Jaycar Boost and Fuel Control

[C_DawG]

Interesting stuff SydneyKid, can the two controllers share a common plug to the h/c?

Or do you have to unplug one and shift the cable to the other when making adjustments?

Just interested becauase I would most likely build them into the same chassis.

[funkymonkey]

what's the sampling rate of the boost controller?

[Sydneykid]

Interesting stuff SydneyKid, can the two controllers share a common plug to the h/c?  

Or do you have to unplug one and shift the cable to the other when making adjustments?

Just interested becauase I would most likely build them into the same chassis.

Just looking at the circuit diagrams, I would say you can only have one plugged in at once as they use common pins. You may be able to switch the data streams over though, rather than physically unplug the Controller from one and plug it into the other.

[mcnamg]

or get an rs232 switch that you can strip out of its metal box and put into the dash somewhere to allow switching.

sk i have seen flat rs 232 cables we have them hanging off the back of our pcs at work cant figure out what they connect to tho. looks like a ribbon cable with a tiny flat rs232 connector at the end i will try to take a pic

[Sydneykid]

what's the sampling rate of the boost controller?

The data source is one injector, it doesn't matter which one. So the "samples" will be supplied at 1/2 engine rpm, the IC is much faster than that. It will increase as the engine rpm rises, which is coincidentally just what you would want. Perhaps not "coincidentally" maybe the Sillycoon Chump thought about it.

[MANWHORE]

everything that you've said so far makes perfect sense. Now, all I;m waiting for before going ahead, is your real world test results to see if the little beauty performs as it's supposed to.

Also, I'll wait to see how many things need to be connected up.

And then next comes the fuel modifyer. hehehe

Cheers Gary

[Sydneykid]

As you can see I have finished building the kits, the boost controller was the last one. It took around 1.5 hours to build. If I get time i will connect them up over the weekend, I will leave the fuel at zero (no correction) until I get time on the dyno. But I might give the boost a tweak straight away. If I do, I will post up the results. Regardless I will do before and after runs on the dyno.

It took me around 3 hours to fully read the instructions and background theory, then build the Fuel Adjuster and calibrate it. Then about 1 hour to build the Controller and about 1.5 hours to build the Boost Controller. All up around 5.5 hours of easy, no rush work. There is a bit of set up (calibration) involved in the Fuel Adjuster. The Controller has no set up, just adjust the display brightness. The Boost Controller has to be set up (calibrated) in the car, but it looks pretty simple.

There are only 8 connections to be made in the car, and the power supplies (+ and - 12 volts) are common, so that's really only 6 connections. I will make them all at the ECU, saves running wires under the bonnet. If someone has access to a good copy of the Stagea ECU pin out, this thread would be a good place to put it up. The connections are;

Fuel Adjuster;

Red = 12 volts +

Black = 12 volts -

Green = input from AFM

Black = output to ECU (where the AFM used to be connected)

Boost Controller;

Red = 12 volts +

Black = 12 volts -

Green = input from injector

Black = output to the standard solenoid

PS; the Jaycar guys asked me to rate the kits when I was in there yesterday. Well I rate them as one of the best kits I have assembled, good instructions with pictures, easy to read, well laid out boards and all required components are included. I am no electronics engineer, and I had no problems. "Highly Recommended" would be my summing up.

[Robo's]

SK

Have you ever tried there Ignition Control???

[Jay95R33]

Good work SK.

Apparently the Stage (series 1) ECU has the same pin out as the R34 GTT. It certainly has the same plug that's for sure.

Here's a link to the pinouts for the R34 GTT.

http://members.iinet.net.au/~jay77/R34ECUpinouts.pdf

Cheers

J

[Sydneykid]

I though it might be handy if I added the ECU pins I intend to use;

Fuel Adjuster;

Red = 12 volts + * Pin 31

Black = 12 volts - * Pin 32

Green = input from AFM * the cut wire that used to go to Pin 54

Black = output to ECU (where the AFM used to be connected)* Pin 54

Boost Controller;

Red = 12 volts + * Pin 31

Black = 12 volts - * Pin 32

Green = input from injector * Pin 101 (cylinder #1)

Black = output to the standard solenoid * the cut wire that used to go to Pin 104

I have now fully tested them and the connections are as posted above.

[Sydneykid]

Does anyone know if Stageas have peak hold injectors? I am getting erratic signals from #1 injector switching at the ECU, which is usually a sign of peak hold injectors. But I thought all RB25DET injectors were high impedance, usually peak hold uses low impedance injectors. Anyone measured the impedance of Stagea injectors?

[Jay95R33]

How did you go SK ? Any luck with the injector ?

[funkymonkey]

I remember skylinegeoff telling me that he had to wire in some resistors to his injectors when he replaced them with aftermarket ones so that the injectors worked properly with the signal. He may be able to shed some light on the topic.

[GTRgeoff]

Nup. I have some toyota 440cc injectors that are low impedence (3.3 ohm) so I need the resistors to protect the ECU. Daresay it will have little to do with the suspected peak hold facility on the Stag injectors.

Time to throw a big auto multimeter on it SK and sample the injector signal. Oh...and the impedence

[Sydneykid]

Maybe time to visit my best friend the electronics engineer, he has a nice scope and the knowledge to use it. I don't want to build a Jaycar peak hold adaptor if I don't have to.

PS; I got sick of waiting, so at 4.00 am today I rerouted the vacuum hoses and worked the boost up to 0.5 bar, goes a lot better than 0.3/0.4 bar. Zero cost, 10 minute job.

[tigerleo62]

PS; I got sick of waiting, so at 4.00 am today I rerouted the vacuum hoses and worked the boost up to 0.5 bar, goes a lot better than 0.3/0.4 bar.  Zero cost, 10 minute job.

How, what?? What did you do that cost nothing and only took 10 minutes?

[Sydneykid]

How, what?? What did you do that cost nothing and only took 10 minutes?

I thought everyone with an RB25DET knew how to do it. You just disconnect the solenoid (vacuum, not electricaly), connect the boost feed directly to the wastegate and use the (standard) restrictor to bypass the desired amount back into the turbo inlet. The standard byspass hole of 1.25 mm bypasses enough air flow for 0.5 bar. Tools needed = one pair of pliers and 10 minutes.

PS; If you want more boost you can drill out the bypass, 1.5 mm = more boost (around 0.7 bar) 1.75mm = a bit more (around 1.0 bar). But the Jaycar Boost Controller needs the bypass to relieve trapped pressure between the solenoid and the wastegate actuator. So I don't want to redrill the restrictor only have to solder it back up again.

[Jay95R33]

One thing I've been thinking about. Being an electronic boost controller, what does it use to sence the boost presure ? Does it have it's own map sensor? or does it figure out what it needs to do by going off the duty of the injector that you need to tap into ?

It's also something I need to find out about the Unichip boost control module, does it need a map sensor.. If so I'll have to source a one and install it cause the Stagea's don't have one from factory - no boost gauge..

J

[tigerleo62]

I thought everyone with an RB25DET knew how to do it.  You just disconnect the solenoid (vacuum, not electricaly), connect the boost feed directly to the wastegate and use the (standard) restrictor to bypass the desired amount back into the turbo inlet.  The standard byspass hole of 1.25 mm bypasses enough air flow for 0.5 bar.  Tools needed = one pair of pliers and 10 minutes.

No , not me - I know nothing, and now realise that I know even less...

Any links to pics/diagrams that illustrate the bits you refer to? As I said - I know nothing - except how to replace the panel filter! I once had a Mk I GT 440 Consul Cortina that I knew what did what and could even fix when minor things went wrong, but now days when I open a bonnet I just go "Hmmm, engine" and that's as far as it gets!

[Sydneykid]

This is the 10 minute no cost boost to 0.5 bar rerouting of the vacuum hoses. Disconnect the two vaccum hoses from the solenoid. Then connect the boost feed (from the cross over pipe on the left of the picture) to a the standard T piece. Connect one side of the T piece directly to the wastegate actuator (on the right of the picture). The remaing connection on the T piece goes back into the inlet via the BOV return pipe (on the standard fitting). Make sure to put the the standard brass restrictor in that vacuum hose to bypass the desired amount back into the turbo inlet. The standard bypass hole of 1.25 mm bypasses enough air flow for 0.5 bar.