I think cam is 228/232 112... mild... already been tuned.
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
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.Originally Posted by joecar
Bigger cams see bigger differences when adjusting EOIT.
Congratulations on getting your new job.BTW: I recently started on a new job (Dec 3rd), I now work at www.karmaautomotive.com
I hope you're happy working there.
ok , this cam has only 6 degrees overlap.
Last edited by joecar; February 6th, 2019 at 09:41 AM.
Hey thanks.Congratulations on getting your new job.
I hope you're happy working there.
There's a lot to learn, but I am having a lot of fun here
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?
1998 GMC Sierra K1500 5.7/4L80E, longtubes, 411 w/COS 5, marine cam/intake, Whipple. 91 octane at 6000'.
1997 GMC Sierra K3500 7.4/4L80E, 411 w/COS 3, Whipple, small cam.
2004 Corvette Z06 with longtubes.
Hmmm... now you've got me thinking.
Do you feel like doing a little experiment for me?
Depends on how easy it is/isn't.
1998 GMC Sierra K1500 5.7/4L80E, longtubes, 411 w/COS 5, marine cam/intake, Whipple. 91 octane at 6000'.
1997 GMC Sierra K3500 7.4/4L80E, 411 w/COS 3, Whipple, small cam.
2004 Corvette Z06 with longtubes.
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.
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