Please guide me on how to datalog.

**Shawn1989** · 12-01-2014

Lol I died laughing.

Anyways
Cant remember what my builder said.
Can I run a heavier weight to compensate for it?

**steveo** · 12-01-2014

just some stuff to keep in mind

as a general rule, loose clearances like high volume pumps and thick oil. tight clearances like thinner oil and high pressure pumps.

you can mix grades of oil. if you're running 5w30, it's ok to add a bit of 20w50 to it until it does what you want.

a bit thicker oil wont hurt anything EXCEPT if you're running a weaker stock oil pump drive gear with a hv pump and thick oil something will probably break on you eventually.

something else to keep in mind is that 3psi of oil pressure at hot idle IS within factory specs for a smallblock chevy, although i wouldn't accept that on an engine that i built.

oil pressure at idle depends a lot on your tune. if you have a rough idle, the pump doesn't have constant momentum and you'll get really low jumpy oil pressure.

does the pressure come up quickly if you rev it a bit?

**Shawn1989** · 12-01-2014

You just made me feel a lot better with that post lol

the oil pressure shoots up when I give it throttle

**dave w** · 12-01-2014

I combined both logs and crunched the data logs with an Excel spreadsheet. I did not find any Closed Loop BLM in the data logs, so I don't really know if the AFR is rich or lean. I've posted screen shot of what I did find in the spreadsheet. I wonder what is happening with KNOCK?

I recommend tuning Open Loop only with a Wide Band O2.

dave w

**Shawn1989** · 12-01-2014

thanks for everything dave. i am going to get ahold of a wideband tomorrow or the day after.

Originally Posted by Fast355

I can tell you first hand that 17 psi with 61# 350 injectors is less than you need for the engine to run cleanly up to 5,500 rpm. You need more like 22-24 psi and to dial back the fuel in the tune. 17 psi is only good for about 285 HP.

285hp is what i was rated at before i rebuilt the engine and you are pretty close to it with the rebuild with vortec heads.
SO
i found the calculations if this is correct.......

http://www.dynamicefi.com/TBI_Fueling.php

330hp * .45 = 148.5 pounds of fuel per hour (#/hr)
148.5 / .85 duty cycle = 174.7 #/hr
174.7 / 2 injectors = 87.35 #/hr per injector.
SQ(87.35 / 61) * 13 = (2.05)*13 = 26.65 psi/injector

^^^that is with their bsfc.... dunno what 9.5:1-10ish:1 and vortecs would fall under..... if its .5 then the fuel pressure will need to be 32.91 ........ SO, with that being said;

does this sound about right? to me, it makes sense TO AN EXTENT. I say this because it "stutters" at WOT in the higher rpm as if its being starved of fuel.....
however, upon startup the car seems to get too much fuel.... sometimes it hesitates to start unless i feather the throttle a tad or lower fuel pressure..... SO will i have to start it with 16psi then raise it up to 27/33 after its running?