TC and LSD questions
#1
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
i tried to search for relative info but still a bit confusing, so why not ask here ![Smilie](https://www.clublexus.com/forums/images/smilies/smile.gif)
i know with the TC it will raise the idle rpm a bit, is that right? and that will also give more hp at the wheel? what's the idle rpm, from what i read it's adjustable? now does that mean if i start my car, run it for 10 mins until the car is at normal running temperature, and i sit at the red light, the rpm would be at like 3000rpm? wouldn't that be high and quite noisy? and isn't that be quite bad for fuel economy?
and with lsd (say trd), what's the advantage above the stock one? what exactly does it do and how does it help traction, hp, etc... with an upgraded tc?
thanks guys, i figure i will never do intake or exhuast on the gs4, but these two, i am interested
![Smilie](https://www.clublexus.com/forums/images/smilies/smile.gif)
i know with the TC it will raise the idle rpm a bit, is that right? and that will also give more hp at the wheel? what's the idle rpm, from what i read it's adjustable? now does that mean if i start my car, run it for 10 mins until the car is at normal running temperature, and i sit at the red light, the rpm would be at like 3000rpm? wouldn't that be high and quite noisy? and isn't that be quite bad for fuel economy?
and with lsd (say trd), what's the advantage above the stock one? what exactly does it do and how does it help traction, hp, etc... with an upgraded tc?
thanks guys, i figure i will never do intake or exhuast on the gs4, but these two, i am interested
![Smilie](https://www.clublexus.com/forums/images/smilies/smile.gif)
#2
![Arrow](https://www.clublexus.com/forums/images/icons/icon2.gif)
well what it does is spin both wheels instead one. puts more power to the ground, so i hear. yet to get 1. i am keeping the exaust stock for now too. but i definatlly reconed getting a better airfilter. trd or k&n make stock replacements. definatly better then the stock filter, and isnt noisy. hope that helps , good luck
#3
Lexus Champion
iTrader: (1)
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
the TC is mostly for increasing efficiency through the drivetrain, you know, that 20-22% loss of bhp and rwhp. so, it increases effective hp like you said.
that 3000 rpm thing isn't true, i don't think. cause you're right, that's very very high. i think you're referring to the stall, which is 2400rpm or 2800, depending on which lsd you get. 2400 works with one lsd, 2800 works better with another lsd(ratio).
i think this is the guts of it. the TC will toss more power at your wheels, and you'll just spin them wildly with TC alone. the lsd puts power to the grippier wheel(say for cornering really), but together, they'll just launch you faster. you get the extra power and extra grip that needs to go with it.
i hope that is accurate and helpful
that 3000 rpm thing isn't true, i don't think. cause you're right, that's very very high. i think you're referring to the stall, which is 2400rpm or 2800, depending on which lsd you get. 2400 works with one lsd, 2800 works better with another lsd(ratio).
i think this is the guts of it. the TC will toss more power at your wheels, and you'll just spin them wildly with TC alone. the lsd puts power to the grippier wheel(say for cornering really), but together, they'll just launch you faster. you get the extra power and extra grip that needs to go with it.
i hope that is accurate and helpful
#4
Pole Position
Join Date: Oct 2002
Location: North Carolina
Posts: 395
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
Originally posted by rominl
i tried to search for relative info but still a bit confusing, so why not ask here![Smilie](https://www.clublexus.com/forums/images/smilies/smile.gif)
i know with the TC it will raise the idle rpm a bit, is that right? and that will also give more hp at the wheel? what's the idle rpm, from what i read it's adjustable? now does that mean if i start my car, run it for 10 mins until the car is at normal running temperature, and i sit at the red light, the rpm would be at like 3000rpm? wouldn't that be high and quite noisy? and isn't that be quite bad for fuel economy?
and with lsd (say trd), what's the advantage above the stock one? what exactly does it do and how does it help traction, hp, etc... with an upgraded tc?
thanks guys, i figure i will never do intake or exhuast on the gs4, but these two, i am interested
i tried to search for relative info but still a bit confusing, so why not ask here
![Smilie](https://www.clublexus.com/forums/images/smilies/smile.gif)
i know with the TC it will raise the idle rpm a bit, is that right? and that will also give more hp at the wheel? what's the idle rpm, from what i read it's adjustable? now does that mean if i start my car, run it for 10 mins until the car is at normal running temperature, and i sit at the red light, the rpm would be at like 3000rpm? wouldn't that be high and quite noisy? and isn't that be quite bad for fuel economy?
and with lsd (say trd), what's the advantage above the stock one? what exactly does it do and how does it help traction, hp, etc... with an upgraded tc?
thanks guys, i figure i will never do intake or exhuast on the gs4, but these two, i am interested
![Smilie](https://www.clublexus.com/forums/images/smilies/smile.gif)
In summary, a higher-stall TC will:
1. not give more HP
2. improve torque multiplication
3. not raise idle rpm
4. raises transmission fluid temps (most recommend trans cooler w/higher stall converter)
5. can lower gas mileage (on the scale of 1-2mpg Lexus 2800 stall application).
Good write-ups on LSD can be found here, here, and here.
After riding in two TC-equipped GS4's and a few stock GS4's, the Dragon TC would be the best bang-for-the-buck performance mod IMO
Last edited by tomtnc; 01-06-03 at 10:49 AM.
#5
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
Originally posted by tomtnc
After riding in two TC-equipped GS4's and a few stock GS4's, the Dragon TC would be the best bang-for-the-buck performance mod IMO
After riding in two TC-equipped GS4's and a few stock GS4's, the Dragon TC would be the best bang-for-the-buck performance mod IMO
#6
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
wow, thanks guys, great info, i have a much better idea now
damn i wonder why i never get what i want with searches but you guys always come up with some good stuff.
gotta learn more about stall rpm more tonight. i always thought it's the idle rpm when your car is idle, guess it's not huh?
![Smilie](https://www.clublexus.com/forums/images/smilies/smile.gif)
gotta learn more about stall rpm more tonight. i always thought it's the idle rpm when your car is idle, guess it's not huh?
#7
Pole Position
Join Date: Oct 2002
Location: North Carolina
Posts: 395
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
Originally posted by cyclemax
In your opinion, can the TC benefit be realized without the LSD, or will the hard launch capability go "up in smoke"?
In your opinion, can the TC benefit be realized without the LSD, or will the hard launch capability go "up in smoke"?
From posts regarding this subject by GS4 owners with TC / without LSD, I get the impression that an improved 60' (vs. stock TC) is more difficult to achieve on stock rims/tires vs. the typical aftermarket rims/tires package.
Hopefully someone here that has has experience with TC / no LSD can answer your question better than I have.
Trending Topics
#8
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
Originally posted by rominl
i tried to search for relative info but still a bit confusing, so why not ask here![Smilie](https://www.clublexus.com/forums/images/smilies/smile.gif)
i know with the TC it will raise the idle rpm a bit, is that right? and that will also give more hp at the wheel? what's the idle rpm, from what i read it's adjustable? now does that mean if i start my car, run it for 10 mins until the car is at normal running temperature, and i sit at the red light, the rpm would be at like 3000rpm? wouldn't that be high and quite noisy? and isn't that be quite bad for fuel economy?
i tried to search for relative info but still a bit confusing, so why not ask here
![Smilie](https://www.clublexus.com/forums/images/smilies/smile.gif)
i know with the TC it will raise the idle rpm a bit, is that right? and that will also give more hp at the wheel? what's the idle rpm, from what i read it's adjustable? now does that mean if i start my car, run it for 10 mins until the car is at normal running temperature, and i sit at the red light, the rpm would be at like 3000rpm? wouldn't that be high and quite noisy? and isn't that be quite bad for fuel economy?
![Smilie](https://www.clublexus.com/forums/images/smilies/smile.gif)
#9
Pole Position
Join Date: Oct 2002
Location: North Carolina
Posts: 395
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
Originally posted by rominl
gotta learn more about stall rpm more tonight. i always thought it's the idle rpm when your car is idle, guess it's not huh?
gotta learn more about stall rpm more tonight. i always thought it's the idle rpm when your car is idle, guess it's not huh?
"If you're not familiar with stall speed, it is the maximum rpm at which the engine will turn before the converter will allow no more slippage. In other words, it's the maximum speed at which the impeller will turn before the turbine starts to move."
"A higher stall speed generally gives more torque multiplication, which improves acceleration. The highest amount of torque multiplication is achieved when the engine reaches its maximum stall speed just before the car starts to move. It peaks out as the transmission starts to turn, and then diminishes as the speed of the turbine wheel catches up with the impeller."
#10
Guest
Posts: n/a
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
After the hight stall TC installed, due to the higher torque multiplication, you'll spins your rear wheels at hard start or corners all the time. With the LSD, you can pretty much eliminate those un-necessary wheel spins and get your power to the ground efficiently.
I had the LSD installed 2 months after the TC, I'd say both of them should be must have straight from the factory.
I had the LSD installed 2 months after the TC, I'd say both of them should be must have straight from the factory.
#11
Forum Administrator
![](https://www.clublexus.com/forums/images/ranks/rank-admin2.gif)
iTrader: (2)
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
Originally posted by cyclemax
In your opinion, can the TC benefit be realized without the LSD, or will the hard launch capability go "up in smoke"?
In your opinion, can the TC benefit be realized without the LSD, or will the hard launch capability go "up in smoke"?
![Smilie](https://www.clublexus.com/forums/images/smilies/smile.gif)
Most of the time you'll get the benefit of the TC without the LSD. Definitely quicker off the line, but you can experience wheel spin (aka burnouts) depending on a number of variables including:
- grip of your tires (remaining tread, softness of tire compound, heated, etc)
- road surface (including hard straigh-line launch, dips in road, angle of launch uphill)
- other variables that impact the power output of your car (my GS runs much stronger in the cool weather, for example)
I would not hesitate to recommend getting the TC installed without an LSD. IMO it's by far the biggest bang-for-buck performance mod you can make to your GS. However, if I had the opportunity and means to do them both at the same time I would certainly go ahead and do it.
I honestly did not feel the need to get an LSD until I went to a quarter mile track with my GS. The track surface was less-than-ideal with lots of rubber and some fluid, and I had severe traction problems. Although I put on a good show for the crowd by lighting up our tires in a HUGE cloud of smoke, leaving burnt rubber all over the back underside of our cars
![Cool](https://www.clublexus.com/forums/images/smilies/cool.gif)
Last edited by DaveGS4; 01-06-03 at 01:57 PM.
#13
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
I just bought a new GS430 and I thought that it already had an LSD, but I have noticed that it seems like the paassenger wheel it the only one spinning on a corner. DOes anyone know for sure whether I have an LSD or not?
#15
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
Originally posted by marcianof
I just bought a new GS430 and I thought that it already had an LSD, but I have noticed that it seems like the paassenger wheel it the only one spinning on a corner. DOes anyone know for sure whether I have an LSD or not?
I just bought a new GS430 and I thought that it already had an LSD, but I have noticed that it seems like the paassenger wheel it the only one spinning on a corner. DOes anyone know for sure whether I have an LSD or not?