Extreme Performance Torque Converters (Available)

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802SHO

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Torque Converter Evolution—Why This Became a Critical Focus

To frame this correctly, it’s important to start with where my understanding of torque converters actually was earlier in the build.

On my previous setup—stock engine and stock transmission—the car produced strong results, but not exactly all on the same run. My best sixty-foot was a 1.66, while my best eighth-mile (7.1 @ 99 mph) and best quarter-mile (11.06 @ 123 mph) occurred together on a separate pass. At the time, like most people on the platform, I believed the majority of performance lived in the engine, turbos, and tuning. The torque converter felt more like a supporting component than a defining one.

As my build progressed and I began collecting parts for what would become my new build starting in November 2020, I purchased the GearHead torque converter in late 2021 or early 2022. At that point, it seemed like a safe decision. Options were limited, technical transparency across the platform was minimal, and GearHead had an established reputation. I didn’t yet have the experience or broader drivetrain understanding to question stall characteristics, lock-up strategy, clutch capacity, or how converter design fundamentally affects how power is applied—not just how much power is made.

Why The GearHead Converter Became a Concern

As power goals increased and the scope of the build expanded, my expectations for the torque converter changed. What initially felt like a conservative choice began to raise legitimate questions—not because of opinions or forum noise, but because of real-world outcomes and the absence of hard technical information.

One of the most telling data points was Ryan Spencer’s single-turbo SHO. A single-turbo setup places significantly higher transient and sustained torque demand on the drivetrain than a comparable twin-turbo configuration, especially during launch and early gear acceleration. That converter did not survive sustained use, despite the car only recording a best quarter-mile of 11.50. The unit was later sold to Jordan, who ultimately had to have a new converter built anyway. That wasn’t a case of extreme power or abuse—it was a mismatch between converter design and torque demand.

At the same time, I began looking for actual technical documentation on the GearHead converter: stall behavior under load, clutch configuration, friction materials, lock-up strategy, torque limits, thermal considerations. None exists publicly. Not on a website, not in documentation, and not even in detailed manufacturer disclosures. Descriptions consistently rely on general statements—brazed fins, custom stator, stronger lock-up—without defined specifications or a documented performance envelope.

This isn’t about talking down on anyone or attacking a business. Technical evaluation requires technical data. If full specifications exist, I genuinely welcome them and would be happy to reassess. Until then, relying on a critical drivetrain component without documented limits or design intent becomes a real risk as torque, traction, and load increase.

That realization pushed me to stop accepting “this is what people use” as a sufficient answer.

Exploring Alternatives and Hitting Dead Ends

My next step was to look for alternatives with actual history in converter engineering. I started with Circle D, largely because of their early involvement with the platform going back to the early 2010s. Historically, higher-stall converters from that era did improve sixty-foot times, but often at the expense of trap speed—an indicator of inefficiency or excessive slip on the big end. It’s also important to remember that tuning strategies and direct-injection understanding were far more limited at the time, especially when constrained within SCT’s narrow scope, which still limits visibility today.

I filled out Circle D’s custom request form in detail. I received a generic response stating the converter wasn’t in their catalog—which is expected for a custom request. I followed up to clarify intent and application, but that follow-up went unanswered. That path ended there.

I then reached out to ATS regarding their Freeman 6F55 converter, specifically asking about performance-oriented options or stall variance. Their response was straightforward and professional: they do not currently offer performance variants or custom configurations for this transmission. Another dead end.

At that point, it became clear that the traditional answers for this platform simply no longer existed in a way that supported where this build was headed.

Precision of New Hampton—Performance Division: What They Actually Build and Why It Matters

That’s what led me to keep digging—and ultimately to Precision of New Hampton’s Performance Division.

What immediately separates Precision of New Hampton from anything previously available on this platform is that they don’t offer a single vague “performance” torque converter. They offer a scalable performance ladder, ranging from OEM-quality remanufactured units, to mild and moderate upgrades, all the way to fully custom Stage 3 EXTREME converters built for serious torque and competition-level use. That alone makes them a true one-stop shop for any level of build.

At the extreme end—where my build lives—the converter stops being a background part and becomes a load-management device. This is where PNH focuses their engineering. Furnace-brazed internals prevent fin deflection and hydraulic loss under load. Anti-ballooning protection and billet components prevent shell distortion at high boost and RPM. Reinforced spline interfaces and hardened hubs address shock loading common in AWD launches. Multi-disc lock-up clutches allow lock-up to actually hold torque instead of slipping and turning power into heat.

In real terms, this means the engine finally gets loaded the way it wants to be loaded.

Instead of rolling into boost as vehicle speed climbs, the converter allows the engine to come up on torque immediately. On the brake, the car can build boost instead of creeping forward. At launch, torque multiplication is controlled instead of chaotic. That directly translates to harder, more repeatable launches and meaningful sixty-foot improvements—not because more power was added, but because more of the existing power is now usable.

From a drivability standpoint, I’m not pretending this behaves like stock—and it shouldn’t. Light throttle and casual stop-and-go will feel a little delayed compared to an OEM converter. That’s the trade-off. But once you’re into moderate throttle, the payoff is immediate. The converter is already coupled, throttle response is instant, and the car feels locked in and connected. Mid-throttle acceleration feels on rails because the drivetrain is no longer slipping its way into motion.

That same coupling advantage carries through the gears. Instead of falling out of the powerband or bleeding energy as heat between shifts, torque stays available and usable all the way through the quarter-mile. The engine stays where it wants to be, the turbos stay lit, and the transmission stops being a limiter and starts acting like a multiplier.

Platform First — The Actual Build Process

This converter represents a platform-first application for the 6F55—not because Precision of New Hampton is new, but because this is the first time their Stage 3 EXTREME performance path is being applied intentionally and end-to-end to a high-power AWD build.

My request was explicit: a Stage 3 EXTREME, multi-disc lock-up converter with a target 3,000 RPM stall, engineered around a high-torque, boosted AWD application. I outlined approximate horsepower and torque goals, along with ET targets—deep into the 10s on 93 octane and into the 9s on E85 with supplemental methanol.

Before anything moved forward, they verified I was serious and not tire-kicking. An initial $1,000 commitment was required before escalation. Once accepted, the request was sent directly to the plant manager. From there, a firm $2,400 total was issued for a fully custom build, internally classified as SSAX—their designation for extreme, application-specific converters beyond standard performance offerings.
IMG 7547IMG 7553IMG 7554
I was asked again if I wanted to proceed under that classification. I did. A unique part number was created, the build was formally accepted, and billing is being completed today.

That process matters. This isn’t an off-the-shelf part, a reman, or a lightly modified unit with assumed limits. It’s a converter reviewed, approved, classified, and built at the manufacturer level around a defined torque curve, stall requirement, and performance goal.

Future Updates

I’ll continue updating this thread as the converter moves through final specification, build, and validation. Once it ships, I’ll document delivery, unpacking, and installation, followed by real-world street impressions and track data as tuning and testing progress. At that point, results will replace theory—launch behavior, coupling characteristics, drivability, sixty-foot performance, and down-track efficiency will all be logged and shared.

For anyone following along at any stage of their build, Precision of New Hampton isn’t limited to extreme custom work. They offer everything from solid OEM-quality remanufactured converters to mild and moderate performance upgrades, all the way up to fully custom extreme-duty solutions. Whether your goal is reliability, improved street performance, or a purpose-built race converter, they function as a true one-stop shop.

If you’re evaluating torque converter options at any level, I highly recommend checking them out. GOPNH.Com
IMG 7474
 

myplague5

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Just curious, were you going through one of their affiliate shops or through a shop you were working with? I tried to get an estimate from them in December and they said they only go through automotive shops or one of their affiliates.
 

802SHO

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Just curious, were you going through one of their affiliate shops or through a shop you were working with? I tried to get an estimate from them in December and they said they only go through automotive shops or one of their affiliates.
I originally filled out the form to choose installing myself or rebuild myself. There was an error and my request for a quote wasn’t populating. I went back and changed it to “I didn’t know” and no I didn’t need a recommendation to a shop. Then it submitted. I did include all the info about my transmission build. Idk if that helped.
 

4sfed

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Are you currently running the stock converter or a different aftermarket converter? ...just wondering what your comparison is against.
 

802SHO

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Are you currently running the stock converter or a different aftermarket converter? ...just wondering what your comparison is against.
Right now the car is on a GH converter.

But honestly, this isn’t a comparison. What I’m having built doesn’t live in the same universe as OEM or GH, and that’s the whole point. OEM was never designed for big torque hits, brake-boosted launches, or sustained high-load coupling. It does what it was meant to do, but once you push well beyond stock power, you’re outside its operating window fast.

The GH converter is a different problem. There’s no published stall behavior tied to torque curve, no defined power rating, no internal specs, no real documentation. It exists on reputation alone. At moderate power, that might be acceptable. At the level I’m operating, mystery equals risk, and risk compounds quickly once you start leaning ******* the drivetrain.

What I’m doing with Precision of New Hampton is something else entirely. This is a custom, motorsport-grade, multi-disc lockup, anti-ballooning converter built around my actual power level, torque output, intended use, quarter-mile goals, and a requested 3,000 rpm stall. Internal reinforcements are selected for the load it’s going to see, not what someone hopes it can survive. This isn’t an “upgrade,” it’s purpose-built.

That’s when it finally clicked for me: the torque converter isn’t just along for the ride. It’s the gatekeeper. It decides whether your engine is allowed to use its power or whether it’s forced to fight the drivetrain the entire way down the track.

So let me walk you through what actually changes when you install a converter like the one I’m having built.

From a dig, this thing is going to be straight-up abusive. A true 3k stall matched to the torque curve means the engine is already loaded where it wants to live before the car even moves. No waiting, no lazy ramp, no slipping its way into boost. You’re on the brake, the drivetrain is loaded, boost is there, and when you let go it’s instant violence. The hit isn’t chaotic either — it’s controlled, repeatable, and brutal. That’s how you turn AWD and weight into an advantage instead of a liability. Short times drop because the power is finally being transferred instead of turned into heat.

Now the part people don’t expect — rolls.

Once you’re already moving, the converter is either locked or right on the edge of lockup. Throttle response becomes immediate. No flare, no delay, no mush. You roll into the throttle at 60–80 mph and the car just goes. It feels like the engine is bolted directly to the tires. Mid-throttle is violent. WOT is relentless. The power doesn’t surge and fall — it stays on, gear after gear, all the way out the back.

That’s the real unlock. This isn’t just about launching harder. It’s about never giving the power back. Between shifts, through gears, deep into the top end, the drivetrain stays coupled. No soft spots. No hesitation. No waiting for it to come back. Just continuous acceleration that feels faster than the numbers suggest.

This is what happens when the converter stops being a compromise and starts being an amplifier. The engine has always had the power. Now the drivetrain is finally built to let it show.

Dig or roll, this setup doesn’t ask permission anymore. It just takes it.
 

mattr66usa

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The gearhead converter was designed to provide maximum value (price) while holding 600 WHP under lockup and stall for stock location turbos. I mean you are not at 3-4x the cost of the GH converter, but it is what you need for your monster power build. I wouldn't expect you to try and push that much power through a stock size converter. It just won't work because you don't have enough fluid surface area. The strength of the lockup clutch is what's most important for a street car, you will need some stall for the bigger turbos.
 

802SHO

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Quick update on the Precision of New Hampton (PNH) SSAX converter build, and why the questions coming back from their build team are exactly what you want to hear if the goal is to make the car dangerous instead of just different.

You’ll see in the screenshots that they asked whether I’ve run a factory converter with this setup and what it stalled at. That isn’t uncertainty. That’s them anchoring the new design to a known mechanical baseline before reshaping everything downstream.

Yes, the OEM 6F55 converter lives roughly in the 1800 to 2200 RPM range. I ran it on my previous setup and that’s exactly how it behaved. On the current setup, the converter in the car is still OEM based and functionally behaves the same way. There is no meaningful early torque multiplication and no real ability to load the engine hard before the car is already moving.

To be clear, I don’t have clean launch data on the current setup. The car never made it to hard launches due to tuning limitations, ECU intervention, and earlier system mismatch. Most of my testing was single gear pulls starting higher in the RPM range, so I’m not claiming the car has no power below 3000 RPM.

That said, even in those pulls, including the old setup, the car didn’t instantly come alive the moment it crossed 3000 to 3300 RPM either. The takeaway isn’t a magic RPM number. It’s load.

This build isn’t about chasing a stall number on paper. It’s about loading the engine, building a few PSI before the hit, and letting the drivetrain do its job. Universally, regardless of platform, leaving with 3 to 4 psi instead of zero results in a harder leave. That’s physics.

When PNH asks what the factory unit stalled at, they’re not guessing. They’re determining how aggressively to move the coupling point, how early to start torque multiplication, how hard the stator should work, and how much hit the drivetrain will see, without turning the converter into a slipping heat pump on the big end.

This is a one and done converter. Multi disc lockup, anti ballooning, built around my powerband, torque curve, turbo sizing, and intended use. If the goal is to leave with load and boost instead of waiting for it to show up, targeting a 3000 RPM stall makes sense for this application.

Once this goes in, everything changes.

This is launch violence. Launches stop being soft guesses. The car loads immediately, hits the tires, and either hooks or tells me exactly what it needs. Sixty foot improves. The ladder effect shows up hard because once a converter multiplies early, it doesn’t give the power back. That’s where the gains live, especially from the eighth to the quarter where this car has always felt loose and slow.

This is roll race violence. Roll racing gets just as ugly. Instead of rolling into boost, it flashes straight into the usable part of the curve and stays coupled when it matters. No delay. No waiting. Just acceleration on command.

The fact that PNH is asking these questions before finalizing the build tells me this isn’t a catalog part. This is motorsport grade work. They’re not selling a stall number. They’re engineering how the drivetrain delivers power, how it survives the hit, and how it stays efficient at speed.

This is the missing link.
 

kryptto

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this is master craft for rebuilding a high performance version of our transmission. you have those upgraded custom built clutch pads if I recall, maybe I missed in your post here. this Precision NH seems to be at least from my observation the only custom built made for high end applications.
 

kryptto

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very cool, is that a grease or paint? I don't do transmission work or have experience
 

bpd1151

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Really wish this was available when my engine and trans went back together. Ugh.

PM me (or just text me) what the price was..... maybe i'll just order one in advance (of an anticipated trans failure at some point down the road).

I think I incensed my builder with the front AND rear LSD's last week.

He looked downward, sighed, and quipped "I just got done buttoning up that rear end".

I was like "I know, but all these delays, coupled with new product coming out (mainly thanks entirely to you Andrew) just compels me to keep throwing stuff at you".

So, like, you don't want this to be a never ending project, let's get it done where it's at, and move on from there.

Matt (@maxpower) did agree so hopefully we can see some semblance of completion (this year).

Really impressed with all that you've done thus far Andrew. Not just for your own build mind you...... but also to contributing to the few goons out there (like me) that still want to advance the platform.

Appreciate you my friend.

Sent from my SM-S928U using Tapatalk
 

802SHO

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very cool, is that a grease or paint? I don't do transmission work or have experience
It’s purpose built. These guys seem all about data than looks. Looks like the rattle can paint wasn’t dried enough and they laid it down on something.
 

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