>>>LET High-Stall Torque Converter (HSTC)<<<
#27
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E63 biturbo
Will this be a liability on cars which already have traction problems accelerating in 1st gear? If not I am interested in 2 units, both for CLS55s
#28
Super Member
I'm wondering the same thing. If we already have trouble hooking up from a standstill, how will this help improve 60' ETs? Or perhaps this is a mod for the people running DRs?
#30
When most folks launch its at 800-1200 rpms and times as low as 1.65 are generally cut. So if the torque converter is set to 1500 rpms or more (likely to snap axels) basically the extra torque at 1500 over 1000 is enough to generate a 0.2-0.4 (per LET) drop in ETs from an extra 50 wtq. Seems optimistic? Do I understand this correctly?
Also why would a torque converter lower 60-130mph times? I don't understand that once the car is rolling.
Also why would a torque converter lower 60-130mph times? I don't understand that once the car is rolling.
I was afraid that this would happen, but after much R&D the drivability is AMAZING !!!
Jamusa told me that his Mercedes Tech, after putting on 100+ break-in miles on his car, asked if the unit was modded at all.
You can tell he didn't stomp on it.
If anything, my modded car is less twitchy around town than it was....more stock-like in that regard. A firmer stab at the pedal an all hell breaks loose.
1.67 60-foot to 1.5x 60-foot, with over 3/4 tank of gas (duh) and snow tires on the front.
I went to a track rental down South, and was running late for the track. This meant that there was no time for a swap out of the snows. At the last fill-up, I also forgot to NOT put gas in my car, and ended up with waaaaay too much fuel.![smash](https://mbworld.org/forums/images/smilies/smashfreak.gif)
The 60-130 times were done with a GTech ProRR, averaged over 9 runs with each setup. I thought I had done 10 before the HSTC, but there was only data for 9
I think the advantage from a roll is compounded - hence the difference between the track times and roll-on times. The car simply jumps out now when hammered...like it dropped 5 passengers.![thumbs](https://mbworld.org/forums/images/smilies/thumbsup.gif)
Best - mod - ever. (Comicbook Guy voice)
Jamusa told me that his Mercedes Tech, after putting on 100+ break-in miles on his car, asked if the unit was modded at all.
![EEK!](https://mbworld.org/forums/images/smilies/eek.gif)
If anything, my modded car is less twitchy around town than it was....more stock-like in that regard. A firmer stab at the pedal an all hell breaks loose.
1.67 60-foot to 1.5x 60-foot, with over 3/4 tank of gas (duh) and snow tires on the front.
I went to a track rental down South, and was running late for the track. This meant that there was no time for a swap out of the snows. At the last fill-up, I also forgot to NOT put gas in my car, and ended up with waaaaay too much fuel.
![smash](https://mbworld.org/forums/images/smilies/smashfreak.gif)
The 60-130 times were done with a GTech ProRR, averaged over 9 runs with each setup. I thought I had done 10 before the HSTC, but there was only data for 9
![Stick Out Tongue](https://mbworld.org/forums/images/smilies/tongue.gif)
I think the advantage from a roll is compounded - hence the difference between the track times and roll-on times. The car simply jumps out now when hammered...like it dropped 5 passengers.
![thumbs](https://mbworld.org/forums/images/smilies/thumbsup.gif)
Best - mod - ever. (Comicbook Guy voice)
#31
MBWorld Fanatic!
Torque Converter Science
http://www.carcraft.com/techarticles...ers/index.html
...It took the addition of a small device called the stator to increase the efficiency of the fluid coupling and transform it into a torque converter. The stator redirects fluid from the turbine to the impeller, radically increasing the force of the fluid entering the impeller and multiplying the torque input from the engine. Basically, the fluid exits the center of the turbine and is redirected by the stator back into the impeller. This is a very slick trick and can be worth up to 2.5 times engine torque! This means that at a 2:1 torque multiplication ratio, an engine that is making 300 lb-ft of torque at a stall speed of 2,500 rpm will actually apply 600 lb-ft of torque to the input shaft of the transmission as the car leaves the starting line.
This sounds really great, and it is. But the catch is that this torque multiplication doesn't last very long. The multiplication factor is based on the speed difference between the turbine and impeller. At stall speed, the impeller is spinning at engine rpm and the turbine is stopped. This creates the greatest speed difference between the turbine and the impeller and therefore the maximum torque multiplication. Once the brakes (or the transbrake) is released and the vehicle begins to move, the turbine spins up and the speed difference between the two diminishes. Generally, by the time you reach the 60-foot mark on the dragstrip, torque multiplication is effectively eliminated and the turbine and impeller speeds are close to achieving what converter manufacturers call coupling speed.
This sounds really great, and it is. But the catch is that this torque multiplication doesn't last very long. The multiplication factor is based on the speed difference between the turbine and impeller. At stall speed, the impeller is spinning at engine rpm and the turbine is stopped. This creates the greatest speed difference between the turbine and the impeller and therefore the maximum torque multiplication. Once the brakes (or the transbrake) is released and the vehicle begins to move, the turbine spins up and the speed difference between the two diminishes. Generally, by the time you reach the 60-foot mark on the dragstrip, torque multiplication is effectively eliminated and the turbine and impeller speeds are close to achieving what converter manufacturers call coupling speed.
#33
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2004 E55 White
What is the stall speed raised to? The stock stall seems to be about 1200 RPM. I have played with higher stalls before and they do work wonders. IMHO anything over 2000 RPM's makes your car drive like a snowmobile.
#35
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W211 E55
When most folks launch its at 800-1200 rpms and times as low as 1.65 are generally cut. So if the torque converter is set to 1500 rpms or more (likely to snap axels) basically the extra torque at 1500 over 1000 is enough to generate a 0.2-0.4 (per LET) drop in ETs from an extra 50 wtq. Seems optimistic? Do I understand this correctly?
Also why would a torque converter lower 60-130mph times? I don't understand that once the car is rolling.
Also why would a torque converter lower 60-130mph times? I don't understand that once the car is rolling.
I wasn't expecting the roll-on benefits-the stall must be flashing when I hit it, since the car jumps forward much harder than before.
Originally Posted by sfkarp
What is the stall speed raised to? The stock stall seems to be about 1200 RPM. I have played with higher stalls before and they do work wonders. IMHO anything over 2000 RPM's makes your car drive like a snowmobile.
Originally Posted by NSX2NV
Seems like a good mod. Can't wait to hear more about install price.
#36
MBWorld Fanatic!
No, you will just lurch forward and hear clank clank clank
Torque converters in general allow you to launch higher in the rpm range and therefore launch harder. Definite gains in the 1/4 mile if your drivetrain can handle the abuse. Some negatives are: decreased gas mileage and a sloppier feeling pedal under the stall speed. The car will rev but the car feels like the trans is slipping kinda. Then it hits the stall speed and just grabs and goes. Th eharder you launch, the more stress you put on parts. This is exactly why I break so many axles. Anything above 1500rpm launch and my axles snap like twigs. My axles are probably much smaller than the other models but also remember that it is much lighter and making wayyyy less power.
It will be interesting to see how these cars handle the harder launches
Torque converters in general allow you to launch higher in the rpm range and therefore launch harder. Definite gains in the 1/4 mile if your drivetrain can handle the abuse. Some negatives are: decreased gas mileage and a sloppier feeling pedal under the stall speed. The car will rev but the car feels like the trans is slipping kinda. Then it hits the stall speed and just grabs and goes. Th eharder you launch, the more stress you put on parts. This is exactly why I break so many axles. Anything above 1500rpm launch and my axles snap like twigs. My axles are probably much smaller than the other models but also remember that it is much lighter and making wayyyy less power.
It will be interesting to see how these cars handle the harder launches
![thumbs](https://mbworld.org/forums/images/smilies/thumbsup.gif)
![Big Grin](https://mbworld.org/forums/images/smilies/biggrin.gif)
#37
Out Of Control!!
Yea I talked to Frank at DSS. I have to send him an axle to look at and should cost around $2k. I'm saving up for a down payment on a house so mods are on the backburner for now.
#38
Member
Higher stalls are great with 2 caveats.....
1-They increase tranny temps......and high tranny temps are what kill trannies. It would be very interesting to track tranny temps before and after this mod. I doubt it would make a huge difference---but if you are running the car in a high temp environment and beating on it--->it may really hurt the tranny. I recall Finny (who has a stock tranny but a high HP car) said his 2003 tranny was badly heat warped when he took it apart. Nothing a larger tranny cooler cant fix. Im sure you guys have watched this...any data?
2-TRACTION--these cars make so much low end torque. I have 285's on the back and my STOCK car cant take full gas. I cant imagine what a pulley/header/tune with a TC is like. Your traction control light must flash like a disco ball.
#39
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2001 clk55 AMG
Exotic---you finally got your wish aye?
Higher stalls are great with 2 caveats.....
1-They increase tranny temps......and high tranny temps are what kill trannies. It would be very interesting to track tranny temps before and after this mod. I doubt it would make a huge difference---but if you are running the car in a high temp environment and beating on it--->it may really hurt the tranny. I recall Finny (who has a stock tranny but a high HP car) said his 2003 tranny was badly heat warped when he took it apart. Nothing a larger tranny cooler cant fix. Im sure you guys have watched this...any data?
2-TRACTION--these cars make so much low end torque. I have 285's on the back and my STOCK car cant take full gas. I cant imagine what a pulley/header/tune with a TC is like. Your traction control light must flash like a disco ball.
Higher stalls are great with 2 caveats.....
1-They increase tranny temps......and high tranny temps are what kill trannies. It would be very interesting to track tranny temps before and after this mod. I doubt it would make a huge difference---but if you are running the car in a high temp environment and beating on it--->it may really hurt the tranny. I recall Finny (who has a stock tranny but a high HP car) said his 2003 tranny was badly heat warped when he took it apart. Nothing a larger tranny cooler cant fix. Im sure you guys have watched this...any data?
2-TRACTION--these cars make so much low end torque. I have 285's on the back and my STOCK car cant take full gas. I cant imagine what a pulley/header/tune with a TC is like. Your traction control light must flash like a disco ball.
Last edited by BlackOnBlackCLK; 01-31-2009 at 12:21 PM.
#40
Out Of Control!!
Exotic---you finally got your wish aye?
Higher stalls are great with 2 caveats.....
1-They increase tranny temps......and high tranny temps are what kill trannies. It would be very interesting to track tranny temps before and after this mod. I doubt it would make a huge difference---but if you are running the car in a high temp environment and beating on it--->it may really hurt the tranny. I recall Finny (who has a stock tranny but a high HP car) said his 2003 tranny was badly heat warped when he took it apart. Nothing a larger tranny cooler cant fix. Im sure you guys have watched this...any data?
2-TRACTION--these cars make so much low end torque. I have 285's on the back and my STOCK car cant take full gas. I cant imagine what a pulley/header/tune with a TC is like. Your traction control light must flash like a disco ball.
Higher stalls are great with 2 caveats.....
1-They increase tranny temps......and high tranny temps are what kill trannies. It would be very interesting to track tranny temps before and after this mod. I doubt it would make a huge difference---but if you are running the car in a high temp environment and beating on it--->it may really hurt the tranny. I recall Finny (who has a stock tranny but a high HP car) said his 2003 tranny was badly heat warped when he took it apart. Nothing a larger tranny cooler cant fix. Im sure you guys have watched this...any data?
2-TRACTION--these cars make so much low end torque. I have 285's on the back and my STOCK car cant take full gas. I cant imagine what a pulley/header/tune with a TC is like. Your traction control light must flash like a disco ball.
2- Anything below 60mph and full throttle will result in my car going sideways on street tires. The cold temps outside are partially to blame though. It's quite fun! I keep traction control off most of the time
#41
My biggest concern with this mod is daily drivabilty. I asked a few members for their opinions on this mod and they all basically said the same thing "daily drivability will suffer". They do all agree that it will definitely help in 1/4 mile but that's about it. This is the one thing holding me back right now and if I could get a little more reassurance I would pull the trigger. I actually already have a install lined up if I do get it.
#42
I dont know who or which member you have spoken to regarding driveability,but speaking from personal experience i've found the car to drive much better than before.I must admit that i was a little skeptical at first,because i wanted enhance performance along with good driveability,i turned out to be much better....i have logged on close to 3000 miles on the car,and cant tell its there unless you get into it,then all hell break loose...night and day difference.
#43
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#44
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05 C55
1000 is steep for a converter, even though its a benz. is anyone using this?? http://www.importperformancetrans.com/722.6.shtml
#45
I dont know who or which member you have spoken to regarding driveability,but speaking from personal experience i've found the car to drive much better than before.I must admit that i was a little skeptical at first,because i wanted enhance performance along with good driveability,i turned out to be much better....i have logged on close to 3000 miles on the car,and cant tell its there unless you get into it,then all hell break loose...night and day difference.
#46
Out Of Control!!
1000 is steep for a converter, even though its a benz. is anyone using this?? http://www.importperformancetrans.com/722.6.shtml
#47
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05 C55
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#49
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Mercedes
So I took up wayne's (chicagox) offer on taking his car for a ride. I have to say that I am completely amazed!
Firstly, drivability is very good. I know that with my modded car, I get some jerkyness off of the line, after driving wayne's car it is completely gone! It is nearly impossible to tell that it is installed in the car under normal driving, but once you get on the gas it is just incredible fast!
Secondly, the stall is set perfectly for the car. The power comes in smoothly but definetlly noticable! The car hauls like crazy at speed. We spun tires all the way through 70mph!!!! I have driven stage 5 renntech cars and they do not even compare to the power wayne's car can put down.
The car drives like stock with the new converter.
I will be getting one for sure!
Thanks again to Wayne for the ride and the future new torque converter!
Firstly, drivability is very good. I know that with my modded car, I get some jerkyness off of the line, after driving wayne's car it is completely gone! It is nearly impossible to tell that it is installed in the car under normal driving, but once you get on the gas it is just incredible fast!
Secondly, the stall is set perfectly for the car. The power comes in smoothly but definetlly noticable! The car hauls like crazy at speed. We spun tires all the way through 70mph!!!! I have driven stage 5 renntech cars and they do not even compare to the power wayne's car can put down.
The car drives like stock with the new converter.
I will be getting one for sure!
Thanks again to Wayne for the ride and the future new torque converter!
#50
Out Of Control!!
I cant remember right now, I think it was 2600, but may be 2800