Blown Hawk

I'm about to put in 42# SVO injectors for the ATI Blower. Are there any walkthrough sites? What about sealant, locktight, anything like that? Do I need to prep the new injectors?

Also, where in LS1Edit do I need to alter to account for the larger injectors?

Any help you guys could give on installing injectors would be appreciated.

Thanks guys,
BH

1dirtyZ

iTrader: (1)

just use a petroliuom based gel / lubricant.
or just lightly coat the o-rings that are on the injectors with a light film of oil so they slide in the rail easier.

you will have to change the injector flow rate table. i have mine set at 6.5 gm/sec @ 0 kpa if i remember correctly for my svo 42's. do the conversion to make sure.

Blown Hawk

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by 1dirtyZ:
<strong> just use a petroliuom based gel / lubricant.
or just lightly coat the o-rings that are on the injectors with a light film of oil so they slide in the rail easier.

you will have to change the injector flow rate table. i have mine set at 6.5 gm/sec @ 0 kpa if i remember correctly for my svo 42's. do the conversion to make sure. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Will any petroliuom gel work, like Vasoline, or do I need an automotive type? As for the Edit changes, you mention a conversion, what are you referring to? Is it simply finding out what size my old injectors were, and then find out how much larger the new injectors are % wise? Then multiple that number over the whole table?

Does the difference between advertised flow and actual bench flow matter?

Thanks bro.

BH

Black LS1 T/A

Try this spreadsheet:

http://www.speeddemonmotorsports.com...ectorscale.xls

To get all your values to rescale correctly per KPA, just put in the Injector Rated Flow Rate, your Fuel Rail Pressure at WOT and your Injector Rated Fuel Pressure, and VOILA!, a rescaled set of values for your injector.

Note... I have had some guys disagree with the formula Chris Bennight uses to come up with his values, so it's your call. But, I can attest to the fact that it won't blow your engine. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> He has an email address if you have questions about it: chris@bennight.com

Now, you will need to drive it a while and check your LTrims. If they are positive, just go back to his spreadsheet and lower the ACTUAL fuel rail fuel pressure to get a rescaled set of values to put in. You could raise or lower you IFR table by a percentage, but this way, you get to see some useful info that may help you determine your injectors efficiency or idiot-check what you think your fuel pressure is at the rail.

Hope that helps. Someone critique what I just said to make sure I'm not stearing Blown Hawk wrong.

Good luck!

BLMONGOOSE

If you notice after you complete this table the flow rate numbers increas as the kpa increases.

What do you think happens when kpa increases and the flow rate number increases?
The car is leaning out as it inreases RPM's and Boost!! <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />

What I did is get the value at 25 kpa and set it all the way across the table. So when you hit the graph tab you will have a staight line all the way a cross.

Once you have this complete. You can start the car and drive it around. But I would take it to the dyno and get it tuned properly before you start getting on the gas. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Blown Hawk

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Black LS1 T/A:
<strong>To get all your values to rescale correctly per KPA, just put in the Injector Rated Flow Rate, your Fuel Rail Pressure at WOT and your Injector Rated Fuel Pressure, and VOILA!, a rescaled set of values for your injector.
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Thanks so much for that spreadsheet. Very helpful. But I have a question... Where do I find what my fuel rail pressure and injector rated fuel pressure values are? Or are the values entered in the spreadsheet constants and all I need to do is plug in 42 for Injector rated flow rate. Sorry to sound like such a newbie, but I got to start somewhere <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

BH

Black LS1 T/A

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Blown Hawk:
Thanks so much for that spreadsheet. Very helpful. But I have a question... Where do I find what my fuel rail pressure and injector rated fuel pressure values are? Or are the values entered in the spreadsheet constants and all I need to do is plug in 42 for Injector rated flow rate. Sorry to sound like such a newbie, but I got to start somewhere <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

BH </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Whatever injectors you buy, the spec should tell you what they are rated as and what they are tested at. You should have a fuel pressure guage to tell what the fuel pressure is at the rail.

I think Ford SVO 42's are tested at 39.6 pounds. Some say a bit different. Stock LS1 Pressure is 58#'s.

Blown Hawk

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Black LS1 T/A:
<strong> Whatever injectors you buy, the spec should tell you what they are rated as and what they are tested at. You should have a fuel pressure guage to tell what the fuel pressure is at the rail.

I think Ford SVO 42's are tested at 39.6 pounds. Some say a bit different. Stock LS1 Pressure is 58#'s. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I have the Injectors right here in front of me, but no spec sheet came with them. I could always call TByrne and ask them to send me one. Assuming your numbers are correct, would I need to plug in values as follows?

Injector Rated Flow Rate: 42
Your Fuel Rail Pressure: 58
Injector Rated Fuel Pressure: 39.6

? Or do I need to find out the flow rate of these injectors specifically at 58#s?

I have a fuel pressure gauge but was planning on installing that the same time I did the Boost guage, AFR Gauge, fuel injectors, inline fuel pump, and Blower. I can always put the gauges in early if that helps me fiugure these values out. Wouldn't looking at a fuel pressure be sort of an inaccurate way to decipher my fuel rail pressure? Could ATAP tell me this info?

One last thing I'm wondering. Would the addition of an inline fuel pump increase my furl pressure? Or will the fuel pressure regulator maintain the same 58#s and the inline pump is only there to make sure the Fuel Managment system can maintain that fuel pressure under heavy boost?

Sorry for all these questions, but you are really helping me understand all this stuff Black LS1 T/A. Thanks bro.

Mike

Black LS1 T/A

"Injector Rated Flow Rate: 42
Your Fuel Rail Pressure: 58
Injector Rated Fuel Pressure: 39.6"

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


"? Or do I need to find out the flow rate of these injectors specifically at 58#s?"

Nope. You need to put in the pressure they are tested at. Many other aftermarket injectors are tested at 3-Bar, which is 43.5 PSI.

"I have a fuel pressure gauge but was planning on installing that the same time I did the Boost guage, AFR Gauge, fuel injectors, inline fuel pump, and Blower. I can always put the gauges in early if that helps me fiugure these values out. Wouldn't looking at a fuel pressure be sort of an inaccurate way to decipher my fuel rail pressure? Could ATAP tell me this info?"

The fuel pressure guage is connected to the end of the fuel rail, so it better be the right number. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

You ABSOLUTELY MUST install your fuel pressure guage before you start running your car at boost. I consider it more important than the boost guage. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> You ALWAYS need to be assured you have adequate fuel going to your motor. <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> You don't have to install it before your FI is in. But, it may be nice to see how the guages read before-hand to understand the differences afterwards.

"One last thing I'm wondering. Would the addition of an inline fuel pump increase my furl pressure? Or will the fuel pressure regulator maintain the same 58#s and the inline pump is only there to make sure the Fuel Managment system can maintain that fuel pressure under heavy boost?"

If you don't change the fuel pressure regulator and only add an in-line pump, the regulator will try to maintain fuel pressure, assuming the pump is up to it.

"Sorry for all these questions, but you are really helping me understand all this stuff Black LS1 T/A. Thanks bro."

Not a prob, man... that's what we are here for!

Mike [/QB][/QUOTE]

2000silverbullet

iTrader: (5)

I just installed the same injectors and it seems that I have a vacum leak. Do the O rings that come with the svo 42# injectors need to be changed or do all LS1's run like crap untill they get tuned after this MOD? Anybody have an idea?

BLMONGOOSE

I believe the test pressure for the 42lbs is 300kpa which if you plug it into the formula in the spreadsheet should be 43.5lbs.

the values I used was:

Injector rated flow rate: 42
My fuel rail pressure: 60
Injector rated fuel presure: 43.512

Then I got the number at 25kpa= 6.7479 rounded it off to 6.75 and set this value across the board.

You got to make sure to lower your timing in high octane spark table or you car will go BOOM! <img border="0" alt="[cry]" title="" src="graemlins/gr_cry.gif" />

The spark table is allot tougher to modify than the fuel. I played around with mine but Iam not an expert at spark or timing so I dont want to be responsible for any damage you do to you car.

HINT.

Set all timing number including and above 4000RPM to 18. then between 1500 to 3600 multiply all values by .90. you should not have any values above 28 degrees of timing between 1500 to 3600RPMs.

After you do this you can start you car and monitor it with ATAP. If you hear any knocking or pinging or see KR while you drive the car lower the timing some more.

DONT DRIVE HARD TILL YOU GET THE CAR TUNED BY A PROFESSIONAL ON A DYNO!!!

Godd luck. I hope this helps.

Blown Hawk

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by BLMONGOOSE:
<strong> I believe the test pressure for the 42lbs is 300kpa which if you plug it into the formula in the spreadsheet should be 43.5lbs.

the values I used was:

Injector rated flow rate: 42
My fuel rail pressure: 60
Injector rated fuel presure: 43.512

Then I got the number at 25kpa= 6.7479 rounded it off to 6.75 and set this value across the board.

You got to make sure to lower your timing in high octane spark table or you car will go BOOM! <img border="0" alt="[cry]" title="" src="graemlins/gr_cry.gif" />

The spark table is allot tougher to modify than the fuel. I played around with mine but Iam not an expert at spark or timing so I dont want to be responsible for any damage you do to you car.

HINT.

Set all timing number including and above 4000RPM to 18. then between 1500 to 3600 multiply all values by .90. you should not have any values above 28 degrees of timing between 1500 to 3600RPMs.

After you do this you can start you car and monitor it with ATAP. If you hear any knocking or pinging or see KR while you drive the car lower the timing some more.

DONT DRIVE HARD TILL YOU GET THE CAR TUNED BY A PROFESSIONAL ON A DYNO!!!

Godd luck. I hope this helps. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">OK what are the advantages/disadvantages of going with your system, using a constant value, versus Black LS1 T/A's system of having the value increase as load increases? Why did you choose the value at 25 kpa?

I'm definitely not gonna get on it till it gets on a dyno. But I'm the only prefessional that's gonna tool with the tuning, unless you guys think that's a colassaly bad idea.

As I see it there's three areas in LS1Edit that need to be altered to account for a new blower:

-Injector Flow

-Timing

-Air/Fuel Ratio

You guys agree? I plan on having an iron clad plan before slapping that blower on <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

BH

BLMONGOOSE

I believe using the constant value is safer. Because as the injector flow rate numbers increase the car runs leaner. Why would you want to run leaner at higher RPM and under more boost????

Using the constant value will assure that the car will not go lean as you increase boost and RPM's. I used the 25kpa value because that is the value that the car runs on partial throttle.

Hint: To make it run richer you should adjust the fuel enrichment vs. RPM tab in LS1 Edit.

There is nothing wrong with the spreadsheet the blackls1T/A recomends to use. But that is a starting point. I my self used that same graph to start tuning my car. And after some research and calls to different tuners I was told to leave it at a constant value?

My advise will put you tuning closer to what you need to properly run your car.

BLMONGOOSE

Any body else have any thoughts about leaving the injector flow rate constant. lets help out Blown Hawlk out a bit. I believe he is a little weary about taking my advise.

You guys with more experience have any comments on my advise?

cablebandit

iTrader: (37)

I left mine constant but only because i was using a rising rate regulator that raises fuel pressure 1 psi per psi of boost. That essentially equals a zero change in fuel pressure no matter how much boost you run. Also....my regulator LOWERED fuel pressure while I was cruising and showing a vaccuum. if you do not have a regulator that is boost AND vacuum referenced, you can not enter the same number all the way acroos the ls1edit injector table.
My number was 5.71 using a 99 vette stock Maf and SVO 423 injectors. This gave me 0 to -3.0 ltrims and was just a little rich up top. You definitely need a fuel pressure gauge.

DaveSchott

iTrader: (5)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by BLMONGOOSE:
<strong> Any body else have any thoughts about leaving the injector flow rate constant. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Y'all did see this, right ==> http://ls1edit.slowcar.net/tuning.html

You can't do much beyond making the car run right at part throttle without feedback on parameters such as LTrim and knock retard, O2, etc.

After plugging in SVO 42's it was easy to get my car behaving properly at part throttle. First step before I turned the key was to lower fuel pressure back to a sane level (a tuner set it to 70 pounds - don't ask). Since the stock system was designed to run around 60, I set the fp to about 56-58. Then, I started car up and used ATAP to monitor Ltrims, and as expected were way rich. So I used a multiplier to get them down near zero.

Now as far as using a constant in the table vs a scaled value, if you have a referenced regulator the conventional wisdom is to put in a flat value and let the regulator add fuel? whatever. at part throttle, the pcm dynamically corrects for errors in fueling up to 25%, so if you get close to 0 at most ranges its fine. The issue is the transition to open loop, or WOT. I've read here that you want Ltrim slightly negative or zero so the Ltrim value is not thrown in to WOT along with the PE values.

Check out the tuning guide link.

Blown Hawk

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by BLMONGOOSE:
<strong> I believe using the constant value is safer. Because as the injector flow rate numbers increase the car runs leaner. Why would you want to run leaner at higher RPM and under more boost????
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Maybe I just don't understand what the Injector Flow Rate table is controlling. By it's name I would assume as the flow rate increases more fuel is dumped into the cylnders as load rises. I'm not really sure how Load and RPM work together. But if I have a constant flow at 25 kpa, then once I'm above 25 I'm getting less flow than if my values increased. So would this essentially lean me out even more? This is my fear. If you could explain how I'm wrong or how your method prevents a lean state, that would be really helpful.

Mike

BLMONGOOSE

Its an inverse graph, As the number you input increases it send less flow to the injector.

I learned this the hard way. After I installed my 42# I started the car without adjusting this table the car ran like crap for about 2 minutes then my plugs got all fouled up and it shut off on me. So when I went into LS1 edit, if I remember correctly the number started at 4.XX started increasing value as kpa increased.

How did I get the 42# to give less gas, I increased the the number to 6.75. Now why would I want to end up with a 7.XX at 65kpa or higher when the engine is under heavy load and needing the most fuel? Thats why I use a constant value.

I tried doing an inverse graph but that didnt work either because I made the car too rich at high RPM's. With the injector and power enrichment working together the car was way too rich. I actually had someone tell me I had fire coming out of my exhaust pipes under WOT. And after a WOT run I could smell gas and it was coming from my exhaust pipes.

Blackbird

I like Cable's way and have done the same.

Rising rate regulator is the only way to go.

Makes tuning soooo much easier and consistant IMHO.

Black LS1 T/A

I'm going to make two arguments, and you guys tell me if I'm thinking wrong:

1.

IAW the LS1-Edit Document, "If you change the fuel pressure, you can calculate the new injector constant use this formula:

RatingNew = (sqrt (PressureNew/ PressureOld)) * RatingOld"

In the Inj Flow Rate table, injector constant is used because the LS1 does not have a manifold vacuum regulated fuel pressure. So, as manifold vacuum changes (and rail pressure stays constant) the pressure drop across the injector changes, so the injector flow/constant itself changes.

The Injector Flow Rate in Grams per second, is a function of the intake manifold Vacuum in Kpa and is matched to the flow rate of your injector.

If you put in a bigger fuel injector than stock, theoretically you increase the gm/sec per kpa to inform the computer of the difference in the injector size (it will use this constant to compute Fuel Flow Rates per kpa).

2.

That is a different train of thought from, say, why change the values to adjust LTrims or change the A/F Ratio.

Let's say the larger injectors you have are not supplying enough fuel.
The logic is, you make the computer think the injector is smaller than it is, causing it to command a rate of fuel flow that exceeds what the injector would normally flow, based on the injector pulse width commanded by the computer.

So, decrease the IFR values per kpa, you will make the computer think you have a smaller injector, and it commands more fuel based on the injector size you lied to it about.

A Multiplier value per RPM in the RPM/PE table supplements the Inj Flow Rate table fuel flow when you are at WOT.

I would think GM had a reason for scaling the Inj Flow Rate table the way they did, so I don't think I'll make it flat until someone comes up with a compelling rationale as to why I should, when it is the RPM/PE table's function to do that.

If my thinking is whack, please... somebody set me straight. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />