Why is the turbo so anxious??

25 i-FORCE MAX

I’ve noticed since ownership the turbo engages with full blast from the slightest pedal depression. Isn’t this bad or called “lugging?”

My previous vehicle had a psi gauge and I always tried to keep the turbo from engaging while driving unless slightly until I’m over around 3,500 rpm. This was also a vehicle that put out max torque at 1,500 rpm’s.

Example; enter highway, stuck behind semi doing around 50mph, traffic is not heavy, I wait for car on the left to pass and I depress the accelerator slightly to change lanes and get up to around 65 cruising speed before the next group of cars comes up behind me. Turbo and MAX gauge go full spool.

Even going downhill, let off the gas, engine turns off, start going up hill again, depress the pedal, engine starts back up and then turbo is maxed out.

Anyone have this issue? Any tips?

 

Any time you hit the gas and put the engine under load, the turbo (or supercharger) will spool up and you'll see positive pressure (boost) on the gauge. As the engine "catches up" to the load, boost will roll back once the intake pressure reaches equilibrium. The only turbo I've had was on a diesel and it stayed in boost most of the time unless I was coasting. I've had two supercharged cars, one with a positive displacement blower and one with a centrifugal compressor. They made their power quite differently but both were a lot of fun.

 

There's a reason it makes peak torque at like 1700rpm...

 

Small turbo, tuned to get into boost early

 

I had a CVT turbo breifly, it was the only type of stupid transmission where you cold hold boost, but it required 3/4 throttle.

Like others said, boost early, then it eases off and the engine takes over. It's not designed for peak, but for load and economy.

 

Boost that shows up late is called turbo-lag

They went to great lengths to design a system that would spool up quickly at low rpms. That little 4 banger needs the help

Not sure why you'd want to keep the system under boost or "neutral" all the time. Are you afraid you're going to hurt something?

 

I read about “lugging” by spooling up to max boost at low rpm as bad for the engine. That’s really the only reason. I never had a turbo before that and always hear so much bad feedback about them.

Pretty much have been avoiding mashing the gas or heavy throttle until a proper rom to keep from “lugging”

 

Thank you for the responses everyone. If this is not a big deal and normal operation, I’m quite relieved and will end up spending a lot less time trying to “manage” too much boost at low rpm.

Still seems like the boost is excessive with the slightest depression of accelerator pedal. You would think boost at 25-50% under light acceleration would be plenty.

 

Depends which gear you’re in…

This transmission is actually tuned properly. It will hold a specific gear and build boost to keep from downshifting at times. Which is a wonderful thing.

 

We’ve all been waiting for a responsive, torquey Tacoma since 2005!

 

Mine doesn't behave any differently than expected for an engine that develops peak torque at low RPM. Turbo behavior is also changed from the load, mode and driving style. My driving gets highest average MPG in the family, I'm not slow, and when I was in the back seat I saw family members or friends just not the smooth drivers I am.

Long ago I drove semis and being smooth made a difference there too. Cat, Cummins or Detroit engine didn't make a difference, and my MPG was higher than other drivers in same tractors. You can be smooth and not slow.

 

What you makes you say it’s a wonderful thing? This is only my 3rd automatic transmission in 20+ years. If I need to make a pass or ascend from a valley, downshift. For engine efficiency, wouldn’t it be better to have a proper downshift to begin the ascent instead of spooling full boost in the same gear?

It takes longer. 3-4 seconds to maintain speed going uphill while turbo slowly increases rpm to climb VS a single downshift which is instant.

Am I painting a decent enough picture so you can imagine how this would negatively affect a driving situation?

Of course if this is the way it is, well then I have to accept it and get a twin turbo v6 next time around.

 

That’s awesome! Even my brother was like “these trucks have come so far”

The sales guy put the truck in sport (which I did not realize) and my initial test drive is why I bought the truck 15 minutes later. Impressively torquey from a stop… I’m not knocking the truck and have nothing to compare to. This truck is incredible for the value!

 

This! I like to think of myself as a limo driver. Smooth braking, no whiplash when breaking and like to keep a steady speed. I get seasick with people that mash on the gas and then brake or do that thing where they keep pepping the gas on the highway to speed up and then let it engine brake then pep the gas again to speed back up.

It sounds like I read something, was misinformed about low rpm and full boost being bad and since then, have modified my own driving behavior.

Also sounds like I need to enjoy the truck but also don’t be afraid to unleash the F1 driver hidden deep down within each and every one of us!

 

Downshift to get into the power band on NA engines, or wait for the boost and make the power band come to you...

Seems like Toyota made the right choice. Turbo engines need to be driven and shifted a little differently.

I don't have a 4th gen, but my daily is a turbo charged car. Its took some time to go from a regular NA car to a turbo car. You are always dancing around that turbo lag. Since the 4th gen has a small quick spooling turbo you wait a lot less time.

 

Toyota didn't hang that thing off the side of the engine so you could drive around not using it.

Just drive the truck. Rev it up, get it into the power band and use the turbo. These things aren't delicate little flowers

 

Its most likely the twin scroll design, quicker boost pressures and simpler than VVT. Boost isn't going to build up slow and come in late like single scroll turbos

 

Sometimes I wonder if the people worried about turbo lag know how long a second actually is

it does not take 3-4 seconds to spool up boost on an engine that’s already hauling you uphill in boost

 

OP, are you going by the boost gauge or sound? If the former, you’re pushing the gas too hard for your desired. If the latter, the sound of spooling is not the same as boost

 

Going by the gauge.