EMU = Electronic Boost Controller?

[valmes]

I just had an idea… Hope someone more "electronically minded" can say if it can be done… or point out to "trouble spots".

Well, Greddy seems to plan something new (and expensive, I guess) to go along with e-manage Ultimate(EMU), since Profec e-01(electronic boost controller(EBC)/e-manage blue programmer) is not compatible with the new unit.

So I thought about getting manual boost controller(MBC) or making one myself or even going Apexi AVCR route (duh… selling one ebc to get another) … While trying to make my own MBC, I decided our stock wastegate solenoid valve(Pic.1), could in fact be used together with e-manage Ultimate to work as an Electronic boost controller!

Using EMU Auxiliary Output connected to wastegate solenoid valve (just change connections as shown on Pic.2) we can dial in a boost in auxiliary output control table. Rpm vs. Relative pressure (Pic.3) could be used to make it simple… or you can even try using "engine load" as reference (as was suggested by Autospeed.com… in one of the articles on "DIY electronic boost controller")!

Can it be done?

[michaeli]

Way too technical for me to comment but I can certainly see your logic... Nice idea!!!

[valmes]

According to this article: The Independent Electronic Boost Control
Wastgete Solenoid Valve has to be pulsed to get a good boost curve.

With the example above (first post - using Aux. output and tables) we are going to get either 0% or 100% Duty Cycle... ether fully open or fully shut. But if we use additional (sub injectors) feature, we can set WSV Duty Cycle to anything in 0-100% range... I think that should work...

16x16=256 points to fine tune the boost curve!

[ako]

Totally doable. All an avc-r or anything uses is essentially the same solenoid you factory one is, albiet probably a lot higher quality. You're mainly paying for the programming work.

So you're right - if you take the time to work out how to pulse it and when, it should work in the exact same manner as most other EBC's will. A lot of aftermarket chips for WRX's use the factory BCS in this exact manner actually to give varying boost across the rev range, so there you go, proof right there

[valmes]

If so, it can also be done on a Blue e-manage (Now it looks like value for money at price tag of 289$ ) using sub-injector signal A or B and sub-injectors tables to pulse the WSV in much the same manner as on Ultimate e-manage...
With optional "switch"(just switch which sub injector pulse is applied to WSV) you can even change the settings on the go... without connecting to your laptop. Low/High boost maps...

Here, some info out of an Autospeed article:
"How the Solenoid is Pulsed
Unless it’s set so that it’s ether fully open or fully shut, the boost control solenoid is pulsed 10 times per second. When only a small amount of air is required to pass through it, the time that the solenoid is open for is very short. When lots of air needs to pass through it, the solenoid is open for much longer. This opening time is called ‘duty cycle’ – the expression has the same application as with injectors.

Most boost control solenoids will work over the range of 5-80 per cent, giving 75 different levels of airflow through the valve. Since you can set the solenoid airflow at 1.5 per cent injector duty cycle intervals, there are thousands of different values that are available to control boost! But don’t panic: if you want a smooth boost curve, road tuning soon shows the values to use - once the map has been started, the rest of the figures are easy to select. We’ll cover more on boost tuning next week."

[valmes]

One more article...
How does an electronic boost controller work?

Right now our system is a controlled "boost leak"* which means designers didn't care (why bother if you can safely attain a 280bhp level?) and vented it to intake (low pressure side) using stock WSV... that can contribute to pressure drop seen by Paul and others who've been using MBCs!
... and we were trying to keep the system completely sealed. On Pic.2 WSV now works "in reverse" and doesn't allow any air to escape. The question is how much PSI can stock solenoid hold? Anyway 150 psi solenoids are cheaply available... Graiger solenoid air control valves

*PS: If you look at Pic.1 our WSV sits aside of the wastegate pressure control line... so it can only control pressure applied to wastegate actuator by venting enough out of this line...

[ako]

*Thinks about getting crafty with a LINK sub-injector controller*


Actually, there are off the shelf DIY kits for doing this exactly this, using the factory boost control solenoid. www.jaycar.com has them - pretty DIY looking, but it works on exactly the same principle as using the e-manage.

Also - like you said, since you can actually map the e-manage sub output with regards to revs, you can increae the duty with revs - and combat the boost drop off the VR4 is afflicted with

[valmes]

That's worked!!!

Using sub-injectors channels A and B (have to wire them both to a single ground/control wire on stock boost solenoid, cutting original one off) on Blue e-manage and just re-routing the hoses on stock Boost Control Solenoid Valve - we have created a working EBC which can be controlled by sub injector tables!!!
You just have to put a T piece (with a small opening to atmosphere) to vent pressure off when solenoid is closed. That one goes after solenoid, but before actuators.

Didn't fine tune it yet... but at first glance = 100% across table gives us stock Boost levels, 0% across table = unlimited boost!!! Did put in some other values (we held 0,9, but had it spiking... so have to work those things out), but our notebooks battery had died... so will continue later (prob tomorrow).

You can actually save as many tables as you would like... Stock boost (along with timing, airflow, injectors maps), small power up, race settings...

[enigma]

That's worked!!!

Using sub-injectors channels A and B (have to wire them both to a single ground/control wire on stock boost solenoid, cutting original one off) on Blue e-manage and just re-routing the hoses on stock Boost Control Solenoid Valve - we have created a working EBC which can be controlled by sub injector tables!!!
You just have to put a T piece (with a small opening to atmosphere) to vent pressure off when solenoid is closed. That one goes after solenoid, but before actuators.

Didn't fine tune it yet... but at first glance = 100% across table gives us stock Boost levels, 0% across table = unlimited boost!!! Did put in some other values (we held 0,9, but had it spiking... so have to work those things out), but our notebooks battery had died... so will continue later (prob tomorrow).

You can actually save as many tables as you would like... Stock boost (along with timing, airflow, injectors maps), small power up, race settings...

Cool! But I want to use the sub injectors for nitrous control

I could always revert to the thumb method and sell the AVCR!!

[valmes]

BTW you have to set JP5 and JP6 inside the e-manage from "open" to 1-2...

[enigma]

I now have the subinjector map controlling a relay which in turn switches my nitrous on and off.

So it comes on at 3000rpm and goes off at 6500rpm

However, with the subinjectors set to come on 100% duty cycle the relay actually energises and deenergises many many times per second. Not good!

Well I say that it does, well it did! I fitted a capacitor accross the coil and now I have a nice on or off controllable by rpm.......

coolio!

How did you get round this with the boost control Valmes???

[valmes]

I didn't... that is exactly how boost solenoid is working (pulsing it to be closed/opened multiple times per second, thus its called a duty cycle... same as with injectors dc). For your application using auxilary output on EMU or VTEC output on Blue e-manage could be a better solution. It has - ON/OFF conditions instead of Duty Cycle.

Here is map btw I made to be able to control boost via Karman Hz signal...

[enigma]

The trouble with the duty cycle is that it works 3 times per 2 revolutions on our V6 engines to match the injectors.......this means 100% is not 100% and I guess that 50% is not 50% either........I also summise that because of this boost could be a bit wavy....although the timescales we are talking are small.

[valmes]

With only one subinjector channel connected - yes... but when you wire in both channels simultaneously - they are working as planned that is at 100% DC solenoid is fully open all the time!

[enigma]

So if I connect the outputs together it will work?

hmmmmmm.....interesting! No time to play now before tomorrow though!