Low Imp Injectors

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billr
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Re: Low Imp Injectors

Post by billr »

The MS3X will drive low-Z injectors, but you must use external series resistors, as discussed previously. The JBPerf board is pretty easy to assemble, don't be afraid of a "kit".

Jean, Is there going to be a successor to the V2.0 board? That "final limited batch" sounds scary!
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Re: Low Imp Injectors

Post by racingmini_mtl »

billr wrote:Jean, Is there going to be a successor to the V2.0 board? That "final limited batch" sounds scary!
Yes there is a successor planned. It will have up to 8 drivers. However, I don't know yet when it will be available. If you have an interest in such a unit, let DIYAutotune know. That may help speed things up.

Jean
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Peter Florance
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Re: Low Imp Injectors

Post by Peter Florance »

racingmini_mtl wrote:I only sell them in kits and not assembled unit. Also, the version you linked is not ideal with with an MS3/MS3X setup because you would need to bypass the MS3X and there isn't much space to install the board inside the MS3 case.

With an MS3/MS3X setup, you're much better off with this version: http://jbperf.com/p&h_board/v2_0.html#Buy. I'm out of stock at this time but I will have a final limited batch available in about 2 weeks (there will be a small price increase of about $5). However this is still sold in kit form. There maybe someone here on the forum who could assemble one for you. Maybe Peter Florance?

Jean
Possibly. Can you elaborate on how this board connects to MS3X? Can MS3X drive the board directly?
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dvanderk
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Re: Low Imp Injectors

Post by dvanderk »

If the MS3x can drive low-z injectors do I just need to put a resistor inline to each signal wire of the fuel injectors? I'm assuming no driver board is even required? Can you elaborate on this please, because I really prefer simplicity.
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Re: Low Imp Injectors

Post by Peter Florance »

dvanderk wrote:If the MS3x can drive low-z injectors do I just need to put a resistor inline to each signal wire of the fuel injectors? I'm assuming no driver board is even required? Can you elaborate on this please, because I really prefer simplicity.
You'll need 3.3 ohm resistors in series with each injector.

I think we used 10 Watt and they don't even get warm.
Peter Florance
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Re: Low Imp Injectors

Post by racingmini_mtl »

Peter Florance wrote:
racingmini_mtl wrote:I only sell them in kits and not assembled unit. Also, the version you linked is not ideal with with an MS3/MS3X setup because you would need to bypass the MS3X and there isn't much space to install the board inside the MS3 case.

With an MS3/MS3X setup, you're much better off with this version: http://jbperf.com/p&h_board/v2_0.html#Buy. I'm out of stock at this time but I will have a final limited batch available in about 2 weeks (there will be a small price increase of about $5). However this is still sold in kit form. There maybe someone here on the forum who could assemble one for you. Maybe Peter Florance?

Jean
Possibly. Can you elaborate on how this board connects to MS3X? Can MS3X drive the board directly?
It basically connects the same way as a resistor pack and it has its own external case. The difference is that there is a need to have additional 12V and ground wires to power the board and 4 additional grounds which are the injector grounds. So it can be driven directly by the MS3X injector outputs which only see a very small current.

Jean
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billr
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Re: Low Imp Injectors

Post by billr »

You are talking about the new board, right? I have my two "old boards" connected to the MS3 10-pin header, no need for the MS3X for injectors.
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Re: Low Imp Injectors

Post by racingmini_mtl »

billr wrote:You are talking about the new board, right? I have my two "old boards" connected to the MS3 10-pin header, no need for the MS3X for injectors.
No, I'm talking about the V2.0 board. What you're talking about is the V1.1 board which I will continue to carry.

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billr
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Re: Low Imp Injectors

Post by billr »

Oops, I should have gone to your site to be sure what the different versions are before posting! (I did look at the schematic, but it doesn't identify which board it applies to...)
dvanderk
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Re: Low Imp Injectors

Post by dvanderk »

Wait im confused... why are you still saying you need a driver board on the ms3x? (note that im running fully sequential). If I just need to put a resistor inline to each injector why not just go that route?
billr
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Re: Low Imp Injectors

Post by billr »

Well, we are coming around in a circle on this... you can use the MS3X with just resistors, but earlier in this thread was some debate about whether P&H (the separate board) is better than resistors, and whether any improvement P&H offers justifies the cost of the additional board. You are going to have to make that decision.
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Re: Low Imp Injectors

Post by dvanderk »

AEM builds an injector driver system with a HUGE heatsink for 299.99. Seems to be a reputable brand im just curious if people have had these drivers fail because im not a fan of making my setups complicated (more to fail).
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Re: Low Imp Injectors

Post by aarc240 »

There is no reason not to simply use resistors like the OEMs usually do.
Just remember that in all choices of hardware the OEMs will always opt for the cheapest solution that is saleable rather than the best solution.
My experience has been that the low-Z injectors with resistors run hotter and don't seem to be quite as consistent from freezing cold to stinking hot days.
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Re: Low Imp Injectors

Post by jonr »

I agree that consistency is the primary concern. Does it open and close in the same amount of time under all conditions? Higher voltages and lower impedance tend to help.
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dvanderk
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Re: Low Imp Injectors

Post by dvanderk »

So why do OEM use high imp for there applications, if low imp is cheaper?

I hear low imp is the way to go, however I found a company named injector dynamics that is supposed to make the best injectors based upon the bosch injectors. From all the articles I read, the 1000cc have the tuning ability of 600ccs and are much easier to idle.

http://www.injectordynamics.com/ID1000.html

Any comments?
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Re: Low Imp Injectors

Post by Fabio421 »

Hello, I have the MS3x box and the car I am installing it in currently has low Z injectors. I would like to utilize these injectors for the short term and have read that I can drive these injectors without a seperate board or bank of resistors if I use the PWM output. I have no idea what PWM stands for, what it is, or how I would go about doing this. WHat is the disadvantage of using the PWM for this? I'm sorry for all the questions but the manual says very little about this.

Thanks in advance for your help.
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Re: Low Imp Injectors

Post by SymTech Laboratories »

You have to use the two main board injector drivers in order to use PWM current limiting. The MS3X injector drivers aren't capable of it.
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billr
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Re: Low Imp Injectors

Post by billr »

PWM means "pulse-width modulation", a very common means of controlling (limiting) power delivered to an electrical device. In this case, PWM would be used to limit current in the low-Z injectors, to keep from hurting both the injectors and the drivers; but you will run into PWM in other areas, like controlling some idle valves, fuel pump, fans, etc. If you are going to run sequential fuel from the MS3X eventually, then you might as well get some resistors now and not waste time playing with PWM parameters and wiring to the mainboard drivers (of which there will only be two, so batch-injection is all you can do). If you get the resistors from a place like Digi-Key then I think they are pretty inexpensive; I wouldn't bother with an off-the-shelf "resistor module". I like P&H, but a lot of people are quite happy with resistors so that may be as far as you have to go
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Re: Low Imp Injectors

Post by JAM »

I have not used the resistor method but have used the boards from jbperf.com and can say that I found them easy to assemble and had no problems tuning with them, they just worked right from day 1 and never looked back. I also had great support from jean on all of my stupid questions and never felt like i was stranded on the project. I used 2 boards on a v8 application. I am not sure all of the cause and effect but i was impressed with how well the system tuned 120# injectors to a nice idle. (I had nothing to compare to with this specific application)

Can someone tell me how the low Z injector open time is affected between using the lowZ driver boards vs the resistors? It would seem to me that the drivers would give shorter more consistent open times which would be most noticeable at low pulse-widths?

Jean,
I will be setting up another v8 in the future, may be a ways out before i get to it but I was hoping for the new board with 8 circuits on it. It sounds like there is some question on the future of that board. Is there a chance that it will get canceled or just delayed for a time?
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Re: Low Imp Injectors

Post by racingmini_mtl »

JAM wrote:Jean,
I will be setting up another v8 in the future, may be a ways out before i get to it but I was hoping for the new board with 8 circuits on it. It sounds like there is some question on the future of that board. Is there a chance that it will get canceled or just delayed for a time?
The 8-driver board will come one way or another. There should be more about it in the not too distant future.

Jean
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