Ok new to working with VCM HPT and new to tuning. I have mechanical auto diesel certificate (not a licenced mechanic) so I know something about cars and am coachable...LOL

here is what I am doing. Getting the car ready for 60lbs injectors and currently setting up my tune. IE - bigger injectors, delete rear 02, stuff like that. so he is my next hurtle I need help with.

I have calculated the G/Sec I wanted in the injector flow rate table. problem encountered was the the PCM table has a max value of 8 that you can put in so I recalculate the table of what I wanted and put in values based on 8 being the max. this is what I came up with.

New values for flowrate rate table for 60lbs/rated with 43.5 fuel PSI

7.303 7.381 7.458 7.548 7.622 7.697 7.771 7.856 7.929 8.000 8.071 8.154 8.224 8.293 8.362 8.441 8.508
8.575 8.642 8.719 8.784 8.849 8.924 8.988 9.051 9.114 9.187 9.249 9.310 9.372 9.443 9.503 9.563

New values that can be put into table with 8 being max value.

60lbs with down pipe and 2.6.hpt
Injector Flow Rate vs. KPA VAC
6.110 6.175 6.239 6.314 6.377 6.439 6.501 6.572 6.6330 6.693 6.752 6.821 6.880 6.938 6.995 7.061 7.118
7.174 7.229 7.294 7.348 7.403 7.465 7.519 7.572 7.624 7.685 7.737 7.789 7.840 7.899 7.949 8.000

just kept it linear.

now how do I compensate for the difference? Injector offset (offset vs. volts vs. map)?
or do I do anything? that would not seem right to me....but.

 

I'm not sure how you would go about doing that. I used the normal methom for mine. I'll email you my 60lb, 2.6" tune if you want to compare. It's pretty fine tuned on my car.

 

normal method huh..... This is how I have been guided so far from the HPT forum. I am very interested as to what you are referring as the normal method.

please send me your tune. PM sent.

 

Sorry, didn't get your PM

 

I've wanted to know how these magic 60lbs injector numbers keep coming up. Can you post up how you calculated them?

Nate

 

I used a spread sheet that converts it. Then I used math to make it linear to the maximum 8. I have not gone through the complete spread sheet but it does what ever injectors you have and converts it from stock. it will do it for other vehicles as well. I cant remember exactly where I got it from on HPTUNERS but it is on there.

Why, do you not believe the values? in comparison to stock tune and GMS2 and the 60lbs injector #'s I found it looked to be accurate. the injectors are like 69lbs/hr at 58psi fuel pressure as they are rated for 60 at 43.5psi.

are they wrong? whats up.

 

I had to set mine to all 8 until -64 kpa. then rescale the maf table to compensate,
7.30322 7.38110 7.45813 7.54700 7.62231 7.69702 7.77087 7.85632 7.92871 7.99988 7.99988 7.99988 7.99988 7.99988 7.99988 7.99988 7.99988 7.99988 7.99988 7.99988 7.99988 7.99988 7.99988 7.99988 7.99988 7.99988 7.99988 7.99988 7.99988 7.99988 7.99988 7.99988 7.99988

I think your numbers in the boosted section are low on the 2nd table.If I was you I would set all the ones to 8 that were over the max and then use the other #'s after that. I think our fuel press is like 58 psi

 

NO, i believe you, cept it seems that everybody gets little different numbers. I have not yet seen this spreadsheet, so when i don't understand something 100% I want to know how it works. Crap...i can't find the spread sheet on hpt yet.

Nate

 

well from what I understand it is not that critical as long as it is linear the easier to fine tune. if it is not it can still be done. I just looked at a tune that had a linear curve up to about -30 KPA and then it was set to 8 from there in every field. you could theorectically put 8 in all fields and still tune it based on that but that is difficult as only one section of the 35 would be close to what you need for the injectors. I made it linear so I can custom tune based on a real curve. percentage wise each setting will need to be increased. it will work out. and another thing that I am understanding now is that I have not found anyone who has used the injector offset feature to my knowledge.

later.

 

ok. Still waiting for that spreadsheet, but its beginning to make more sense. As for the injector offset feature..i have no idea why/how to use/set it up..and if it would be useful.

Nate

 

Make the last number in the table an 8. Then figure out what the last number in the table should actually be. Say 5.52 + 76% for the 60's. Then figure out the difference between the two. That number is the % for your flowrate modifier. Then 8/(stock flow rate variable) = what gets added percentage wise to all the numbers under 8 in the last column.

 

or you can just compensate in the PE table

 

PM me your email address, I'll help ya out with a comparison tune

 

wow, im going to hate life when i do the 50's

 

well I compensated alright but it runs still rich but not to bad. I have surging at an idle sometimes that seemed to get worse when putting the flowrate modifier to 1.19 across the board. LOL

but it is working out