Cubic Inch and Cylinder Vol

[Phantom409]

New to this and I'm not sure if I found an issue with the half assed tune that was put in my car.
I down loaded a few tunes for 408's just to have a look and there Engine and Cylinder Vol. were way different.

My engine was set as a 5.7 and my Cylinder Vol. was .70821
The other tune I downloaded was very similar to mine, N/A and his engine was set as a 6.0 and had .83578 Cylinder Vol.

After seeing this I'm questioning the guy who did my car and they are a big company.
Can this affect the way my car runs?
I know this might be a simple/stupid question but my mind is about to blow from info over load LOL

[Phantom409]

Cylinder head CC is 69 if that is needed with a -6cc piston

[nkautz]

408 = 6.68592l 6.68592 / 8 = 0.83574

[Phantom409]

Thanks for the help
Could that effect the way the car runs?

[nkautz]

Doesn't seem to affect it much, honestly

[Phantom409]

Alright, thanks again

[JasonS5555]

It might help to post your actual tune.

Jason

[Phantom409]

The config file is idle only with some little revs.
The car will not start unless I prop open the TB blade with a screw driver till she warms up.
If I give it gas and let off right away she will die unless I feather the throttle closed.

[Phantom409]

I changed the engine type from 5.7 to 6.0 and the Cylinder Vol to the .8xxxx

[mowton]

So in a Gen 3, the cylinder volume plays a part in the Speed Density air fuel calculation based on the volumetric efficiency (VE). I am not sure if the tuner actually retuned the stock VE table because HPTuners automatically changes the VE table based on changes to the cylinder volume parameter which you performed when you went to the .83xxx.

The tune is still set to the blended mode which means under 4000 rpm, the PCM calculates the fueling using the MAF, but validates it against the Speed Density results. If large enough differences exist (rapid acceleration/deceleration or known as Dynamic), the PCM will use the fueling as defined by the Speed density results to "fill in" while the MAF air flow catches up (known as static) or rpm exceeds 4000 rpm.

Need to see the original tune before you changed the volume.

The VE should be tuned (to at least 4000 rpm) and the cyl vol should be correct prior to that.

Ed M

[Phantom409]

I can switch it back and post it up

[Phantom409]

Changed file back to .70821 and a 5.7 V8

[mowton]

Changed file back to .70821 and a 5.7 V8

So it looks like he tuned the VE with the incorrect cyl vol so he compensated for the erroneous parameter. I would put it back to the way he had it, or change it and retune the VE. Really depends on how you are. If the car is running good and you don't have any issue then you could leave it alone.

Tough call.....I like everything to lineup technically and accurately, so it would play havoc on my mind and I would fix it :-)

Ed M

[Phantom409]

The car runs like crap, can't even drive it.
It don't make enough power IMO to flash the converter.
I would like to fix it but like you said......he has it so messed up I don't know where to start.
Going to put the correct Cyl. Vol. back in and from what I can tell the Injectors are way wrong (SVO 42lb Green Tops) and just dumping fuel considering I have blown thru 5 sets
of plugs now.
He said he also tuned it for SD but the car wants a MAF witch I'm ok with I just have to get it to run right.

I'll make changes, data log it till I get idle right then when this snow melts I'll get it out and drive it around to get the rest.
Thanks for your time, I appreciate it.

[mowton]

The car runs like crap, can't even drive it.
It don't make enough power IMO to flash the converter.
I would like to fix it but like you said......he has it so messed up I don't know where to start.
Going to put the correct Cyl. Vol. back in and from what I can tell the Injectors are way wrong (SVO 42lb Green Tops) and just dumping fuel considering I have blown thru 5 sets
of plugs now.
He said he also tuned it for SD but the car wants a MAF witch I'm ok with I just have to get it to run right.

I'll make changes, data log it till I get idle right then when this snow melts I'll get it out and drive it around to get the rest.
Thanks for your time, I appreciate it.

Sounds like you should start over and make things right. start with the correct cylinder vol and injector data. The 42 Green tops flow like 52.2 at 58 psi (4 bar). Do you have the right data for these injectors? All the other injector parameters are quite different from stock.....

Ed M

[Phantom409]

49.61048801 49.91967562 50.22695997 50.53237577 50.83595671 51.13773546 51.43774374 51.73601236 52.03257122 52.32744941 52.62067517 52.91227597 53.20227854 53.49070887 53.77759225 54.06295332 54.34681606

This is what I came up with for 0-80 Inj Flow vs KPA

[mowton]

Ford to GM Injector Data Conversion R3.xlsx

Without giving away copyrighted data (yes, I do have ethics) I can tell you the flow at 58 psi is 52.2....Above is a great tool compliments of Dave Steck for calculating GM injector data from Ford parameters. Works pretty good. The 42 Green Tops was included in his offering :-)

Thanks Dave.

Ed M

[Phantom409]

Is that sheet for the 42's or do I need to edit that?
Then my next green horn question is how?

[mowton]

Is that sheet for the 42's or do I need to edit that?
Then my next green horn question is how?

There are tabs along the bottom.....double click on the 42 Green Top

Ed M