Jaycar Boost and Fuel Control

[Sydneykid]

well after an exhausting 20 pages, i have read the whole thread, very nice info indeed..

im going to purchase the IEBC and give the thing a go on my sr20det

one thing i have to add, is that i noticed you guys are running a sort of 'bleed' to overcome the issue with the trapped air between the solenoid and the wastegate. this is the same issue that JE came across when he made his audi pneumatic boost controller with the pressure regulator and pressure relief valve, and the solution was a one way valve going from the regulator (in this case solenoid) to wastegate line, feeding back to the pre relief valve (in this case solenoid) boost/vacuum line. when you pull off the throttle and the pressure differential reaches above the cracking pressure of the one way valve, it will dump the pressurised air trapped in that hose back into the intake.

this will save the hassle of finding the right size hole that bleeds just the right amount, stops any air from being vented to atmosphere, and i would say should making tuning of the IEBC somewhat easier and more predictable because there is no air being bled out of the system.

heres a diagram of how it should be hooked up:

when your on boost, the pressure pre solenoid will be greater then or equal to post solenoid, so therefore the one way valve will stay shut at this point, and allow the solenoid to function normally.

I will have to have a a think about this suggestion, there must be an issue with doing it this way. Since JE was responsible for both the IEBC and the Autospeed (2 valve) boost controller. I have to wonder why he didn't use the same one way valve in the IEBC design as he obviously knows about it.

Quickly thinking about it, the issue could be when you want to slightly close the wastegate (not completely close it). An example, I have to close down the wastegate (reduce the duty cycle) as the turbo starts to run out of airflow at progressively higher rpm. There is still boost in the solenoid input, so the one way valve won't open and the wastegate won't close down. The retained boost (between the solenoid and the wastegate actuator) will hold the wastegate open (too far) and the boost will progressively drop.

The second issue (again after a quick think) could be the pulsing of the solenoid. A one way valve could mean that every pulse of the solenoid may well be felt by the wastegate actuator, this will quickly wear the diaphram. The small vent would remove the impact of the pulsing, as it vents off the surges of air as the solenoid pulses. The one way valve won't open (and vent the pulses) because the boost pressure is higher on the inlet side of the solenoid.

Thinking even more about it, the crux of the problem (with using a one way valve) is on many occasions (when boost has to be vented) there is higher pressure on the inlet of the solenoid. So the one way valve won't open, to allow that necessary pressure to be released.

I will have to think about it some more, if there is chance that it may work I could easily test it. There are a few cars I could borrow the one way valve off.

[AlexCim]

Oh also fellas, when i set my duty cycle to 100% the whole input range, using the std stagea restricter as my vent, how come i cant drop the boost below 7PSI. I thought at 100% it would drop to standard...

If i was to fix this with a smaller vent, wouldnt that have problems with my boost spiking issue before which needs a larger vent?

[Sydneykid]

Ok,

Well i have done my boost controller install and tune this weekend.

I have to admit, its very very good at holding boost. I have however some odd problems. I also find that my stag stuggles to hold boost a bit. I had to drop the duty cycles at high rpms quite a bit to get it at the right boost. I want to use 9-10psi, and at 5500 i need a duty cycle of about 64 to keep that, where at 4000rpm its up at 80. Is that difference too big? (sign of turbo wear or something?)

First, teh stagea is 100% standard but an autometer boost gauge and a pipercross filter.

Anyway, my other problem. I get boost spikes. I have hooked it up all right, but between 1 and 2, i get boost spikes to about 12psi. I was thinking this could be due to the fact that my vent isnt big enough/or too big? The above idea looks good, but where do i buy such a 1 way valve to plumb it in? I think i will do it like above.

Let's start with boost spikes, mine does the same and I knew it would before I started. I mentioned it in the first couple of posts. It's only logical, the IEBC gets its input from injector duty cycle, in an auto you don't lift your foot on gearchanges, hence no change in injector duty cycle. This means the IEBC holds the wastegate in the same position during the gear change. As soon as the gearchange is finished, the load changes, as does the injector duty cycle and the boost is corrected. It is noticeable in the upchange to 2nd, but not much at all in the upchange to 3rd and zero on the upchange to 4th.

It doesn't worry me and I haven't noticed any flairing on the upchanges which would indicate it's an issue for the gearbox. Maybe with another 50 rwkw it will be, but by then I suspect an upgraded valve body will be necessary anyway and that will shorten the gearchange time as well.

As for decaying boost levels, yep the standard turbo runs out of airflow. That's the great thing about the IEBC, you can close the wastegate litttle by little to compensate. I am down to 60% as well in the duty cycle.

As for one way valves please read the previosu post.

[Sydneykid]

Oh also fellas, when i set my duty cycle to 100% the whole input range, using the std stagea restricter as my vent, how come i cant drop the boost below 7PSI. I thought at 100% it would drop to standard...

If i was to fix this with a smaller vent, wouldnt that have problems with my boost spiking issue before which needs a larger vent?

I am not sure I understand the question. When standard our Stagea had 4-5 psi on the low setting and 6-7 psi on the high. When I fitted the IEBC, using the standard Stagea restrictor as a vent, it ran at 6-7 psi all the time. The 4-5 psi is the standard ECU limiting the power in 1st and 2nd via the standard solenoid. I don't really consider that"standard boost", I reckon that's 6-7 psi.

Using a a larger vent won't help the gearchange bonus boost (as per the previous post) if the solenoid is closed and will only help marginally (if at all) when the solenoid is open.

[AlexCim]

can i drop the boost even more then 6-7psi with a smaller vent(more push onto the actuator)? What results will this have with my gear shifts etc

Thanks SK

[Sydneykid]

can i drop the boost even more then 6-7psi with a smaller vent(more push onto the actuator)? What results will this have with my gear shifts etc

Thanks SK

Yep, a smaller vent will mean lower duty cycles for the same boost or lower boost at the same duty cycles. I can't imagine driving my Stagea with less than 6-7psi, I would waste a heap of petrol because it would be flat out all the time.

[_cap_]

has any1 here tried the ibc with a normally open solenoid ...the reason i ask is that if any part of the circuitry fails or the solenloid itself then on a normally closed solenoid it will stay just that,normally closed and A: blow the turbo if you have a standard rb25dett like myself and/or B:create massive amounts of boost ...allright i guess if u have a boost cutout but i dont either

hey sydneykid ..do you think the way you have done it that u could set that 1 way valve to a max boost pressure and doing that create a fail safe type system as i would really like to go with the normally closed solenoid as im convinced it will give better and boost and faster spool up than the normaly closed

[AlexCim]

CRAP.!!! I fried a resistor!!!!! ARGH

Happend while switching from high to low boost...the stupid switch jaycar provides stays inbetween open or closed for too long and it just fried.... i replaced the resistor and its still screwed....

Its stuck on load point 64...lucky, high boost is 10psi there and low is 7psi there so i got it on low for now....get ready for a fun weekend of diagnosis!

Btw, its the resistor infront of the little upright IC with teh heatsheild, its a 10R resistor...(i think i fried the IC)

[tang0]

well, i finally finished the wb02 sensor kit today ...

building :-

Its slightly more in depth that the jaycar kits, there are a LOT more components, as you can see, and some of the solderwork needed is a little more fine ... a nice small soldering iron is a must ...

having said this, its by no means a complex build, the documentation from the website is great, and its really just a case of checking you have everything in the correct place, then re-checking it before you solder it in place.

a couple of notes, i did not use the plate that the 8 pin sensor plug came with, i just bolted it into the case, the used wires to connect to the main board ... seems like a slightly easier thing to work with ...

RUN THROUGH THE CHECKLIST !!

there is a huge document on things to test using the wbconfig software ... some of it is a little hard to understand at first, but its all just hex at teh end of the day. there is a neat little 'auto config' button that basically does the calibration for you, but its worth running through all the tests before you plug in your sensor.

thats about it for now ... next i have to go off and buy a sensor mount thingy for the exhaust, and take it out for a spin and see what happens !

[Sydneykid]

has any1 here tried the ibc with a normally open solenoid ...the reason i ask is that if any part of the circuitry fails or the solenloid itself then on a normally closed solenoid it will stay just that,normally closed and A: blow the turbo if you have a standard rb25dett like myself and/or B:create massive amounts of boost ...allright i guess if u have a boost cutout but i dont either

hey sydneykid ..do you think the way you have done it that u could set that 1 way valve to a max boost pressure and doing that create a fail safe type system as i would really like to go with the normally closed solenoid as im convinced it will give better and boost and faster spool up than the normaly closed

The standard ECU prevents any damage:cheers:

[Andi]

Ok not sure if its been asked before as I haven't had the time to go through 20 pages so I'll ask anyway.

If I was to get both the iEBC and DFA and install them, set the 2 maps from the iEBC for 12psi and 16psi and then tune the DFA for 16psi;

How would the car then run on 12psi as the DFA is set for 16psi? Will there be any problems with AFR's etc?

Thanks,

Andy

[Sydneykid]

Ok not sure if its been asked before as I haven't had the time to go through 20 pages so I'll ask anyway.

If I was to get both the iEBC and DFA and install them, set the 2 maps from the iEBC for 12psi and 16psi and then tune the DFA for 16psi;  

How would the car then run on 12psi as the DFA is set for 16psi? Will there be any problems with AFR's etc?

Thanks,

Andy

Boost is irrelevant, its all about airflow and the AFM measures that.

[Andi]

So if I tune the DFA for 16psi I won't have any dramas when I run the boost setting for 12psi?

[Sydneykid]

So if I tune the DFA for 16psi I won't have any dramas when I run the boost setting for 12psi?

Boost is irrelevant, at 12 psi and 6,000 rpm it has the same airflow as 16 psi at ~5,150 rpm. The ECU (via its fuel map) uses the AFM to sense the airflow and squirt the right amount of fuel in for that airflow. Similarly for the ignition timing mapping. The ECU doesn't give a flying fark about the boost, after all boost is simply a measure of resistance to airflow:cheers:

[_cap_]

does the ecu protect from overboost on a r33 ....im not sure how this works ...does it measure boost somehow or does it do it with the fuel cutout ..ie more boost more fuel needed = fuel boost cut or does one of the vacumm lines of the intake manifold run to a boost cut device somewhere ...just want to make sure before I finally hook up the solenoid into the system....cheers sydneykid ..oh by the way i was reading an old nz forum thread ...did u ever do a blower /turbo boost setup and if u did how did it go man

[Sydneykid]

does the ecu protect from overboost on a r33 ....im not sure how this works ...does it measure boost somehow or does it do it with the fuel cutout ..ie more boost more fuel needed = fuel boost cut or does one of the vacumm lines of the intake manifold run to a boost cut device somewhere ...just want to make sure before I finally hook up the solenoid into the system....cheers sydneykid ..oh by the way i was reading an old nz forum thread ...did u ever do a blower /turbo boost setup and if u did how did it go man

Boost is irrelevant, the ECU knows the airflow via the AFM, it has protective mapping (Rich & Retard strategy) that kicks in whenever the airflow gets too high. As would happen if the wastegate actuator hose was busted on a standard car and the wastegate stayed closed. Which is the same as the normaly closed solenoid failing when using an IEBC. So Nissan has a system that will save your ass.

PS; this can also apply to an aftermarket ECU (eg; Power FC) if you apply appropriate mapping.

[CEF11E]

That's a good result, well done for a first time effort at tuning.  Can you please post up your load point corrections.  It will be a helpful reference.

I think you may have achieved more than the graph shows, with no intercooler it was probably heating up the inlet airflow after 4 power runs.  This would have dropped the last run's power reading.  

Sorry for the delay, I have been sick for a week. I have noticed the car was sluggish under 3500 rpm since the tune so i changed the loadpoints 61~66 and it fixed the problem. The car is now even more powerful and responsive.

PLEASE NOTE!!!!!! dont under any circumstances use these loadpoints as a "how to tune your car" guide as every engine is different. and this map is for a VG20det, a very different beast to the rb20/25. :uh-huh:

[AlexCim]

OK, ITS OFFICIAL, my ebc is ****ed!!

that resistor didnt fix anything...

i replaced LM2940 and it still does it.

I think ill just buy a whole new kit and keep this broken one as a track car type of a thing, where i only need 1 load point

[Andi]

Thanks for that SK. Just needed to make sure. Although I do have another question for you.

On the Stagea I parralleled into the #1 injector trigger signal at the ECU.  In fact ALL of my wiring (for both the IEBC and the DFA) was done at the ECU, ZERO wiring went anywhere else.  If you do a search you will find the appropriate ECU pin out for your model.  This is what I used for the Stagea which is the same as for an R34.

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

Ok so from that post and from my ECU pinout here: http://www.gti-r.com/Reference/EcuPinouts.gif

To install the DFA I connect the green wire (input) to pinout 16 and the black wire (output) to pinout 17?

To install the iEBC I connect the green wire (input) to pinout 101 and the black wire (output) to pinout 111?

And when I say connect I suppose splicing the original ECU wires and soldering on another wire right?

Oh and where are the 12+ and 12- wires? I can't seem to find it on that ECU pinout diagram.

Thanks,

Andy

[benl1981]

Hey Cefie..is that % load reduction? Thats a lot at the medium-high load. How much fueling do you reckon this would trim? Approx 10-15% at those loads?

Have you had trouble with pinging?

I know it will be different for rbs etc..just curious

thanks