Idle surge and weird noise
#22
TECH Senior Member
#23
TECH Senior Member
iTrader: (39)
THIS. Because of the rear gear ratio. At the same MPH, a deeper gear is going to keep the RPM's higher and it has more gear multiplication or mechanical advantage.
It also has to do with the load on the engine which is a direct effect from rear gear. Especially with a 4.88, if that's indeed what it has.
Without doing the math, I've worked 12 hours today and I don't care too, at 40mph with a 4.88 gear your RPM's are obviously going to be higher than a 3.23 gear set. With the converter locked up, with a 3.23 gear it's going to load or cause a lot more strain on the engine due to load or mechanical advantage. With a deeper gear, the rear end is going to be doing more work than the engine(so to speak).
Think of it like riding a ten speed bike. At lower speeds, it's better to be in a lower gear because of gear multiplication and the multiplication of torque. If you are in a higher gear and lower speeds, the more work/force you have to do, or in this case the engine.
It also has to do with the load on the engine which is a direct effect from rear gear. Especially with a 4.88, if that's indeed what it has.
Without doing the math, I've worked 12 hours today and I don't care too, at 40mph with a 4.88 gear your RPM's are obviously going to be higher than a 3.23 gear set. With the converter locked up, with a 3.23 gear it's going to load or cause a lot more strain on the engine due to load or mechanical advantage. With a deeper gear, the rear end is going to be doing more work than the engine(so to speak).
Think of it like riding a ten speed bike. At lower speeds, it's better to be in a lower gear because of gear multiplication and the multiplication of torque. If you are in a higher gear and lower speeds, the more work/force you have to do, or in this case the engine.
#25
TECH Senior Member
#26
got it tuned today, runs 100x better but surges every once in a while. Also he made the converter lock only on wide open throttle or above 75mph. Drove it home and the car still does the same shuddering around 40 but goes away if I barely press the brake. Also it made 288 rwhp I have no clue why, they couldn’t figure it out either.
Last edited by Caulin; 12-01-2018 at 12:39 AM.
#27
THIS. Because of the rear gear ratio. At the same MPH, a deeper gear is going to keep the RPM's higher and it has more gear multiplication or mechanical advantage.
It also has to do with the load on the engine which is a direct effect from rear gear. Especially with a 4.88, if that's indeed what it has.
Without doing the math, I've worked 12 hours today and I don't care too, at 40mph with a 4.88 gear your RPM's are obviously going to be higher than a 3.23 gear set. With the converter locked up, with a 3.23 gear it's going to load or cause a lot more strain on the engine due to load or mechanical advantage. With a deeper gear, the rear end is going to be doing more work than the engine(so to speak).
Think of it like riding a ten speed bike. At lower speeds, it's better to be in a lower gear because of gear multiplication and the multiplication of torque. If you are in a higher gear and lower speeds, the more work/force you have to do, or in this case the engine.
It also has to do with the load on the engine which is a direct effect from rear gear. Especially with a 4.88, if that's indeed what it has.
Without doing the math, I've worked 12 hours today and I don't care too, at 40mph with a 4.88 gear your RPM's are obviously going to be higher than a 3.23 gear set. With the converter locked up, with a 3.23 gear it's going to load or cause a lot more strain on the engine due to load or mechanical advantage. With a deeper gear, the rear end is going to be doing more work than the engine(so to speak).
Think of it like riding a ten speed bike. At lower speeds, it's better to be in a lower gear because of gear multiplication and the multiplication of torque. If you are in a higher gear and lower speeds, the more work/force you have to do, or in this case the engine.
#28
TECH Junkie
One way or another I would not put in a stock converter. Without knowing what cam you're running I would go with something like a yank ss3600
#29
#30
TECH Junkie
This video is my converter cruising down the freeway at 80 mph then going wot 4-3 downshift. Tighter converters will not stall as high and will give lower shift extensions. Also depends on how much power one is making and how they are making there power.