Jaycar Boost and Fuel Control

[David Kemps]

thanks.

In looking at the picture it looks like the top port of the solinoid is to the intake, and the bottom is t-piece to the actuator and blow off valve. is this correct?

how is this different from stock?I'm looking at my engine still trying to work out.

Another question, so the solinoid is fully open at max boost, fully closed at minimum boost?

Also, can you change the quickness it takes for the boost to build up with the jarcar kit? or is it to do with how you plumb the solinoid in?

thanks

[Sydneykid]

thanks.

In looking at the picture it looks like the top port of the solinoid is to the intake, and the bottom is t-piece to the actuator and blow off valve. is this correct?

how is this different from stock?I'm looking at my engine still trying to work out.

Another question, so the solinoid is fully open at max boost, fully closed at minimum boost?

Also, can you change the quickness it takes for the boost to build up with the jarcar kit? or is it to do with how you plumb the solinoid in?

thanks

Hi David, you have the vacuum hose layout correct.

As for standard, one vaccum hose goes from the intercooler return to the wastegate via a T piece. The other vacuum hose off the T, goes to the solenoid so it can bleed off some boost. The bleed (outlet of the solenoid) goes back into the inlet to the turbo (via the BOV pipe).

The solenoid is a normal fully closed and so no airflow passes to the wastegate actuator whne no current is supplied. That gives you the most boost the turbo can supply at that time. To lower the boost, the solenoid pulses and lets some airflow to the wastegate actuator so it opens and controls the boost. This may not lower it, it might stop it from going any higher or slow down its rate of increase. It depends on how much the solenoid opens.

Since the Jaycar design is in series with the wastegate actuator, it is the best I have seen at controlling the boost increase. It ensures absolutely zero boost gets to the wastegate actuator, so it stays closed until the controller tells the solenoid to let some airflow pass through it. Other designs (electronic and bleed valves) are parallel to the wastegate actuator, so a little boost always finds its way to the wastegate actuator.

Hope that helps:cheers:

[David Kemps]

thanks a lot for that, my friend (an electronics engineer) made up a map sensor actuated boost controller, but i connected it to the standard solenoid in the standard position and nothing changed.

now I will connect it in the way you have described and it should work, if it doesn't i will definately buy the jaycar kit.

thanks

[Blk33]

Dear SK

I have read with interest your articles on the Independent Boost Controller (IBC).

During the Christmas holidays I bought Performance Electronics for Cars to read while lazing on the beach. (great read for those interested) The controller caught my eye and I duly purchased one with the hand controller on my return from holidays. Unlike you, mine is still sitting in the cupboard in my workshop unmade!

My turbo let go early in January, I took you advice and got it GCG hi flowed and have just finished reassembling and installing it after cleaning out impellor bits from the FMIC and replacing the clogged up CAT. The car is running again but I haven't really given it a run yet.

What caught my eye in the original article was that the boost solenoid in series with the actuator, as did you. A couple of question for if you don’t mind.

I run a Wolf plug and play and it has an internal boost controller which is programmable on bleed every 125 RPM. I thought I might convert it to a series type still using the Wolf. Any thoughts?

I then read your articles and I must have missed the IBC is controlled by load on the injector. (a few zzzzzs on the beach) I like the idea of 110K with or without boost and more engine response controlled by the throttle – less lag?. I used to have a 260Z with triple Webers and I miss the instant throttle response of a NA engine. Maybe I should disable the Wolf boost control and use the IBC instead? (My original idea after reading the article)

I also like the idea of flat boost at 7000 RPM. My experience with the old turbo was boost fall off at max RPM. Is this a function of the controller, turbo or just controlled better with the IBC?

My last question is Fail Safe. What happens if the IBC fails, solenoid stays closed, max boost?

Cheers Rob

[Sydneykid]

A couple of question for if you don’t mind.

I run a Wolf plug and play and it has an internal boost controller which is programmable on bleed every 125 RPM. I thought I might convert it to a series type still using the Wolf. Any thoughts?

I don't think you can, the Wolf is set up like all EBC's, it expects the solenoid to be in parallel with the wastegate actuator. So it closes the solenoid to decrease boost. That's the wrong way for solenoids in series, they need to open to lower boost.

I then read your articles and I must have missed the IBC is controlled by load on the injector. (a few zzzzzs on the beach) I like the idea of 110K with or without boost and more engine response controlled by the throttle – less lag?.

It certainly feels more responsive than any boost controller I have tried.

Maybe I should disable the Wolf boost control and use the IBC instead? (My original idea after reading the article)

It's a thought, but keep in mind it isn't as easy to program as an aim type boost controller, you have to set it up load point by load point and it is time consuming.

I also like the idea of flat boost at 7000 RPM. My experience with the old turbo was boost fall off at max RPM. Is this a function of the controller, turbo or just controlled better with the IBC?

The rules still apply, it will hold boost as long as the turbo is capable of producing the airflow. No boost controller can overcome that

My last question is Fail Safe. What happens if the IBC fails, solenoid stays closed, max boost?

Basically exactly the same as what happens if the standard car busts/pops off a vacuum hose, the wastegate stays closed. The standard ECU protects the engine in those cases, make sure you set up yours to do the same

Hope that answered your questions:cheers:

[Sydneykid]

Just finished tuning the Stagea with the Jaycar Boost Controller & Digital Fuel Adjuster. There was a half hour window where the 4wd dyno and the operator were both free at the same time. Tuning took all of 20 minutes on the rollers with Dyno Dave running the Dyno Dynamics and your truly pushing the buttons on the Jaycar Controller.

With ZERO mechanical changes (std exhaust, std intercooler, std airfilter etc), just the 2 Jaycar electronic controllers fitted, we managed 132 4wkw at 10 psi running a nice and safe 11 to 1 AFR's. At midday on a 30 degree plus day, with no temperature correction applied. That's a good 30% improvement over standard, for an all up cost of $380 in parts and dyno time. That's what I call good bang for my buck.

As well as making more power, I also leaned out the AFR's to a more fuel economy friendly 14.5 to 1 at the lower rpms (off boost). The standard AFR's were 12 to 1 off boost and went as high as 9 to 1 on boost, not good for power or fuel economy. I would have liked to go a little leaner than 11 to 1, but the ignition timing was getting a bit advanced as I pulled more fuel out of it with the DFA lowering the AFM voltage. It was the usual piggy back compromise, no doubt exacerbated by the standard exhaust, compliance cat and standard intercooler. I could trick the standard ECU just so much, then it would pull ignition timing and dump a whack of fuel in.

My biggest single observation with the Jaycar DFA was how easy it was to get rid of the usual RB25DET power dip around 4,250 rpm. With 100 settings at 128 load points I could fine tune it so easily. There is simply NO DIP, and anyone who has tuned an RB25DET will tell you that is hard to achieve with piggy back controllers.

Next step is to fit the cat back exhaust and I am expecting to pick up a good 20 4wkw with that.

[Jay95R33]

Good results SK. 30% is great.

Shame you don't have the software for the unichip, try and get rid of my damn dip.. lol

J

[Lone]

I made in similar conditions at midday 139kw at 4wheels or was it 149kw aahh crap

[Jay95R33]

Oh, SK. Did you slow the increase of boost across that 4250rpm point to help reduce the dip (as we were chatting about before), or did you manage to get rid of the dip soley by using the DFA ??

Thanks

J

[Sydneykid]

Oh, SK.  Did you slow the increase of boost across that 4250rpm point to help reduce the dip (as we were chatting about before), or did you manage to get rid of the dip soley by using the DFA ??

Thanks

J

Hi J, it was getting up to 11 psi (maybe 11.5) on the boost at that rpm, so I trimmed it back to 10 psi. But I don't think that made much difference to the dip at all, comfirmed by a quick power run.

I spent a few minutes around that rpm point and lowered the AFM voltage, at a few load points. That leaned it out obviously, but it also advanced the ignition. I just kept going with the adjustments until the ecu went rich and retard, they seem to do that because there is a missmatch between the rpm, throttle postion and afm voltage. Maybe even a little pre-ignition from the knock sensor. I think the ecu then believes that there is an issue (dud afm for example) and tries to protect the engine, hence the rich and retard. So I backed it off from that, very slightly until the ecu stopped going rich and retard. I figured that was going to be the best I could get. A quick power run, bingo no dip.

In summary, a juggle between fuel and ignition and make sure the boost doesn't overshoot on the climb, which is very rapid at that point.

BTW, the ecu behaves very much like an R34GTT one, the rich and retard intervention is very quick and quite savage. Much more so than the earlier ecu vintages.

[Jay95R33]

Ahh, good stuff. I'll give that info on to the tuner and see if it helps.

Cheers

J

[666DAN]

BTW, the ecu behaves very much like an R34GTT one, the rich and retard intervention is very quick and quite savage

Sure is, the 25GT one seems to be the same if not worse

[Lone]

SK: I think you have played before with the SAFC, in your opinion which was the better between it and the jaycar product and what main differences between the two..

In the case of average upgrades (full exhaust, 11psi or so and front mount) which would be the more cost effective way to go?

[Sydneykid]

SK: I think you have played before with the SAFC, in your opinion which was the better between it and the jaycar product and what main differences between the two..

In the case of average upgrades (full exhaust, 11psi or so and front mount) which would be the more cost effective way to go?

That's a tough one, obviosuly with the SAFC you don't have to build it yourself, from a bag full of components. The wiring to the ECU is pretty much the same, so no advantage there. The later SAFC's are very good in that they have 2 "maps" one for full throttle and one for less than full throttle, usually around 70% switch over, using the TPS as a reference. That's a good feature as you can tune the WOT for max power and trim the less than 70% for economy. The SAFC only has a handfull of load points (based on rpm) and good extrapolation between them. So its is quick and easy to set up and gives a good result.

The Jaycar DFA, has 128 load points and very good interpolation between them (not that it needs it) with that many. The load points themselves are solely based on AFM voltage, so you don't need the 2 TPS based maps. You can tune power and economy based on the AFM load. You don't have to input all 128 load points one by one. For example, at idle, the Stagea was up to load point 40 already. Plus the A/F ratios were OK from 40 up to around 95, then it needed leaning out. So I only had 30 or so load points to tune, not many more than the SAFC with 2 maps.

I don't think there would be 1 rwkw difference in the power obtained using the 2 units. They both have enough tuning resolution and smarts to optimise the A/F ratios as much as the standard ecu will let you. Having driven cars fitted with both (now that I have the Jaycar in the Stagea) there appears to be no difference in how "nice" the car drives. They both drive "nicer" than when they were standard with just the boost turned up. The gearchange quality is not affected at all with either.

Bottom line, if you can read, follow instructions and solder OK then there is simply no comparison. The ~$80 price for the DFA is hard to argue with, compared to ~$500 for the SAFC. I can think of a whole pile of go faster stuff I could buy for ~$420, the only thing is you don't get a blue screen.

[Lone]

Thanks so much for that SK, your posts are so informative which is great to see, and everything I thought would be the difference between the two you did mention, perosnally I think Ill go with the S-AFC, easier to tune as you said which of course means less tune points but with the standard turbo and cams etc. I dont think I will be going for a big varience, great to see that you can also tune for WOT and 70% or thereabouts, one thing Ill hand to the RB25 over the starlets I have worked with is the fact the tps shows a varience whereas a lot of Toyotas are open or closed

The blue screen would make me happy as easier to tune with in the car so to speak, although I wouldnt relaly want to touch anything after a tune on the dyno, and with the avc-r I dont want two bloody blue screens, too damn ricey for me!

Ill have to really weigh up my options in what to do, I really want to lean it out a bit as it was very much on the rich side on things when we ran it on the dyno. How can you tell which 'series' SAFC it is? Is there any easily identfiable marks/visual differences?

[Sydneykid]

How can you tell which 'series' SAFC it is? Is there any easily identfiable marks/visual differences?

The lastest SAFC I have used had a joy stick instead of the 4 buttons on the front. Nengun have them on special at the moment for ~$420 delivered, that's less than some people want for used ones.

[siksII]

for people with bleed valves, would you say using the jaycar ibc makes a big difference in the way the car will drive? ie. bigger than changing from an ebc to the jaycar ibc?

also will the difference in boost control feel bigger in a non standard car ie my car with full exhuast, fmic, adj cam gear, powerfc etc?

i used to have a standard gtst and now with my current one there is a lot more lag, (i guess because fmic and piping) so would do anything (cheap) to reduce the lag.

[Maxx]

SK: i have bought the Fuel adjuster today

and going to build it sometime this weekend.

just wonder will the jaycar one able to work with different AFM?

as the SAFC can work with the Z32

and what's information the hand controller showing? they looks HUGE, specially with the 25 pin plug.

If the didn't show anything informative, I am thinking of disconnect it once the car get tune

cheers

[Sydneykid]

for people with bleed valves, would you say using the jaycar ibc makes a big difference in the way the car will drive? ie. bigger than changing from an ebc to the jaycar ibc?

also will the difference in boost control feel bigger in a non standard car ie my car with full exhuast, fmic, adj cam gear, powerfc etc?

i used to have a standard gtst and now with my current one there is a lot more lag,  (i guess because fmic and piping) so would do anything (cheap) to reduce the lag.

If you are running just a simple bleed valve then the IBC will make a big difference in how fast boost builds. This is because the bleed vlave still lets some air pressure get to the wastegate actuator, the closer it gets to its bleed off pressure the more it lets work. The IBC ensures that absolutely zero air pressure gets to the wastegate actuator until it opens the solenoid. This means you get the fastest possible boost build for that turbo on that engine. No other boost controller I have seen can give that absolute control.

just wonder will the jaycar one able to work with different AFM?

as the SAFC can work with the Z32

Absolutely, it will do it easily.

what's information the hand controller showing?

When connected to the DFA, the Controller shows the AFM load point and the amount of correction you have applied. When connected to the IBC, the Controller shows the injector load point and the amount of correction you have applied.

I don't have mine connected all the time, the Controller itself isn't that big and it looks OK, but the plug is damn ugly.

Hope that helps guys:cheers:

[ICE12]

SK any chance you can come to Darwin and install onw for me. Hahahaha

When I can get the money will think of installing one.

Cheers ICE