I think cam is 228/232 112... mild... already been tuned.
Printable View
I think cam is 228/232 112... mild... already been tuned.
BTW: I recently started on a new job (Dec 3rd), I now work at www.karmaautomotive.com :santa1:
Yeah the VE can change, but it's like aaronc7 already said... the actual VE of the engine doesn't change but what does change is how well the fuel is atomized and mixed in the cylinder charge (which affects how well it burns) and that means you may need to adjust your VE table after changing EOIT.Quote:
Originally Posted by joecar
Bigger cams see bigger differences when adjusting EOIT.
Congratulations on getting your new job. :cheers:Quote:
Originally Posted by joecar
I hope you're happy working there.
ok , this cam has only 6 degrees overlap.
Hey thanks.Quote:
Originally Posted by statesman
There's a lot to learn, but I am having a lot of fun here :cheers:
I mentioned to my boss taking a car to the local drag strip, he thinks it can be arranged... :)
I just thought I'd come in here and muddy the waters a bit. Some guy recently posted on Youtube about converting his LT1 over to a 411 PCM with minimal effort. He made the assertion that one could convert a 96-97 OBDII car to a 411 by simply pinning in a 411. The OBDII LT1 and Vortec 350 share crank reluctors and sensors, coils, similar ICMs, etc. I can't believe nobody has made this connection yet. He went to the extent of modifying his intake manifold to accept a distributor to run the 1X Vortec cam sensor. Later, he unplugged it and observed that the engine ran no differently. This got me curious, so a week and change ago I unplugged my cam sensor and have been driving the truck ever since with no apparent change in driveability. This guy wasn't full of crap. He stated that by disconnecting the cam sensor, you put the engine into batch fire mode for the injectors. Well for a race car running a stock motor, this really doesn't matter at all. I may be able to get a rule change implemented as the good Optisparks are not getting any cheaper and for a lot of people are a perceived downfall to the platform. Moreover, it really got me to thinking about this thread. Some people really believe it makes a difference, but others like me and this Youtube dude clearly have altered injection timing with no apparent effect. Mind you my 1500 is not a race car, I like to lug it around with a locked converter uphill at 1500 RPM so for it to still do what it does really begs the question how much does this really matter?
Hmmm... now you've got me thinking.Quote:
Originally Posted by Supercharged111
Do you feel like doing a little experiment for me?
Depends on how easy it is/isn't. :D
Oh it's not all that difficult. Since you're running without a cam sensor and possibly in batch fire mode (which I'm not entirely certain that it does put you in permanent batch fire mode), I'd like you to do a log of your trims while driving (to establish a baseline for your fuel trims) and then change {B3703}Injection Timing Trim to 2.55 across the board and then do another log of your trims while driving. I've never understood the purpose of that table... it doesn't appear to do anything in normal mode, so I was thinking that maybe that table is used when in batch fire mode... although even that wouldn't make a whole lot of sense, but anything is possible with GM.
I think I can handle that.
Interesting... we'll see what B3703 does.
Going to play with the calculators when some decent weather breaks. My cam has a good amount of overlap, so I guess I should see a change.
Got some data yesterday, but I goofed and logged LTFTs with and without cam sensor, didn't change the value at all. Will re-engage tomorrow and add STFTs as I ASSume you were after those as well. Fair warning, after yesterday's logs truck isn't looking so hot. Left side ran lean and stayed that way, right side didn't alternate enough so take it for what it's worth.
Yeah, we will need STFTs as well. If it does change anything, the change might be small and only show up on STFTs.
If the left side is significantly lean, you should probably investigate that before worrying about this experiment.
Wideband lives in the left bank and showed 15-16:1, truck got weird after I corrected CMPRET and did a CASE relearn. It's been getting quirky lately, there's definitely a mechanical issue waiting to be discovered. I really didn't expect the effect to be so significant, the root cause is buried deeper than just a bad O2.
By utilizing the 2 external inputs of my V1, or with the converted EGR and A/C inputs. Could monitor camshaft, crankshaft sensors as well #1 spark and #1 injector. Does the scanner support enough resolution to get something useful? What is the sampling rate? Kind of like picoscope output.
When opening a stock 97C5 tune file in hptuners the boundry value is shown and quite different from later values.
7.22 boundry and 4.78 normal(B3702)
Attachment 22741
Scantool logs pids at 10Hz for LS1A/LS1B/P01 and 40 Hz for E38/E67.
1997/8 LS1's do have various differences compared to later LS1's.