E38 and Scaling for ID1000's

[HawkZ28]

I searched and have read and reread a bunch of threads and posts, several by some of our more experienced and trusted members here, but am still confused if I need to scale or not.

I have a 2011 Sierra/E38 that's running about 8-10 PSI through a procharger D1SC. I will be installing ID1000 injectors.

I'd read that the "later" E38's are clamped at 127lb/hr, and no scaling is required. When I input the IFR data from ID, it flatlines off the clamp from 508-768 kpa. I'm assuming I need to scale, or am I safe letting it flatline? I plan on installing a Walbro 450, but don't plan on going above stock fuel pressure, or above 12psi boost.

I appreciate any explanations as to why go one direction or another to help me learn. I'm trying to earn my "U" to replace the O's in tooner.

[blindsquirrel]

What are the conditions where the delta between your manifold pressure and fuel pressure will be able to get to more than 480 kPa? You would need fuel pressure higher than 58 PSI with MAP less than 80 kPa, at the same time... and it's usually not possible to do both those at the same time unless something is broken or designed wrong. Or you live in a universe with different physics than the one where planet earth is.

[Realizm]

I searched and have read and reread a bunch of threads and posts, several by some of our more experienced and trusted members here, but am still confused if I need to scale or not.

I have a 2011 Sierra/E38 that's running about 8-10 PSI through a procharger D1SC. I will be installing ID1000 injectors.

I'd read that the "later" E38's are clamped at 127lb/hr, and no scaling is required. When I input the IFR data from ID, it flatlines off the clamp from 508-768 kpa. I'm assuming I need to scale, or am I safe letting it flatline? I plan on installing a Walbro 450, but don't plan on going above stock fuel pressure, or above 12psi boost.

I appreciate any explanations as to why go one direction or another to help me learn. I'm trying to earn my "U" to replace the O's in tooner.

Hi, Hawk. I use the ID1050X and didn't need to scale. So far on 13-15 lbs boost I'm good. It does flatline on the higher end, but so far it has been fine since. Attached is my tune. E38 ECU from a 2011 C6 Grand Sport, D1sc on a 3.6" pulley. I hope it helps.

9-28-22-c6gs-O2 mV update - CTF.hpt

[HawkZ28]

What are the conditions where the delta between your manifold pressure and fuel pressure will be able to get to more than 480 kPa? You would need fuel pressure higher than 58 PSI with MAP less than 80 kPa, at the same time... and it's usually not possible to do both those at the same time unless something is broken or designed wrong. Or you live in a universe with different physics than the one where planet earth is.

If I'm understanding this correctly, I'd need to be well over 480kpa+ fuel pressure, and basically idling/grandpa cruising around town for both conditions (MAP 80kpa or below) to occur(?).

Since the pump, in my case, runs 300kpa in 'low', and 400kpa in 'high', I can disregard the upper range that I won't be running in.

[HawkZ28]

Hi, Hawk. I use the ID1050X and didn't need to scale. So far on 13-15 lbs boost I'm good. It does flatline on the higher end, but so far it has been fine since. Attached is my tune. E38 ECU from a 2011 C6 Grand Sport, D1sc on a 3.6" pulley. I hope it helps.

9-28-22-c6gs-O2 mV update - CTF.hpt

Appreciate it! I was going to order those but got a deal from SDPC I couldn't pass up on the ID1000's.

I know how much fun my truck was with just the D1SC and catback- that has to be a fun driver.

[blindsquirrel]

The delta is not using MAP, as that's an absolute value. Rail pressure is in gauge pressure (using normal atmosphere as relative zero). MAP uses absolute, or really-truly zero none-at-all pressure as zero. 480kPa Delta would be 58psi (400kPa) & 80kPa vacuum (gauge) (or 20kPa MAP (absolute)). A N/A engine at WOT or KOEO would be 58psi and 0kPa vacuum, for 400kPa Delta. A boosted engine with fixed 58psi and 14psi boost (100kPa gauge, 200kPa absolute) would be 300kPa Delta.

There are 3 types of pressure readings you can make. Absolute, which uses a perfect vacuum as the reference point, which is what the MAP reads. Gauge, which uses normal atmosphere as the reference point, which is what the rail pressure uses. And then differential pressure, which is solely the difference between one point (the injector inlet, in the rail) and another point (the injector outlet, in the intake runner), which is what the Delta uses. The Delta is gauge-absolute agnostic, it's only the difference between over here and over there.

[blindsquirrel]

What are the conditions where the delta between your manifold pressure and fuel pressure will be able to get to more than 480 kPa? You would need fuel pressure higher than 58 PSI with MAP less than 80 kPa, at the same time... and it's usually not possible to do both those at the same time unless something is broken or designed wrong. Or you live in a universe with different physics than the one where planet earth is.

This part right here...

with MAP less than 80 kPa

MISTAKE! That should be MAP less than 20kPa, or the same as 80kPa vacuum.

[HawkZ28]

This part right here...


MISTAKE! That should be MAP less than 20kPa, or the same as 80kPa vacuum.

The delta is not using MAP, as that's an absolute value. Rail pressure is in gauge pressure (using normal atmosphere as relative zero). MAP uses absolute, or really-truly zero none-at-all pressure as zero. 480kPa Delta would be 58psi (400kPa) & 80kPa vacuum (gauge) (or 20kPa MAP (absolute)). A N/A engine at WOT or KOEO would be 58psi and 0kPa vacuum, for 400kPa Delta. A boosted engine with fixed 58psi and 14psi boost (100kPa gauge, 200kPa absolute) would be 300kPa Delta.

There are 3 types of pressure readings you can make. Absolute, which uses a perfect vacuum as the reference point, which is what the MAP reads. Gauge, which uses normal atmosphere as the reference point, which is what the rail pressure uses. And then differential pressure, which is solely the difference between one point (the injector inlet, in the rail) and another point (the injector outlet, in the intake runner), which is what the Delta uses. The Delta is gauge-absolute agnostic, it's only the difference between over here and over there.

That helps a TON, and makes more sense now. Appreciate it.

When I read delta, I need to mutter quietely "difference" like I'm the Brick from Malcom in the Middle.

[HawkZ28]

Another question- I noticed there's differences between injector data listed on ID's website vs FIC (Clinic) website. Is one better than the other?

[blindsquirrel]

Most likely that would be because they are different injectors.

[Realizm]

Another question- I noticed there's differences between injector data listed on ID's website vs FIC (Clinic) website. Is one better than the other?

They are two different companies, different injectors. Is one better than the other? Hard to say, I'm sure both are fine. I trust Injector Dynamics, but I haven't heard anything bad about FIC. Looks like the FIC 1000's are about $880, the ID1050-XDS is $1075. That is a pretty big price difference for similar performance. BTW, the injectors are rated at 43.5 psi, our fuel systems run 58 psi so the ID1050-XDS would be 1229cc/117lb/hr and the FIC 1000's will be 1155cc/110lb/hr.

I notice the FIC's have a shorter injector min pulse, probably helps smaller engines for some people. I'm sure you'd be fine with either one of those injector brands. You could likely sell your old injectors to make some of the money back.

According to FIC's power calculator:

FIC 1000's @ 58 psi making 1155cc/110lb/hr, 95% duty cycle, on a supercharged engine:
E85
Horsepower supported @ crankshaft: 1350
Horsepower supported @ wheels: 1148
Gasoline
Horsepower supported @ crankshaft: 1755
Horsepower supported @ wheels: 1492

ID1050-XDS @ 58 psi making 1229cc/117lb/hr, 95% duty cycle, supercharged engine
E85
Horsepower supported @ crankshaft: 1437
Horsepower supported @ wheels: 1221
Gasoline
Horsepower supported @ crankshaft: 1868
Horsepower supported @ wheels: 1588

I'm guessing either brand should have plenty of headroom, and no need to scale anything yet, thankfully.

[HawkZ28]

They are two different companies, different injectors. Is one better than the other? Hard to say, I'm sure both are fine. I trust Injector Dynamics, but I haven't heard anything bad about FIC. Looks like the FIC 1000's are about $880, the ID1050-XDS is $1075. That is a pretty big price difference for similar performance. BTW, the injectors are rated at 43.5 psi, our fuel systems run 58 psi so the ID1050-XDS would be 1229cc/117lb/hr and the FIC 1000's will be 1155cc/110lb/hr.

I notice the FIC's have a shorter injector min pulse, probably helps smaller engines for some people. I'm sure you'd be fine with either one of those injector brands. You could likely sell your old injectors to make some of the money back.

According to FIC's power calculator:

FIC 1000's @ 58 psi making 1155cc/110lb/hr, 95% duty cycle, on a supercharged engine:
E85
Horsepower supported @ crankshaft: 1350
Horsepower supported @ wheels: 1148
Gasoline
Horsepower supported @ crankshaft: 1755
Horsepower supported @ wheels: 1492

ID1050-XDS @ 58 psi making 1229cc/117lb/hr, 95% duty cycle, supercharged engine
E85
Horsepower supported @ crankshaft: 1437
Horsepower supported @ wheels: 1221
Gasoline
Horsepower supported @ crankshaft: 1868
Horsepower supported @ wheels: 1588

I'm guessing either brand should have plenty of headroom, and no need to scale anything yet, thankfully.

Most likely that would be because they are different injectors.

Thank you both- I really screwed up and thought Clinic was a dealer for ID, and thought the injector data was for ID1000 injectors. After paying more attention, I realize it is in fact a different injector altogether.

Again, appreciate you tightening me up on everything!

[blindsquirrel]

Doesn't really matter for this application with huge injectors and only 10psi, but don't forget when doing the calculations that boost plus non-referenced fuel system cuts injector flow rate as boost increases. (decrease in flow is the same as an equal amount of reduction in rail pressure)

[UMSTuning]

So anyone in the know...is the calculation clamped at 127lb/hr or just the settings? like can we offset it with one of the multipliers or is it 127 max unless you scale?

[HawkZ28]

So anyone in the know...is the calculation clamped at 127lb/hr or just the settings? like can we offset it with one of the multipliers or is it 127 max unless you scale?

Clamped at 127lb/hr.

[UMSTuning]

Thanks!