60lb Inj. Problem

[redhardsupra]

SPA as in Short Pulse Adder

[SJSchafer]

Yea, it is perfect. The problem is that you can set the MAF cells in the short PW areas as low as you want and still be pig rich. That's why I want to filter out everything below about 2 ms and get the MAF in line there. From there, we do the necessary math to exptrapolate what the MAF should be in the areas of MAF that are only effected by low PWs. Once that is done, we have a known MAF and offset. Any errors are SPA related. Tune the adders untill we get 14.7. These adder numbers will not by technically correct, but necessary for most people to be able to idle at 14.7 and not dump fuel during decel.

Right now I am idling at over 1ms PW and decelerating at over .9. The lowest decel I get is .796 at 3800 rpm and 15kPa. This is because the correct adder numbers will not let the PWs go low enough. I can cut a cell value in half and still get the same AFR in that cell.

[RWTD]

LOL, that's some work for sure. Have you considered going to a return style based system, so you can get the vacuum/boost reference regulation?

[RWTD]

Also, what are you doing to get around the IFR limit? If you aren't, I would suggest you scale down the necessary tables/scalars in order to keep from having to rape your injector values.

Also, it's possible that if you scale that you should also scale the Short Pulse table, based on what GB stated to me in private discussion.

[SJSchafer]

As for the IFR limit, I scaled the number back by 1.25% and used the modifer to broing it back to where it needs to be. I may actually go to a return style, but most people won't do that. I want a tune that will work for everyone. Here is my plan:

Right now the problem is that I have a couple of unknowns. I have my injectors coming back from Paul Yaw and the numbers to go with them. I decided that I am going to throw the 42s back in and tune the MAF and VE with those and my stage 2 pulley. My car should handle the 42s fine at low PWs. Once I have a known MAF and VE, I will put the 60s back in and tune the adder. It will be much easier to tune the adders with a known MAF values. Then I'll take a look at the VE table. Once all that is done to my satisfaction, I'll throw my 2.8 in and away I go.

I am so looking forward to getting past fuel and getting on to timing!! Right now I have perfect idle and no hunting except occasionally at cold start. A few errors besides that, but not a lot. Mostly a little rich at .800-.900ms and some lean spots down below .700ms.

[RWTD]

Hmmm, I just found another post that scaling the Modifier table will not work. See here:

http://www.hptuners.com/forum/showth...266#post107266

Read his post #19, as well.

However, in that same thread, it seems that it was tested to work on a 4-cyl setup. Can you verify?

[SJSchafer]

Hmmm, I just found another post that scaling the Modifier table will not work. See here:

http://www.hptuners.com/forum/showth...266#post107266

Read his post #19, as well.

However, in that same thread, it seems that it was tested to work on a 4-cyl setup. Can you verify?

My answer:

http://www.hptuners.com/forum/showth...629#post109629

[RWTD]

My answer:

http://www.hptuners.com/forum/showth...629#post109629

I replied.

[SJSchafer]

I replied.

As did I to you.

[BLOWNZO6]

***Updated 11-15-2007 - Changed the Minimum Pulsewidth data I previously gave, and removed comments about zeroing out the short pulse adders. Also, see my post #165 within this thread for a more detailed explanation, as well as some important information!***

Here's some data we use on the Fords for the SD 60s (aka 62.7# at 43.5 psi, aka 72.39 at 58 psi):

Minimum Pulsewidth:

0.949859619140625

Injector Compensation for Battery Voltage:

VOLT    PW ms
15.99	0.33886
15	0.33886
14	0.41210
13	0.48925
12	0.59082
11	0.74121
10	0.93359
8	1.44628
6	2.54101
0	2.54101
0	2.54101
0	2.54101

Use the interpolation command to fill in the values between those voltage ranges.

As an example, I took a 2000 Silverado 5.3 file and figured in the correct values for the table based on the above data. Due to minimum value requirements on the GM pcms, the values won't match up exact, but I made them as close as possible. And, no, I haven't tested this out yet, but I'm trying to get Kenny (BigKID) to do just that as I type this, LOL!

Min Injector Pulse:

RPM        	0	400	800	1200	1600	2000	2400	2800	3200	3600	4000	4400	4800	5200	5600	6000	6400	6800	7200	7600	8000
Min InjPW	0.95745	0.95745	0.95745	0.95745	0.95745	0.95745	0.95745	0.95745	0.95745	0.95745	0.95745	0.95745	0.95745	0.95745	0.95745	0.95745	0.95745	0.95745	0.95745	0.95745	0.95745

Offset vs. Volts vs. VAC:

This particular vehicle has a regulated system, FYI, hence the same values at all the various vacuum ranges.

	0	5	10	15	20	25	30	35	40	45	50	55	60	65	70	75	80
4.5	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826
5.0	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826
5.5	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826
6.0	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826	2.54826
6.5	2.27359	2.27359	2.27359	2.27359	2.27359	2.27359	2.27359	2.27359	2.27359	2.27359	2.27359	2.27359	2.27359	2.27359	2.27359	2.27359	2.27359
7.0	1.99893	1.99893	1.99893	1.99893	1.99893	1.99893	1.99893	1.99893	1.99893	1.99893	1.99893	1.99893	1.99893	1.99893	1.99893	1.99893	1.99893
7.5	1.61746	1.61746	1.61746	1.61746	1.61746	1.61746	1.61746	1.61746	1.61746	1.61746	1.61746	1.61746	1.61746	1.61746	1.61746	1.61746	1.61746
8.0	1.44961	1.44961	1.44961	1.44961	1.44961	1.44961	1.44961	1.44961	1.44961	1.44961	1.44961	1.44961	1.44961	1.44961	1.44961	1.44961	1.44961
8.5	1.31228	1.31228	1.31228	1.31228	1.31228	1.31228	1.31228	1.31228	1.31228	1.31228	1.31228	1.31228	1.31228	1.31228	1.31228	1.31228	1.31228
9.0	1.19020	1.19020	1.19020	1.19020	1.19020	1.19020	1.19020	1.19020	1.19020	1.19020	1.19020	1.19020	1.19020	1.19020	1.19020	1.19020	1.19020
9.5	1.05287	1.05287	1.05287	1.05287	1.05287	1.05287	1.05287	1.05287	1.05287	1.05287	1.05287	1.05287	1.05287	1.05287	1.05287	1.05287	1.05287
10.0	0.93080	0.93080	0.93080	0.93080	0.93080	0.93080	0.93080	0.93080	0.93080	0.93080	0.93080	0.93080	0.93080	0.93080	0.93080	0.93080	0.93080
10.5	0.83925	0.83925	0.83925	0.83925	0.83925	0.83925	0.83925	0.83925	0.83925	0.83925	0.83925	0.83925	0.83925	0.83925	0.83925	0.83925	0.83925
11.0	0.74769	0.74769	0.74769	0.74769	0.74769	0.74769	0.74769	0.74769	0.74769	0.74769	0.74769	0.74769	0.74769	0.74769	0.74769	0.74769	0.74769
11.5	0.67140	0.67140	0.67140	0.67140	0.67140	0.67140	0.67140	0.67140	0.67140	0.67140	0.67140	0.67140	0.67140	0.67140	0.67140	0.67140	0.67140
12.0	0.59510	0.59510	0.59510	0.59510	0.59510	0.59510	0.59510	0.59510	0.59510	0.59510	0.59510	0.59510	0.59510	0.59510	0.59510	0.59510	0.59510
12.5	0.53407	0.53407	0.53407	0.53407	0.53407	0.53407	0.53407	0.53407	0.53407	0.53407	0.53407	0.53407	0.53407	0.53407	0.53407	0.53407	0.53407
13.0	0.48829	0.48829	0.48829	0.48829	0.48829	0.48829	0.48829	0.48829	0.48829	0.48829	0.48829	0.48829	0.48829	0.48829	0.48829	0.48829	0.48829
13.5	0.44251	0.44251	0.44251	0.44251	0.44251	0.44251	0.44251	0.44251	0.44251	0.44251	0.44251	0.44251	0.44251	0.44251	0.44251	0.44251	0.44251
14.0	0.41199	0.41199	0.41199	0.41199	0.41199	0.41199	0.41199	0.41199	0.41199	0.41199	0.41199	0.41199	0.41199	0.41199	0.41199	0.41199	0.41199
14.5	0.36622	0.36622	0.36622	0.36622	0.36622	0.36622	0.36622	0.36622	0.36622	0.36622	0.36622	0.36622	0.36622	0.36622	0.36622	0.36622	0.36622
15.0	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570
15.5	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570
16.0	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570
16.5	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570
17.0	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570
17.5	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570
18.0	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570	0.33570

This should be a bit of help for everyone.

Just wanted to give a thanks for this information.
I plugged it in on a 427 TT car I am tuning and it seems to work well.

Just wanted to give you some feedback. I have another TT car that I am going to be doing that is a stock cube, stock bottom end, will be interesting to try it out on that.

Thanks again!

[SJSchafer]

Keep in mind that those offsets change with different rail pressures. While those numbers may work for one fuel rail pressure, they may be too high or too low for another.

Also the table above is with a regulator. So we would need to know the pressure at at least one location in the map.

[BLOWNZO6]

Keep in mind that those offsets change with different rail pressures. While those numbers may work for one fuel rail pressure, they may be too high or too low for another.

Also the table above is with a regulator. So we would need to know the pressure at at least one location in the map.

Maybe I missed it but what rail pressure were you assuming here?

[SJSchafer]

Not assuming a thing. Just that offsets change with pressure( which is a fact rather than an assumption). I do not believe that the offsets given were ever specified for a particular rail pressure, so I just want to make sure that before people just go using those numbers thinking that they will fix everything, they know that they should get some specifics around the psi at the fuel rail. If you want to give me your pressure, I will tell you what the offset should be. I just need to do some simple math. If you have a regulated system, the pressure at a certain level will do just fine.

[BLOWNZO6]

Not assuming a thing. Just that offsets change with pressure( which is a fact rather than an assumption). I do not believe that the offsets given were ever specified for a particular rail pressure, so I just want to make sure that before people just go using those numbers thinking that they will fix everything, they know that they should get some specifics around the psi at the fuel rail. If you want to give me your pressure, I will tell you what the offset should be. I just need to do some simple math. If you have a regulated system, the pressure at a certain level will do just fine.

Can you share the sheet you are doing the calc with... I just like to understand the actual data and how it was derived, not just for someone to throw me numbers?

My system is referenced and the pressure at idle is 48psi.

Thanks for the follow up.

[SJSchafer]

Can you share the sheet you are doing the calc with... I just like to understand the actual data and how it was derived, not just for someone to throw me numbers?

My system is referenced and the pressure at idle is 48psi.

Thanks for the follow up.

Not a problem. I have the actual offset values for those injectors tested at 58psi for everything from 80kPa VAC to -120kPa VAC. If I remember correctly 10 psi is about 60 something kPa, so I just need to send you the right row. Unfortunately, my laptop is at home today, but I will get you those numbers this weekend, if that's cool. Keep in mind, that you still need to figure the low PW adders. I have a set of adders that are being verified as we speek.

BTW - I need to know where you idle (kPa-wise) or your pressure at barametric.

[code4]

Can you share the sheet you are doing the calc with... I just like to understand the actual data and how it was derived, not just for someone to throw me numbers?

My system is referenced and the pressure at idle is 48psi.

Thanks for the follow up.

Would be so kind as to send it my way too?

I run 58 base & idle at 51 psi on a referenced system.

[SJSchafer]

Sure, That's easy. I just copy the -1kPa row from mine.

[BLOWNZO6]

Not a problem. I have the actual offset values for those injectors tested at 58psi for everything from 80kPa VAC to -120kPa VAC. If I remember correctly 10 psi is about 60 something kPa, so I just need to send you the right row. Unfortunately, my laptop is at home today, but I will get you those numbers this weekend, if that's cool. Keep in mind, that you still need to figure the low PW adders. I have a set of adders that are being verified as we speek.

BTW - I need to know where you idle (kPa-wise) or your pressure at barametric.

The car idles right at 52

[SJSchafer]

The car idles right at 52

Cool. 48 psi at 52 kPa MAP. I'll get on it this weekend.

[BLOWNZO6]

Cool. 48 psi at 52 kPa MAP. I'll get on it this weekend.

Thanks I will probably end up with more base pressure after the dyno yesterday, that is why I was asking about the actual calculation.

Thanks for your help.