Alright guys, I am trying to wrap my head around the torque modelling/ virtual torque on a Gen 4 and want to make sure I understand it as best I can so I am not jumping blindly into it.
I understand that the values in the virtual torque table respond directly to the set amount of torque my engine will produce at whatever the given spark value is. Torque basically translates to a set amount of air going into the engine. That's the simple part.
I have read all kinds of mixed opinions on this and have even come across guys that say to not even bother with it.
From most stuff I have read if you do not change the values to match your torque increase with a cam or whatever you have changed the engine wont produce its full torque capacity.
I know putting the car on the dyno would be the best option however that is not an option for me, so I am wondering what the best way to go about this is?
Here are my thoughts.
My factory LS3 makes 426 foot pounds of torque at approx. 4600RPM
The spark 30 table on my MAP virtual torque table shows 433 ft/lbs @ 4800 rpm which is right in line with what the car is making.
The camshaft I am using along with the long tube headers, X-pipe and CAI made 530 WHP and 500 Ft/lbs of torque @ 4600 RPM with the identical setups on other cars
Corrected to FWHP would be roughly 580 HP and 553 ft/lbs.
So knowing these values I would have to multiply my MAP/Spark tables by 1.3 to come up with 563 ft/lbs at 4800 RPM which falls in line with my particular setup.
My after market cam seems to make peak torque @ 4600 just as the stock camshaft does so that should make things a bit easier to figure out.
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As far as the idle goes, the stock engine ran around 30 KPA at idle(650 RPM) with 13 degrees of base ignition timing
My current cam runs 57 KPA at idle (800 RPM) with 18 degrees of base ignition timing
I am noticing small amounts of negative torque values in the idle areas for the stock camshaft.
I know that you want negative torque at idle or very close to the actual idle torque to reduce the integral air table from adding unwanted air causing stupid stuff for example my little throttle idle blip I have been cursed with lol
So is the proper way to just transfer those negative torque values from 30 KPA on the table to the 57/60 KPA area on the table?
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Engine torque can be logged with VCM scanner. Are you able to log torque and plug those values back into the appropriate spots on the torque tables?
I might be overthinking this or be right out to lunch but how do all you guys do this?
As far as the Airmass tables in Virtual Torque goes, how does one figure out the correct torque values for these?
The values are a little bit different than the Map Based torque tables.
On the spark 30 table it shows peak engine torque values between 1200-2000 RPM.
Attachment 142651
That does not seem right to me.