low impedance injectors?
05-31-2004, 04:34 PM
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low impedance injectors? dunno if should post this here or in the tunning - electronic section.
i read in a web site that you can use low impedance injectors in place of hi impedance ones ( stock type) when using a factory pcm (on a buick), all you have to do is replace the injector fuse with a beefier one (20 amp).
can this be done on an ls1 pcm??
here's the link:
http://www.conleyracing.com/index.htm
go to articles, click on how to tweak your GN/T, then go to #3 "injectors: sizing and type". look halfway down the page.
i read in a web site that you can use low impedance injectors in place of hi impedance ones ( stock type) when using a factory pcm (on a buick), all you have to do is replace the injector fuse with a beefier one (20 amp).
can this be done on an ls1 pcm??
here's the link:
http://www.conleyracing.com/index.htm
go to articles, click on how to tweak your GN/T, then go to #3 "injectors: sizing and type". look halfway down the page.
06-04-2004, 07:15 AM
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no no and no.
low impedance are usuall peak and hold. ie Massive amps to open fast, then hold low amps to hold open.
saturated are just a constant amp load.
The poor peak n holds using the resistor trick will burn up esp at high duty cycle (100%).
poor analogy: Spray your 20lb tank of nitrous dry in one run, see how the motor feels afterwards versus spraying 1/4 mile at a time. (best i could come up with)
how about this: amp rated at 2 ohms, you run it at 1ohm load, runs great during winter for short period, but in summer, it cuts out on overtemp protection (most good amps have this) or smokes. nother bad analogy
but you get the idea. You buy a standalone or a SATurard->Peak &hold converter system ($399?) and it does the correct job of letting you use massive injectors and
having that stock driveability due to min injector pulsewidth benefits of P&H
low impedance are usuall peak and hold. ie Massive amps to open fast, then hold low amps to hold open.
saturated are just a constant amp load.
The poor peak n holds using the resistor trick will burn up esp at high duty cycle (100%).
poor analogy: Spray your 20lb tank of nitrous dry in one run, see how the motor feels afterwards versus spraying 1/4 mile at a time. (best i could come up with)
how about this: amp rated at 2 ohms, you run it at 1ohm load, runs great during winter for short period, but in summer, it cuts out on overtemp protection (most good amps have this) or smokes. nother bad analogy
but you get the idea. You buy a standalone or a SATurard->Peak &hold converter system ($399?) and it does the correct job of letting you use massive injectors and
having that stock driveability due to min injector pulsewidth benefits of P&H
06-04-2004, 08:05 AM
#3
Originally Posted by samz28
no no and no.
low impedance are usuall peak and hold. ie Massive amps to open fast, then hold low amps to hold open.
saturated are just a constant amp load.
The poor peak n holds using the resistor trick will burn up esp at high duty cycle (100%).
poor analogy: Spray your 20lb tank of nitrous dry in one run, see how the motor feels afterwards versus spraying 1/4 mile at a time. (best i could come up with)
how about this: amp rated at 2 ohms, you run it at 1ohm load, runs great during winter for short period, but in summer, it cuts out on overtemp protection (most good amps have this) or smokes. nother bad analogy
but you get the idea. You buy a standalone or a SATurard->Peak &hold converter system ($399?) and it does the correct job of letting you use massive injectors and
having that stock driveability due to min injector pulsewidth benefits of P&H
low impedance are usuall peak and hold. ie Massive amps to open fast, then hold low amps to hold open.
saturated are just a constant amp load.
The poor peak n holds using the resistor trick will burn up esp at high duty cycle (100%).
poor analogy: Spray your 20lb tank of nitrous dry in one run, see how the motor feels afterwards versus spraying 1/4 mile at a time. (best i could come up with)
how about this: amp rated at 2 ohms, you run it at 1ohm load, runs great during winter for short period, but in summer, it cuts out on overtemp protection (most good amps have this) or smokes. nother bad analogy
but you get the idea. You buy a standalone or a SATurard->Peak &hold converter system ($399?) and it does the correct job of letting you use massive injectors and
having that stock driveability due to min injector pulsewidth benefits of P&H
Another more cost effective option is to use a resistor pack.
Resistor packs are common as OE items in many imports. Typically 6 ohms per injector. These resistor packs are usually ceramic wire-wound types with high power dissipation. There are no issues with resistor pack failure provided the wattage rating of the resistors is high enough. At 13.5V the power dissipation is apx. 17W across the 6 ohm resistor so a 25W rated unit would be in order. Keep in mind that the 17W dissipation is only under 100% DC. Under normal conditions it will be a small fraction of 17W.
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06-04-2004, 10:13 AM
#5
The resistor pack would get warm but not so hot that you could not touch it. There are many things under the hood of your car which get much hotter.
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06-04-2004, 03:14 PM
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Don't do that...go to http://www.acceleronics.com/ and order one of the impedance converters if you are looking to do this off of the factory PCM.
I had one on my car and it worked fine with 85lb. injectors. Actually, I have my box for sale for $240 shipped if you are interested. You would need to order the other side of the connectors from LJ at acceleronics since mine are still on my car, but I bet that these would not cost more then $25 or so.
I had one on my car and it worked fine with 85lb. injectors. Actually, I have my box for sale for $240 shipped if you are interested. You would need to order the other side of the connectors from LJ at acceleronics since mine are still on my car, but I bet that these would not cost more then $25 or so.
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06-04-2004, 03:51 PM
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now you tell me about selling the box scott, 
i already have the 72's on order, i think it would be more economic to buy the 72's alone than it is to buy the converter and a set of low imp. injectors.
i saw that site before, but i didn't know if anyone had it on their car. how do you like it?
i already have the 72's on order, i think it would be more economic to buy the 72's alone than it is to buy the converter and a set of low imp. injectors.
i saw that site before, but i didn't know if anyone had it on their car. how do you like it?
06-04-2004, 04:50 PM
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The box worked pretty well, the problems that I ran into was the stock computer not being able to lower the injector pulse-width enough with the larger injectors. I was runing 83# SD injectors in the car at the time.
The car would start to load up anytime it sat at idle or in a part-throttle fuel cell for 30 seconds or so. A blip of the throttle would clear it out and then it would be fine.
I was running the 83s on the stock 346 and my Incon setup, so it was probably way too much fuel, but I wanted to see what would happen. If you were using a 75# injector then it would probably be ok.
The thing to keep in mind with the large high impedance injectors is that they will tend to be sluggish. The low Z injectors will be a lot 'snappier' at the same size.
1dirtyZ, let me know how the high impedance 72s work out for you.
The car would start to load up anytime it sat at idle or in a part-throttle fuel cell for 30 seconds or so. A blip of the throttle would clear it out and then it would be fine.
I was running the 83s on the stock 346 and my Incon setup, so it was probably way too much fuel, but I wanted to see what would happen. If you were using a 75# injector then it would probably be ok.
The thing to keep in mind with the large high impedance injectors is that they will tend to be sluggish. The low Z injectors will be a lot 'snappier' at the same size.
1dirtyZ, let me know how the high impedance 72s work out for you.
