MY99TAWS6

iTrader: (3)

Can anyone give me the ifr values for my new 120 injectors that got from Lonnie at a few different fuel pressures .I have boost referenced reg so know its just one value you put across the table. I will likely be running 40psi or so but might run 58psi for now as running low boost for lkely this season. Car is already scary fast and traction is hard to come by.

I have HP tuners. I can't run that spreadsheet for some reason have tried and tried they have on hptuners site.I need to get the car running shortly.

So would appreciate if someone can crunch the numbers for me for say 40psi, 43.5 psi and 58psi.

Here are the injectors specs.
http://www.racetronix.com/INJL120.html

MY99TAWS6

iTrader: (3)

I got buddy to give me values from the hptuners spreadsheet. His computer can run them. I also found program on hptuners editor but it gives weird numbers for the 120s compared to that spreadsheet.

Lonnies Performance

iTrader: (16)

Remember to recalculate the flow numbers to correlate with the reduced fuel pressure you are running. 35# base pressure is closer to 106# with this injector.

This is a good suggestion for those running big boost & high fuel flows.

With a big enough injector, you can reduce your base pressure so at high boost the car does not have a huge boost referenced pressure value. It is easier on the pumps when doing this & can help the idle quality.

MY99TAWS6

iTrader: (3)

My nitrous has warning in manual that shouldn't go under 55 psi base. The kit is ls1 specific and ls1 stock fuel pressure is 58psi. So not sure what efffect trying to run say 40 is going to have on the kit. I will talk to zex about it .For now going to run 58psi and not likely every have boost past 15psi. Which is 73psi total . Thought read the walbro pumps can go to 85psi ??? These are walbro 255 or what again? Talon guys run their walbro 255 to like 70 or more psi frequently with no problems. running like 95 pound injectors at 30 or 35 psi.

I would like to run lower fuel pressure but not sure can with the spray now.? And if the single pump is pushed too hard at say 73psi then maybe need to run both simultaneously not have the second one on the hobbs switch?

Lonnies Performance

iTrader: (16)

You need to fix your nitrous system instead of compromising everything else in the fuel system.

Keep in mind, your injectors are rather large, so you can afford to lower the base pressure.

Second, although the pumps are capable of high pressure, the flow of any pump drops off as pressure is increased. Running a 120# inj. at 58psi base is equivalent to a 140# injector.... not necessary for your car. You will get the most out of the system if you keep the max pressure around 60psi.

This has nothing to do with staging the pumps either.... leave the hobbs switch intact.

You should start at a lower pressure so you retain the better idle characteristics (as well as boost reference) & get the most out of your setup.

Call you nitrous manufacturer & get the correct fuel jets, or....
Since there is a 16% difference in your flow based on 40 vs 58psi, you could run say a fuel jet from your kit rated at 100hp & a nitrous jet rated for 85hp & get the correct A/F ratio.

Call me if you need help...

MY99TAWS6

iTrader: (3)

So you think the only difference running say 45 psi base instead of the 55 recommended minimum on the nitrous is that would need to change fuel and nitrous jets to compensate. So it don't have to be certain base pressure to trigger solenoids or anything like that. ? I will talk to zex or you can look at the jetting and figure out which to use??
The instructions for the kit are on the net with jet sizes listed.
Its 82032 kit. The nozzle jets remain the same for like 75,125,175 shot and only change for the bigger 200,250 and 300 shots. The distribution blocks of course change with the different hp ratings.I wanted to run around 125 shot I think although do have fully done up engine so mabye 175 or 200 is no big deal. Still seemed easier to run say 15psi on the turbos and get say 850rwhp and then use the nitrous to get closer to say 1000rwhp.Rather than run a bigger nitrous shot and less boost? Boost is also cheaper than using up nitrous.

So I should have better idle at say 45psi than 58? I thought low impedence were known to run nice at pretty much any fuel pressure.? Would I gain flow by running the two pumps continuously rather than having just the one come in under boost? They seem pretty quiet so that isn't really a factor or would that mean too much flow at idle or something?

Sorry still a bit confused. Anyway the kit looks nice lonnie and should have the car fired up next day or two. Just working on my 3bar start up tune right now.

Lonnies Performance

iTrader: (16)

Low impedence injectors do respond faster & therefore will allow better idle characteristics, but you must remember you are running a huge injector. Since a larger injector has to be open less time to provide the same amount of fuel than a smaller one, you get to a point that the pulse width needed is shorter than the opening time. This is where you have problems, as you either get no fuel or too much & cannot control the mixture.

My analogy here is like trying to drink out of a fire hydrant like a water fountain. It is either off, or you have too much.

A lower pressure makes the injector smaller & therefore easier to control.

As for staging the pumps, you run 2 only when needed. Running them continuously will add unnecessary heat to the fuel & increase the load on the charging system. There is absolutely no benefit to running them continuously. If this feature was not needed, I would not provide it.

As for nitrous, remember their ratings will be lower than you actually see as forced induction cars gain more power on the bottle. Start low & work your way up.

Call Zex & get the distribution jets for the 82062 kit & look at that instruction manual online. You will see how the fuel jets are increased for 40# fuel pressure. A few of your jets interchange.

Don't worry, I'll lead you in the correct direction.

MY99TAWS6

iTrader: (3)

Ok Lonnie understanding it now. So not a problem running lower pressure with the spray just have to swap out some jets. Easier said than done with the intake on the engine as you have to modify the nozzle fuel jets not just the distribution blocks but they are bigger as you said and bigger could mean less clogging potential.

Oh well not going to use the nitrous right now so not going to worry too much and also staying really low boost for awhile. Will likely set base to 40 or 43.5 and take it from there.So it looks like if you don't swap jets you go leaner as you lower fuel pressure thru the nitrous kit.
Wonder how much leaner. Would the fact that am running 11 to 1 for the boost help there as my afr is boost referenced in speed density? I wouldn't go past 11.5 every on boost and wonder how much a 125 shot would lean it down if still had the bit smaller fuel jets?

MY99TAWS6

iTrader: (3)

And where does nitrous try to be for afr? As said am targeting 10.5 to 1 with 10% ethanol fuel which gives .5 point higher from what I have read since stoic on it is 14.11. I guess coudl set my stoic to 14.11 but dont' always run 10% meth 94 octane .Some places don't have it and sometimes you get stuck with 10% ethanol fuel and it don't say on the pumps here so figure if did run straight gas than still safe at 10.0 Or could possilby go to 11 gas and 11.5 10% ethanol but then heard not so great for couple back cylinders with my intake better to run a bit richer .
Stuff can get a bit confusing!
Anyway appreciate your help and advice.
Just talked to zex and they confirmed what you were saying. Sure just run bigger fuel jets like that other kit would be close at least as starting point.
And it don't matter if run the nitrous lower pressures just means have to change to richer fuel jets.

Sorry for doubting but like to double check this stuff!

With luck fire up the car tonite or tommorrow very close now. Did bunch of extra stuff so thats why it wasn't up and running with the new fuel system sooner.We checked pumps and they work fine.But didn't check hobbs obviously.

Lonnies Performance

iTrader: (16)

Start with 40# base pressure with vac line off....
Then replace vac line & pressure will drop to probably 35 at idle.

Yes, the nitrous system is designed to richen a lean motor (12.5:1) to appprox 11:1 or richer. Considering a 125 shot is about 1/3 of the total power on a stock motor & will only be about 1/8 of your engine, it will not have that great of an effect on the overall mixture.... even if it is lean, because of your lower fuel pressure. If you start safe on your base AFR & timing, you can probably try it with the standard jets without much risk.

I personally would try the 75 kit first & see what happens. Think of it this way, adding 75hp to your car is only about 10% additional fuel requirement. Theroetically that would only lean the car out 1 AFR point from 11:1 to 12:1 with no additional fuel added.... meaning no fuel solenoid used at all.

So, by putting in the 75hp N2O jet & the 125hp fuel jet, you should be very safe for the first pull. Then reduce the fuel jet until it gets to the reading you want. Start low & safe & work you way up. If you let your intelligence & finances stop you instead of the greed for power, it should survive the experience.

MY99TAWS6

iTrader: (3)

Ok making sense now Lonnie.
So how about this..if just run a 75 or 125 shot could I maybe run the kit as dry then since it will always be 11.0 under boost and nitrous only works at wot so its also of course under boost. So maybe that 125 shot would jump it to say to 12.0 but then that might be too lean under boost. So guess if set things at 10.5 a bit more rigch then might jump to say 11.5 with 125 shot still or would i have to have 10 .0 and then it would go to say 11.5? Staring to get a bit complicated again..sorry.

Just was trying to see if didn't even need to run fuel jets since they could clog possibly and take out a cylinder but guess have some safety from the richer mixtures going to be running under boost anyway.
At least I have 3 bar sd tuning now so that helps of course. Can have the tuning like 12.8 Na off boost and whatever you want on boost. I like speed density I think.

I think will run 43.5 right now for base . Since dont have injector value for 40. There is spreadsheet can have my friend run it my computer won't let me. Hptuners has injector calc but it dont' seem to work on the bigger injectors.That spreadsheet found think on ls1tech but for sure on hptuners will calc out the injectors.

Lonnies Performance

iTrader: (16)

Flow is calculated as squareroot of (new pressure/standard pressure) x injector size ..... =sqrt(40/43.5) X 120 = 115 I would start here & see if you can get it to idle cleanly.

No you cannot run it as a dry kit, I was only making an example.

No you cannot run it without nitrous jets. I really recommend you get the correct jets.

12.8 N/A is ok, but you will almost never see full throttle without at least some boost.

MY99TAWS6

iTrader: (3)

Ok just wondering about doing it as dry setup. Yes will get proper jets when start to use it. Will have to pull intake off as doubt can change them out in the car since they require different nozzle jets for that low pressure not the much easier to change distribution block jets.

Used your formula and actually injectors say they are 114.9 at 43.5 not 120. So got 110.18 so guess try that. They were rated 111.1 at 43.5 with heptane .114.9 with gas.
sqrt(40/43.5)times 114.9 = 110.18 think thats right

Lonnies Performance

iTrader: (16)

Youare correct, just used 120 as a reference.