Jaycar Boost and Fuel Control

[Sydneykid]

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 ?

J

I have the Jaycar Boost Controller working perfectly now, just needed a bit of fine tuning as per the instructions. It uses injector duty cycle as the reference, and has 64 load points with 100 settings (0 to 100%) for each load point. So it has no need for a map sensor. I am not going to get too deep into the theory, there is a full description on how it works in the instructions and in the book from Jaycar called Performance Electronics for Cars. Simply put, the injector duty cycle is very linear with the engine's airflow and thus its boost level.

Since the solenoid is plumbed in series with the wastegate actuator, absolutely no pressure can get to the wastegate until the Boost Controller pulses (opens) the solenoid. This results in the fastest possible boost build. In the case of the Stagea this means I can hold it against the torque converter and get 0.6 bar at 2,600 rpm. With standard boost, the torque converter used to hold at 2,250 rpm, obviously the extra boost (and therefore power) pushes the rpm a bit higher. It obsolutely rockets off the line and quickly gets to 0.7 bar (10 psi) which I will be using as my boost limit until I put the ball bearing hi flow on it.

I have kept the Stagea wastegate closed until load point ~20, for this purpose. As the airflow rises, so does the injector duty cycle, it is quite simple to set the solenod duty cycle (between 0 and 100%) to allow the required pressure to act on the wategate actuator and hold the 0.7 bar at that injector opening. I repeated that for load sites from ~20 to 64. It is 100% from ~30 to 64, if I find the boost dropping off up high (rpm and therefore injector duty cycle) I can close the wasegate a bit to make sure it holds 0.7 bar.

It took me about 25 minutes of passengering and setting up the boost curve. I may have to fine tune it a bit over the next few days as I encounter more widespread conditions. But at the moment the boost just sits there at 0.7 bar, totally stable.

It works and it works well, for ~$80 and half a day of my time I reckon the Jaycar Independant Electronic Boost Controller is a good thing.

This the vacuum hose plumbing now;

Here are the two Jaycar units installed in the glovebox, I used velcro to hold them as I have to get to the rear to plug in the hand controller.

This picture shows the connections at the ECU plug, they were soldered and taped. The Jaycar wires are the red, green and black. Unfortunately both units have the same coloured wires. If I ever do this again, I will buy some different coloured wire so I don't have to keep checking that I have used the right one. The R34 ECU plug diagram is accurate so the connections are as I previously posted.

The Digital Fuel adjuster is connected up ready to go, I have not loaded any corrections. I need to know the A/F readings as I make changes, so I will do that on the dyno with the fast and wide lambda sensor up the pipe. Should be good to see the results from simple electronics only, no mechanical changes.

Hope you all enjoyed reading this as much as I did making them. I will post up the dyno sheets as soon as it has a run.

[tigerleo62]

Thanks for the pic, SK!

[LBR33]

Looking forward to the results.

[Sydneykid]

Looking forward to the results.

I have been doing a little bit of fine tuning on the boost controller, it holds 0.7 bar rock solid from 2,500 rpm to redline. I can get 0.6 bar for launch, it is so quietly quick, very stealth, no rev, rev, dump no wheelspin. Just see ya........................

That's a good result for the Boost Controller. I am verrrrrrrrrrry busy this week, we have a new control tyre in Production Cars, Yoko's after many years of Dunlops. Maybe get on the dyno next week to set up the Fuel Adjuster and confirm the power outputs.

[RiverSide]

This may sounda bit silly.......but does everyone understand what is being said? All this seems a bit "over my head" to be honest. That puts me in a predicament as i am very keen on the boost control unit but am baffled as to how I could possibly make it work.

I apologise i have entered the world of stagea....lol as i do not own one but i would really like to fit one to my RB20det.

If you happen to find the time sydneykid.......do you think you could possibly send me an email with a short "guide for dummies".......or even just let me know if someone with VERY limited electronics experience would be able to complete such a project?

Cheers

Riverside

[Sydneykid]

This may sounda bit silly.......but does everyone understand what is being said?  All this seems a bit "over my head" to be honest. That puts me in a predicament as i am very keen on the boost control unit but am baffled as to how I could possibly make it work.

I apologise i have entered the world of stagea....lol as i do not own one but i would really like to fit one to my RB20det.

If you happen to find the time sydneykid.......do you think you could possibly send me an email with a short "guide for dummies".......or even just let me know if someone with VERY limited electronics experience would be able to complete such a project?

Cheers

Riverside

Hi, ask yourself three questions;

Can I read and understand instructions?

Can I operate a multimeter or can I teach myself to operate a multimeter?

Can I solder or can I teach myself to solder?

If yes to those questions, then pop into your local Jaycar and buy a copy of the book Performance Electronics for Cars (by Silicone Chip). It costs ~$20 and if nothing else, the introduction chapters will teach you a lot about how the electronics in a modern car operate. It has FULL instructions with great pictures and diagrams, the best I have seen for kits.

The only additional thing you will have to do on an RB20 (over the example Stagea RB25) is to buy a boost control solenoid. Plenty of RB25 owners are not using their standard solenoids as many have EBC's with their own solenoids. So you should be able to pick up an RB25 solenoid pretty cheaply.

Hope that was of some help:cheers:

[RiverSide]

Well i answered yes to all three so it looks like i will have to visit my local Jaycar store.......Thanks heaps for your help SK.

If i have any troubles i assure you that you will be the first port of call.

[elbee111]

Gday all,

I am interested in giving one of these, or both a go at some time. I have not heard of them before as I gave up reading SC some time ago. (just got a bit boring)

Presently have a bleed valve set to about 11 psi. This has been in the car for just over 2 years with no problems except for the dullard installing it the wrong way around at first.

A few Qs. (I know that they look like statements, but I am just hoping that I understand what is being achieved here)

1. The upper limit of the boost is set by the stock restrictor in the line ?

2. Adjustment of the value of full boost is by drilling out the restrictor if you wish to increase this value ?

3. The 0-100% at the various load points refers to a percentage of "full boost" ?

4. The advantage over a bleed valve is that you can set your boost level compared to "full boost" at a specified level, when it comes on, and you can maintain "full" boost by setting these load points ?

Interested in any feedback.

El Bee

[Sydneykid]

Gday all,

I am interested in giving one of these, or both a go at some time. I have not heard of them before as I gave up reading SC some time ago. (just got a bit boring)

Presently have a bleed valve set to about 11 psi. This has been in the car for just over 2 years with no problems except for the dullard installing it the wrong way around at first.

A few Qs. (I know that they look like statements, but I am just hoping that I understand what is being achieved here)

1. The upper limit of the boost is set by the stock restrictor in the line ?

Nope, other way around, the BOTTOM level of boost is determined by the restrictor size. The solenoid is in series with the wastegate actuator, not parrallel like most electronic boost controlers. Currently I have the standard sized hole in the restrictor ~1.25 mm. That is too big to get boost lower than 0.5 bar, which is no problem for "high" boost (0.7 bar), but not low enough for "low" boost. So I am going to solder up the restrictor hole and drill it out to 1 mm. That means more airflow goes to the wastegate actuator so it opens earlier, thus lower boost.

2. Adjustment of the value of full boost is by drilling out the restrictor if you wish to increase this value ?

Nope the other way around. If you want higher boost you have a bigger hole so that less air goes to the wastegate actuator.

3. The 0-100% at the various load points refers to a percentage of "full boost" ?

Nope, it refers to solenoid duty cycles, 0% = closed, 50% = open half the time and 100% means open all of the time. If you want less boost, you increase the solenoid (opening) duration.

4. The advantage over a bleed valve is that you can set your boost level compared to "full boost" at a specified level, when it comes on, and you can maintain "full" boost by setting these load points ?

Sorta, you can keep the wastegate FULLY closed, because the solenoid is in series with it. So there is no way that even the slightest amount of pressure can open the wastegate. It stays tightly shut until you punch in a % opening at the appropriate injector duration. With the standard turbo I can get 0.5 bar holding it against the standard torque converter (~2,300 rpm). With the standard boost control system it would make hardly any boost at all until 2,500 rpm.

There are a number of advantages of this system, obviously you get the fastest boost build possible. But you can also do tricky stuff, like set it up so that you don't get any boost while cruising at say 110 kph. Noting that it isn't speed or rpm driven, it is injector duty cycle driven. So you can still have boost at 110 kph if you want, you just have to increase the injector duty cycle by puting your foot down.

Having driven many turbo cars with all sorts of boost controllers I find this one makes the 2.5 litre engine feel the closest to a 6 litre engine all of the time. This is because of the duty cycle driving the boost, you can control the power much more accurately with the throttle. When using an aim type EBC (pick a boost target and it will try and hold it), you can back off and still have max boost. This makes driving on the throttle rather tricky. That doesn't happen with this system, back off the throttle a little and the boost backs off with you. Put your foot down and the boost comes back straight away as the wastegate closes immediately.

That's another advantage, you don't have to wait for the MAP sensor to catch up, with airflow waves moving up and down, sometimes long hoses. Injector duty cycle changes are instantaneous, plus you get accelerator enrichment, so there is more boost faster.

As for the "low" boost setting, this system means I can have two completely different boost curves, not simply a lower max boost setting. So for the rain I can bring boost on slower, but still have the same max boost. So I can have my 0.7 bar, but not arriving until 40% injector duty cycle instead of 18%. I can always drive it on the throttle and control the power via the injector duty cycle (my right foot). That's quite different to the usual EBC's that have rpm or kph dependant boost ramps. From experience I can tell you that a 40 kph boost trigger is a bitch when you want a little more throttle to control the slide at 38 kph. Just 2kph more and you get max boost, back off a little and you get nothing, until 40 kph again.

Sorry that was a bit of a rave, hope I answered your questions:cheers:

PS, there are a couple of dissadvantages of this type of system, maybe in another post.....

[elbee111]

Thanks SK,

Will try and digest this further. You sound like a convert to this system (with some reservations?).

Will keep watching at this point and trying to get the old head around the concepts.

Enjoy!

El Bee

[Sydneykid]

Thanks SK,

Will try and digest this further. You sound like a convert to this system (with some reservations?).

Will keep watching at this point and trying to get the old head around the concepts.

Enjoy!

El Bee

You will know when I am totally converted, I will remove the Power FC Boost Control Kit from the race car and replace it with a Jaycar Intelligent Boost Controller. I ain't there yet.

[elbee111]

You will know when I am totally converted, I will remove the Power FC Boost Control Kit from the race car and replace it with a Jaycar Intelligent Boost Controller.  I ain't there yet.

Well put

Let's see.

El Bee

[Angry]

hi ..diggin this up again .. but i have a question

i'm looking to buy both of these kits ... inparticular im wondering about the boost solinoid... says u use one from a rb25 ....

alternatively ..i have a Greedy soleniod .. dont remember what type.. but it was on a GTR ..that had the boost controller pulled from the car in a smash and grab.. so it has no plugs ..just wire and a soleniod.....

is this useable in this application....coz i'll order these kits tommorrow for sure.

thanks

Matt

Any further results SK?

[Sydneykid]

hi ..diggin this up again .. but i have a question

i'm looking to buy both of these kits ... inparticular im wondering about the boost solinoid... says u use one from a rb25 ....

alternatively ..i have a Greedy soleniod .. dont remember what type.. but it was on a GTR ..that had the boost controller pulled from the car in a smash and grab.. so it has no plugs ..just wire and a soleniod.....

is this useable in this application....coz i'll order these kits tommorrow for sure.

thanks

Matt

Any further results SK?

Hi Matt, the Jaycar Intelligent Boost Controller will work with any solenoid, you have to "tune" it, instructions on how to are in the book. The advantage of using the Nissan solenoid is that is what was used by JE in the design process, so the tuning is a bit easier. But it's no big deal, only takes a couple of minutes extra.

I haven't had time to stick it on the dyno to give a definitive power increase, but it will be the same as for any Boost Controller. Add 0.3 bar to the max boost and take out the standard low boost in 1st and 2nd.

The real advantage is the way the car drives and the dyno sheet ain't gunna show that. My previously posted comments cover that as best I can.

I see no reason so far why the Jaycar Digital Fuel Adjuster won't work exactly the same as any other AFM voltage bender. Except it has a LOT more load points and very fine adjustments are possible at each point, something around 0.005 of a volt I am trying to find a spare hour next week to throw it on the dyno, tune it and stick up the results.

Remember the Stagea has NO other mods, no big exhaust, standard filter, standard compliance cat, standard intercooler, I will even remove the inlet air scoop and air deflector for the test. I will also test it in 4wd, it's an auto and I use it for towing the race car, so I am not going to lean it out to squeeze the last frop of power from it. Bottom line, don't expect to see big horsepower, just note the increase over standard with ZERO mechanical mods.

PS, I have a heap of parts almost all ready to go on, ball bearing hi flow turbo, split dump/engine pipe, 3.25" exhaust, hi flow cat, panel filter, FMIC and an adj exhaust camshaft pulley. Plenty of stuff for 200+ 4wkw and I have other cars with similar mods (not using the Jaycar stuff) to compare to.

[MANWHORE]

Hi Gary

You mentioned above that it has some disadvantages too. What are they? From what you've said, it seems the goods. and you can't argue with the price.

[Angry]

thats gonna be one quick towcar !!! lol

inregard to the fuel adjuster... seeing it works with duty cycles (from what i can gather) ... in my case if i retain STD ecu ..but bolt in larger injectors .. is it possible to use this controller for that purpose? rather than over fueling it to hell?

or is this fuel adjuster more for fine tuning AFRs?

Matt

[Sydneykid]

thats gonna be one quick towcar !!! lol

inregard to the fuel adjuster... seeing it works with duty cycles (from what i can gather) ... in my case if i retain STD ecu ..but bolt in larger injectors .. is it possible to use this controller for that purpose? rather than over fueling it to hell?

or is this fuel adjuster more for fine tuning AFRs?

Matt

Hi Matt, it has enough adjustment to handle larger injectors no problems. But (there is always a but) when you bend the AFM voltages a lot, the ignition timing is also affected. So you may end up with too far advanced ignition in order to get the A/F ratios right with the larger inejctors. As I have said many times before, piggy back (benders) are a compromise. You might have to run it a bit rich so the ignition timing is not too far advanced.

If you are only going up a little in injector size (say 370 to 480 cc's) then it might be OK. But I doubt that you would get a good tune with 550 cc injectors.

Hope that helps:cheers:

[Sydneykid]

Hi Gary

You mentioned above that it has some disadvantages too. What are they? From what you've said, it seems the goods. and you can't argue with the price.

For around $70 for an electronic boost controller with this sort of logic, why would you buy a bleed valve. I will put up a post on what I perceive as dissadvantages to balance the advantages (nothing is perfect) thta I have already listed. I want to do a liitle more testing and check my programing, I am going to give it a run with the video camera on the boost gauge and the controller. Then I will verify that I have the settings optimised. I am trying to squeeze and hour into late next week on the dyno, then I can get a print out on the power graph of the boost curve. I will post it up then and list out any dissadvantages that I confirm.

[David Kemps]

SK - I have a few questions.

So am I right when I say that when the solinoid is fully open in the new configuration that you've shown the boost is at it's lower limit eg. 0.5bar and when fully closed the car will boost as much as the turbo can at that particular revs? so upper limit.

sounds like a good cheap solution to controlling boost.

Dave

[Sydneykid]

SK - I have a few questions.

So am I right when I say that when the solinoid is fully open in the new configuration that you've shown the boost is at it's lower limit eg. 0.5bar and when fully closed the car will boost as much as the turbo can at that particular revs? so upper limit.

sounds like a good cheap solution to controlling boost.

Dave

Hi Dave, the lowerlimit is the wastegate activator spring rate (in the case of a Stagea that's ~0.3 bar) plus the little bit of pressure that escapes out the bleed off restrictor (in the case of the Stagea around 0.1 bar). Yep, the max is whatever the turbo can make, I have seen over 1.5 bar with the standard turbo (not that it would alst long very long with that sort of load.

Interestingly, that is more than I have seen with any other standard turbo, this is because this type of boost controller (solenoid location actually) that uniquely ensures that ZERO boost gets to the wastegate actuator. I have yet to see another style that does that, they all let a little boost pressure go to the wastegate actuator.