Transmissions, Torque Converters and Rear Gearing - How to Improve RWHP
#11
06-28-2009, 08:33 PM
Record Breaker
I think you are missing the point AF, the faster the engine gets into the middle of the torque curve, or power sweet spot, the more efficient the entire drive train will be. A stall converter will lock up at 2000 rpm as well as it's intended stall, if the engine is not working very hard, it will lock up just fine at about any rpm, however, if the mass(truck) is under stress (load) the converter will allow the engine to get to an RPM well up in the torque curve where it will make more power to offset the increased drag/torsion of the weight of the truck etc.
Which would be better in the mud? bogging at 1000 rpm or the engine gennin at 2500 rpm?
Which would be better in the mud? bogging at 1000 rpm or the engine gennin at 2500 rpm?
#12
06-28-2009, 08:41 PM
Champion
Info from TCI site
So with all the questions going on I figured I post up this thread as more of a knowledge thread when it comes down to those of us looking to improve how our power is getting to the ground and just as an FYI for those just curious about what can be done to improve it. Please only post information that is based on facts about our trucks and the transmissions in them or relative to any questions asked in this thread and not personal opinions.
I'll start with a few questions I have had for a while now that I am looking to install my new TC soon...
- How do TQ Converters and the OD on our transmissions work together? Basically why is the stock TC set to 2300rpm when at stock cruising at 65-70mph my engine rpms were well below that around 1900rpm? Even with 4.56 gears the rpms are just below that at 2200rmps which leads me into my next question...
- Is the TC only for acceleration or should it be active or "locked" at cruising speeds? When just cruising around town Im barely above 1500rpms so its technically slipping and not locked when cruising on the highway Im barely under it right around 2200rpms so its still technically not locked. Now accelerating is an entirely other story as I see the upper 3000rpms in the city and on the highway while accelerating. So really the ONLY times it would be "locking" is during acceleration, and thats with the stock converter.
I'll start with a few questions I have had for a while now that I am looking to install my new TC soon...
- How do TQ Converters and the OD on our transmissions work together? Basically why is the stock TC set to 2300rpm when at stock cruising at 65-70mph my engine rpms were well below that around 1900rpm? Even with 4.56 gears the rpms are just below that at 2200rmps which leads me into my next question...
- Is the TC only for acceleration or should it be active or "locked" at cruising speeds? When just cruising around town Im barely above 1500rpms so its technically slipping and not locked when cruising on the highway Im barely under it right around 2200rpms so its still technically not locked. Now accelerating is an entirely other story as I see the upper 3000rpms in the city and on the highway while accelerating. So really the ONLY times it would be "locking" is during acceleration, and thats with the stock converter.
DESCRIPTION:
The first step into serious high performance, the Breakaway® is a great torque converter for moderately modified street machines and weekend racers also used as daily drivers. It provides approximately 2400 to 2600 rpm flash stall without negatively affecting part throttle driving. Designed for efficiency at highway cruising speeds and to launch hard at wide open throttle, the Breakaway® is a fantastic all-around torque converter.
Features: Furnaced-brazed fins, needle bearings, hardened pre-ground pump hub, computer balanced Benefits: Harder launches, quicker acceleration, improved low end power, bolt-in (no modifications required), 1,000+ rpm increase in stall over stock
This states different numbers than what has previously for stated stall speeds.
#13
06-28-2009, 08:43 PM
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#14
06-28-2009, 08:59 PM
Champion
#15
06-28-2009, 09:08 PM
Record Breaker
#16
06-28-2009, 09:09 PM
Champion
But I also understand the question you are asking. If you are not stressing the converter it will try to lockup. Sort of like have a wieght on a rubber band. the distance between the end with the weight and the end you are holding will settle out to a certain lenght, but if you jerk your end up the rubber band will stretch depending on how hard you pulled. Using more wieght would be the same as having a heavier vehicle. Or if the rubber band doesn't stretch when pulled it is effectively locked up. As I stated above in addition to the normal TC stall we also have a TCC. (Clutch)
#17
06-28-2009, 11:03 PM
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#18
06-29-2009, 12:31 AM
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#19
06-29-2009, 01:31 AM
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#20
06-29-2009, 10:09 AM
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