VE table calculation for 60#

[Behold]

I have on order my Siemens 60# injectors. There going in to my Holden VT LS1 with LS1B controller. I'm running a COS5 OS and its tuned for 42# at the moment but I'm doubting the VE Table is that great as the injectors are a bit of guessed data.

Am i right i need to scale my VE What do I need to do? do I take a standard table scale it and add 5% and scale up my BOOST table to match and go for an AUTO VE tune and see what it shows? Is there any other areas that need changing to suit the 60#s????

Thanks

Oh to add. Reason I have moved to the 60s is I hear there good. There is usable injector data and although running 5psi that's likely to be upped to 8-9 psi once intercooled and my 12rib pulleys are all set up.

[nevinsb]

Hi, depending on which 60LB injectors you have, the best bet would be to find an existing tune with the injector parameters for the ones you have. Those values need to be fixed before you change the VE table. There are values for injector flow rate, small pulse, and voltage, and timing.

[Behold]

That's a given. I have some data from a couple of tunes I grabbed a while ago. Not sure how accurate it is. There Siemens and are the same as I believe is on the Greg banish DVD/data. So many here will have some knowledge and on a few other sites and worst case I can buy the DVD.

Once the IFR, All the different Offsets/PW Are in. There is some scaling needed. Just what I heard. This is because of a limitation on the OS? I think some of the injector data also needs scaling.

I might be wrong. Hence checking.

[joecar]

No... when you insert the injector values/tables for the new injectors the VE table should be left alone

( of course, if the VE table was not corrected originally, then it will still be in the same uncorrected state )

you would have to scale the IFR/VE under the following circumstances:
- exceeding the MAF limit;
- exceeding the IFR max limit (60 lb/hr injectors do not exceed).


The LS1 PCM sets a limitation on the MAF at 512 g/s... so you might be running into this, so you will need to scale MAF, VE, IFR.


[ i.e. you're running into the MAF limitation not the IFR limitation ]

[nevinsb]

I'll take a look when I get home. Are they the skinny Simmons injectors? I think I have a tune for the Bosch 60LB injectors.

[Behold]

Perfect Joe. I'm not running a MAF (got rid of that slow responding, bottleneck causer!!) I was told the 60s were over the limit. I'm assuming this is where they meant. So easy job. Put the Injector info in and then re auto VE to remove the problems caused by my 42s.

Nevin, there Siemens Deka units. FI114961 (EV1 compatible) the same as the P/N m-9593-lu60 for the ford racing.

[Behold]

Hi mate,

Here's my ls1b cos5 tune with 60lb siemens injectors.

Hope it helps.

Cheers.

Thanks for that. Ill take a look and compare with some of my others.

[eficalibrator]

Nevin, there Siemens Deka units. FI114961 (EV1 compatible) the same as the P/N m-9593-lu60 for the ford racing.

These will require scaling to work correctly in the older ECMs. They flow ~60#/hr at 3bar, and closer to ~73#/hr at GM's 4bar nominal pressure, which is beyond the ECM limit. Plan on about 24% reduction to stay within the ECM's capability while still retaining the most resolution possible. I did this exact scaling example in the second DVD when I was calibrating a supercharged Z06.

Remember that any injector errors will likely lead to a mirror-image error in the airflow model (whether it's MAF or SD) that can eventually give you weird driveability quirks. If your previous 42# data was off a bit, you may find yourself "fixing" areas of the VE model now that you have new injectors with new data.

[joecar]

Ah, I was in a hurry and I forgot about 3-bar -> 4-bar scaling :doh:(4-bar flowrate exceeds range), thanks Greg.

[Behold]

Ah, I was in a hurry and I forgot about 3-bar -> 4-bar scaling :doh:(4-bar flowrate exceeds range), thanks Greg.

So is it just the Flow you scale? or do all the PW and Adders need scalling too? then drop the VE by the same percentage.

As to the current VE Im thinking its going to be a mess that need almost a complete redo. Nothing a VE Tune will not clear :D

[joecar]

Only the IFR is scaled (the pw and adders cannot be scaled).

Yes, scale VE table same percentage as you scale the old IFR table...

and then scale IFR for new injectors (i.e. multiply by sqrt(72/50))

old: 42 lb/hr @ 3-bar = 42*sqrt(4/3)*1.035 = 50 lb/hr @ 4-bar
new: 60 lb/hr @ 3-bar = 60*sqrt(4/3)*1.035 = 72 lb/hr @ 4-bar

1.035 being the relative density of octane wrt to heptane (fluid used to rate injectors).

[joecar]

Do this: scale your IFR and VE down by the same percentage, and then redo your VE and MAF tables.

[Behold]

Whats the limit in the ECU??? The values are not hitting max. Is there another correction table that can't cope? I have my injectors now and am starting to build my tune.

Thanks

[joecar]

Depends on the ECU...

LS1B: limitation is MAF maxes at 512 g/s.
E38/E67: limitation is IFR maxes at 8 g/s or 16 g/s depending on OS.

[Behold]

Right well I'm on a MAFLESS tune on COS5 on a LS1B ecu.

Does that mean I do not scale anything? Set the IFR up as it should be. The adders etc as per usual and bobs your uncle and all that.

[Behold]

Any confirmation on my statement? Not running a maf on a ls1b ecu means I do NOT need to scale on my ecu for 60# injectors????

[joecar]

That's correct, if you're not running into those limitations then there is no need to scale anything.

[Behold]

Excellent. Thanks. Should make life a bit easier.

To the computer!

[joecar]

i.e. during tuning of your LS1B keep an eye on MAF to see if it hits 512 g/s...

if it does hit, then you have to perform scaling (IFR, VE, MAF, and all tables that reference airmass or airflow).

[Behold]

Bit surely if I'm mafless its not an issue what it hits? It's set so the maf is never read. So I can go with full scale on my injectors making life a bit easier.

[joecar]

MAF-less: you won't hit the MAF limit, so yes no need to scale anything.

[Behold]

Glad that's sorted!!! Lets hope it all goes smoothly. Then its on to fine tuning.