Ok guys, I think I am nearly complete with my auto ve tuning. My last log had bens mostly in the 98-99 range, and a few cells with a bit more correction than that.
1. My main VE table is something on the order of 40% less in the idle region than stock, and my hot starts are not that great. For a hot/warm start I have to push the throttle to get it to start. If I compare the 800 rpm and 400 rpm cells of my main VE to the cranking VE table, the values differ significantly. I know I need to modify the table, but how it is usually done? If my 800 rpm column is off by say 40% approximately, do I scale the entire VE map by 40%, or do I use the 400,800,and 1200 rpm columns and scale each of the cranking VE map accordingly, and make the percentage scale linear between those three rpm points. For example, if on my main VE table if the values differ by 30% from stock a 400, and the values differ by 40% from stock at 800, and the values differ by 20% (I'm just throwing numbers out for an example). Then would I scale the cranking VE table at those rpms by those percentages, and then try to scale it linearly between, so between 400 and 800 it would get scaled by 35%, etc.
That's an airflow issue. I left the cranking VE alone and made the changes to {B4343} Startup Friction Airflow Correction.
2. My next question is w/o usage of an eddy current dyno, and sitting at high rpm points and high load for extended periods of time, how do you map those cells? Thus far to get all the cells I have, I used a lot of brake pedal modulation to hold me in those rpm cells while I kept the throttle in one particular MAP cell. My brakes just arent' up to the task of holding back near WOT at high rpm areas.
Sometimes it's hit or miss. Trying to hit one cell is hard enough...but, you really want data from the center of the cells. Set your filters wisely and this can be achieved. If I get time later, I'll see if I can pull my filter data.
3. When taking off from a stop, I often get some KR (up to 4 or 5 degrees sometimes). This occurs right after I let out the clutch, and start rolling. Once I hit ~1800-2000 rpms with the vehicle speed around 10-15 mph, it gets some KR. I've looked at the logs, and sometimes it looks lean compared to the command, and sometimes its not. I targeted those cells paricularly hard when I was doing my last round of auto VE, those were the cells that corresponded to BENs over 1.0. That range was between BENs of 1.03 and 1.07. I hope that takes care of it. If you'd like, take a look at my before and after tunes, and the logs that lead me to make those changes.
BEN's at idle are going to be inaccurate with the duration of your cam, which means reverting back to closed loop most likely won't be an option for you. As for fueling, keep an eye on the WB. 15:1~15.5:1 should be ok for idle.
4. I often stall when the car comes down to idle, mostly when stationary, sometimes when coasting to a stop. When the car gets very close to a stop, then it wants to idle very rough, and sometimes it will save itself, sometimes not. I have played with the overspeed/underspeed timing corrections a bit, but not sure I have enough. Can someone with a trained eye take a look and see if maybe I'm just not going agressive enough. Also, I made some changes to the throttle cracker, based upon the idle tuning tutorial in the stickied in the tutorials section. I have not drove the car since those changes. I hope that helps.
The idle controls were adjusted to help get you in the right direction for this (too many to list).
5. There is a table in the Fuel->Mixture folder, B3609 called "PE Delay Counter Adjustment". Stock my table is all filled wiht ones. I looked at many of the modified tunes on holdencrazy and it looked like all the other tables were ones. Joecar suggested that I make that table all zeros. Does anyone else have experience with this? I'm unsure of how this table works with the single adjustment parameter B3608 called "Delay before Engering PE Mode"
Not sure if it's a source of problems or not. But, I reduced it anyway. Can't hurt.
6. There are areas in my main VE talbe that are over 100, sometimes up to hte 105 range. I know these number arne't truely a volumetric efficiency, but does this seem realistic?
Change your options to show VE as grams*K/kPa. Then, you don't have to worry about percentages anymore.
I would very much appreciate any and all help on these questions and concerns.
I have attached several items. Two are tune files. The first one is the before tune, then I have several logs. One log is about an hour long and consists of highway driving at varying loads trying to be VERY smooth on the throttle as much as possible. Then there is a log where I wanted to target idle BENs, so I did that seperately. Then there is a log with a fewll WOT or near WOT pulls. I have also attached the tune file I applied changes to based upon those three logs.
My basic modifications are MS4 cam, dual 3.5" intake, LS6 manifold, 1 7/8" long tubes, dual 3" exhuast, M6 trans, in a 2800 lb FD RX-7.
Once again it appears that there is a problem with the database and I cannot upload the files. I will upload them as soon as it allow me to. In case anyone wants to take a look before I am able to upload the files, I can email them as well. I'm near a computer 95% of the day, so I can email probalby within 5 minutes of you giving me your email address.
Thanks,
Kevin