8AT Transmission Slip?

I noticed the Tacoma in this video did a weird thing when shifting around 72mph at WOT. Has anyone with the 8AT experienced this?


At 0:46 and again at 1:36

 

No

 

Looks like torque management, not slip.

 

Problem with adding a aftermarket exhaust on a turbo engine . You lose back pressure .

 

That doesn't mean anything.... The turbo itself creates back pressure for the engine. Having a free-flowing exhaust on a turbo motor creates no issues.

 

Our Honda Pilot does something very similar in the 4-5 shift with anything > 40% throttle.

 

For sure... it only helps. The whole back pressure makes tq is nonsense.

 

Ehh wrong

 

I think you need to do some reading on how a turbo works lol.

 

I'm no expert but I am pretty sure the turbocharger itself introduces some back pressure, but a free flowing exhaust is good for a turbo car.

 

It's not nonsense at all and is incredibly important for exhaust scavenging. On my other car, you lose a significant percentage of your horsepower by sizing up the exhaust diameter. For turbo engines however, the bigger the better.

 

https://www.youtube.com/watch?v=_PVXvHkr-Vs

 

Do clarify then. With every turbo'd car I played with in the past reduced restriction post turbo was always key aswell as isolating a smoothing out exhaust gas before entering was always key.
This sounds alot like n/a mentality where balancing back pressure to limit scavenging/valve float is the goal

 

From personal experience, dyno before and dyno after, 20hp was lost by using an 80mm diameter exhaust vs a 60mm. Supercharged 4cyl. Helps the engine flow way more air as it increases exhaust velocity.

 

Turbo backpressure is the pressure that builds up in the exhaust system due to the turbine wheel’s operation.

 

That's the fun thing about cars... you can make general statements but there is always an exception. For the most part a larger, freer flowing exhaust will make more power. There many things that play into scavenging of exhaust and its not just the pipe size. They showed pretty well in that video, great series if you've never watched it, that the smaller pipe did nothing to help low end power and only killed it on the top.

 

Turbo Aside, adding a freeer flowing exh def makes more power up high closer to WOT and the expense of low end HP, it just shifts the engine's power curver higher. Nothing is free. Large diameter exhausts can reduce velocity which is less efficient at low RPMs = less power in those ranges. Factory sizing of the exh is a compromise between the two since few run at WOT and mostly at lower RPMs. Since many equate torque with low end power it's often referred to that way but that's incorrect, peak torque is likely higher with a larger exh but it doesn't help anything on the low end and often makes it worse.

 

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Exhaust "back pressure" is nonsense. What you want is exhaust scavenging. This is achieved through primary pipe diameter and length, along with collector diameter and length. Too large or small of these diameters and lengths can reduce scavenging, reducing power output at the rpm range desired. A turbo is driven by rapidly expanding exhaust gas, not back pressure, and exhaust design will be different. There are a ton of resources available to use to get a good understanding of how all this applies to horsepower and torque production in a 4 stroke engine. Turbocharged engines go way back, it's not a new technology.

 

No dog in this fight, but in that video, that is a *heavily* modified carbureted engine, and the video is sponsored by a tuning shop.

"Result may vary."