Nistune Forums

Is this possible? I've done a lot of searching, and have found info on controlling the factory boost control solenoid with the ecu, but could a person wire the AEM boost control solenoid into the factory wires somehow to control boost with the nistune? I am just looking at options, and figured if I could save myself the $300 from buying the AEM boost controller/gauge, I could just buy the solenoid which is under $100...anybody have any experience on this?

What about using this MAC solenoid that I've heard about? I'm having a hard time finding info on how to control boost using the nistune anywhere...is it better/easier to just get a boost controller?

Suggest a boost controller as only a few ECUs have imbuilt boost control and I havent investigated the full functionality of these just yet

Ive seen a company in the states that are able to wire in some sort of knob for the z32's. It would be so nice if there was some sort of table where you can just input a number and it would automatically regulate the boost with an aftermarket solenoid.

Just thought I'd share what I did to solve my electronic boost control problem. I bought a simple PWM (Pulse Width Modulator) kit $25 and setup an Opamp input circuit with two controls. One control (0-5vdc) manages the setpoint (Boost level) and the other is the input from my MAF, both 0-5v signals. These are DC analog signals and the outpot of the Opamp circuit feeds into the PWM. This converts the DC analog voltage into a Duty cycles Square wave pulse. 0-5 vdc results in 0 100% duty cycle pulses. I then built a simple boost air bleed using a cheap fuel injector and fed the output of the PWM into the injector. Works an absolute treat and I can set my Boost from my dash. Apart from my time the whole controller cost under $100 to built. Just a note for your information because I use the MAF signal, what I ended up with was actually a Power controler not boost controller. (Could do boost control by installing a poost pressure transducer to replace the MAF meter signal). My power to the ground is now 320 hp at 3800 rpm at 24 PSI and is the same right through to 8000 rpm at 12 PSI. The reason I decided to control Power and not boost was becasue I have a CA18DET motor in a very, very light car and was undrivable when the boost came on. Very peaky power/boost behaviour. Changing to the controler to measure the MAF turned the car into a very drivable fun vehicle. Cheers Richard

Nissanclubman wrote:Just thought I'd share what I did to solve my electronic boost control problem. I bought a simple PWM (Pulse Width Modulator) kit $25 and setup an Opamp input circuit with two controls. One control (0-5vdc) manages the setpoint (Boost level) and the other is the input from my MAF, both 0-5v signals. These are DC analog signals and the outpot of the Opamp circuit feeds into the PWM. This converts the DC analog voltage into a Duty cycles Square wave pulse. 0-5 vdc results in 0 100% duty cycle pulses. I then built a simple boost air bleed using a cheap fuel injector and fed the output of the PWM into the injector. Works an absolute treat and I can set my Boost from my dash. Apart from my time the whole controller cost under $100 to built. Just a note for your information because I use the MAF signal, what I ended up with was actually a Power controler not boost controller. (Could do boost control by installing a poost pressure transducer to replace the MAF meter signal). My power to the ground is now 320 hp at 3800 rpm at 24 PSI and is the same right through to 8000 rpm at 12 PSI. The reason I decided to control Power and not boost was becasue I have a CA18DET motor in a very, very light car and was undrivable when the boost came on. Very peaky power/boost behaviour. Changing to the controler to measure the MAF turned the car into a very drivable fun vehicle. Cheers Richard

Can You post some photos and diagrams?
Thanks in advance ...

Sorry about the poor quality of the schematic. The LM324N is a quad opamp pack and the pin numbers on the sketch aren't right but gives you the basis of what I did. I'll post an actual drawing over the next few days. This opamp was also selected becasue it doesn't need a split rails +/- power supply a standard 0 - 12vdc will do.
http://www.dz863.com/datasheet-82877206 ... Amplifier/

I have a variable POT mounted on the dash to dial up power/boost setpoint. It affectivly controls the OpAmp gain and output to the PWM. It is infact a reverse gain control. Lower the gain will reduce the injector bleed to the actuator and increse HP. Pretty simple really.

The PWM is which takes the output from the OpAmp circuit is a kit - http://www.velleman.eu/downloads/0/illu ... 4_rev3.pdf

Injectors were $10 for the set off eBay.

As with all things in the real world there is a bit of setting up to do. I have built in a simple adjustable by-pass bleed to the intake so I can control the actuator sensitivity (Open and close rate). I have also built in a gain setup pot to tune the OpAmp circuit to approximately the range it will be used. Fine tuning is managed by the Set Point pot on my dash.

Hope this helps. Happy to chat off line if you need. Cheers Richard

Thanks Richard I'll post my result after we build our controller .

I love it! Always good to see something designed by somebody who knows what they're doing instead of buying X brand $800 EBC only to find that the instructions are in Japanese and nobody knows how to work it...

I'd probably just use a MAC valve for the solenoid. Actually, even better I'd use the solenoid from an S14/15 cos they're a lot cheaper! But otherwise this looks like a great approach. Having just dealt with a Datto 1600 with a 280rwkw SR in it, this could be just the ticket to add a bit of much needed control!

You could also use the TPS voltage as the other input rather than MAF/MAP? I guess it's not really load sensing then. Have to try it really...

Pete L

I know that Arduino board has programable PWM output, and a MAC valve is drive by PWM.
but the Arduino output voltage and amp load is too weak for driving a MAC valve, I have both item but I don't know what device to link between them, anyone has any idea ?
I'm in the process of learning Arduino programming, I know that it can connect any type of sensor as an input, temperature, pressure, G, hall...whatever, output display on a LCD, PWM or analog output to driving any device, I think it would be a fun project to make an automatic pressure sensing boost contorller with LCD screen.

Hi Pete, Yes My initial thinking was to use Nissan solenoids and I tried both from the CA and RB family as well as a number of after marked ones which supposedly worked with PWM signals. Unfortunately they just didn't respond freely enough to the PWM Frequency even through the board is adjustable (60 - 1200hz. I then put the signal directly onto one of my injectors and it seemed to work a treat. So I just went an and built my own from Injectors. Cheers Richard

Hey Richard,

Yeah, most of them are useless. You gotta get the ones from the later models - the ones that actually control boost with PWM, rather than the older ones that are just used to lower boost if the ECU thinks something bad has happened.

S14/15 are the go. Very different animal to the older ones. They'll rattle away under PWM drive forever. Cos that's how Nissan use them in the OEM configuration.

Louis,

My son has just started playing with the Arduino. You could just grab a "motor drive shield" and use it to drive the solenoid. They're designed for PWM. Or even simpler - just use a FET that has a logic level input. I've used the STP30NE06 before. They come in the prototyping-friendly TO220 package, have a quite low on resistance (= minimum heat) and can be driven straight from the Arduino's TTL level outputs.

An even simpler circuit can be made from a single LM324 chip (same one Richard used). I played with this some years ago but never did anything with it. Richard has renewed my inspiration though, so I might break out the proto board again! They have 4 op-amp elements in them. You can use 2 elements to make a triangle wave generator. You then feed this into a third element configured as a comparator with the other side driven by your boost/load input. Result = variable PWM output to drive your FET. Aaaah - the wonderful forgotten world of analog electronics!

PL

Guys, have a look at the Jaycar IEBC. It is a electronics kit that you can build yourself or also buy it pre-built.
It's pretty straight forward and allows full mapping of solenoid output vs. injector duty cycle.

There is a hand controller that allows you to program it. $50 for the unit, $50 for the controller. It's good if you have a few mates that have the IEBC because you can share the controller around. There are two maps that you can program, so Hi/Low, or whatever else you want. I will be using my 2nd map as the fail-safe map for my water/methanol kit.

It basically spreads your injector duty cycle along 64 load points, so each point represents 1.56% of duty cycle. For each load point you can then specify (0 - 100%) what duty cycle you want your solenoid to operate at. There are a bunch of other things you can do do like set output frequencies and all that but I don't think that needs to be touched.

I'm using it with a 3 port MAC valve and it holds boost perfectly. I have used it in the past with my standard SR20 solenoid and it worked well with that as well.

For those of you who want to use both ports on an external waste gate, it can also be utilised for this as the map is fully programmable.

http://autospeed.com/cms/title_The-Inde ... ticle.html

http://autospeed.com/cms/title_The-Inde ... ticle.html

Only thing that I will stress though is make sure your solenoid stays normally open when power is disconnected in case the unit craps itself! Because it is a build-it-yourself kit, there is a chance that a component may come loose and there goes your boost control! Unlikely though, as long as you mount the unit properly and double check all your solder points

Cheers,
Matt