Eurocharged Canada

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LET High-Stall Torque Converter
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LET Motorsports is proud to announce the release of the final piece of the performance puzzle - The >>>LET high-stall Torque Converter (HSTC)<<<

This modified factory unit is designed to put more of the power you already have to the ground, without sacrificing drivability at all. Some customers have reported better-than-stock drivability with the HSTC installed !!!

Stall Speed is increased several hundred RPM to a more performance-oriented level, which varies depending on your supporting mods. The low- and midrange are substantially improved, with no loss in top end - the HSTC retains all factory lockup characteristics, as well as an improved Stall-to-Torque Ratio (STR)

This unit will net you a 0.250-0.400 second reduction of your quarter-mile times, and possibly more. Thousands of development miles have been put on these modified units with no failures and no warranty issues, so you can remain confident in this mod for years to come. Use of a factory core means no flagging or refusal of warranty work.

The HSTC is an ideal first mod, as well as being a great final mod to complete your performance package. The HSTC is docile around town, yet enhances your car's acceleration unlike any other mod available, at any price.

Pricing is set at $1200.00, with an additional (refundable) core charge.

Promotional pricing, for the first run of units, will be offered at $999.99 !!!! (plus shipping)

Please add your name to the list below to guarantee your spot - this promotion ends February 28th !!!


Yes! I'm interested in the HSTC !!!


1) loungin14
2) 01bolt
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kindafast

Nice...
Do you have dyno sheets and 1/4 times with and without it?

Eurocharged Canada

We have some E55 dyno sheets, but the tracks here are closed.

This has put a ~4400# E55 close to 11-flat, with a 1.5x 60-foot.

More track times, including C32 times, to come.

You WILL see the first non-NOS 10-second run later this year.

jturkel

im guessing with an increased stall, for running 1/4 mile times, it would be beneficial, or even necessary, to run some DRs to hook up now with this?

msheredy

Out of curiosity what is the factory stall on the 32's torque converter?

Eurocharged Canada

DRs help.

The mind-blowing thing about this mod is the midrange kick....60-130 times dropped almost a full second !!!

There will be a learning curve on the launch, since there is a great deal more torque actually hitting the pavement....much like a pulley/tune combo.

jturkel

how strong is the rear end? DRs and this or LSD with some decent power must put some kind of strain on it, now?

hooleyboy

is this only for the C32?

kindafast

No way!? On a C32?

I sure hope it doesn't turn out like the other 10 second project...

*cough* TT C32 *cough*

just kidding

Eurocharged Canada

The C32 rear is decently sized for the application. We are already seeing cars spraying nitrous out of the hole without breakage, and this is less of a shock to the driveline.

Eurocharged Canada

No-we offer this for the 55s, 55Ks, and 65s as well.

loungn14

the 10's are on the E55, however......11's will be us c32 folk...

wawy

This is rather interesting to say the least..

DarkXerox

Does it fix the tranny jerk?

turbo16lbs

And the question of the hour is finally asked.

ScottW911

If it does, that alone would be worth the price of admission.

SilverBulletAMG

BIIIINGO!!! That is the million $$ question in my mind. If it truly fixes that damn 1500rpm jerk, I would pay double the price!

And how intense is the install on something like this? What are the actual parts being ordered?

turbo16lbs

Now, now let's not get ahead of ourselves. I mean we are in a recession afterall.

Maddydaddy

I too am hanging on an install quote. I love to drive, but have no talent with the wrenches. So upgrades have to have labor figured in for me. How much of my mechanics new yacht do I need to cover to get this swapped?

ChicagoX

Your comments have been forwarded to the appropriate persons, and the price should be adjusted promptly to address your request.




I'm glad I got mine early!

















Kidding, but I wouldn't be surprised if it fixes the issue. You will, however, get a surge at a higher RPM as the stall speed is reached.

hooleyboy

I should be able to ****** one of these up by the end of Fed, at the moment I'm still frying fish.

ImportLabSRT

Jerry....you know Im in!


Yes! I'm interested in the HSTC !!!


1) loungin14
2) 01bolt
3) importlabsrt
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moparrbust

What's the stall increase over stock? I know in my Crossfire(same transmission) it would only stall to 2000-2100 stock and I had a custom TC built up as well that bumped it up to 2600 and is still VERY streetable. I even fabbed up a custom external tranny cooler setup to keep the temps at bay. I have yet to make it out to the track for results(since I couldn't launch above 1200rpms at Famoso........I was on my street tires) but will be racing Feb. 7th.

If anybody needs their TC installed in Las Vegas I can do the install for a nominal fee. I work on M-B's(and most other high end/exotics) every day.

Gramma_Benz

For people like me, that aren't quite exactly sure what all this means, I found this; please don't take it as 100% truth, just something I found:


What will a higher stall torque converter do for my car?

1. A higher stall torque converter will multiply the torque of your engine to put more power and torque to the tires! The high stall torque converter will "slip" the engine into a higher rpm range where there is more torque and horsepower. This will make your car haul ***!


What kind of performance gains will I see with a high stall torque converter?

2. Our customers typically see a .5 reduction in quarter mile times, traction permitting. Highly modified cars with ported heads and bigger cams have seen gains of over 1 second!


What is the difference between "brake stall" and "flash stall"?

3. Flash stall is the maximum your engine's torque can stall a torque converter. In essence flash stall and full stall are nearly identical. If you had a transbrake, you could find full stall by putting your foot to the floor and reading your tach. For argument sake, let's say we're testing a 3500 stall Yank ST 3500. If you had a transbrake, you would see around 3500 rpms. If your motor was at idle and then you suddenly floored the throttle, you might see slightly more (maybe 100 rpm more) stall for a half second as the momentum of the motor's internals "flashed" the converter a small bit above its true stall rating. Brake stall, on the other hand is a very subjective thing. For most, it's the highest stall you can achieve before your tires spin. This varies greatly based on many factors: Traction, gearing, brake clamping force, and engine torque. With a ST3500, I may only be able to get 2200rpm "brake stall" on the street with street tires...any higher rpm and the motor torque would overwhelm the tires. But if I was at the track with racing slicks on the starting line, I might be able to get 3200 brake stall before the motor torque overwhelmed the tires. See...brake stall is very subjective. Yank rates their converters based on their intended application. A ST 3500 will stall 3500 rpms in a stock LS1. If you had a 422 and wanted a ST 3500, the converter you received would still stall 3500 because it would be built around the torque of a 422, not a stock displacement LS1. Yank checks the stall of their converters and their competitors by using either a trasmission dyno or a "tranny tricker" in the vehicle tested. With the tranny tricker, you can place the vehicle in 2nd or 3rd gear and stab the throttle to the floor...making it easy to read both flash stall and full stall.


What will happen to my fuel economy?

4. Very little. If your vehicle originally came with a lock-up clutch, your Yank Performance Converter would also have a lock-up clutch. You may need to apply slightly more throttle for driving around town, but you should not see a noticeable drop in fuel economy.


Is a transmission cooler needed with my high stall converter?

9. Not typically with the street strip converters below 3000 stall. For more hard-core racing applications (or converters over 3000 stall speed), a trans cooler is always cheap insurance to protect the transmission when "hot-lapping" the car.

Stall speed --- the rpm that a given torque converter (impeller) has to spin in order for it to overcome a given amount of load and begin moving the turbine. When referring to "how much stall will I get from this torque converter", it means how fast (rpm) must the torque converter spin to generate enough fluid force on the turbine to overcome the resting inertia of the vehicle at wide open throttle. Load originates from two places (1) From the torque imparted on the torque converter by the engine via the crankshaft. (This load varies over rpm, i.e. torque curve, and is directly affected by atmosphere, fuel and engine conditions.) (2) From inertia, the resistance of the vehicle to acceleration, which places a load on the torque converter through the drive train. This can be thought of as how difficult the drive train is to rotate with the vehicle at rest, and is affected by car weight, amount of gear reduction and tire size, ability of tire to stay adhered to ground and stiffness of chassis. (Does the car move as one entity or does it flex so much that not all the weight is transferred during initial motion?)

Note: While referring to the resistance of the vehicle to move while at rest, the torque converter's stall speed and much of its characteristics for a given application are also affected by the vehicle's resistance to accelerate relative to its rate of acceleration. This resistance has much to do with the rpm observed immediately after the vehicle starts moving, the amount of rpm drop observed during a gear change and the amount of slippage in the torque converter (turbine rpm relative to impeller pump rpm.) A discussion involving how resistance to acceleration affects a torque converter involves more theory than fact and must involve all the dozens of other variables that affect rpm and slippage. The primary thing we want to remember about torque converter stall speed is that a particular torque converter does not have a "preset from the factory" stall speed but rather its unique design will produce a certain range of stall speeds depending on the amount of load the torque converter is exposed to. This load comes from both the torque produced by the engine and the resistance of the vehicle to move from rest. The higher this combined load the higher stall we will observe from a particular torque converter, and conversely, the lower the load, the lower the stall speed. Naturally, if the engine is not at wide open throttle we will not expect to observe as high a stall speed as we would under a wide open throttle.

Another point concerning engine torque is that we are only concerned with what we'll call the "relevant range" of the engine torque curve when discussing initial stall speed. This means if our particular torque converter chosen has a design that should produce a stall speed in a range of say 2000 to 2600 rpm given the application then we would refer to this as the relevant range of our interest in the engine's torque curve for this particular torque converter. In other words, only the torque characteristics of the engine torque in this rpm range will affect the amount of stall speed we actually observe. If we are using a high horsepower/high rpm engine that does not make much torque before 3000 rpm, it does not matter that the engine makes excellent torque over 3000 rpm if we are trying to use the torque converter in this example because its relevant range is 2000-2600 rpm and we would expect to see poor stall (2000 rpm or less) due to the poor torque produced by the engine in this range.

Efficiency and torque multiplication

A torque converter cannot achieve 100 percent coupling efficiency. The classic three element torque converter has an efficiency curve that resembles an inverted "U": zero efficiency at stall, generally increasing efficiency during the acceleration phase and low efficiency in the coupling phase. The loss of efficiency as the converter enters the coupling phase is a result of the turbulence and fluid flow interference generated by the stator, and as previously mentioned, is commonly overcome by mounting the stator on a one-way clutch.

Even with the benefit of the one-way stator clutch, a converter cannot achieve the same level of efficiency in the coupling phase as an equivalently sized fluid coupling. Some loss is due to the presence of the stator (even though rotating as part of the assembly), as it always generates some power-absorbing turbulence. Most of the loss, however, is caused by the curved and angled turbine blades, which do not absorb kinetic energy from the fluid mass as well as radially straight blades. Since the turbine blade geometry is a crucial factor in the converter's ability to multiply torque, trade-offs between torque multiplication and coupling efficiency are inevitable. In automotive applications, where steady improvements in fuel economy have been mandated by market forces and government edict, the nearly universal use of a lock-up clutch has helped to eliminate the converter from the efficiency equation during cruising operation.

The maximum amount of torque multiplication produced by a converter is highly dependent on the size and geometry of the turbine and stator blades, and is generated only when the converter is at or near the stall phase of operation. Typical stall torque multiplication ratios range from 1.8:1 to 2.5:1 for most automotive applications (although multi-element designs as used in the Buick Dynaflow and Chevrolet Turboglide could produce more). Specialized converters designed for industrial or heavy marine power transmission systems are capable of as much as 5.0:1 multiplication. Generally speaking, there is a trade-off between maximum torque multiplication and efficiency—high stall ratio converters tend to be relatively inefficient below the coupling speed, whereas low stall ratio converters tend to provide less possible torque multiplication.

While torque multiplication increases the torque delivered to the turbine output shaft, it also increases the slippage within the converter, raising the temperature of the fluid and reducing overall efficiency. For this reason, the characteristics of the torque converter must be carefully matched to the torque curve of the power source and the intended application. Changing the blade geometry of the stator and/or turbine will change the torque-stall characteristics, as well as the overall efficiency of the unit. For example, drag racing automatic transmissions often use converters modified to produce high stall speeds to improve off-the-line torque, and to get into the power band of the engine more quickly. Highway vehicles generally use lower stall torque converters to limit heat production, and provide a more firm feeling to the vehicle's characteristics.

A design feature once found in some General Motors automatic transmissions was the variable-pitch stator, in which the blades' angle of attack could be varied in response to changes in engine speed and load. The effect of this was to vary the amount of torque multiplication produced by the converter. At the normal angle of attack, the stator caused the converter to produce a moderate amount of multiplication but with a higher level of efficiency. If the driver abruptly opened the throttle, a valve would switch the stator pitch to a different angle of attack, increasing torque multiplication at the expense of efficiency.

Some torque converters use multiple stators and/or multiple turbines to provide a wider range of torque multiplication. Such multiple-element converters are more common in industrial environments than in automotive transmissions, but automotive applications such as Buick's Triple Turbine Dynaflow and Chevrolet's Turboglide also existed. The Buick Dynaflow utilized the torque-multiplying characteristics of its planetary gearset in conjunction with the torque converter for low gear and bypassed the first turbine, using only the second turbine as vehicle speed increased. The unavoidable trade-off with this arrangement was low efficiency and eventually these transmissions were discontinued in favor of the more efficient three speed units with a conventional three element torque converter.

SRTpowa

subcribed. I would love to have one now but I will wait for others to test. Thanks LET for your hard work.