Z28Camaro30Ann

iTrader: (15)

Ok, so I went from 30# SVO's and smaller heads/cam/displacement to 42# Injectors and a bigger setup. I switched the car into Speed Density mode via TunerCats and I was trying to use VEMaster for my VE Tables but it didnt change ANYTHING...My SD tune is WAAAYYYY off. The second I started the car my O2's went into the 1000 ranges and my BLM's sunk to 108 and sat there. I looked at the percentages and it was pulling 15.6% from both Left and right LTerms and 20% from both STerms at idle.

I Went into my Main VE Table and I changed the ranges from 50-70 kPa and 400-1200 rpms. I lowered them by 30% and the trims moved up to 117/130. I reverted back to the original VE Numbers, then took out 40% and the trims went to 132/145. I just reverted back and dropped the VE Numbers 38% and have not ran it yet.

My question is, do I need to lower the ENTIRE VE table by 35-40% or what?? I noticed when I was out road testing it that it was at 108 constantly on the BLM's...So I know they are rich as well.

chief455

iTrader: (21)

I am far from a tuner - but I'd look at your injector size constant number - try using that to change your entire range richer/leaner

Z28Camaro30Ann

iTrader: (15)

No. I want that to be set at what my injector size actually is. Changing that constant doesnt only affect idle it affects ALL Rpm's all conditions. Changing it to the wrong point could make it VERY difficult to properly tune WOT once idle is tuned..or tune Idle once WOT is tuned...or cruising tunes...The VE Tables control AFR at each rpm in relation to the MAP. I can tune idle without touching WOT or Cruising numbers. If I adjust the injector constant, it changed EVERYTHING fuel related.

nitrous2fast

iTrader: (2)

your idle should be in the 20-30 kpa range....unless you are running a rather large cam and idling at 1000rpms...

Z28Camaro30Ann

iTrader: (15)

My kpa at idle is always between 55 and 65. Once in a while it breaks 65 but not often. Engine off my kpa is 85, WOT is us between 78 and 85, and cruising it varies between 45 and 70 depending on speed, rpm and throttle. My idle is set for 850 but it bounces from 825 to 925

nitrous2fast

iTrader: (2)

what tb are you running?

Z28Camaro30Ann

iTrader: (15)

Professional Products 58mm. Also I am at 12:1 compression

nitrous2fast

iTrader: (2)

do you have your tb blades cracked? you have the stock idle air passages being used??

Z28Camaro30Ann

iTrader: (15)

They are very slightly cracked. The TPS is at 0%, the voltave is at .57 and the IAC Position is around 45. It is using the stock IAC Valve.

Bigtoyz

iTrader: (2)

I am working on the samething trying to lean it out a bit. I'm in the lower 14's for A/F ratio trying to get it to 14.7 I've locked into Open loop just to get that straight.

then work on the MAF side for closed loop should be easier since the open loops settings are right cause closed loop uses some closed loop maps.

But if I am thinking right if you lower the numbers in the VE table you are adding less fuel cause it is less effient right?

I'm hitting 30-40 kpa for idle and 14.2-14.4 a/r at 800rpm

I want it a little richer below 800 rpm to aid in starting.

Z28Camaro30Ann

iTrader: (15)

If you want to aid starting, leave the Open Loop tables and VE tables alone. You need to edit the tables labeled:

Crank Volumetric Efficiency vs %TPS vs RPM (edit the column for 0% TPS to help it get going without touching the gas)

Initial Startup AFR Enrichment vs Coolant Temp (edit the area for the coldest coolant temp you will see to the highest you will be cranking the motor at...temps are in celsius. The higher the numbers, the more fuel you are adding...they are multipliers so keep them small and add a little at a time)

Those will aid your starting. Another thing that will help is adding more timing to the table labeled:

Closed TPS Spark Advance (this helps idle and helps smooth the transition from crank to idle...just remember that the timing you set in this category OVERRIDES any timing settings in your Open Loop table as long as your TPS is at 0%.

T/A KID

iTrader: (12)

What ECU you running, and your map at idle is right for a cam car. 25-30 is like stock stuff.

BTW when you first start your car your in OL fueling so no fuel trims, those only kick on after several seconds of running.

Engine off, key on MAP kpa should be around 100 (depends on where you live, but close to that)

You can tune the VE table or just disable it and run MAF only.

If you positive 15-20% at idle just go to your MAF and subtract that percent to the corresponding MAF HZ range.

Z28Camaro30Ann

iTrader: (15)

I am running an OBD1 PCM from a 94 LT1.

Engine off kPa never goes above 85. I am in Denver, Colorado...5200+ ft above sea level lol.

I prefer to tune the VE tables in SD mode to get them as close as possible so that I can make minor adjustments from there.

Bigtoyz

iTrader: (2)

Im at 900-1600' and have it in SD mode as well. Set the error code for the MAF so that dont show up and unplugged it. Set 255 in the tables needed to keep it there if plugged in or not.

It starts good and all, but want it a little leaner at idle. running 224/230 cam 114+4 9.3:1 cr, 97 OBD2, Have Innovate LM-1 and rpm converter hooked up to TPS and MAP at the minute. Gonna work on IAC and the CLT sensor hooked up as well.

chief455

iTrader: (21)

Once you return to running closed loop MAF, doesn't the ECM utilize VE tables only when in open loop SD - as in during warm up - then it goes into closed loop and maps fuel based on BLM's learned in such mode?
Also, once in closed loop MAF, all the time spent on higher VE tables is never looked at by the ECM.

My point is all the VE tuning in SD will do is get you close at part throttle
(3,000 rpm and lower I believe) in open loop MAF like you want, but the rest of the ranges will require tuning with a wideband in closed loop MAF during higher throttle, PE and WOT.

Bigtoyz

iTrader: (2)

I had read somewhere that closed loop uses the VE tables also. I'll see if I can find that info again.

chief455

iTrader: (21)

From the VEMaster download website:

EE: 94-95 Corvette, Camaro/Firebird, Impala, and other LT1-based B-bodies. Note that the VE tables are used only in the backup Speed Density mode on these cars (i.e. as long as the maf is plugged in and working, VEMaster will have no apparent effect.) You can also explicitly enable SD mode via Tunercat or LT1Edit.

Since this program was designed to improve drivability and not top-end power, I recommend tuning no higher than the default setting of 3000 rpm. There are two reasons for this. One, any time you swap in a more radical cam for the stock cam, your VE will suffer at lower rpm's. However, at higher rpm's, the more radical cam will first equal, then exceed, the volumetric efficiency of the stock cam. At these higher rpm's, though, it is safe to assume one will be operating at W.O.T., and the fuel can more easily be controlled by adjusting the Power Enrichment table. Second, the fuel trim cells in stock form end at 2000 rpm. So from 2000 rpm on up, you only have that one set of learns. Presumably, most of the data (and driving) you will be doing will be closer to 2000 rpm than not. Therefore, the accumulated learns your car has in the 2000+ rpm cells will mostly be based upon data in the 2000-3000 rpm range, and thus should not be applied to higher rpms.

Bigtoyz

iTrader: (2)

What I have been reading up on is the 96-97 OBD2 and I swear for them I read that Ve table was used........I just have to find it but I did find something else of interest.

"When you go WOT, the fueling scheme changes somewhat, and becomes a kind of mix between the closed loop and open loop modes. The new mode is called PE, or Power Enrichment." and is for 96-97 OBD2 info.

Z28Camaro30Ann

iTrader: (15)

I see your point, HOWEVER, what happens if your MAF goes out while you are at WOT? What happens if your MAF gives out while on a cruise or a road trip? What happens if you are at the track and want to compare SD vs MAF times?

Just because they are not "used" when the MAF is operational (which is not 100% proves as far as I know), doesnt mean you SHOULDN'T tune the VE Tables across the board. I am still trying to learn how to do this, but you also are in PE mode at 24% throttle in some cases (like going up a hill) and guess what PE uses....Open loop fueling because the PCM does not correct fueling in PE. SO if you MAF gives out and the VE Tables arent right, all of a sudden you could have a MASSIVE lean or rich problem at WOT at who knows what RPM and the possibility of damage, or you are stranded on a highway somewhere because you AFR is screwed because your VE tables are set to stock...

Plus, if the PCM DOES for some reason use the VE Tables in conjunction with the MAF tables in MAF mode, I would rather them be correct for peace of mind.

I also would like to do some back to back pulls between SD mode and MAF mode to see what happens just for my own experience...I need the VE Tables tuned for that.

NOW....can we please get back to the point on this topic and move forward??? lol

chief455

iTrader: (21)

We are helping each other learn a few things - it's all good.

I am ready to try an SD tune on my car with a 2 bar MAP - so I'm with you.
I wish VEMaster went the entire rpm range!

My first reply to use injector constant was because you noticed full rich at idle and cruising aound. Sounds like since your increased injector size change the tune went rich.
I was thinking, easy way to lean the entire scale = small change to that constant. It COULD get most of your driving air/fuel closer and make tuning the WOT % change to AFR easy enough as well....