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I think this is all false knock... this is my KR data from before i took 4 degrees out.
And this is after..... ill post an actual log on it for you all... just want to make sure im doing it all right.
this is what my blms look like.......
here is my spark table..tablmy cam is the XM276HR, i have flat top pistons, with the head gasket and the decking the blocks and heads have im about 11.2/1 compression.
The car runs great, hardly any surging and my vac hangs about 14-15.
Re: Vortec, 383 TPI MAF tune guidance and questions.
11.2:1 with vortec iron heads and that cam??with tpi? I dont think that’s necessarily false knock. Thats way up there on cylinder pressure with iron heads
try another 4 deg out and see if it goes away. Maybe target slightly lower blm for abit more rich condition
Re: Vortec, 383 TPI MAF tune guidance and questions.
ok, I sure will.... I just let it idle but this is what its looking like right now, I popped the new chip in. I will get a good driving one tomorrow morning when I go to work. and thank you for your help.
im not sure how to post the data log file. so I put it in a zip file hoping it would work.
Re: Vortec, 383 TPI MAF tune guidance and questions.
you can check the settings I have, figure it would be easier this way, I want to learn how to do this the right way, I have been learning the best I can. there is sooooo much to learn.
thanks everyone.
Re: Vortec, 383 TPI MAF tune guidance and questions.
I think you got the hang of the process so far its just that 11:1 on iron heads with a smallish cam with tpi’s huge torque producing effect in the sub 3000 rpm range, i think you will have issues with knock and have to lower timing substantially.
Cranking compression test could help indicate what cylinder pressures might be. Much over 200 tends to get tougher on pump gas
Re: Vortec, 383 TPI MAF tune guidance and questions.
Ok, so took a scan of it this morning and wow it really cleaned up.... ill post it when i get somewhere with internet(im a truck driver/hazmat fuel hauler...)
Ill post the log..... here is a pic of what it looks like now though..
Re: Vortec, 383 TPI MAF tune guidance and questions.
Yeah 120-124 maybe depending what it correlates to with a wideband. Heavier throttle and loads that may not quite be a PE event may want to be mid higher 13’s afr to keep cool. Stoich on 10% ethanol fuel is closer to 14.1-14.2 now. Mid 13’s is ok for moderate part throttle higher lv8 loads.
Re: Vortec, 383 TPI MAF tune guidance and questions.
Ethanol will actually help with your detonation issues - it runs cooler and generally increases effective Octane. Honestly that much compression on iron heads with a relatively mild cam..... you would benefit from E85, which is in the neighborhood of 106 Octane. It's essentially race fuel you can buy for $3 a gallon.
In any case - richen it up and it's not going to want a lot of timing. Good heads don't need as much timing anyway. Timing is a crutch for poor flame propagation through the cylinder. Really efficient heads such as the 4G63 Mitsubishi heads only run about 4-6 degrees up top under boost. Don't worry about trying to give it a "lot" of timing - give it what it wants.
Re: Vortec, 383 TPI MAF tune guidance and questions.
Yeah it matches well and its gonna make gobs of power because of the compression. Just at the limit of the fuel. E85 or even E50 would fly in that thing
Re: Vortec, 383 TPI MAF tune guidance and questions.
It can be harder on fuel system components and pumps/injectors. You would need atleast 30%-40% more fuel to run e85. Larger injectors and more pump flow capability depending on hp.
Re: Vortec, 383 TPI MAF tune guidance and questions.
I took that other 4* of timing out all across the board, is it suppose to get leaner when i do that?
Also when i attempted to make it more rich, she starts shaking. Also the knocks came back when it got richer.. can you shed some light on that? On why.. i guess it doesn't quite make sense to me.
Re: Vortec, 383 TPI MAF tune guidance and questions.
On the timing where it showed little knock i took 1* of timing out of each of those cells..and now i think back to my blm.... question on the blm.
If im targeting a little lower than 128 which is 14.7 afr and my computer is targeting 14.7 but really want 14.0 wouldnt the computer fight me to bring it back up to 14.7?
Not sure if i worded it correctly.
I attached the bin, and the data log. I hope Im doing it right.
after I put a new chip in should I see instant results or is it mandatory to go drive it for 20 min?
Last edited by happyhapka; 12-21-2019 at 01:28 PM.
Re: Vortec, 383 TPI MAF tune guidance and questions.
When timing is pulled, burn happens later and can be incomplete going out the exhaust. Giving impression its lean as theres unburnt air.
richer and shaking maybe its missing? Seems odd it would do that. Go by feel tho and give it what it wants to run best at
new chip try disconnecting ecm power to reset things. Targeting lower by adding fuel the ecm will try to correct back. You can adjust the o2 swing points (rich/lean offsets) to help bring target afr up or down as needed. I think the table is soemthing like 02 milivolts rich lean versus Lv8. Something like that. Are you using the expanded xdf for 6e$? Using 6e for chip?
12-19-2019, 01:41 PM
