Low-Imp. Injectors on MS3X?

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gndan
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Low-Imp. Injectors on MS3X?

Post by gndan »

Hello,

I am going to be switching to low-Imp. 120# Injectors on my car soon and am running MS3 w/X. They are 2.2ohm, do i need to run in-line fuses or anything else in the system to run them? If so what do i need to run for a resistor? Here is the link to them-http://www.racetronix.biz/itemdesc.asp? ... 4x&eq=&Tp=

Thanks, Dan
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Re: Low-Imp. Injectors on MS3X?

Post by WeDgE83 »

I thought about running resistors with mine as well, until I read how much it slows down the injectors. I bought a used AEM Peak&Hold box instead...
Peter Florance
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Re: Low-Imp. Injectors on MS3X?

Post by Peter Florance »

Yes you need resistors. They will run if you don't have the PW excessively long, but I killed a few driver transistors before I got Req fuel correct. :x
I can repair them but it's not worth the risk.

I used 3.3 ohm (25w I think)

I need to measure the opening time at low voltages. The car is a little hard starting cold.
Peter Florance
PF Tuning
81 BMW Euro 528i ESP Car
60-2 Wheel LS2 Coils, Low Z Inj
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racingmini_mtl
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Re: Low-Imp. Injectors on MS3X?

Post by racingmini_mtl »

How many cylinders does your engine have? For a DIY solution and with a 4 cylinder this is a possibility: http://jbperf.com/p&h_board/v2_0.html. And I have a new version that will work for up to 8 cylinders.

Jean
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gndan
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Re: Low-Imp. Injectors on MS3X?

Post by gndan »

The injectors will be installed on my 3.8 liter v 6 buick grand national. I'm interested in the do it yourself option.
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Re: Low-Imp. Injectors on MS3X?

Post by racingmini_mtl »

The new 8-driver box should be available in a couple of weeks. I'll announce it here.

Jean
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gui67
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Re: Low-Imp. Injectors on MS3X?

Post by gui67 »

I use 2 Peak and hold V2 board from Jean with the MS3X on my V8: no problem.
I wish the 8 cylinder version was available 1 year ago...
gndan
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Re: Low-Imp. Injectors on MS3X?

Post by gndan »

Great are you waiting on parts, is that delay? I would like to up and running in the nextcouple weeks
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Re: Low-Imp. Injectors on MS3X?

Post by racingmini_mtl »

I'm waiting for the boards and components. Then there is a need to do some assembling and testing.

Jean
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y8s
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Re: Low-Imp. Injectors on MS3X?

Post by y8s »

yeah good luck and buy a shoehorn.

here's what a 4 channel setup looks like:

inside top view of expander board / ribbon / peak & hold board
(note the cut 10-pin ribbon cable where i intercepted the injector signals)
Image

stealing the grounds and output pins off the expander injector outputs
Image



I suppose less wire could be used but that's hard when the P&H board is bolted to the case and the expander has to slide in from the side.
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Re: Low-Imp. Injectors on MS3X?

Post by racingmini_mtl »

y8s wrote:yeah good luck and buy a shoehorn.
That's an interesting setup and well done. However, the 8-channel driver I'm talking about is an external box that has it's own power supply and connects directly to the MS3X injector outputs (or any other ECU for that matter). So no shoehorn required here...

Jean
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wes kiser
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Re: Low-Imp. Injectors on MS3X?

Post by wes kiser »

Why not just try resistors, and if you have issues purchase Jean's 8 driver board when available? Leave a place for it in your harness, and just connect the resistors there.

I have ran many setups with resistors, as well as bench tested their response with resistors installed (dynamic flow tests) and they are really not that evil for linearity and response. When firing them sequentially, PW generally doesn't drop low enough for it to be a problem until you get into the 1400+cc injector range with gasoline. Remember, many OE ecu's fire lowz injectors with resistor packs. When firing in batch, it is more beneficial to operate them properly.

Jean, when do you expect to have the 8 cylinder lowZ box for sale in relatively large quanitity?
86 Rx-7, swapped to 2.3 ford turbo (BW EFR 6758), ms3/ms3x sequential fuel /waste spark, ls2 coils
88 Tbird 2.3t, Microsquirt Module (PIMP), TFI ignition
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Re: Low-Imp. Injectors on MS3X?

Post by racingmini_mtl »

wes kiser wrote:Jean, when do you expect to have the 8 cylinder lowZ box for sale in relatively large quanitity?
Depends what quantity you're talking about and if you're talking about DIY kits or something else. Email me for more details.

Jean
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Peter Florance
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Re: Low-Imp. Injectors on MS3X?

Post by Peter Florance »

wes kiser wrote:Why not just try resistors, and if you have issues purchase Jean's 8 driver board when available? Leave a place for it in your harness, and just connect the resistors there.

I have ran many setups with resistors, as well as bench tested their response with resistors installed (dynamic flow tests) and they are really not that evil for linearity and response. When firing them sequentially, PW generally doesn't drop low enough for it to be a problem until you get into the 1400+cc injector range with gasoline. Remember, many OE ecu's fire lowz injectors with resistor packs. When firing in batch, it is more beneficial to operate them properly.

Jean, when do you expect to have the 8 cylinder lowZ box for sale in relatively large quanitity?
Wes, have you checked opening time at low voltages?
Peter Florance
PF Tuning
81 BMW Euro 528i ESP Car
60-2 Wheel LS2 Coils, Low Z Inj
Co-Driver 1999 BMW E46 DSP car.
y8s
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Re: Low-Imp. Injectors on MS3X?

Post by y8s »

an external box would definitely eliminate shoehorning. but I was cheap and it cost more.

Incidentally, anecdotal evidence floating around the internets suggest that newer saturated (high impedance) injectors are much better performers than their predecessors and this narrows the gap between high impedance and low impedance injectors.

but my opinion is that resistor packs are a negative compromise in injector performance. hence the shoehorning of the P&H board. In retrospect, it might have been not that much more expensive to just buy new saturated injectors for my particular application.
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Re: Low-Imp. Injectors on MS3X?

Post by gndan »

Y8s or anyone for that matter, why couldn't I just mount the 2- four driver boards ill need for a v6 externally? Or did you only do that to allow for a "package" fit? I want to order these boards asap to get my car back on the road especially with the shipping time from canada to illinois. The injectors are 120#s so with gasonile they will have to be very precise at idle on my 3.8 v6, so I don't think resistors will do.

Thanks all, Dan
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Re: Low-Imp. Injectors on MS3X?

Post by racingmini_mtl »

Dan,

You could mount two 4-driver boards externally (V1.1b) but you'll have to provide 5V to them and also provide a 5V injector signals. When mounted internally, this is easy to do by taking 5V from the proto area and directly connecting to the CPU. But you don't want to do that with an external box since you don't want to expose the CPU pins outside of the MS box. So you would need to use some sort of buffer or use the MS3X outputs and use inverters in your outside box.

My external V2.0 4-driver board (and the upcoming 8-driver board) has an on-board 5V supply and the needed inverters to take the MS3X injector signals directly. So it is a packaging advantage of having everything already on one board that is designed to fit a specific enclosure. You can contact me directly if you need more details.

Jean
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atomic6
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Re: Low-Imp. Injectors on MS3X?

Post by atomic6 »

gndan wrote:Hello,

I am going to be switching to low-Imp. 120# Injectors on my car soon and am running MS3 w/X. They are 2.2ohm, do i need to run in-line fuses or anything else in the system to run them? If so what do i need to run for a resistor? Here is the link to them-http://www.racetronix.biz/itemdesc.asp? ... 4x&eq=&Tp=

Thanks, Dan
I think you should stick to your original idea(from turbo buick) of running the high z 80 lb injectors, even with the running base fuel pressure you should be OK to over 700 hp, and that t-66 is maybe going to get you there on a really cold day. If you are getting near the max on those injectors, you could bump the base pressure up to 50 lbs for a little more fuel.

Doing this alone will greatly simplify your MS3 install. I love the peak and hold boards Jean sells( I have many sets in use) but it is complication and expense not necessary, because six of the 80s will get you there and will cost less than $300.

Just look for the ev-1 verison of this auction.

http://cgi.ebay.com/ebaymotors/Siemens- ... ccessories

Make your install easier not more complicated, you will like the Squirt/Buick combo much better. :D
1986 G.N. (sold)
1967 Nova II wagon (sold)
ex-MSer
gndan
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Re: Low-Imp. Injectors on MS3X?

Post by gndan »

Atomic its funny that you say that I pulled the trigger on 80#s today. I figured I have 3 injectors in the charge pipe I could control with secondary injection anyways if I needed more fuel. I have had the ms3x in for 1400 miles and its running flawless so ill leave it be with High-Z.

,Dan
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Re: Low-Imp. Injectors on MS3X?

Post by Peter Florance »

I did some quick testing with Low Z injector and 3.3 ohm resistor, using the accelerometer pcb that I brought to 2008 megameeting
At lower voltages, there's a big difference in opening times with and without resistor. At 13.2 volts it was difficult to see any difference. That may explain my customers cold starting issues if battery is not fully topped off.
Perhaps I will be able fix with battery correction voltage...

Note this tester does not yield actual dead time measurements but I thought it would be useful as a relative test.
Peter Florance
PF Tuning
81 BMW Euro 528i ESP Car
60-2 Wheel LS2 Coils, Low Z Inj
Co-Driver 1999 BMW E46 DSP car.
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