Gauging interest on Custom Large Hi. Imp. Injectors

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Mar 3, 2003 | 02:09 PM

#21

Black LS1 T/A

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From: Raleigh, NC

Re: Gauging interest on Custom Large Hi. Imp. Injectors

One of the vendors answered my question on the other board:

<blockquote>quote:<hr />
All Delphi and Siemens injectors are tested at the factory to make sure they are within their manufacturing spec and that there are no duds.

The acceptable manufacturing tolerance for Siemens is 5%. This does not classify as flow-matched injectors. Flow matching is a value-added service provided only by the aftermarket and not by the manufacturers. A flow matched set is typically within 1.5% or less. Some vendors flow match their injectors statically (wide open) and some both statically and dynamically (opening and closing).

Jack
Racetronix
<hr /></blockquote>Go to the other board to get more info about the injectors. There are two people that I saw there that could get them to you.

Mar 3, 2003 | 02:47 PM

#22

smokinHawk

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From: Columbus, ohio

Re: Gauging interest on Custom Large Hi. Imp. Injectors

how much HP can these 55lbers support?

Mar 4, 2003 | 12:52 AM

#23

Black LS1 T/A

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From: Raleigh, NC

Re: Gauging interest on Custom Large Hi. Imp. Injectors

The 55#'ers are here!

I got the Injectors... each has a fuel aroma. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> Does that mean they were flow-matched? Or are injectors always subjected to fuel in some way when manufactured/otherwise tested?

Is it possible for me to get the spec sheet if they were? That would be helpful in tuning them.

Thanks. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Mar 5, 2003 | 12:08 AM

#24

Black LS1 T/A

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From: Raleigh, NC

Re: Gauging interest on Custom Large Hi. Imp. Injectors

Well, I got the 55#'ers in.

I did a quick adjust on the Inj Flow Rate table just for a baseline and I did a quick couple of WOT runs. (I've got some work to do with the LTFT's.)

I was commanding over 22 ms pulse widths (so I was already at 100% Duty Cycle with the 42's) and, at the dyno, could not keep A/F ratio below 12.1:1 by the time I reached 6300 RPMs. O2's started to nose-dive at that point as well, even though desired PW was increasing.

Now, at only 15 or 16 ms PW, I have more fuel than I did with the 42's. Matter of fact, I have to adjust my shift points downward again... I guess with the additional fuel in the upper RPMs, it rev'd quicker and spun more, even with the ET Streets! I banged the rev limter, which is set at 7000 RPM's! <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> (This cam is supposed to be good for 7500. But, I am targeting eventually taking it no higher than 7000 RPMs. If I can get the boost up and get power, I may only shift it around 6500. But, according to calculations with my torque and power curves, 7000 RPMs in 1-2 and 2-3 shift and 6800 RPMs in the 3-4 shift are my optimal shift points.)

If it doesn't rain too much this week, I hope to give some updates. Wish me well! <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Mar 7, 2003 | 07:38 PM

#25

superchargedZ

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From: San Diego, CA, USA

Re: Gauging interest on Custom Large Hi. Imp. Injectors

<blockquote>quote:<hr />Originally posted by Black LS1 T/A:
 Well, I got the 55#'ers in.

I did a quick adjust on the Inj Flow Rate table just for a baseline and I did a quick couple of WOT runs. (I've got some work to do with the LTFT's.)

I was commanding over 22 ms pulse widths (so I was already at 100% Duty Cycle with the 42's) and, at the dyno, could not keep A/F ratio below 12.1:1 by the time I reached 6300 RPMs. O2's started to nose-dive at that point as well, even though desired PW was increasing.

Now, at only 15 or 16 ms PW, I have more fuel than I did with the 42's. Matter of fact, I have to adjust my shift points downward again... I guess with the additional fuel in the upper RPMs, it rev'd quicker and spun more, even with the ET Streets! I banged the rev limter, which is set at 7000 RPM's! <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> (This cam is supposed to be good for 7500. But, I am targeting eventually taking it no higher than 7000 RPMs. If I can get the boost up and get power, I may only shift it around 6500. But, according to calculations with my torque and power curves, 7000 RPMs in 1-2 and 2-3 shift and 6800 RPMs in the 3-4 shift are my optimal shift points.)

If it doesn't rain too much this week, I hope to give some updates. Wish me well! <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> <hr /></blockquote>Do you still have the 42lb injectors? Righ now with my 38lb injectors I am at 22ms at 5500rpm...do you think it would be worthwhile to get the 42lb's or should I just go with the 50lb's?

Thanks for the help...

Jason

Mar 8, 2003 | 08:29 PM

#26

Black LS1 T/A

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From: Raleigh, NC

Re: Gauging interest on Custom Large Hi. Imp. Injectors

A much as I'd like to sell them to you, I don't feel the difference between 38 lb and 42 lb injectors is that significant. It would help some, but only marginally. 36 to 42 was a big enough spread for me to take that plunge, but you may be better off with a larger injector than 42's, if the 38's aren't working for you.

If someone convinces you they would still be helpful, let me know. I haven't put them up for sale yet.

Mar 23, 2003 | 03:54 PM

#27

Black LS1 T/A

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From: Raleigh, NC

Re: Gauging interest on Custom Large Hi. Imp. Injectors

Injector Offset table changes is an area I need to explore.

I bought the new Seimens Deka Hi-Z 55# injectors and, though I observe more fuel delivery, I had to lower Inj Flow Rate values below calculated values for the Injector Size, Test Pressure and Rail Fuel Pressure in order to achieve zero LTFT's at WOT and below zero during cruise and part throttle.

After tuning for non-positive values, it ranges from about -1.6 to -14.0 depending on idle, low throttle cruise or modest %TPA.

I get about -1.6 to 0.0 at around 15% or more throttle.
It varies about -14.5 to -4.5 or so at around 0.6 to, say, 10 %TPA.
At idle, it drifts upward until it reaches about -1.6.

When I tuned it with calculations closer to actual size/tested PSI/Rail FP, this wide range of values just made me bump Inj Flow Rates down further and further keep LTFT's from going positive.

The question:
Is there any intelligent way to go about calculating and adjusting Inj Offset for injectors that are othjer than stock?
I think I understand someone has such an animal for SVO 42's. But, what about a set of injectors like mine?
Could it possibly be better to use such a table as used for the 42's as being at least better than the stock Injector Offset and go from there as an example?

Thanks

Apr 15, 2003 | 10:27 AM

#28

Black LS1 T/A

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From: Raleigh, NC

Re: Gauging interest on Custom Large Hi. Imp. Injectors

OK... I'm having problems keeping zero to negative LTFT's with these injectors when I take the injector constant (Inj Flow Rate table) to about where they should be for the size injectors. Before, I just made the constants say they were smaller injectors in order to get zero/neg LTFT's.

But, now, with adequate fuel, when I do that, I run too rich, which would make me have to lower the RPM/PE table below stock. Is there some different Injector Offset for this injector that I should be accounting for?

I don't know what to do here. What is your opinion?

Thanks!