astra 1.4 8valve lpg turbo.
Turbo Mini Forums

thats good news jean , thank you , i read about the 2amp stuff in here ..


http://www.megamanual.com/ms2/

this bit ..


''If you use resistors that limit injector current to less than 2 amps, you can disable the PWM mode (by setting PWM% to 100%, and time threshold to 25.4msec) and treat the system as high-impedance. To limit the current to under 2 amps, you need: ''

so i have a range of 2 to 3 ohms , would you go for the 3 or the 2 ?

Edited by robert on 2nd Nov, 2012.

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

Robert,

If you want to experiment with P&H, I have a spare P&H board fully assembled with the "standard" (ie, petrol) value components and a spare bare board plus all the key components that you could experiment with different sense resistor values and/or timing resistor/capacitor values (the datasheet tells you how to work them out depending on what you want).

You're welcome to borrow either or both.


EDIT - for resistors, I'd start at 3ohm and see if the injectors actually open against gas pressure with a low battery voltage. If you have to use 2ohm, put your finger on the injectors to make sure the coil parts aren't getting too hot when they are operating.

Edited by Rod S on 2nd Nov, 2012.

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

I agree with Rod about the resistors.

And if you take him up on his offer, what you could try if the standard components don't work very well (which I suspect will be the case) is to use a 0.07 Ohm current sense resistor (instead of the standard 0.1 Ohm) to increase the hold current and a 51K timer resistor (instead of 39K) to increase the time out to about 5.1ms. Both of these have been reported to result in a working setup.

Jean

http://www.jbperf.com/

gosh chaps ,very kind of you rod ,and thanks jean for the data on values . what i will do is try with the 3 ohms ,and if that doesnt work ,give your bits a try rod .

again thanks for the help .

regards
robert

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

ok 4 of these bad boys on the way ..

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

oh yeah!

I just had someone posting the specs on my forum for the new Valtek type 34 and they are much better suited for my P&H drivers: http://forum.jbperf.com/download/file.php?id=262.

As you can see, they use 4A/1A peak/hold currents and they open well under 2ms. So they can use my standard components.

Robert, I know that's not very useful for you but I thought you and others might be interested to know.

Jean

http://www.jbperf.com/

thanks jean , any info relating to the subject is of interest ,and i appreciate the input . they sound a lot lot faste than my ones ...

injector specs....

2 POWER OF COIL 48 W – 144 W

3 PILOTING TYPE PEAK and HOLD

4 TIME FOR PEAK CURRENT 4,5 ms
6 RESISTANCE 3 Ohm +-4% - 1 Ohm +-4%
12 OPENING TIME 3,3 ms

13 CLOSING TIME 2,2 ms

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

One thing I don't see in your specs is the flow. If your injector flow a lot more than the type 34, they could be physically bigger which would explain why they are slower.

Jean

http://www.jbperf.com/

good point jean , i only know that the valtek 30 uses a calibtated nozzle for each injector ,that is varied in size depending on bhp requirement , so the inj itslef will flow the max with a 4mm nozzle ,and then it is sized down to a smallest of 2.5mm for lowest power .


i had to solve the problem of how to fix this super sensitive air temp sensor in this rail..



so i gave up on the wierd metric 1mm thread in the end ,and used an alternative approach ...

bought a cheap t piece ,and lathed a flat on one side...





this allowed me to fit the sensor in the side ,and have it directly in the gas stream





then i used the third leg ,with a machined bung in ,to mount the pressure guage





and last of all , i did the pressure feed to the reducer ,and blocked the old breather hole .

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

noicely dun ! ( been brushing up on my Englush)

That sir, is not rust, it is the progressive mass reduction system

http://aseriesmodifications.wordpress.com/

Robert,

Those specs look very strange...

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

Rod,

If I remember correctly from information I got some time ago, there are two different models available and the specs presented here simply lists these in a very obscure way. It should be done in two columns to show the two different models.

Jean

http://www.jbperf.com/

Jean,

This was the datasheet I was looking at (similar to others I saw).

http://www.europegas.pl/documents/VALTEK_tech_spec.pdf

If there is more than on version with different resistances between 1ohm and 3ohm I guess it would help Robert if he could find out which he has.

At such low values, the choice of series resistor (rather than P&H) must be quite carefull ??

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

Well, I can't find something clear but if you look at the information here: http://www.valtek.it/Prodotti/Rail-iniezio...Gpl-Metano.aspx you'll see that the injectors are available with different coil impedance values. What is curious though is that none of the values shown there is 3 Ohm.

Jean

http://www.jbperf.com/

Edited by robert on 10th Nov, 2012.

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

Robert, in that link

http://fuelsforum.rasoenterprises.com/view...t=1062&start=15

It seems like he was using Jean's P&H board plus 1ohm resistors (first post in the thread on the first page).........

That would make a lot more sense if the coils are 1ohm.

It really depends on what your coils really are ???

Can you measure the DC resistance reasonably accurately down at 1-3 ohms ???

EDIT - reread it and it seems he started with P&H then went for 1ohm resistors....

Must read things more carefully....

Edited by Rod S on 10th Nov, 2012.

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

using a analogue rs meter ,and two digital meters ,one a fluke ,and flickers from 3.1 to 3.0 ohms .
are there any other tests i could do on them rod ? i have a 2 channel scope.or perhaps just bung em in and see what happens .

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

these people are selling the 1 and 3 ohms versions , looksl like they are colour coded ..

http://www.lpgshop-24.de/Autogas-LPG-Injek...ek-Typ-30-Rail/

Edited by robert on 10th Nov, 2012.

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

That's interesting. And it seems most people have the 3 Ohm version because I've only seen the red ones (not that I've seen many or any other way than in pictures).

And using the meter is sufficient to know which one you have. The scope would be useful in seeing how fast they react but you need to do that on a functional setup for it to be meaningful.

Jean

http://www.jbperf.com/

i have emailed the chap in the thread using the 1 ohms .

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

As per Jean, a good meter (and backed up by more than one in your case) is enough especially now there seems to be more information confirming that there is more than one version.

So knowing yours are 3ohms, if you put them in series with a 3ohm resistor, they will attempt to open with half the current they expect.

The only way to know is to try..... which seems to be what the others have been doing, experimenting until they have something that works.

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

i wonder if its possible to work out the max safe amps for the ms2 ,from the components specs ?

also if i use 4 channels ,one per injector,would that reduce the amps load per channel?

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

If you have a standard MS2, it only has two channels.

The one you linked to a page ago is the kit - did you get it as a kit or has someone else assembled it ???

The reason for asking is the kits can be built several ways which affects which injectors they can drive - particularly whether they are built for low z injectors or not - but as the basic kit, they can still only do two channels.

If built in the standard way for low z - which uses PWM to limit the holding current - the ratings are quite high (personally I think the limit is the PCB tracks and the connector pins rather than the MOSFET outputs) but in standard form - because of the way it uses the CPU outputs for the PWM as well as the basic injector drive - it can only run 2 channels, hence it can only run batch or semi-sequential output.

To run them as 4 channel sequential - and the articles and datasheets suggest LPG prefers 4 channel sequential - means you have to modify the MS2 slightly and install 4 channels of output drivers and run the MS2-Extra code.

The main reason the likes of myself, Paul, Graham do this is to run the siamese/staged version of the MS2-Extra code but the modification allows 4 channel fully sequential for any "normal" 8 port engine to run 8 port fully sequential.

The modification involves doing away with the PWM drive on the original two channels and putting in a new driver board - usually Jean's 4 channel high z, or his (4 channel) P&H board (for low z) along with a small modification to the CPU daughterboard and the removal of a few parts (which may not have been installed in the first place depending on who built the kit).

Plus a few wires to connect it all up.

The rating of the (now) 4 channels is dependant on the parts used but given what Jean mentioned earlier about a few value changes, his P&H board would be my choice (and I have one you can borrow if you want to try that way).

If you want to go down that route, I'll obviously help with the detail but I suggest the first thing is to see if you can get away with resistors - forget the MS2 for the moment, just pressurise them with LPG and see if they open cleanly with a resistor and low battery, and then see if they get too hot :)

EDIT - for clarity

Edited by Rod S on 11th Nov, 2012.

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

thanks rod ,good stuff , it ws built for me ,and has all the bits in it i think ,it definately has all the flyback circuitry in it ,and a full compliment of the heat sink row of transistors .

do you think its feasable to use compressed air for theinjector test , i was thinking of hooking it up to my regulated garage compressor ,and adjusting it to the max bar of hte vapouriser , i think thats 2.7 so about 40 psi , and seeing what hapens , i can also run it through an ammeter to monitor amps .

it strikes me that , if the ms2 can cope with a lot more than the 2amps i read about in the manual ,then i could run a much lower resistor ,and reduce the likelyhood of injector malfunction .

haha just read back and realised joe sugested trying it on a compressor a week ago , hes too quick by half .!

Edited by robert on 12th Nov, 2012.

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