low impedance injectors and resister packs

[Munki]

Hi

I am wiring up a 4agze to an adaptronic. As you may know the 4agze are low impedance; about 2 ohms. I have not got the stock resister pack so my question is can i simply run a resister between each power feed? or is there more to the resister packs than a bunch of resisters? will 8 or 10 ohms be ok or do i need specific information to determine what is needed?

cheers

Daniel.

[Munki]

oh and anyone know the min operating current of toyota injectors 1-2 amps?

[DrNick]

Yes you can wire up resistors, but you need them to be of a high wattage. The little carbon film ones you get from Dick Smith electronics are not good enough.
I like to buy my components made by Vishay Siliconix at work but there are lots of other companies that make resistors. Vishay make some nice 25W ones which have aluminium heat sinks on each resistor etc and bolt holes for mounting. They run at just under $10 each.

[MWP]

Ill ask something on this topic too...

On my 3SGTE (std injectors) with Microtech, the factory resistor packs are currently wired in.
Since the Microtech can handle low impedance injectors, can i remove the resistor packs?

[Munki]

Funny you should ask this. I removed a microtech with x4 ignition to put in my adaptronic, there was no resister pack wired up.

[Munki]

and cheers Dr nick, I was eyeing off some 20w resisters, might pay to locate the factory resister pack it seems.

[Hen]

DrNick is on the money. If you add resistors (which is fine) they need to be reasonably high power resistors.

But check your ECU. If the ECU can handle low impedance injectors then forget all about resistor packs and wire the injectors direct to the ECU. It's simpler and performance wise you get a tiny decrease in injector opening time (better control at low duty cycles with big injectors). I'd assume nowadays all aftermarket ECUs can drive low impedance injectors, but check before you go believing me.

Hen

[Munki]

Yeah the adaptronic says it can run low imp injectors;

"They can be used with or without external resistors (standard on many vehicles with low resistance injectors), or with high or low impedance injectors. The difference to the ECU is that increased heating will take place with lower impedance injectors, and therefore if you are using very low value
injectors at very high duty cycles, it would be a good idea to monitor the heatsink
temperature to make sure the ECU doesn't get too hot."

Just concerned with what is "too hot". Seems a little vague to me so i thought the extra safety the resisters provide would be beneficial.

[wilbo666]

Run them peak and hold with the Adaptronic

No need for resistors.

Cheers
Wilbo

[RA35GT]

http://www.adaptronic.com.au/forum/i...hp?topic=131.0

http://www.adaptronic.com.au/forum/i...hp?topic=533.0

[YLD-16L]

Yeah the adaptronic says it can run low imp injectors;

"They can be used with or without external resistors (standard on many vehicles with low resistance injectors), or with high or low impedance injectors. The difference to the ECU is that increased heating will take place with lower impedance injectors, and therefore if you are using very low value
injectors at very high duty cycles, it would be a good idea to monitor the heatsink
temperature to make sure the ECU doesn't get too hot."

Just concerned with what is "too hot". Seems a little vague to me so i thought the extra safety the resisters provide would be beneficial.

I run low impedence injectors on my adaptronic at fairly high duty cycles and kept an eye on the ecu case (heatsink) at the track because if it was going to get hot it would have been at sustained high injector duty cycles as seen on the circuit. Every time I checked it the case was barely even warm to touch, in fact I wouldn't have even said the case was warm at all.

So it definitely didn't need the resistor pack.

"Too hot" is too hot to keep your hand on the case, i.e. 60 - 65 deg C +.


As for the other question, the microtech doesn't need the resistor pack for the injectors.

[CrUZida]

MWP, my Microtech runs 2 x 7MGTE injectors per driver. From memory they are 2.5ohms each, so the ECU is seeing about 1.2ohms per driver.

I drove to Sydney and back like this, some days were up to 1200km's a day.
No issues what so ever.


The ecu was also configured (when I bought it) for high impedance injectors.
I just changed them over with no changing of settings (I doubt there is a setting change though).

[JustCallMeOrlando]

I ran my low impedance 7MGTE injectors on my Adaptronic in three batches of two. This was the recommended way to install them, no resistors required. As above, drove to Sydney and back, no worries at all.

[thechuckster]

Do you have to 'tune' the PWM and/or peak and hold settings for low-Z injectors with thewww adaptronic?

You have to with MSefi unless you use one of the daughter boards like this: http://www.jbperf.com/p&h_board/index.html

[MWP]

MWP, my Microtech runs 2 x 7MGTE injectors per driver. From memory they are 2.5ohms each, so the ECU is seeing about 1.2ohms per driver.
....

Thanks, ill give it a go.

Im hoping that doing so will increase the accuracy of the <1mS opening times, making for more precise idle & cruise tuning.