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Hard launch transmission disengages

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#1
Hi all,

I'm wondering if anyone has experienced the same issue I am having. When I brake boost to as close to 2600rpm as I can get and then launch it will get up to around 30-40MPH then it feels like the transmission disengages. It'll bounce off the rev limiter and just coast until I let it wind all the way back down to idle. I don't have to stop the vehicle and I don't feel it re-engage but once it drops below 2000rpm I can accelerate like normal again. It seems like it has a load sensor to protect the trans and it only happens on cooler days (below 60°F). I'm on a Livernois Motorsports 93 octane tune and have Fenfab intake, charge pipe with raceport bov, downpipes, diffy stiffy and a Whipple intercooler. I'm not sure if it's a tuning error with the TCM or if maybe it's time to call up level 10 and get a bulletproof trans put in. It comes and goes so it's hard to recognize other constant conditions. It's happened 4 or 5 times in the year and a half I've been abusing it. Anyone else have this issue?

Thanks.
 

UNBROKEN

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#2
If you can catch it on a datalog that’ll be the best way to figure it out.
And Level 10 has been hit or miss lately…
 

TMac

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#3
Agree on datalog. Are you saying this is the "canned" 93 tune, but you have all the other upgrades? Are you seeing any CELs? Have you checked for any codes being thrown?
 

I Bleed Ford Blue

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#4
I think what you are experiencing is the computer seeing wheel spin and cutting power. Try holding the brake as hard as you can and only go to 2400 rpm tops. It happened to me a couple of times, then I learned to hold the brake as hard as I can and try not to go all the way to the breakaway point. Trust me, it makes a difference. Every vehicle is different, but on mine the tires try to break loose at about 2500 rpm, but I also have the standard brakes that come with the factory 20's.
 

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#5
He's wheel spinning at 30-40mph?
 

CareerFiremanGuy

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#6
Hi all,

I'm wondering if anyone has experienced the same issue I am having. When I brake boost to as close to 2600rpm as I can get and then launch it will get up to around 30-40MPH then it feels like the transmission disengages. It'll bounce off the rev limiter and just coast until I let it wind all the way back down to idle ...
If you're bouncing off the rev limiter, you're probably spinning the tires and you're not actually going 30-40 mph.
 

OP
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Thread Starter #7
If you can catch it on a datalog that’ll be the best way to figure it out.
And Level 10 has been hit or miss lately…
I haven't messed with the Livernois device too much. I'll have to look into how to datalog on it.

Agree on datalog. Are you saying this is the "canned" 93 tune, but you have all the other upgrades? Are you seeing any CELs? Have you checked for any codes being thrown?
Yes, it's the stage 4 93 octane canned tune. I've never been on a dyno or sent a datalog. All upgrades listed are currently on it. No CEL or traction lights, I did get an airbag light after a few hard launches a couple weeks ago but I did get some wheelhop so I assumed it rattled something and the light went away after that drive cycle before I could scan it. I could try and look in the history.

I think what you are experiencing is the computer seeing wheel spin and cutting power. Try holding the brake as hard as you can and only go to 2400 rpm tops. It happened to me a couple of times, then I learned to hold the brake as hard as I can and try not to go all the way to the breakaway point. Trust me, it makes a difference. Every vehicle is different, but on mine the tires try to break loose at about 2500 rpm, but I also have the standard brakes that come with the factory 20's.
He's wheel spinning at 30-40mph?
I had that thought too but wouldn't I see the TCS light flash and I would think it would cut throttle and rev down instead of bouncing off the limiter. I could be wrong but that has been my experience in other vehicles. A few of the occurrences I've heard the tires squealing and assumed that was the issue but this last time it planted and threw you back hard for about 1.5-2 full seconds before doing it so idk if it was spinning that time or not.

If you're bouncing off the rev limiter, you're probably spinning the tires and you're not actually going 30-40 mph.
Redline in 1st is right around 50MPH, wouldn't I be seeing that instead of 30-40? Also if I was essentially doing a 4 wheel burnout wouldn't it have a tendency to pull one direction instead of staying straight?

I apologize if any of my replies seem ignorant. I'm new to AWD and this level of power so I'm trying to make sense of it all. Thank you all for your responses.
 

Cdubya

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#8
I hope you are using Forscan for diagnostics. It'll capture errors that do not light up a CEL. With your mods, I wouldn't be quick to blame the tune or the transmission just yet. Plenty of potential for install errors with a Whipple, intake, etc.
 

OP
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Thread Starter #9
I hope you are using Forscan for diagnostics. It'll capture errors that do not light up a CEL. With your mods, I wouldn't be quick to blame the tune or the transmission just yet. Plenty of potential for install errors with a Whipple, intake, etc.
How would and intercooler or intake install error cause the engine to bounce off the limiter without putting power through the driveline exactly? Under normal driving its fine, it's only ever happened while launching after brake boosting in cooler ambient temps and even then it's a pretty rare occurrence. The first time it happened I only had the intercooler and tune ar the time.
 

TMac

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#10
I'm not sure the OP isn't possibly correct in thinking it's a torque-related issue. He should probably ask @ZFGracing about it. Certain cars I've seen tuned- particularly VAG platforms- do employ torque sensing mechanisms in the driveline with the ECU taking preventive measures to forestall breakage. I'm not sure whether Ford utilizes this approach, or whether tuners like ZFG disable it. The fact that it only happens during colder temps, the fact that he has a "canned" tune, combined with the other mods might be triggering this behavior.
 

OP
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Thread Starter #11
I'm not sure the OP isn't possibly correct in thinking it's a torque-related issue. He should probably ask @ZFGracing about it. Certain cars I've seen tuned- particularly VAG platforms- do employ torque sensing mechanisms in the driveline with the ECU taking preventive measures to forestall breakage. I'm not sure whether Ford utilizes this approach, or whether tuners like ZFG disable it. The fact that it only happens during colder temps, the fact that he has a "canned" tune, combined with the other mods might be triggering this behavior.
That's what I was thinking. Unfortunately for me it seems more people have gone with 5 star and ZFG on this platform. If I could find another one with the same Livernois tune it might help in determining if what you're saying is the case or not. Livernois has always seemed to stick with max power before any sacrifice in reliability on their canned tunes so I could see them leaving a factory feature that protects the driveline enabled. There are plenty of other ST's making the same or more power than I am on a stock trans so either I got a premature failing trans (not impossible but unlikely with the low frequency of the issue) or something is telling it to stop sending power through the driveline. I might just be at that torque threshold and the denser air allows it to make enough power to trigger it.
 

TMac

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#12
That would be my first educated guess. I'm not convinced of a driveline failure, since according to your posts, it retains driveability and function after it happens. And, with it only happening when the temp is low equating to more torque, it seems a reasonable possibility.
 

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#13
So my 2022 ST is doing the same thing with the livernois 93 stage 4 tune & E-30 tune, it almost feels like its missing 2nd gear. It doesn't do it all the time and I'm launching at about 2400 rpm. My husband and I are going to try the ZFG tune on my ST and he will stay with the LMS tuning on his, we will post updates as we go.
 

Cdubya

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#14
If I could find another one with the same Livernois tune it might help in determining if what you're saying is the case or not. Livernois has always seemed to stick with max power before any sacrifice in reliability on their canned tunes so I could see them leaving a factory feature that protects the driveline enable
I have the Livernois stage 4 93. I dont do 0-60 runs and dont do brake launches so maybe cant compare. I have experienced what you are talking maybe twice. Both times getting on throttle--suddenly its like further throttle does nothing and rpms drop. then very slowly the rpms pick up and everything seems fine. I have heard this described on stock explorers too though. I havent experienced this recently and certainly is not reproduceable by me. Is your reproduceable?
 

OP
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Thread Starter #15
So my 2022 ST is doing the same thing with the livernois 93 stage 4 tune & E-30 tune, it almost feels like its missing 2nd gear. It doesn't do it all the time and I'm launching at about 2400 rpm. My husband and I are going to try the ZFG tune on my ST and he will stay with the LMS tuning on his, we will post updates as we go.
Keep us updated for sure. It would be good for the community to know if it's something some tuners disable and some don't. Not that Livernois is bad, just maybe for a customer that's focusing on reliability more than track performance.
I have the Livernois stage 4 93. I dont do 0-60 runs and dont do brake launches so maybe cant compare. I have experienced what you are talking maybe twice. Both times getting on throttle--suddenly its like further throttle does nothing and rpms drop. then very slowly the rpms pick up and everything seems fine. I have heard this described on stock explorers too though. I havent experienced this recently and certainly is not reproduceable by me. Is your reproduceable?
I can't reproduce it on demand, but it seems to be more likely when the temps are below 65° outside. If stock ones are having the issue as well then I think what TMac said is probably the most plausible theory.
 

TMac

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#16
If this were a manual transmission car, everyone would immediately diagnose it as power-related clutch slip. I am not an expert on the 10R series transmissions, but based on my own observation on how good they are in Eco and Normal modes of off acceleration coasting- they must have engineered something similar to disengage the input shaft from the planetary gearset. If that's the case, for those of you experiencing this phenomenon, it's probably NOT a good thing for the transmission.
 

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#17
So my 2022 ST is doing the same thing with the livernois 93 stage 4 tune & E-30 tune, it almost feels like its missing 2nd gear. It doesn't do it all the time and I'm launching at about 2400 rpm. My husband and I are going to try the ZFG tune on my ST and he will stay with the LMS tuning on his, we will post updates as we go.
Once he sees the difference in yours, I predict he will have a ZFG tune on his very quickly.

LMS had the same issue a few years back in the SHO world. I was one of many that had the issue, hard launch and all the sudden when it should be in 2nd gear it felt like it went to neutral. They told us all we had issues with our cars and it had nothing to do with their tune. Luckily the internet exists and many of us were able to find each other and compare notes on what they told us. They ended up changing something in their tune after about a year, but most of us had moved on to other tuning companies by then.
 

Cdubya

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#18
Was looking at some of the older threads on "power loss" and bad gas seems to be a frequent mention.
 

OP
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Thread Starter #19
So I have some interesting data from the Dragy that may reinforce the driveline protection theory. I have my 4 quickest valid runs with quite different mods and conditions.

This run is from September, 2021
Screenshot_20220921-192604_dragy~2.jpg

This one was from 2 days ago before the E30 tune.
Screenshot_20220920-170941_dragy~3.jpg

This one is from yesterday on E30
Screenshot_20220921-191237_dragy~3.jpg

This one is from early this morning while the DA and temp was low Screenshot_20220922-063242_dragy~3.jpg
Both tunes are LMS stage 4. It seems like something is preventing it from breaking the 12.5 sec. barrier. I'm not familiar enough with reading PID data to know how to see if it's pulling timing or fuel to reduce torque output but it seems like E30 with boltons should be noticeably quicker than just 93 and an intercooler.
 

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Cdubya

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#20
Shouldn't you be using a Livernois ethanol tune? As far as I know, the Livernois device can datalog but not sure how you would read the file. Maybe only they can make read it.
 

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