1SlowHoe

iTrader: (28)

I'm trying to get a tune worked out for an increase in cubic inches from a 367ci (Stock 6L) to a 408ci. At the same time I'm going from 42# injectors to 60# injectors.
I got some help from a tuner via PM over on tech. I wanted you guys to tell me what you think. He has HPT so I'm not sure the graphs are exactly the same between programs. He did give me 17 values which is exactly how many were in my table so that's a good sign.

**Notice how the current tune has the same values while the new tunes increases.

I have attached both tunes so you with the software can look through them...if you don’t have the software you can go to EFILive.com and download a trial version which will allow you to view but not save changes..
Thanks!
CURRENT TUNE:


408 W/60# INJECTORS TUNE

SRTKLLR

iTrader: (1)

I am by no means a tuning expert but if you swap out injectors and your tune before had the same numbers all the way down they should be that way after just with bigger numbers.

I think the 03 and older return style uses the same numbers in all the cells and the 04+ with the return-less fuel system scales the numbers based on manifold pressure.

I have an 03 and when I switched from the stock 25lb injectors to the 62lb(@ 43.5 PSI) all I changed was the IFR to 72lb(since the fuel pressure is 58 PSI) in all the cells.

1SlowHoe

iTrader: (28)

Mine is a return style but the FPR is vacuum/boost referenced. Mine was originally a "Flex Fuel" truck so it always has funky little differences from most 2002 models.
I do think you are right in that the numbers should be the same, but what number should they be? If it as a simple injector upgrade then it might be easier but I'm also trying to account for the bigger cylinder volume...

SRTKLLR

iTrader: (1)

I went from a stock 5.3 to a 6.7(408 ci) when I changed the injectors. The size of the engine should have no bearing in the IFR table. Their is another place where you can change the displacement but it is used for calculating hp/tq and maybe some other things.

Now, your VE table will definitely need some work though.


If your FPR's base pressure is set at 58 PSI then you need to put the flow rat of your new injectors at that pressure. The FPR will add pressure to compensate for the boost but I don't think it should effect your IFR table.

What pressure is the rating of your injectors? Probably 3 bar(43.5 PSI) so your 60lb injectors are more like 70lbs at our 58PSI(4 bar). Did you get a flow sheet with your injectors?

1SlowHoe

iTrader: (28)

No info on the injectors. They are coming installed on a TVS2300. So whatever Magnacharger uses, pretty sure it's 43.5 PSI.
My fuel pressure sits at about 40psi at idle and hits 58psi at WOT. I think that's different from non flex fuel trucks. I had something like 39# injectors stock from the factory.

Fix my VE table

I'm really just looking for a "get me running" tune. I'm not gonna go beat on it. The closest dyno is 3 hours away so I need to be able to get it there without ruining my engine lol. I can always mail in my PCM to Nelson or Wait4Me but I have the software so I’d rather not pay if I can help it.

SRTKLLR

iTrader: (1)

I just looked at your tune but it is not your original(stock) tune. I just wanted to see if the cells were all the same.

But regardless, if you were running correctly with the 42lb injectors with all the cells being the same then just switching to bigger injectors should also have all the cells the same.

It looks like your tune has 45.635567 in all the cells of the IFR table. So that means that number is what 42lb injectors flowed at 43.5 PSI flow at 58 PSI. Given that your 60lb injectors flowed at 43.5 PSI are about 69.22 at 58 PSI. That is what should be in your IFR table unless the injectors were flowed at 58 PSI already.

1SlowHoe

iTrader: (28)

That makes sense. I will ask what they were flowed at but I'd imagine they were flowed at 43.5 since that is the standard.

So how do I figure out the VE table?

03sierraslt

iTrader: (22)

Guess to get it started, then tweek it. You plan to run 2bar sd or MAF?

Rhino79

iTrader: (7)

Look in the info box at the top right. Vaccum refernced systems use a base injector setting in each field. Systems that are not vaccum referenced use increasing rates (starting with the actual injuector flow in the first box)

I would definetely go with a sd cos because its hard as hell to try and tune wot fuel on the ve when it maxes just as you go into boost, trust me i've tried...lol And depending on how much boost your running the MAF may max out (probably will).

1SlowHoe

iTrader: (28)

I think I would need to go 2 bar. I'm not sure what is best for me. I thought SD was a little sensitive to intake temps and the weather here fluctuates from teens in the winter to 110 in the summer so would one tune fit the bill? I know nothing of a custom OS. The closest tuners to me, to get a dyno tune, are all using HPT so I'd probably end up with some sort of HPT custom OS tune. (if HPT does that)

It seems like using EFI Live instead of HPT is like using Beta in a world full of VHS