Did I do this right? Video Datalogging

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a91what

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Mod Dude
Apr 6, 2011
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Yes that is the correct information, based on what you found I suggest that you open the TB a bit.

get the car running with the idle valve set at 80% hot. then open the TB a full turn, recalibrate the TPS. The idle will be higher than before, lower the Idle valve duty% until the car idles at the speed you want it to [ likely around 750rpm] The valve duty should be around 30-40% at this point. You are now done and the idle valve is set properly for most installs.

For larger cams i like to set the idle with the IAC unplugged and timing locked to around 20* to around 200rpm greater than the hot idle speed. The idle may be erratic at this point thats ok, we are going to plug the idle valve back in and get it setup so that the closed duty% barely raises the idle speed.
Now we use timing to force the idle down to where we want it, its not uncommon to run in the 0-10* advance range with a very large cam at idle. sometimes the engine will even want negative timing during warmup.
 

GodStang

Member
Nov 20, 2015
27
4
13
39
Yes that is the correct information, based on what you found I suggest that you open the TB a bit.

get the car running with the idle valve set at 80% hot. then open the TB a full turn, recalibrate the TPS. The idle will be higher than before, lower the Idle valve duty% until the car idles at the speed you want it to [ likely around 750rpm] The valve duty should be around 30-40% at this point. You are now done and the idle valve is set properly for most installs.

For larger cams i like to set the idle with the IAC unplugged and timing locked to around 20* to around 200rpm greater than the hot idle speed. The idle may be erratic at this point thats ok, we are going to plug the idle valve back in and get it setup so that the closed duty% barely raises the idle speed.
Now we use timing to force the idle down to where we want it, its not uncommon to run in the 0-10* advance range with a very large cam at idle. sometimes the engine will even want negative timing during warmup.

Thanks for the input. What is the definition of "large cams"? These are Crower Stage III N/A Cams (car is supercharged).
 

a91what

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Mod Dude
Apr 6, 2011
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Hillsborough county
Thanks for the input. What is the definition of "large cams"? These are Crower Stage III N/A Cams (car is supercharged).
When i think large cams they pull poor vacuum at idle and have an aggressive profile. based on your MAP readings you have large cams.
With cams that large sometimes i will use Alpha-N based fuel and ign tables and then add on additional SD based modifier tables. This is an advanced tuning concept however and I dont suggest it unless you have a solid grasp of tuning in general.
 

GodStang

Member
Nov 20, 2015
27
4
13
39
When i think large cams they pull poor vacuum at idle and have an aggressive profile. based on your MAP readings you have large cams.
With cams that large sometimes i will use Alpha-N based fuel and ign tables and then add on additional SD based modifier tables. This is an advanced tuning concept however and I dont suggest it unless you have a solid grasp of tuning in general.

Thanks and this is my first tuning experience so I will hold off on that.