P59 injectors scaling???

[promobass]

Hello, friends. I'm in the market for a Silverado turbo on a P59. There are two sets of injectors 50lb and 75lb. I don't understand if I need to scale the tables for 50 or 75lb injectors? my boost will be 10-12 psi. Do I need this additional table permission?

[Jay@HAP]

Hello, friends. I'm in the market for a Silverado turbo on a P59. There are two sets of injectors 50lb and 75lb. I don't understand if I need to scale the tables for 50 or 75lb injectors? my boost will be 10-12 psi. Do I need this additional table permission?

There are two reasons you would need scale the tune;
1. You are going to exceed the maximum injector size
2. You are maxing out your air mass and you are maxing out your spark table.

I had to do it for reason #2. I have a P01 though.

I scaled mine injectors by 75%., I have ID1000's

Then had to do the same thing to the VE table to keep the fueling the same.

Keep on mind, you will have to redo your spark tables, because the air mass reading after you scale it is going to be different and you run the risk of blowing something up.

I'm running 15psi max right now. Scaling it 75%, lets me use the entire spark table. I first scaled it by 50% and there were several rows of the spark table that I wasn't hitting. Not enough air mass. Changing it to 75% ended up working perfectly in my application.

[promobass]

I understand how scaling works. my operating system supports injectors up to 127lb. The question is, why do I need additional card permission? 13-15 degrees of spark at 10 psi boost suits me just fine. I understand that the card resolution may not be enough at 30psi boost...

[Jay@HAP]

I guess I don't understand your post or what exactly you are wanting to know.

If you have good resolution of the spark table as it is and you are happy with it, I don't see any reason to change it.

[blindsquirrel]

I understand how scaling works so let me say some things and ask some questions that give all the indications that I do not understand how scaling works.

P01/P59 have an injector flow rate limit of 254lb-hr, not 127. Late E38/E67s have a limit of 127... and you have not posted your tune file, which you seem to forget to do on a regular basis... so what you are getting here is speculation which may be incorrect because we do not have any way to see what the hell you are working on.

[2xLS1]

You need to explain what you mean by table permission, card permission.

[kaizen]

I understand how scaling works so let me say some things and ask some questions that give all the indications that I do not understand how scaling works.

P01/P59 have an injector flow rate limit of 254lb-hr, not 127. Late E38/E67s have a limit of 127... and you have not posted your tune file, which you seem to forget to do on a regular basis... so what you are getting here is speculation which may be incorrect because we do not have any way to see what the hell you are working on.

Could it be that the actual limit is smaller?
I have been trying to adjust 80lb injectors on a P01 PCM using forum instructions, but the result is consistently either misfires or an excessively rich mixture at idle.

[edcmat-l1]

Could it be that the actual limit is smaller?
I have been trying to adjust 80lb injectors on a P01 PCM using forum instructions, but the result is consistently either misfires or an excessively rich mixture at idle.

businessman-looking-into-crystal-ball.jpg

[blindsquirrel]

What does "adjust 80lb injectors" mean?

[blindsquirrel]

And look, injector flow rate is the least important of all the data. Especially at low speed/small pulsewidths, the offset & short pulse adder will have much more impact. Flow rate errors/unknowns can be compensated with increasing/decreasing VE/MAF. This is why the guys who only worry about dyno numbers say that 'injector data doesn't matter', because for just making it do a dyno pull, it doesn't matter. If you want it to idle right and drive nice, it needs all the data.

[kaizen]

And look, injector flow rate is the least important of all the data. Especially at low speed/small pulsewidths, the offset & short pulse adder will have much more impact. Flow rate errors/unknowns can be compensated with increasing/decreasing VE/MAF. This is why the guys who only worry about dyno numbers say that 'injector data doesn't matter', because for just making it do a dyno pull, it doesn't matter. If you want it to idle right and drive nice, it needs all the data.

Adjust->Saataa->Tune. Sorry my bad english.

I entered all the data, including offsets and the short pulse adder according to this.

[blindsquirrel]

In the phrase '...according to this.', what 'this' is was left undefined.

You already have another thread where you were getting assistance, now apparently abandoned in favor of tacking your questions onto the end of this other, unrelated thread.

[kaizen]

In the phrase '...according to this.', what 'this' is was left undefined.

You already have another thread where you were getting assistance, now apparently abandoned in favor of tacking your questions onto the end of this other, unrelated thread.

The "this" refers to the attached file: Siemens Deka 80lbs Injector Data.xls

I am asking this here because the previous thread ended with the conclusion that the only option was to buy new expensive injectors (around 700 USD here, thanks to taxes). In this thread, I got the impression that it might be possible to get a GEN 3 PCM to work with 80 lb injectors.

[Alvin]

There is nothing wrong with the 80's.. But they are a full generation behind what is out now for them. They do not run as clean for sure.

Did I read that you want more resolution in the spark table? If so.. an old hack with these things was to command different PE for boost, then remove timing in the spark PE adder for that new PE.