Knuckl3s

so first things first I have read that bpw and bpc have different effectson the ve tables... is this true???
so with that said I calculated my bpw in tp with this equation from a different thread -
BPC = 1461.5 * (cyl size / gm/s of fuel)

For cyl size you find your engine size in Liters. 350 * 16.39 = 5736.5 cc or 5.74 liters Then divide this by 8 to get your cylinder size 5.74/8 = .717L

For say a 65 lb/hr injectors : 65 / 3600 * 453.6 = 8.19 gm/s

So our formula works out to be:

BPC = 1461.5 * (0.717 / 8.19) = 127.95

So our new BPC is going to be 128. Now what happens if you don’t have stock fuel pressure? There is a formula for this as well.

SQRT(New PSI / OLD PSI) x (Injector lbs/hr) = New lbs/hr

Lets try it for 65 lb/hr injectors at 15 psi with an old pressure of 12 psi

SQRT(15 PSI / 12 PSI) x (65 lbs/hr) = 72.67 lbs/hr

my setup is 65lbhr injectors running 16psi fuel pressure with a tb spacer and drop open element. so I plugged my numbers into the equation and got 98 for my bpw. I put that into my bin and burned a chip and engine ran bad. using grumpys intro to tuning thread I set the main sa table and ve tables to start and adjusted from there. I got it to idle ok now but part throttle and more is horrible, it bogs and studders very badly and my ve tables are close to if not maxed and my o2 is screaming lean and my blms are at 150 pretty much all the time. I cant figure out what im doing wrong. I have spent hours in the prom tuning guide book aka my bible and also searching the threads for info.
I will upload my latest bin and datalog for anyone to look at. there is no mph as my speed sensor is disconnected. that's a long story in itself. my datalog is in tunerpro but I could also get one in winaldl if anyone wants, I do have the injector pw in datastream on winaldl. if there is anymore info anyone needs please let me know.
thank you knuck

RBob

iTrader: (1)

BPC (bpw) is too low, I get 115 with the 65 #hr injectors at 16 psi.

RBob.

Knuckl3s

not sure why I keep getting 96.75 for my bpc when I do the equation. but I wont argue with what you came up with. I entered that in and reset my ve and spark tables to anlu stock. adjusted my ve for idle and did a few datalog drives and burns. after about 6 im getting pretty close to 135 blm range around 2000 rpms cruising 60 mph. so a few more should do.
should I focus on my ve tables and main sa table at the same time? or do one at a time starting with ve?

Knuckl3s

ok I need help. I just spent all day today driving and datalogging with winaldl and half the time winaldl would stop sampling after like 2 mins. I was also trying to use aldltobin. but no matter how much I raised my ve tables as soon as the engine goes into closed loop the blms go right to 150. I tried retarding my timing degree at a time and found a sweet spot for open loop start up at 5* at 800 rpm and 30kpa but thats it. I have no idea where to go with this. I have restarted my ve and main spark tables numerous times and always end up in the same place

RBob

iTrader: (1)

EGR and CCP disabled? The other item is the BPC value location in the BIN. There is a single value for when EGR is inactive, and a table of values for when the EGR is active.

RBob.

Knuckl3s

im guessing ccp is the canister purge? I cant find it in the chip(tunerpro), but the only vacuum lines I have coming off the engine are for my brakes and my map sensor off the tb. egr is disabled, havent gotten around to putting a delete plate on yet. how could the location of the bpc be messed up from a factory bin though? if that's what your saying

last night I grabbed fast355's awks bins from the car wont idle in gear sticky in the prom tuning guide book. im gonna try to use his ve tables and spark tables as a baseline and see how the engine responds today.

thanks knuck

RBob

iTrader: (1)

CCP is canister purge, wreaks havoc with VE learning.

The BPC locations are the way they are from the factory. Since EGR is disabled in the calibration then the single value will always be used. On the TBI board here up in the sticky's the "come in for a free tune" thread has a lot of good information in it.

RBob.

Knuckl3s

alright ill look into the ccp thing.
on another note I think I finally figured out my problem. this weekend just out of curiosity started raising my bpc setting in increments of 5 and when I got to 140 it started to richen up. im now at 155 with the ve tables almost mxed I a few areas, should I keep going up with the bpc to get the fueling right?? and why do you think the math is so much different from where it actually wants to run??
oh and if I don't have a mph reading will the ecm still go into highway mode?
thanks knuck