4.8 Computer running a 5.3?

[S.Strehler]

I recently swapped a 4.3 truck to a 5.3 and am currently in the process of working out all of the bugs. While setting my efans and familiarizing myself with hpTuners, I noticed that the computer I'm running is from a 4.8 truck as it says.

I guess my overall question is... Is this going to cause me any issues? Would it be best to get a 5.3 computer or reflash the current one? Are the maf table, fuel table, and such the same? I'm a tuning amateur at best and was hoping to have a good starting platform to learn from.

Thanks everyone.

[93camaro_zzz]

To answer your question, it will matter that it says 4.8. The computer makes airflow calculations based on physically how big your cylinder volume is, and so you are basically running your 5.3 on the stored value of a 4.8. No problem though, you can change it all up. Just download a stock tune for a 5.3 truck from the tune repository, and then it will have a good starting point for you, and the correct cylinder volume. You can do all of this on that 4.8 ecm you have.

[S.Strehler]

That is good news. I've a stock tune out of the repository that looks good to use. Am I going to have to burn credits to use the file? What is my best way of going about the change?

[gofastwclass]

Don't use credits on a file you don't need. Simply use the compare function to view or update the data. It isn't the OS (file) you need, it's the parameters within the OS.

[RonSSnova]

What I found when going the other way from a 5.7 file to a 5.3 file was this:

Clicking the engine size from 5.7-5.3 seemed to not change a thing. As if it's there for info only.
Changing the cylinder displacement did change the VE table.

What I did was probably in the wrong order. I copied the 5.3 VE table over before changing the cylinder displacement. The result was that my copied VE table got changed when I updated the cylinder displacement.

It would have been better I think to change the cyl displacement first. And maybe not even copy the VE table at all. Just let the cyl displacement change the VE and begin tuning.

I also copepod over all sorts of 5.3 parameters to the 5.7 file that I ultimately ended up changing back to the 5.7 tune.

Just my experience.

Ron

[S.Strehler]

So what youre saying Ron, is to change the cylinder volume to reflect 0.66594 (5.3/8) and the VE table will update itself accordingly? I see where there is a drop down to change to a specific liter ie:5.3, 4.8, 5.7, etc... and I think I'm seeing the same that you did... change it, and it does not have any affect on any other variable that I can see.

[93camaro_zzz]

You are correct that all of your fueling will change, but the numbers in the VE table will still stay the same. Those numbers are a percentage of a volumetric efficiency. Since you are changing the volume of the engine, those numbers are now going to correlate to different values now. This is how the computer estimates cylinder airmass. But yes you should definitely have the 0.66594 value in the cylinder volume entry.

[S.Strehler]

Perfect. Thank you for all your help and support. I've got everything swapped over from the stock 5.3 file that is different and the truck seems to run a bunch better. Table to table was quite laborious. Makes me wish I would have known the computer was from a 4.8 before I assigned HP credits to it.

[RonSSnova]

I could have sworn the VE numbers changed after changing the cyl displacement. Of course, after you stare at all those tables long enough, the walls start moving....

And watch out for 93camaro_zzz, he is one of those turbo guys not to be trusted.....

Ha!

Ron

[MikeOD]

Table to table was quite laborious

Next time, open the 4.8 as the main file, open the 5.3 as the compare file, pick compare - view comparison log, then right click on anything you want to copy over and pick "copy over differences"...gets it done almost instantly for you.

[S.Strehler]

Great info. Thanks everyone for the input. Been working crazy hours.. today I get to plat with the truck.