I've been trying to find this question out and can't...

In a turbocharged auto, the pressure is released through the BOV once the user has released the gas pedal... just like a manual basically. However, the difference is that the auto tranny auto shifts without the necessity of letting off the gas.

My local tuner runs Dezod on his tC and says it's the type of kit to where one can have it installed on a totally stock car and be fine.

What will happen to the engine, tranny or turbo itself if you were going at a constant speed with the turbo spooled up? Let's say driving at 3K-3.5K rpm for 20 sec to 1hr at a time giving examples such as long vacation trips. Would that cause possible damage due to excessive boost entering the engine or too much heat buildup?

 

no, because once you are done boosting and traveling at a contant speed, you go from boost to vacuum which means that the engine is pretty much running like it would if it were stock.

 

Yeah, what you are talking about is accelerating like at the drag strip. You would always be in boost, same as if a manual was powershifting.

Normal driving, you would take your foot off of or at least pull back on the gas pedal at some point, and then your out of boost. Even steady cruising, your only in boost when your accelerating. Othherwise, your in vacuum.

 

i know this, what i am saying is would it hurt the engine or anything else if i were in boost for a very prolonged amount of time rather than just a couple seconds?

I just drove a 5hr trip yesterday and noticed that the rpm gauge would have a turbo spooled up the ENTIRE time.

I know that the car can take the turbo but i dont know if it can take it if it's being shot with 5psi for 1,2...5 hrs constantly.

 

You wont be in boost for the 5 hr trip tho.

A turbo charger works off of the flow of exhuast gas and a boost/vacume situation.
You will only be in boost when accelerating in a more than normal situation. If you lightly press the pedal or if you cruise at a constant speed YOU WILL NOT BE BOSSTING. Now if you floor it, yes you will hit boost.

i can drive my car for 30 hours straight up to 127MPH and NEVER hit boost if I dont want to. its all about how hard you press the accelerator. And Once you hit cruising speed (say 60MPH) you cannot be in boost unless you press the pedal harder to increase speed.

So to answer your question, unless you drive for 1,2...5 hours constantly flooring it to get to 60MPH, then hitting the brakes to slow down, then flooring it again to hit 60MPH, you will not be in boost for anyof the ride.

 

oh ok, so the turbo can't spool even if it's over 3,000 rpm unless a large amount of exhaust is consumed at once such as fast accelerating. Thanks.

 

Plus you gotta realize that there are quite a few cars out there that are boosted stock. They have to work too dont they?

 

right, now you get it. I had the same concern when I was learning about turbos.
Just cause your at 4000 rpm, does not mean your in boost. In fact, if can accelerate really slowly annd eventuallly get to 4krpm and never hit boost. but when I'm cruizing on the freeway at 4k, i'm in vacuum, and I push down the pedall and boost kicks in! it's GREAT!

 

Boost only comes in when you are on the gas pedal. You could be cruising at 5k RPM and still not be in boost. So really turbo boost is based on load (which is based on throttle position and RPM).

 

Well, when I'm cruzing at 75 on the freeway, my foot is on the pedal, but it's constant pressure, so I'm not in boost. but when i push the pedal down more, and start accelerating, then boost kicks in.

What I'm curious about is what happens with cruiz control on and you start climbing a hill.

 

unless its a HUGE hill, you probably wont hit boost. Cruise control is very subtle on the throttle and maintains speed. Just like when you arent using cruise and try to maintain speed.

 

Hmm..good point. I've never used cruize on my car yet, but the others I have used on (auto) usually downshift over that hill from Vegas to Cali.

 

Your car should have a bit better MPG after turbo if used right... (or atleast that's the way it works on Corolla XRS' turbos the hit the 38-40MPG mark hwy and 28MPG on city)

It's usually off boost under 3K RPM unless your connections are damn wrong and boost doesn't drop even on idle, then that's a nice fire works show!

 

actually, that all depends on the tune. yes, in thearoy, having a turbo and not getting into boost will give you better mialage, cause yoru throwing charged air into the block.
But you can tune it for more or less however you want.