TheBlurLS1

iTrader: (8)

I have a set of SVO 42lb injectors at my house right now. My stock 28's are hitting 104%+ duty and I'm running way lean according to you guys and my LTFT's.

I've done a little searching and reading and noticed a few people have slapped these in, then multiplied the IFR table by 168%( some did 162%, I guess they had the bigger 98 injectors to start out with?) and they were good to go. I'm kinda wondering if I could throw these in, and make my meek-n-mild cam only car run a little better, or at least a little safer.

What about injector offset? I can't seem to comprehendo what this table is used for.

I'll be using HPT btw.

Anyone have any suggestions to help a n3wb? I'm reading and understanding more and more (at least I am familiar with a few acronyms now )

TheBlurLS1

iTrader: (8)

Oh yeah, here's the thread where I posted a little highway rhomp that I logged. Since then I've put in a 160* stat and reset the fan temps.

https://ls1tech.com/forums/pcm-diagnostics-tuning/531060-ls1edit-hp-tuners-ls1edit-tuning-confirmation-needed.html

Viper

iTrader: (6)

Search some more; use redhardsupra's excel calculator to get the exact values for HPT. No one multiplies anymore as it's not linear. As far as injector offset, getting values for the 42#'s is VERY elusive. Most people leave it alone. You'll have better luck with getting the right tables for those injectors on www.hptuners.com to be honest. But Marcin has some awesome spreadsheets.

I just read your other post, you'll have to probably redo the idle tables too for the FAST 90 setup.

LS1PoweredZ28

iTrader: (2)

I'm running 42lb Delphi's, with the stock injector offset table and they work great for me. Just change your IFR table and you'll be set.

Kevin

TheBlurLS1

iTrader: (8)

Sweet, keep it coming guys!

I put the 90/90 on before I got HP tuners, so I drilled that tiny *** hole out to a little smaller than the one was in the previous TB (stock hole) and it idled/cranked identical. I have no complaints on how the lowspeed/idle/startup is on the car, it couldn't be better. It dies sometimes when cold if I crank it with the a/c on, but once it's running I can click it on.

Or do you mean I'll need to redo the idle tables with the new injectors?

93TAWicked1

iTrader: (28)

Hmmmmm Can .......not.....resist.....USE the search button JK

Actually I'm with you there is alot of conflicting information, and on top of that being newer to tuning I make things ALOT harder then they have to be.

I have the same exact thing going on, I am going to use the redhatsupra's spreadsheet using 42 for the flow and 40 for the fuel pressure what I have found from the searches and HP tuners forums. Then I'm just going to plop those values into the injector table.

I know that isn't the answer you wanted but it is the conclusions I have gotten from the research I've done. I'm going to get my fuel pressure with the trex off a fuel rail pressure gauge.

HP tuners has a scale table too that would probably get you close as well. From what I've read if the injectors are tuned correctly the idle should be fine, but no personal experience.

Its funny because everyone acts like this has been explained and explained but all the searches I've done have gotten some conflicting information, it doesn't seem to be an exact science even the 42# injectors can be different....confusing...

Bobby

Viper

iTrader: (6)

Here's a great post:

https://ls1tech.com/forums/showthrea...light=injector

And I have the 42's as well, left the offset table alone.

As far as the idle, yes it will need redone with the new injectors.

TheBlurLS1

iTrader: (8)

Whew, this is starting to make sense now. I read Marcin's blog and a few threads after I dug around on HPT.com and now I'm starting to understand some of the stuff works now.

I read that some people decrease the IFR table to make the car think it has smaller injectors, thus working them harder and they end up spraying more fuel. They do this in an attempt to command AFR, but it's a LINEAR increase in fuel and causes a rich/lean swing from top to bottom.

I also read that this is a bass-ackwards way of doings things, much like you'd tune a 73 4x4 with a tree-fidy. The proper way is to have precise IFR's, then adjust VE to compensate.

This doesn't really have much to do with swapping injectors on a setup with a decent tune already, but It's more of a thought gathering session.




This damn new Dell computer has some BS programs on it. I tried opening the injector spreadsheet, which it tries to open in "Quattro Pro". The bitch doesn't even have Excel. It will let me view the spreadsheet in Quattro, but not enter any damn values. Only option is has at the top is a big *** "Buy Now!"

Guess I'll have to do some digging for my copy of MS office....

This may be a project for NEXT weekend, as I'm throwing in all new exhaust this weekend.

TheBlurLS1

iTrader: (8)

PS - Now I know how the people who come into my section starting threads titled "Which LT's should I buy?" feel.

BADSZ28

iTrader: (39)

I am doing the same swap and read all the same threads. I have the sheet but no idea how to use it. Seems to be multiple ways of doing this. I guess what is the best way. HPT here too.

RedHardSupra

iTrader: (1)

there's 3 numbers, one is the rated flow (so if it says 42lb/min that's the 42)
another one is rated pressure (if it says 42@43.5psi (or 3bar) then put 43.5 there)
and another is the fuel pressure you're gonna run it at--just measure it with a gauge, but if your fuel pump is stock and healthy it's gonna be really close to 58psi.
the end.

RedWS6 00

Got the 42's. Used RedHardSupras excel calcs. Injectors seems to be rated at 3bar, 43.5psi. This means that in your 58psi system stock for LS1's) you will almost be running 60lb/hr. (EDIT: I meant they almost flow like 50lb/hr, my typo error)

I only changed the IFR (Injector Flow Rate) table, left the injectoir offset table alone. However did reduce the minimum pulse width, as my car required 1.2ms injuector pulse on idle. The minimum pulse witdt wouldn't let it go below 1.6ms.

RedHardSupra

iTrader: (1)

something's not right then, 42lb/hr at 43.5 psi works out to about 48.5lb/hr at 58psi. if you get anything else, try again

Scooter70

iTrader: (1)

See if you can open this in Quattro Pro.

I talked to Marcin about this before I put SVO 30s in my car. He told me that he had a really good tune in his car before he changed injectors. All he did was swap injectors, change the IFR table based on the spreadsheet, and his fuel trims were the same after as before.


Edit: I see that he came into the thread while I was at lunch.

TheBlurLS1

iTrader: (8)

I might be swapping my fuel injectors/rails this weekend. I've been fighting my new exhaust setup since saturday morning. 1-day job it was supossed to be. It's been raining for 3 damn days only taking about 5 minute breaks (enough to get your hopes up). It makes me so sick to see it sitting in the driveway on jackstands with the hood barely cracked (parts sitting all over the engine bay lol).

I might be installing an LS6 intake for a guy, but hopefull he will bail, then again, maby I should hold off on wrenchin for a while!


Scooter - The calculator will open, but my "trial" on quattro pro ran out. It lets me look at it, but not enter any values or change anything, quite annoying. I guess I'll have to bootleg something.

TheBlurLS1

iTrader: (8)

Just a quick question. SD tuning is simply making the car rely on the VE table/O2's/IAT to determine its fueling needs and saying goodbye to the MAF correct?

If this is true, does it mean the MAF is simply a redundant system to backup the VE values or is the VE the redundant system to back up the MAF values? Either way, this should mean that MAF's are there simply to adjust for a more broad range of conditions/changes?

Scooter70

iTrader: (1)

The MAF is the redundant sensor. Many fuel injected vehicles run speed density only from the factory. (I believe that the new Hemi does.) The advantage of the MAF is that it senses (or actually calculates with the help of IAT) the true amount of air entering the engine and bases fueling on that. SD uses the VE table to calculate the fuel needed based on MAP value and RPM. On GM Gen3 motors, the PCM uses a combination of both SD and MAF based on some parameters. At least that's my understanding of it.

If you post up the rated lb/hr and rated pressure of your injectors, I'm sure that someone will run the spreadsheet for you at LSx fuel pressure and post the numbers that you need for your IFR table. Or you could check out the HPT repository and see if there's someone with the same injectors and just copy their IFR table (if you trust it).

-Matt

TheBlurLS1

iTrader: (8)

Good information Scooter. I figured it was either one or the other. I read that the v6 cars only use the MAF for their airflow calcs, never looking at a VE table.

Marcin (RedHardSupra) IM'd me last night and sent me the new IFR table, I might give her a try this weekend and see how it runs. I told him I was putting him on my buddy list, and to be prepared to get bugged.

We had a pretty good talk about how the IFR table is setup, and how wierd it is that it's measured in "Manifold Vacuum" instead of "Manifold Pressure", meaning "0" is atmospheric pressure. Kind of strange considering the other tables use "Manifold pressure".

BADSZ28

iTrader: (39)

Oh. That sheet is easy to use. I just needed a better understanding of the numbers. If I can get my HPT to write to my VCM I will try it.

See5

iTrader: (53)

42s are going to be significant overkill. At idle and midrange they will be throttled way back. 30s would be a better match