Sounds fair enough. i did not realize you were selling them here for that purpose.

But the question remains, does the ls1 indeed have a lean cylinder or two, in that case a flow matched set may not be in the best interest of the motor. I mean the intake manifold cannot be perfect? maybe it can be.

I bet those folks on the Hose (dry) might know which pistons burn the fastest But then again it could be attributed to time without first baselining the motor with matched injectors. GM probably doesn't bother, so a company like racetronix should take the ls1/ls6 and do some analysis for us and tell us if indeed there are any leaner cylinders, then a product to help compensate for poor airflow design in those particular intake designs might help.

I couldn't answer that for the ls1/ls6, haven't owned it long enough.

Hell maybe the ls1/ls6 has per cylinder trims for fuel to combat per cylinder KR. But that is only good till you kick those injectors to static.

 

We are unaware of any of our dealers who have taken the time to install EGT's with a Datalogger on a relatively stock LS1. This is something to look into though.

All said and done it is still better to start with a known commodity when tuning rather than a crapshoot of variables. Any good tech or engineer can tell you that.

 

definitely, would put you one up on the rest. If the ls1 has a weakness, which seems natural, look how damn big the intake is. Then its likely you understand the need to sell correctly flowing injectors to keep it even steven

Hope to see some results or opinions from someone someday. Tis a bitch to tune a motor when one cylinder is leaning out more than the rest, and you dont have a parameter to alter this in the firmware.

Btw can you email me some prices on your flow matched 4 cylinder sets (30#,42#) say if one wanted 5-10% in one cylinder. I do a bit of custom tuning for older vw's with batch fire, so you have piqued my interest. As you know batch fire sucks *** for uneven flow, tuning wise. Might need to recommend your parts to our customers.

 

Wow! More information == more confusion

Seriously thanks for the reply. This is good stuff.


This is all obvious. What is not obvious is whether the 30# SVO injectors for $220 from Summit are not matched, but the $300 ones from sponsors are. I had already guessed the labor involved and was dubious that matching would be $50 or even $80 labor cost. That leads me to believe that Summit has a smaller margin and has economies of scale than the sponsors and both sell the same unmatched injectors. I did not see 30# SVO injectors when I went to your site. Do you have them, and if so how much extra for matching?

Quote:

Originally Posted by Racetronix

Price is the #1 basis on which most people make their purchase when it comes to injectors as the merits of flow-matching is not widely known.

I would think that, in the case of unknown requirements, like the LS1, the benefit of flow matching is directly related to the scatter of the flow numbers. If you know apriori the special requirements of your engine/intake, you can get closer to perfect by matching injectors to cylinders. It is obvious to me that a 10% difference in flow numbers is a bad thing. That is approx. a 1.3 A/F ratio error.

Quote:

Originally Posted by Racetronix

Some vendors even go so far as to lie and tell customers that they are flow-matched from the factory. Flowed yes, flow-matched no! For Siemens and Delphi as long as they fall within +/-5% of their spec. out the door they go. This is a 10% spread!!!

This is what is scary. The spread should follow a bell shape curve, and 90% of the production should be withing +/- 1% or some such. But in any random batch, you could get one of the 5%ers even if you think you are getting matched injectors. I would guess that if they are blister packed with a FoMoCo logo, they are not matched in any case. But this is the reason I pursuing this thread rather than calling up vendors and asking them. I do not have access to a flow tester or EGT gear.

Quote:

Originally Posted by Racetronix

Documents are available which address the problems created by imbalanced injectors via ECM/PCM software algorithms.

I would think this is difficult in practice (without EGT feedback) and our LS1s are no capable of bandaiding injectors.

Quote:

Originally Posted by Racetronix

Hopefully more Speed Shops that cater to the domestic market will get with the program and start to educate their customers in this area.

Or if people read this thread. You are doing a pretty good job of education.

Quote:

Originally Posted by Racetronix

Accel and Holley have seen the future and now offer flow-matched injectors as part of their product line although their testing is no where as involved as smaller more specialized distributors. Remember, most MSD and Holley injectors are ball/seat Delphi ‘Multec 1’ models.

I have stayed away from Accel because I need high impedence injectors, I've heard that I should use Bosch style (pintle?) because the spray pattern is better for LS1s, I've heard that guys have had trouble getting Accell injectors to work right in an LS1, and the fact that offset tables are available for the 30# SVO injectors. Is any of this simply old wives tales?

 

http://www.rceng.com/

^^ GREAT INFO. Sorry if they are your competitor, but they tell alot of truths.

I've found in real life the lucas style injectors with the lighter pintles are better at high impendance high flow for idle control and low load. I guess has to do with the faster opening time. Low impedance folks don't have this problem as much since the injectors behave a little better.

However i've heard conversely at high pressure the lucas light pintle may have more difficulty closing.

How bout some more feedback racetronix. I've learned a bit from you guys already, and would definitely recommend you guys to my buyers (vag world) if you sell at a reasonable price custom sets of injectors.

High end Race systems allow per cylinder trim of fuel injection in sequential (fully) or semi mode. I think TEC3 may iirc, i may be wrong.

But if you don't have this ability to program the GM ECU to do so, then finding the weakness of the intake manifold would be key.

NOW listen to this one and tell me if i'm just blowing smoke: Why would you use direct port nitrous on the LS(1,6,x) intake, if the intake was perfect. Wouldn't you say the nitrous and fuel distribution of a single fogger gives perfectly even distribution or air (and fuel) to each cylinder? If so, then why do direct port (LSX?) setups exist.

This is kinda rhetorical: If there is a need for direct port injection, that means a single fogger or plate system doesn't allow even distribution to all cylinders, thus your need to figure out which cylinders run leaner and why, and sell injectors that could compensate for this.

That way you wouldn't have to tune the richer cylinders, richer than normal to keep the leaner cylinders from leaning out and burning a piston.

Mind you i'm just running these questions by ya'll for my own education, i could be totally wrong, i'm just throwing out questions. Maybe the l33t tuners and fuel guys can step in and explain truly how perfect the intake system of the ls1,6,x is..
and how they deal with the tuning of any imperfections per cylinder.

All it would take is one running getting too much air, and that poor single fogger system would torch a piston real quick right? Conversely an injector that is -10% less flow (unmatched) from gm could aggrevate the situation two fold say if you were spraying dry?

Keep the good info flowing..

 

OMG! I saw that and thought it couldn't be, but it apparently is! Russ Collins of multi-engine Honda drag bike fame! He or the guys he hired really knew their stuff back in that day!

 

Many PCM’s today do have the capability to make minor fueling adjustments on a cylinder by cylinder basis. This capability is mostly limited to part throttle conditions as the main consideration is emissions.

http://www.delphi.com/pdf/sae/1999-01-0546.PDF

Compared to many other motors the LS1 is pretty good when it comes to air distribution. The factory LS1 EV6 Bosch injector tends to exhibit better than average tolerances when compared to the older style Bosch pintle (Ford Motorsport) or Delphi (MSD/Holley) Multec ‘1’ ball/seat types. Keep in mind that there are three different EV6 type injectors that GM uses in the LS1/LS6 motors all of which are made by Bosch for Delphi. This is odd as Delphi has comparable product in the Multec Series II injector lineup? Since Racetronix is not a tuner shop but rather a manufacture/distributor we would require the involvement of one of our dealers to come up with the offset numbers required to compensate for the typical factory LS1 cylinder imbalances.



The Delphi / Lucas disc injectors do not have a pintle for controlling fuel flow. The disc injectors do have a faster opening time that most pintle injectors. Disc injectors do start to lean out at very high pressures but so do most pintle injectors. The question is how high is the operating pressure? GN owners run the disc 42’s probably more than any other injector out there at pressures upwards of 70PSI without any problems. If someone is looking to install a FMU for FI or a dry N2O application which jacks the fuel pressure upwards of 90PSI to compensate for undersized injectors then they are asking for trouble with any low impedance injector. The disc injectors are more resistant to moisture and alcohol-doped fuels thanks to their SS internal parts. Considering many HP car owners let their cars sit over the winter w/o pulling their injectors this is a welcome feature.



Depending on the type of injector the tolerance ‘bell curve’ can vary greatly. The ‘bell curve’ can also vary from lot to lot of the same injector.



Racetronix does not stock 30# injectors but we do have some LS1 injectors that are very close which come flow-matched. Keep in mind these ratings are at 300KPa/43.5PSI not 400KPa/58PSI. If there was enough demand for 30# flow-matched injectors then we might consider making them available.



Racetronix is an Accel dealer but we have had bad experience with some of their 32# and 48# injectors that were used in a customer’s Z06. After some tuning issues we tested the injectors which are advertised as being flow-matched within 1.5% only to find a 13% variation from the leanest to fattest injector. At the time of this problem we were informed of a recall but have not tried any new injectors since the problem was found and rectified. This happened apx. two years ago when the product line was first introduced.



In regards to your multi-port vs. single port fueling w/N2O question… This is like comparing MPFI to TBI. Keeping fuel droplets in suspension at low temps and under low manifold signal conditions is a problem. Perhaps this is why at the track carb motors can compete with N/A FI motors (WOT) but can’t achieve the same gas mileage or vehicle emissions. For example we had a customer competing in a road coarse circuit. At each race he would run out of fuel with his carb motor. He switched over to a FI system using a FAST PCM with WB02. He gained mid range HP due to better fueling & timing control at part-throttle. He was able to tune closer to the edge (more HP) and still maintain a degree of safety. At the end of the race he still had a few gallons of fuel to spare.



Russ at RC is one of the top injector gurus out there and is well respected in the industry. He has written many good articles on fuel injection. RC’s product is of excellent quality and some of the services they provide can not be found anywhere else in the industry

 

yeah i picked up some low mileage balanced rc-eng 30# lucas for $125 at the ford shop. dude needed money and i scored some badass injectors. amazing what you can find hanging at the ford shops when you got the cizzash. Used them on my vdubs though. Excellent quality idle for batched fire low comp motor

 

If you care about the difference between 13.0:1 and 12.8:1,
then you ought to care about a 10% injector flow spread.
Since the leanest injector is going to set your maximum
no-knock timing, and stuff like that.

Fortunately, mass-produced injector process quality will keep
injectors made in the same lot / day / plant grouped a lot
tighter than the spec implies. Most of the time.

So you would have a pretty reasonable chance that flow
matching will buy you jack squat.

It's the work involved in obtaining certainty that's expensive.
Some people will spend the 80 bucks for injectors that make
last-percent tuning a sensible proposition.

On another car I've bought a rack of junkyard injectors and
flowed them all, plus the ones on the car, and put back the
8 most-normal. Doing that new would cost you more in parts
and way more time than a set of 8 done for you. That's not
even counting the time & parts spent in building the tester.

 

This is an incorrect statement. It is common for Racetronix to get injectors that have a wide variance all within the same case / lot code.

Building your own flow-bench is not as easy as hooking up a pump and pulser circuit. There are MANY factors one must consider in order to have accurate measurements such as solvent temp, pressure, aeration, pulsation dampening, drive voltage, clamping etc.

 

your right, the rc-eng.com site tells exactly how the process is done, laser printing the spray patterns and all good ****. I'd still like to KNOW if the ls1/ls6 intake suffers from leanout on XX cylinders. Logic tells me if the air enters from one orifice its likely one cylinder or more might get more air than others.

Maybe those LSX folks can flow bench their product against the stock ls1/ls6 intake and give us advice. I hope they have a flow bench when they made that phatty intake. Matter of fact i might go email them now if they arent around here.

I've just emailed LSX folks with a copy of this thread so maybe than can tell us based on their experience if they choose to. If they reply with an email with valuable information i will post it. Hopefully in their design for a better intake they can inform us.

Knowledge is half the battle..

 

I'm not sure which statement you think is untrue.

What percentage of injectors do you find out-of-bed,
then? If you pick 8 out of a case, how -much- of the
time do you reject one of that group for >X% flow
mismatch? That's your odds.

Not -can- it happen, which we all know. What is the
percentage of time that flow-matched set tolerance
is actually better than random-box-of-8-from-SVO?
99%? 50%?

I'd say 75% rate of getting good enough out of the
box is a "reasonable chance", given the 30% price
premium, and would be interested to see what flow-
matching achieves relative to blind luck and standard
quality control. I'd probably buy the guaranteed ones
myself, but just itching to put some numbers to this
handwaving.

By the way, when you're only concerned with flow
matching, it -is- that easy to make a flow tester.
You don't need absolute accuracy, only repeatability.

Nobody would buy a contraption like mine but work,
it does. I could improve the electronics I guess.
The rest of it is junkyard Ford plumbing, pressure reg
and pulse damping on the Ford rail, can of gasoline
and a graduated cylinder. Rocket science, yeah bo'.

 

Quote:

Originally Posted by jimmyblue

I'm not sure which statement you think is untrue.

This is not the way it works. No injectors are rejected. They are all inventoried and grouped based on the same flow numbers. The injectors that

are farther from the median than most are grouped as well once there are enough to do so or sold as offset injectors. All injectors eventually find a home unless they are defective or outside of an acceptable range.

Quote:

Originally Posted by jimmyblue

Not -can- it happen, which we all know. What is the

I don't think anyone has sat down and done the math on this but looking at a recent 1500 piece lot of the same injector it would be highly unlikely someone would pull 8 injectors out that were within 1% of each other. Maybe Kreskin can? There are simply too many variables factoring in two dynamic tests and a static test. You make this sound like a Casino game where you are trying to calculate your odds in order to place a bet. If a crank manufacture said to you here are a lot of cranks on sale but a few hanging on the wall were machined out of spec enough to throw a bearing would you stand there and ask him how many he had made and approximately how many were bad in order to make your random selection? There is no sound logic to justify this type of buying decision other than the potential monetary savings but at what potential future cost?







Just by eyeballing this data here I would have to say that 70% of the injectors fall relatively even within +/- 3% of the median and the balance are within +/- 5%. The 1-3% range are pretty close qty wise so there is a better chance of getting injectors with a 1-6% spread but still a 30% chance of ending up with a qty that are in the 7-10% spread range. Numbers aside this is not a gambling game. Racetronix typically charges a $10.00 premium per flow-matched injector which is under the 30% premium you quoted.







How can you maintain consistency with your flow bench setup? Your readings will change from one test to the next.

The gauge has no resolution or level of accuracy so regulation is questionable. How do you compensate for solvent expansion with increase in temperature? How do you compensate or eliminate the air bubbles in the fuel? Is your injector power source tightly regulated or does it dip as DC goes up? Does your injector driver circuit provide a consistent output waveform?

 

I just test one injector until its delivered volume quits
changing (this meaning the electronics and the rest
of it have stabilized), test & log the rest of the group,
and retest the first. If the consistency's there, I call it
good.

Shade-tree, sure, but good enough to find the one
that isn't right.

 

yo arent svo 30# injectoer rated at a lower fuel presure the ours?

at are fuel pressure i think they are like 36# right?

 

30# @ 43.5PSI / 300KPa = 34.6# @ 58PSI / 400KPa

 

that sould be fine for me and for 220 you can beat it

 

how much injector sould i have though if im going to run close to 500 N/A

and in the future maybe a small shot?

 

Depends on your max RPM and BSFC.
Guestimate would be 37 or 42# injector @ 300KPa

 

max rpm would be 7000