I have a weird little dip in my VE Table but i can not figure out what is contributing to it. My logs with datamaster and tuner pro both show i'm running rich or near 128 but never lean. I'm just concerned that i might be doing harm to the engine. It caught my attention when i looked at other areas close to the dip. It almost seems like a puzzle but the missing piece doesn't fit. I don't quite understand why and it has to be an obvious reason that i couldn't find in the stickies, or maybe i did and i don't know it. I haven't done any plug checking or shot the headers with the lazer temp reader yet. I'm running a 383 w/ LT4 Hotcam and Stock Ported heads running 730' and SAUJP bin. Any help or direction would be appreciated.


Edit: Figured a little more information might help you and me both.

 

Maybe this will show the VE table a little better.

 

Somethign to think about..

Are you tuning for a pretty VE table or are you tuning for a result?

Sounds like you are on the right track. The cam is going to cut into the volumetric effeciency at low load/ low RPM so what you have is somethign I woudl expect in a setup like yours.

 

I use BLM correction when I am tuning my engines, the VE tables NEVER look smooth, but the engine runs dead smooth, instant power and great response. Apparently it is what the engine likes. Passes smog easily as well. Tune for what the engine wants not what you think it needs.

Could be a timing problem affecting it.

 

The smoothness of the table suprisingly happens to be the result of a few vemaster runs. I haven't done much else with the VE Table myself but was going to lock the blms and try locked blm tuning. I was worried with that dip in the table i might see a excessively lean condition as a result. The only thing that i can think of timing wise is i started with a timing table from a LT1 bin file. I can't say the power is bad but not what i expected (never is though). I was looking more towards driveability though. I figured power would come as needed with that also. I'm going to try and pull the plugs tomarrow if possible to see what is really going on as i have not had the chance to do so.

 

that cam is gonig to require you to pull a bit of fuel near and around idle.

you are on the right track.

 

That big dip is below 1200 rpm.
Tough to put any load on the motor at that rpm w/o an MT.

 

Thanks for the help everyone. I just don't want to blow a motor that i haven't finished paying for yet. Figured asking questions would be the best path to getting ahead. Thanks again.

 

With the bigger cam at idle, you probably won't hit the 20-30-40-or maybe even 50 KPA cells that often.

My little roller 312 has the following cam specs (228/234 @ .050, .510/.525, 110* lobe center idles with 12 in/hg of vacuum in Park/Neutal, holds 800 RPM and 6 in/hg in gear

I have a 2,800 stall and 3.73 gears. Even with 5,500+ lbs and a small engine, it still jumps to 3,500+ RPM almost immediately after matting the pedal. Real tough to really load the engine at slower engine speeds, unless I disable PE mode, keep the torque converter locked, and log driving around town with the engine in the 1,200 RPM range. It has the typical big cam surge under about 1,200 RPM in OD. On level road it will just kinda rump, rump, rump along in OD, foot lightly on the gas, almost no manifold vacuum, actually getting pretty good mileage.

 

Double