Torque Converter Question
thanks

I haved this TC installed long time ago once I got this car so I forgot how it was driving on the freeway with bone-stock. Sorry I couldn't help you on that, whitediamond.
A converter is a converter. It transfers the torque from engine to drive shaft. The aftermarket TC has a higher stall speed and smaller diameter. so it light weight than the stock one. When you push it, the stock TC start moving the car at around 1k rpm while the aftermarket one do the same thing but at slowly ramp up, at around 3k rpm, you feel the thrust that push you all the way out.
Due to the higher slippage rate, it totally changes the gear shift point. At 70 mph highway spped in lockup mode, if you push down the padel, it will down shift 1 or 2 gears immediately depends on how hard you push it. Don't worry, you can drive it with TC in absolute normal way. But when you push it, you know it's there to make the difference. The TC will get you hooked, I took it out for about 4 months and put the stock one back in, I just couldn't justify for the way that the stock TC drives. So after 4 months of dog acceleration, I put the TC back in and the GS was back tio life again:eek:
It's not that much of a mystery. It's simply a viscous coupling between the engine & transmission using the fluid ( under pressure ) in place of a mechanical clutch/pressure plate/flywheel assembly in a manual tranny. The stall speed is similar to slipping the clutch on a manual as well. A stall speed of 3000 rpm DOES NOT mean the car won't move until the engine is turning 3k. It is the approximate rpm at which the converter is fully engaged ( or "locked up" in the newer trannys ) - like a mechanical clutch. Imagine driving a standard tranny but w/o having to row the gears. The T/C will slip & allow the engine to reach it's powerband sooner. How much depends on the amount of throttle pressure U've applied. Floor it & it will "flash" to the stall speed it's designed for ( 3k, in our example ). This is right where the GS4 4.0 begins to make power so acceleration will be maxed out. Drive like my wife ( & her size 6 foot! ) & U'll barely notice it's there - drives almost like stock but with a SLIGHT bit of extra slippage which U'll get used to ( like RA said ). Don't worry about spinning the wheels unless U floor it from idle!! As far as gains elsewhere than off-line, once it hits it's stall speed ( 3k ), it's only advantage is that aftermarket T/C's R built stronger than factory ones & will handle more power ( like a S/C; nitrous or other performance mods ). Downsides - extra slippage generates extra heat ( the #1 enemy of ALL trannies! ). Fight this with a tranny cooler if U drive hard & live in a hot climate - it's not 100% necessary even there but will help. Lastly, U may notice a slight loss of highway mpg due to that aforementioned slippage. However, if U drive above the locked-up stall speed rpm, it will be minimal if at all noticeable. I pulled down 22 mpg cruising at 85-90 mph which was a cruising rpm of 3200 - only got 24 highway mpg before changing the T/C & rear gears ( which R responsible for most of the mpg loss, IMO ). Sorry this is such a long post but I hope it clears up a great deal of confusion about an excellent performance modification!
Guys - From what I've gathered in 25+ years ---CUT---
Almost as long as I have been alive Gramps
heheheSeriously, I am concerned about screwing up the transmission. I really want to keep this car past 130k miles (at least for 4 more years. until I am out of grad school). Plus I have to purchase a new truck after the recent Flooding incident. (And the "It better be at least a 2 carat Diamond Solitaire" fund can’t be touched.
)Where can I get a transmission cooler for the GS and how do I install it? Is it easy? Expensive? Similar to the coolers on available on trucks? Downside? Thanks.
hope I didn’t question you to death.
JacobT,
Since you are nearby (Austin) where did you get your TC installed? I am going to probably go with the Sways first before the l-tuned so I can probably get both done. What was the cost of labor? Thanks.
Trending Topics
Celebrating Lexus & Toyota from Around the Globe
About the cooler - Mo can hook ya up with one as he sold me one when I got my T/C from him. Just any slim-line model will help out - think mine's from EZ Go. If U want to hide it from prying eyes ( service writers ), get some BBQ grill black paint & spray it before installation. Not only will that help it blend into the radiator, the black coloring will help dissipate heat. Like jacob said - run the auxillary cooler in addition to the factory setup. Hope the Houston flooding didn't getcha? I left our office on Dallas Street Wednesday ( in the company car, thank goodness! ) heading offshore so I missed it.
Downtown Houston is still a mess, so is the Medical Center.
The flooding did not get my Lex, but wiped out my Tacoma that was left at "The Parking Spot"
Still waiting for insurance. But I figure I am going to get a Tacoma 4x4 ext. or the new double cab...next.We all still need to setup a meet for the SW. I might be in Louisiana some time next month. I have some work to do at the Convent Refinery, if you are nearby, I'll buy you a few beers Grandpa
.Guys - From what I've gathered in 25+ years of auto customizing & drag racing, the torque converter has got to be THE most misunderstood piece of equipment in a car!
It's not that much of a mystery. It's simply a viscous coupling between the engine & transmission using the fluid ( under pressure ) in place of a mechanical clutch/pressure plate/flywheel assembly in a manual tranny. The stall speed is similar to slipping the clutch on a manual as well. A stall speed of 3000 rpm DOES NOT mean the car won't move until the engine is turning 3k. It is the approximate rpm at which the converter is fully engaged ( or "locked up" in the newer trannys ) - like a mechanical clutch. Imagine driving a standard tranny but w/o having to row the gears. The T/C will slip & allow the engine to reach it's powerband sooner. How much depends on the amount of throttle pressure U've applied. Floor it & it will "flash" to the stall speed it's designed for ( 3k, in our example ). This is right where the GS4 4.0 begins to make power so acceleration will be maxed out. Drive like my wife ( & her size 6 foot! ) & U'll barely notice it's there - drives almost like stock but with a SLIGHT bit of extra slippage which U'll get used to ( like RA said ). Don't worry about spinning the wheels unless U floor it from idle!! As far as gains elsewhere than off-line, once it hits it's stall speed ( 3k ), it's only advantage is that aftermarket T/C's R built stronger than factory ones & will handle more power ( like a S/C; nitrous or other performance mods ). Downsides - extra slippage generates extra heat ( the #1 enemy of ALL trannies! ). Fight this with a tranny cooler if U drive hard & live in a hot climate - it's not 100% necessary even there but will help. Lastly, U may notice a slight loss of highway mpg due to that aforementioned slippage. However, if U drive above the locked-up stall speed rpm, it will be minimal if at all noticeable. I pulled down 22 mpg cruising at 85-90 mph which was a cruising rpm of 3200 - only got 24 highway mpg before changing the T/C & rear gears ( which R responsible for most of the mpg loss, IMO ). Sorry this is such a long post but I hope it clears up a great deal of confusion about an excellent performance modification!
I consider myself a rookie when it comes to the REAL tech side of these cars, although I do well on most installs. That was very helpful and informative, thanks Mean Gene. After talking to buddies who are big into car mods, and reading the postes on this site, I think the idea of SLIPPAGE is what is hardest for most people to vizualize. The idea that the TC does not cause the car to simply rev to the stall speed and all-at-once launch like dropping the clutch on a manual. The analogy of slipping the clutch on a manual is the best comparison Ive heard. Thanks again Gene.....Tiny




