astra 1.4 8valve lpg turbo.
Turbo Mini Forums

Good work so far.

Schrödinger's cat - so which one am I ???

you need to make sure the stepper has the coils wired in the right order, and also that it has the correct internal wiring. IIRC the rover steppers just plain dont work due to there internal wiring (i cannot remember the exact issue now) i ended up using a 2 wire PWM valve off a VW golf.

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

I think ..its a gm 4 wire stepper bi polar ,and wired as per the diags the one with the two ble and two green wires ,with the 4 pins in a row on the connector ..

, but for all I know I have it wired opposite direction .I could not see a test stepper area on ts rod ,where is that ?

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Schrödinger's cat - so which one am I ???

im on ms2 ,and canna find it rod ?

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Are you using the latest firmware? It definitely is there.

http://www.jbperf.com/

probably not jean ,its as it was in 2012 from diy autotune ? yup just checked im on 2.9.0 ....latest appears to be 3.3.1..

I attempted to load it but it tells me I have to short out two pins in the ecu ,

so ill have to do that when I have more time ...bummer! I was looking forward to new stuff to play with .


ah edit:

that 3.3.1 is the ms2/extra ...can I use that ? or do I have to use the ms2 2920 ?

Edited by robert on 27th Jun, 2014.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

I see no reason to use the B&G firmware. More than 90% of MS2 users use MS2/Extra which is now at 3.3.2 (http://www.msextra.com/doc/ms2extra/files/release/ms2extra_3.3.2_release.zip).

However, switching to MS2/Extra will require some work to set everything. And you can't directly use the msq file from the B&G firmware (you could export/import the VE table and the spark table but you would still need to go through everything else).

http://www.jbperf.com/

Robert,

If you are on the original B&G firmware, change to the MS2-E ASAP.

You will have to re-do your base settings but it's worth the effort.

You will need to use the bootload jumper once to make the change but, once on MS2-E, the jumper will no longer be required unless you really mess up......

The use of the jumper is described in the upload instructions for the MS-E code.

Make the change to the MS-E code and everything else will become a lot easier.

Schrödinger's cat - so which one am I ???

thanks chaps !

I will try to get that done this week , will print off all my msq sheets so I can copy the details ...other than the maps which I imagine I can export and import .


latest is ..

mapping going well on rd .mpg up from around 24 mpg to 28.4 .running leaner and leaner to find limits .at 17:1 so far on cruise.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

getting there ,

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

cracked the 30mpg barrier this week , 30.4mpg , not going slowly either . now I have just changed the deccel fuel cut from 70% to 0% so lets see what that does .

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Map time rpm? Whats that when its at home lol ill have to look into that, you have a very tidy line on that graph anyway

Yes i moved to the darkside

Instagram @jdm_brett

thanks brett , yes its coming on ,I may just sneak up on it when its looking the other way and slip it 10 psi , but I think my turbine would have a chokey fit .I have a bigger t25 41mm turbo I could pop on though ....

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Nothing like slipping it 10psi!

I run a supercharger and I don't care the TB is on the wrong side.
VEMS + 12 PSI + Liquid Intercooler = Small Bore FUN!

hmm, interesting new problem.

now its cooler ,around 9 degrees , if the engine pops into the intake, it move the fuel pressure up to around 25 psi from 15 .this combined with the lower voltage at the injectors, due to the cranking of the engine dragging down voltage , means the inj dont operate .

you then have to open a clip to let the pressure out .


plan is to see if it happens again ,and if it does put a bypass switch on the inj resistor pack .

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Yes i moved to the darkside

Instagram @jdm_brett

hmm interesting,

how about a different approach,

lower the resistance, ut then decrease/regulate the voltage upstream back to where the curret is now... you can then add a relay to switch in the full voltage for cranking. much like the pink coil wire...

as its a short cranking burst it should be fine ans long as you dont go mad with the current.

hmmm , god ideas thanks chaps , i wonder what the ecu could cope with and for how long ?

inj 3 ohms ,external temp 9 and below .voltage say ...11v ..

think this may be one for rod !

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

I have to say, rod is pretty damn hot with electrotypedyagnosticals....

yeah id have to agree

im just thinking out loud tbh, what is the voltage at the 14v point on this diagram during cranking?



ive not run through the figures but i have checked my data logs, i drop as low as 9.6v during cranking,
so back to your idea of bypass switch
imo if its only during cranking it may be a useable solution (a relay wired to the starter crank signal to bypass the resistors)
much like the 9v coil getting 12v on cranking on the mini

edit, a voltage drop to 9.6V with no resistors, the injectors would pull 6.4A, i think during cranking and for what 5s this would be acceptable

Edited by Brett on 8th Oct, 2014.

Yes i moved to the darkside

Instagram @jdm_brett

Looking first at the ECU limits question, there are a few "ifs" to that question.

It depends on which version mainboard you have and how "complete" the build is (certain parts are optional depending on the intended use) and which components were supplied (there have been changes to the BOM (parts list) over time).

If it is a V3.0 mainboard - and I say "if" because it became apparent earlier that it has/had the old B&G firmware loaded rather than MS2-E and most newish builds would have been MS2-E driven - it should have a pair of IFRZ34N mosfets installed as the injector drivers. The continuous current rating of those is 29A if the heatsink keeps them below 25C or downrated to 20A if they are allowed to reach 100C. If you were only allowing extra current while starting (as per Joe's suggestion) you could safely assume 29A as they wouldn't have time to heat up. The earlier Mosfets had slightly lower limits.

However, if it is a V3.0 mainboard AND has been fully built there is a current limiting circuit that restricts the injector drive outputs to 14A each. It is an optional circuit hence why I say "if" but is most likely there if it was sold as an assembled unit (rather than DIY) as the company assembling it would want the protection if only for warranty reasons.

So assume you are limited to 14A per chanel when thinking about increasing the current.

Remember, if you do increase the current, the heat dissipation goes up.
That not only affects the power ratings required of any resistors but also potentially the life of the injectors.

For that reason alone, I like Joe's idea of a starting bypass to increase current (or more correctly compensate for lack of current due to lack of voltage) just for a short period of time.

I agree with Brett's maths, 3.2A per injector or 6.4 amps per Mosfet at 9.6V which is nowhere near the 14A limit.
Even if the battery maintained 14ishV during a nice hot start in the middle of a heatwave it would only be a temporary current of 4.75A per injector, 9.5A per Mosfet.

To avoid any issues of current sharing between the resistor banks (EDIT - bit of nonsense removed...), ideally you would need a double pole relay (or two relays) to bypass the two resistor banks independantly otherwise the two banks would be commoned at the relay terminal.

EDIT - probably worth adding that if the battery voltage at the MS2 box (ie, taking account voltage drops through your wiring, ignition switch etc.) drops really low, it doesn't matter what you do to the injector supply, the CPU won't be running to command them open. The CPU needs 5V and the voltage regulator in the box needs an absolute minimum (preferably a lot more) of 6.2V to work.

Edited by Rod S on 8th Oct, 2014.

Schrödinger's cat - so which one am I ???

I haven't gone back to the thread previous pages but why not use PWM instead of the resistor pack? I know there are noise issues but they can be (and have been) overcome in many setups.

That way, you have the equivalent of the resistor bypass since PWM is disabled when cranking.

http://www.jbperf.com/

Yes i moved to the darkside

Instagram @jdm_brett

i thhink it was something to do with the build of the ms brett ,and the ease of trying resistors first ,which just worked fine so left it at that . this morning it started ok ,so i will see how often this problem crops up .

rod it came as a kit , i will have a look at the bill i got from diy autotune cos im not remembering .

thank you for all the ideas and thoughts chaps much appreciated .

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM