boost control using nistune experiences anyone ?

chris2712au · Post by **chris2712au** » Sat Sep 26, 2009 10:36 pm

oh yeah as for the s14 you would have to send MAtt on a witch hunt trough the code cause if they have done it that way there will be a correction map for it and that would set the load int he boost scales instead of TP..

skylinegtrhr · Post by **skylinegtrhr** » Sat Sep 26, 2009 10:47 pm

chris2712au wrote:oh yeah as for the s14 you would have to send MAtt on a witch hunt trough the code cause if they have done it that way there will be a correction map for it and that would set the load int he boost scales instead of TP..

in Service manual it just said that ecu is reading it for calculating fuel control but who knows ...
I think that Matt can use his time for more constructive way for all of us

like cover with NIStune new models (BCNR33,P11,BNR34 ...) and knock count for Board 4 and 3 ...

ge0ne · Post by **ge0ne** » Sun Sep 27, 2009 12:43 am

I mean boost by map. So put a GM 3bar map or an AEM 5bar and no more hustles with AFM's...

chris2712au · Post by **chris2712au** » Sun Sep 27, 2009 8:14 pm

I had a gm delco on my car with a dlp a/d conveter when I was playing with the boost tuning and could see the changes i was making using the AFR 3d trace.. but hey I could get it to do boost 3d trace... it was helpfull especially when looking at the boost transition areas..

Matt · Post by **Matt** » Mon Sep 28, 2009 1:42 am

ER34 starts using consult 2 registers for its boost reporting

CONSULT REG 0x26 = Boost pressure solenoid
CONSULT REG 0x28 = Purge control valve (boost control valve?)

Anyway I started having a go at putting consult 2 registers in but pulled the changes out since it ended up being a lot more work than I anticipated

We are reusing some of the 'unused' registers for map indication and TP is put in the boards at 26,27 unfortunately overriding my boost pressure indication register on the R34. Most of the consult2 registers are not going to provide much information anyway

Need to monitor reg 28 when driving to see if the value is the same as the boost duty cycle

chris2712au · Post by **chris2712au** » Fri Oct 02, 2009 8:17 pm

was thinking about designing an add on board for the nistune.. something really simple but really effective.. what I need is the oscilloscope traces of the stock system at 10, 50, 90 pwm.. my car is off the road atm it just got the turbo checked out and and I had to port a few things while I was at it.. soon it will be top mounted with a 38mm ext.. that should be a bit of fun..

Fordy · Post by **Fordy** » Sat Oct 24, 2009 11:52 pm

chris have you ever thought of using a different 3 port boost solenoid? like a subaru instead of the standard nissan one?

chris2712au · Post by **chris2712au** » Tue Oct 27, 2009 2:36 pm

yeah you could use a 3 port one... however on the block setup I wasnt getting wastegate lockup.. as in the air was bleeding out of the system in the same direction it came from.. so I didnt need to vent it... and for the bleed system well you dont need to pressurize as the spring is doing the work for you..

also on another note there must be some logic in the base image that if the AFM voltage gets beyond a certain value it switches to the boost knock maps... bypassed the knock sensor with a resistor and it still jumps over on the boost maps.. will have to log to see if the timing is doing it to but it doesnt feel like it is ...

chris2712au · Post by **chris2712au** » Tue Oct 27, 2009 2:55 pm

still plotting a response via rpm is not the best way... it is like judging your rod speed by throttle position and gear it does not take into account the road (load)...

it does however feed back a load dependent signal from the boost.. as in the more boost the more air it has to open the wastegate... so it does have some kind of correction.. meaning at 5000rpm no load as in no boost there is no air to open the wastegate so it doesnt matter what setting you have for the solenoid.... this makes the system 3 dimensional well kind of.. so from looking at the actuators point of view you have rpm (engine speed) boost (actuator signal pressure) and bleed (actuator signal relief)..

since the actuator pressure (manifold pressure) can ramp at different rates in different gears it is hard to map a control for it well atleast for more than full load... you would end up with a map for medium load a map for light load as well....

However if we could plot the signal against TP.. different story as the TP is pretty good for calculation the load it might as well be map.. on some of the ecus I think are three dimensional.. but thats for mat to comment..

PL · Post by PL » Tue Oct 27, 2009 3:04 pm

We originally thought the S15 was a 3D map too. But in the end we found that to not be the case. This is still a weird one cos it IS a 3D map. It's just not implemented that way.

Need to do some more testing on this one. Gotta get it working for S14 and R34 too.

PL

chris2712au · Post by **chris2712au** » Tue Oct 27, 2009 10:26 pm

from what I thought it was the ones with the boost sensor that were 3D..
I see it in the flags.. but dont know if it could be optioned for the s15 ECU..

Fordy · Post by **Fordy** » Wed Oct 28, 2009 5:26 am

all the scoobys go from 2 port to a uprated 3 port solenoid and then ecu remap to get the correct boost......

im sure with a little time we can work out and understand how to do this as to me i see it as a big improvement for a standard ecu

i think someone mentioned impedance high or low how do we go about checking the outputs impedance? i'm more than happy to test it out with a uprated 3 port valve once i know im not going to kill my ecu

PL · Post by PL » Wed Oct 28, 2009 7:52 am

Just measure the resistance of the coil in the solenoid with a multimeter. If it's around the same measurement as the stock solenoid then you're OK.

Note that some solenoids have a built-in snubbing diode. This means that you must get the polarity correct or you'll blow the diode/driver. Try it on a power supply/battery first.

PL

Fordy · Post by **Fordy** » Wed Oct 28, 2009 9:21 am

PL wrote:Just measure the resistance of the coil in the solenoid with a multimeter. If it's around the same measurement as the stock solenoid then you're OK.

Note that some solenoids have a built-in snubbing diode. This means that you must get the polarity correct or you'll blow the diode/driver. Try it on a power supply/battery first.

PL

i've got the stock solenoid off the car at the moment and i'm running a gizzmo boost controller instead at the moment.
i'll measure the resistance of the standard solenoid valve and the gizzmo's mac solenoid valve tomorrow at work

PL · Post by PL » Wed Oct 28, 2009 9:48 am

I reckon I've driven a MAC valve from the Nissan ECU before but I'll have to check. I'll dig my old MAC valve out again when I get a moment...

PL