Help with LS1 injector data for 11P

[someguy360]

Hi All,

I was hoping to get some advice from the injector gurus on setting up my spare set of LS1 injectors (Grey 931's) for my 355.

I've currently got Blue Top 775's which are getting a bit long in the tooth and the injector bodies are starting to corrode a bit externally being steel etc.

Rather than getting them serviced and cleaned etc I'd like to swap over to my spare set of LS1 injectors which are the more modern EV6 design and a little better looking and a little quieter.

The flow rates are pretty close and I can use the kinjflow calculator to sort out the minor flow rate difference between the two (25.9lb vs 26.7lb), however I'm wanting to check if anyone has any recommendations on where I should be setting my opening time, injector bias and injector delay in comparison to my old 775's as I know the EV6's are a higher impedance than the EV1's and I wasn't sure if this is likely to affect the opening times etc.

I'll be running the new injectors at the recommended 3.5 bar as I've got an adjustable fuel pressure regulator.

Old injectors:
VR, VS, VT 5.7L (215KW GTS)(Blue Tops)
0 280 150 775 (EV1)
25.9 LB/HR 265 CC/MIN 195.79 G/MIN 15.9 Ohm 3.3Bar OP

New Injectors:
VT, VX, VY V8 5.7L LS1 (INCLUDING CLUBSPORTS, GTO)
0 280 155 931 (EV6)
26.72 LB/HR 274 CC/MIN 202 G/MIN 12.0 Ohm 3.5Bar OP


This is my current setup for the EV1's.


I couldn't seem to find any example bin's for 11P/12P floating around that are using that part number injector to reference so I'm hoping someone can point me in the right direction.

Thanks in advance!

[antus]

They're so close in flow, I think you should just try them how they are, if it ain't broke don't fix it. Otherwise it can get quite difficult to profile injectors. It's something I've looked at recently in my car, I did need to make big changes as I more than double the size of the injectors but I was not able to get meaningful data for this PCM because after doing some research I found out the injector driver chips play a big part in the opening time, as well as other characteristics in the operating system so data someone has posted on the net, or even from the manufacturer is not a perfect match for these PCMs. If your lucky someone might have done it and post some numbers. It'll be the idle and crank that'll be the most concern. So if it starts reliably and if they idle is ok (where its doing very small injection, thus opening time is a large percentage of the injection) then are you good. Under full load when the injection times are longer a minor discrepancy at the opening time end of the pulse is a lot less noticeable. Other internet wisdom I have read was someone was saying that for their rule of thumb for less than 600cc injectors (about 57lb) they would not worry about opening time. I am not sure that is good advice, but comparing two injectors at half that flow rate makes me think you should verify the size of the problem first.

[someguy360]

Thanks Antus, I think thats the safest plan.

I was going to leave the flow rate the same being so close and then just slightly tweak as needed if required, just wasn't sure if the opening times would cause major differences (this is my first time running non EV1 style injectors).

Thanks for the advice!

[antus]

I just edited my post. I had some type-os and added some more thoughts

[Deuce]

Thanks Antus, I think thats the safest plan.

I was going to leave the flow rate the same being so close and then just slightly tweak as needed if required, just wasn't sure if the opening times would cause major differences (this is my first time running non EV1 style injectors).

Thanks for the advice!

You must be back from your trip if you are sending screenshots and specific questions. Lol

Yes, also keen to see if the straight swap causes any hot or cold cranking issues, or throws idle off any.
And if it does, what adjustment and how much is required to bring it back.
Good luck mate