Switching to speed density 94 LT1
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From: Baton Rouge, LA
Switching to speed density 94 LT1
What needs to be done to switch to speed density mode in the PCM? Tunercat has an option to goto speed density mode. Is just flip the flag, unplug MAF and reflash? Or is there something else that needs to be done?
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Joined: Jan 2000
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From: Ocean Springs, MS
yep, just flip the SD flag and go.. be aware that the factory VE tables need alot of work with a modified motor.. just download VEmaster EE and a copy of datamaster EE, let your engine go into closed loop, log a quick drive, run the log and a saved copy of your bin through VE master, smooth it, reburn and repeat as meany times as needed to get those BLMs in line.
Thread Starter
Registered User
Joined: Jul 2005
Posts: 747
From: Baton Rouge, LA
yep, just flip the SD flag and go.. be aware that the factory VE tables need alot of work with a modified motor.. just download VEmaster EE and a copy of datamaster EE, let your engine go into closed loop, log a quick drive, run the log and a saved copy of your bin through VE master, smooth it, reburn and repeat as meany times as needed to get those BLMs in line.
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Joined: Jan 2000
Posts: 222
From: Ocean Springs, MS
found this over on corvetteforum
"VeMaster's default BLM target is 124, but you can raise that if needed. Just remember you want your BLMs to stay a bit below 128, so when you go into PE mode they will lock-in at 128."
"VeMaster's default BLM target is 124, but you can raise that if needed. Just remember you want your BLMs to stay a bit below 128, so when you go into PE mode they will lock-in at 128."
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From: Baton Rouge, LA
Ugh VEMaste+Datamaster == bad tune. I run VEMaster with freescan and it does minor adjustments and the tune works
I ran it with Datamaster and the car wouldn't rev over 2k in neutral and drove like ****.
I ran it with Datamaster and the car wouldn't rev over 2k in neutral and drove like ****.
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From: Ocean Springs, MS
I would suggest making a copy of your tune before you run vemaster on it so you can then compare the two to see the changes inside of tunerpro or tunercat.. remember that the blm's bottom at 108.. so if it does on a certain cell you can only correct for a 15% variance between each log and tune.. takes a few times to get it close and a dozen more to get it perfect..
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Joined: Jul 2005
Posts: 747
From: Baton Rouge, LA
I would suggest making a copy of your tune before you run vemaster on it so you can then compare the two to see the changes inside of tunerpro or tunercat.. remember that the blm's bottom at 108.. so if it does on a certain cell you can only correct for a 15% variance between each log and tune.. takes a few times to get it close and a dozen more to get it perfect..
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Joined: Jan 2000
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From: Ocean Springs, MS
hmm, have you compared a before and after VE to see what it did? You really need to open it in tunerpro, manually smooth large spikes and then use the smooth function in the toolbox to make it perfect.. this way you will not feel any jerking as the pcm pulls VE data from the different cells
Thread Starter
Registered User
Joined: Jul 2005
Posts: 747
From: Baton Rouge, LA
hmm, have you compared a before and after VE to see what it did? You really need to open it in tunerpro, manually smooth large spikes and then use the smooth function in the toolbox to make it perfect.. this way you will not feel any jerking as the pcm pulls VE data from the different cells
This is the results of using freescan
http://breakherthewang.com/SDTunetest_vem.txt
This is the results of DataMaster.
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Joined: Feb 2004
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From: VA
For me it was easier to just do it all in excel, where I can tweak things to my liking, rather than guessing at what if any input filtering VEM is doing.
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Joined: Jan 2000
Posts: 222
From: Ocean Springs, MS
I don't think the problem is with VEM, I've run dozens of logs through it to get a VERY nice tune.. my gues is that if it is the factory VE table it will be far off if any significant engine mods have been performed (cam). You also must be sure you are free of vacuum leaks and have accurate O2 readings, no exhaust leaks, etc to perform this recalibration. Double check your injector constant and cylinder volume is correct as well. What are your mods anyway? Something's def not right:
cell[1400][70] 78.1 1.03 80.9
cell[1400][75] 78.5 1.03 81.2
cell[1400][80] 78.9 0.895 70.7
cell[1400][85] 79.3 0.756 59.8
The VE should only go up as MAP increases, not down.
Have you visually looked at the graph of your new BINs? You will probably see that it contains alot of pits and peaks.. it must be smooth in the end.
cell[1400][70] 78.1 1.03 80.9
cell[1400][75] 78.5 1.03 81.2
cell[1400][80] 78.9 0.895 70.7
cell[1400][85] 79.3 0.756 59.8
The VE should only go up as MAP increases, not down.
Have you visually looked at the graph of your new BINs? You will probably see that it contains alot of pits and peaks.. it must be smooth in the end.
Last edited by Paul94Z; Mar 22, 2007 at 04:19 PM.
Thread Starter
Registered User
Joined: Jul 2005
Posts: 747
From: Baton Rouge, LA
I don't think the problem is with VEM, I've run dozens of logs through it to get a VERY nice tune.. my gues is that if it is the factory VE table it will be far off if any significant engine mods have been performed (cam). You also must be sure you are free of vacuum leaks and have accurate O2 readings, no exhaust leaks, etc to perform this recalibration. Double check your injector constant and cylinder volume is correct as well. What are your mods anyway?