel. It counts the outer holes in real time and can sync within one cylinder and will stay synced. It is setup to provide six channel coil on plug and emulate a distributor so only one input and output is tied up on the MS side. The pic also has a user adjustable tach output that can be calibrated to any tach so we could use his stock 4cyl tach which happened to be pretty far off, or any other tach when he likely changes the cluster. All of this was put on a custom PCB I made to fit in the MS case. Since I was already adding another board for the micro and supporting components I added spots for six IGBT drivers(which we are not using at this time). Two high current outputs used for IAC and VCT solenoids, two optional lower current outputs(not used at this time), and three stage shift light circuits. The board has its own power supply and everything so it could probably be used with just about any ecu that supports a distributor or MS2 or MS3 if he wants to upgrade later. After we get some miles on the setup I will likely make a few small revisions and then I might get a couple professional PCBs made as etching my own PCB is a skill I have yet to master.

The engine actually started on the very first try after verifing the trigger angle with a timing light and the injectors unplugged.

Here is the video, Its obviously super rich but we were happy it actually all worked the first try, we did not expect it to start and somewhat idle so easy.
http://www.youtube.com/watch?v=YjECpbrB0SY

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360 tooth CAS
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Custom Decoder board
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Prototyping on my desk with breadboard and coilpacks. I even had the drill running it over 6000 rpm and a timing light going and everything.
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dylbert
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Re: RB25DET 240SX MS1 Extra All stock sensors and coilpacks

Post by dylbert » Sun Aug 15, 2010 1:28 am

Wow, nice work!

Any chance you could post the schematic/code for the CAS decoder?

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