LT1 Gear swap tuning.
LT1 Gear swap tuning. I'm going to be putting 3.73 gears in my 2.73 car, as well as changing everything in the PCM. My question is this...
Do I simply need to change the gear ratio in that section? Will I need to scale the shift point charts as well, or will tunercat do that automatically when I enter the new ratio?
I would also imagine that I will have to do something to the trans. tables to get lockup and everything correct.
Could somebody go over each table or section that needs to be modified after a gear swap?
Do I simply need to change the gear ratio in that section? Will I need to scale the shift point charts as well, or will tunercat do that automatically when I enter the new ratio?
I would also imagine that I will have to do something to the trans. tables to get lockup and everything correct.
Could somebody go over each table or section that needs to be modified after a gear swap?
The shift points are all in the tables as MPH values. Will those automatically be scaled and adjusted when the new ratio is entered?
EDIT: Hell, I guess I can get on the software and see for myself.
EDIT: Hell, I guess I can get on the software and see for myself.
I just toyed with it a bit. The shift point MPHs do not change when the new ratio is entered. At WOT, the table shows 48 MPH for the 1-2 shift. When I have 3.73s, it'll need to be much lower. Apparently those tables will need to be scaled down.
I just watched a guy tune in a new set of gears using tunercat this weekend. While I don't know all tables that he touched, there were a significant amount. I know for a fact that he modified the shift points and lockup.
In LT1Edit (not that it is the same for you, since you did not say what software you were using) there are two tables. One is rpm. One is mph. Depending on which it is listening to, it will shift according to that table.
**** points
Originally Posted by koolaid_kid
In LT1Edit (not that it is the same for you, since you did not say what software you were using) there are two tables. One is rpm. One is mph. Depending on which it is listening to, it will shift according to that table.
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Originally Posted by Rhino
I just watched a guy tune in a new set of gears using tunercat this weekend. While I don't know all tables that he touched, there were a significant amount. I know for a fact that he modified the shift points and lockup.
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Verdad Gallardo It seems that he scaled the lockup as well, although I didn't get a good look at it due to his laptop getting low on battery and needing to finish up quick. I'll shoot him an email today and see if he can explain what he was doing.
2.73/3.73 = .7319034
Scale every shift table, WOT (norrmal, hot, cold kickdown) and part throttle (normal, performance, manual, cruise) , and every TCC table (normal, manual, hot, performance, cruise) by that amount.
Scale every shift table, WOT (norrmal, hot, cold kickdown) and part throttle (normal, performance, manual, cruise) , and every TCC table (normal, manual, hot, performance, cruise) by that amount.
Yes, you need to scale all the trans tables, if you are using Tunercat after setting up the speedo settings. I manually generate the values and then adjust them based upon my GPS readings. The trans will shift based upon engine rpm AND vehicle speed.
BTW, I was the guy at the Kansas City Camaro Nat's this past weekend, tuning the LS2 '69 Convertible Camaro. The previous "Professional Tuner" did not scale ANY of the trans tables for the 3.5 gears. He used a 4.1 gear file and it was a mess.
Respectfully,
Anthony
BTW, I was the guy at the Kansas City Camaro Nat's this past weekend, tuning the LS2 '69 Convertible Camaro. The previous "Professional Tuner" did not scale ANY of the trans tables for the 3.5 gears. He used a 4.1 gear file and it was a mess.
Respectfully,
Anthony
