Noob Tuner, Please Help. LQ4 6.0L, 76mm, E85, 80lb dekas, 2Bar SD

[jrick11]

Hi, I'm just got my tuning software and read the tune in my car. It was previously tuned by someone else. I need opinions and suggestions on the current tune because most of it just doesn't look correct to me, such as Primary VE table, Injector Data.

Specs: 2Bar SD OS, Stock Lq4 6.0L, LS1 Intake, Single 76mm Turbo, 80lb Siemens Deka Injectors, E-85, Aeromotive BR FPR, Bosch 044 Fuel Pump.

[Jrock]

umm it says you have a 5.3L

[93camaro_zzz]

Jrock is correct, both the drop down menu, but more importantly, the cylinder volume number are both for a 5.3L. Those errors would definitely mess up your VE table, etc. The previous tuner probably tuned around it (Obviously the wrong way).

This is initially what I would do for your tune....

- Correct your cylinder volume. Choose 6.0 from the drop down menu, and then enter "0.7500" for the cylinder volume number.
- Change your Injector flow rate table. I have the exact same 80# injectors, and here is the correct data for them (If you are running 58psi rail pressure):

- Go to your primary VE table and Highlight ALL cells in the 105-210 rows and add the number "36" to those values.
- Now "unrape" your PE table, and set it to something normal, like "1.27". Then, either roll with that, or if you want to use the BE table, then set the BE table to the 1.27, and the PE table to 1.17.
- Get rid of your 98mph speed limiter. lol wtf is that!

Start with those changes and then starting tuning it yourself from there and dial in your VE table. Let me know if you have any other questions. And, do you own a wideband?

[jrick11]

Thanks for the fast replies.

what about the injector offset, pulse corrections, and limits do they look right?

I do have a AEM Wideband

[jrick11]

98 mph speed limiter. lol. It has a th350 behind it, so I'm guessing it doesn't matter. right?

[mecanicman]

Injector data is incorrect for boost referance fuel pressure regulator. Injector size should be the same all the same all the way across the table as should the offset table.

[POWERZONE]

Make sure you fail the MAF sensor via your engine diagnostic tables.

set MAF fail high to 0
set P0101,P0102,P0103 to 0-mil on first error

[jrick11]

So what should I set the IFR and Offset to if it is supposed to be the same all the way across the table?

[jrick11]

Should I use the Unit Conversion in the editor to get the new IFR.

Current INJ Flow: 80 LB
Current Fuel Pressure: 43.5 PSI
New Fuel Pressure: 58 PSI
New INJ Flow: 92.38 LB

So if this is correct I should put 92.38 across the Injector Flow Rate table?

[POWERZONE]

Should I use the Unit Conversion in the editor to get the new IFR.

Current INJ Flow: 80 LB
Current Fuel Pressure: 43.5 PSI
New Fuel Pressure: 58 PSI
New INJ Flow: 92.38 LB

So if this is correct I should put 92.38 across the Injector Flow Rate table?

If the regulator is BR and they are truly 80lbs injectors, just set your table to your new inj flow data based on your new fuel pressure across the entire table.

[jrick11]

The deka 80lb injectors are rated at 80lb/43.5 psi fuel pressure and I'm running 58 psi fuel pressure. So should I still set the IFR table to 80lb even though the IFR is higher because of the higher fuel pressure?

[Jrock]

does the stock lq4 regulator work properly with boost reference ?

[93camaro_zzz]

Jrock, you need to make your IFR table exactly as I had suggested. You do not put your IFR table the same number all the way across with a BR-FPR setup. My car is a boost referenced FPR also, and they do not start bumping your fuel pressure until you enter boost, so in the vacuum regions you would still need to have the correct values. Which are the ones I posted above.

[jrick11]

I was wondering if your car had a br regulator after everyone was saying to make the IFR table the same. Thank you for sharing your data, I will give it a try.

[POWERZONE]

You do not put your IFR table the same number all the way across with a BR-FPR setup .

Remember you are at 1:1 and with a BR regulator, fuel pressure is being controlled by vaccum. No need to hold the injectors open longer as well since the regulator is adjusting the fuel flow. Set the IFR table to the same number across the table(flat curve).

A flat IFR curve table will work.

[mecanicman]

Ok, a lot of misinformation flying around here. If you are running 58 psi, you enter the fuel injectors data for 58 psi. I believe the value should be 81.4 across all cells.

On a vacume/boost referanced regulator the injector data is entered the same across the board.
93camaro_zzz, you need to do some reading, your description of operation is not correct.

A manifold referanced regulator(be it n/a or boosted) keeps the pressure differential between the injector and the intake manifold the same. As vacume increases in the manifold (pressure decrease) it draws more fuel so the pressure regulator decrease pressure to keep flow the same. As pressure in the manifold increases the fuel pressure regulator increases fuel pressure to compensate. It effectively makes the injector flow the same rate under all presure conditions.

Without a fuel pressure regulator, injector size shrinks as manifold pressure increases and size increases with decrease in pressure.

This info is not new guys, it has been discussed at length before. I suggeset doing some searching and reading. As the forum search function is not always the greatest, try using this:

At google search prompt

site:hptuners.com word word word ect.

works for any site, enter the base address(not hptuners.com/forum) with site: infront no space, then a space, then search word, then space, then search word. Works very well.

[POWERZONE]

On a vacume/boost referanced regulator the injector data is entered the same across the board.

A manifold referanced regulator(be it n/a or boosted) keeps the pressure differential between the injector and the intake manifold the same. As vacume increases in the manifold (pressure decrease) it draws more fuel so the pressure regulator decrease pressure to keep flow the same. As pressure in the manifold increases the fuel pressure regulator increases fuel pressure to compensate. It effectively makes the injector flow the same rate under all presure conditions.

Without a fuel pressure regulator, injector size shrinks as manifold pressure increases and size increases with decrease in pressure.

.

Very well said and explained.

[jrick11]

Thanks mecanicman,

I have been reading for a while and from all the information I"ve read you are correct. That was the way I planned to change everything to work with my BR Regulator, but I cant seem to find the correct numbers to put in the tables.

I have found this spread sheet but don't know which numbers to use. Attachment 45519