Cranking VE, generally increase/decrease?

[efizjb]

I've searched and was suprised there was not as much as I would have figured relating to cranking VE.

I know there are many variables, but if I were to ask a for a general answer, for cammed cars do you typically find that cranking VE needs to be reduced, or increased?

My assumption was more air(cam) you need to increase cranking VE...but the few threads I did find led me to believe that most cammed cars end up reducing cranking VE?

from the few threads stating anything about cranking VE, it seemed it is a "outcast" misunderstood table and more people go after friction air or another table.

right now I have periodic stalls on hot restarts (very periodic) but still would like a general theory on what is typically done with cranking VE on cammed cars.

I'll search hot start threads as well, no problem, but in the dark on cranking VE....

thanks!

[efizjb]

So does this mean leave the cranking VE stock?

[SSpdDmon]

My theory was to do it after you do the Main VE....

After I completed my main VE, I did a quick comparison between the stock VE and the new one in Excel. Using the percent difference between stock and new, I altered the cranking VE similarly for the RPM rows in common (400, 800, 1200). I then adjusted the rows inbetween and brought them in line with the ones I just changed.

For example, if the 800 RPM row was generally 45% lower than stock was, I reduced the 800 RPM row in the cranking VE 45%. If the 400 row was 55% below stock, I reduced the cranking VE 400 row 55%. Then, the rows in between were reduced 780-46%, 760-47%, 740-48%, etc. (assuming it's 20 RPM increments - I can't remember for sure).

[efizjb]

Thanks, that gives me a good starting point!

[5.7ute]

There was a cranking VE table excel spreadsheet on Redhardsupras blog. It seemed to do the job. Here it is.

[efizjb]

There was a cranking VE table excel spreadsheet on Redhardsupras blog. It seemed to do the job. Here it is.

I thought I saw that somewhere in the past, thanks guys!

[samh_08]

Funny I was just going to post about that spreadsheet. Does it actually work well? When I just did it, it seemed like the numbers were WAY different. Is stock just off that far?

[5.7ute]

Funny I was just going to post about that spreadsheet. Does it actually work well? When I just did it, it seemed like the numbers were WAY different. Is stock just off that far?

How far out was your main VE table when you finished?
This sheet was just a quick fix to transpose your VE table into the cranking VE table. I have never tried it with a stock tune to see what the factory does but I will have too now.

[hquick]

My stock {B0102} table is set at 75.0 across the board. After using the spreadsheet it looks ALOT different but works well.
I do however get an 'out of range' message on that table now...and I have no idea why.

[samh_08]

My table is also set to around 75 across the board. After the spreadsheet the values start at 39 and rise progressively to 83. Im just curious as to how this works and if it is effective. You would think if you change these values by this much you would get a drastic result, not?