Turbo kick in

[vtmdsm27]

At what point, what triggers, when does a turbo kick in?

Does the 2.4T engine use the turbo for moderate take off? Light take off? Can you go for days without kicking in the turbo if you drive moderately easy?

When it kicks in, does it save gas because there's more power?

[Mean Green]

Originally Posted by vtmdsm27

At what point, what triggers, when does a turbo kick in?

Does the 2.4T engine use the turbo for moderate take off? Light take off? Can you go for days without kicking in the turbo if you drive moderately easy?

When it kicks in, does it save gas because there's more power?

Stock it kicks in around 2500 rpm.

If you have a boost/vac gauge you can keep it on the vac side and not use the turbo at all.

The turbo model has more torque than the na model so the turbo model takes off easier and you can use less gas if you keep your foot out of it.

For myself if I stay out of boost for the whole tankful I can get 5 more mpg. I've done this before, but it isn't as easy to do as you think because of the fun factor of getting on the car.

[vtmdsm27]

So, I just had my first OTR trip, about 55 miles each way. I have a few questions for you ol' pros out there.

I have the '08 2.4T. At 65, I stayed at 2500 rpm, 24.9 mpg At 70, I kicked up to 2700 rpm, 22.5 mpg. Big difference for only 200 rpm!


As I understand, it kicks in at 2500 rpm. But surely it doesn't run when I am simply cruising down the flat highway at moderate speeds . . . that seems to defy the physics of turbocharging.

[nevinsrt]

Originally Posted by vtmdsm27

So, I just had my first OTR trip, about 55 miles each way. I have a few questions for you ol' pros out there.

I have the '08 2.4T. At 65, I stayed at 2500 rpm, 24.9 mpg At 70, I kicked up to 2700 rpm, 22.5 mpg. Big difference for only 200 rpm!


As I understand, it kicks in at 2500 rpm. But surely it doesn't run when I am simply cruising down the flat highway at moderate speeds . . . that seems to defy the physics of turbocharging.

the turbos always spinning from the moment you start it to shut off, because its running off the cars exhaust.
you can make a small amount of boost under 2500 but it wont make full boost untill over 2500.
you can cruise down the highway at 3k+ and still not use the turbo. it all depends on you foot if you stay on the vac side you'll see better fuel mileage

on our last road trip we avaraged 25mpg and we were cruising between 70-80 we went 240mi and use only 9.5 gal of fuel if you have a gauge and stay on the vac side you can get good mileage.

[vtmdsm27]

Thanks for the info. So, I'd like to get a gauge that looks like it would be part of the car. Any suggestions?

[whipplep]

no man, a turbo and a supercharger both do the same thing, the force more air into the engin makeing a bigger explosion and burning more gas, so it will not make it better on gas, but you dont buy a turbo to get fuel efficancy

[bobs turbo pt]

hey nevin the srt looks really nice !!

[nevinsrt]

Originally Posted by whipplep

no man, a turbo and a supercharger both do the same thing, the force more air into the engin makeing a bigger explosion and burning more gas, so it will not make it better on gas, but you dont buy a turbo to get fuel efficancy

yes there both forced induction. yes they make a bigger explosion in side the engine, yes the bigger explosion makes more power

and no they work differently

a supercharger is belt driven and runs on the engines power

a turbocharger runs on exhaust and creates it own atmosphere. the better you get air flowing to it, the more efficent it will work, the less fuel and air will be needed to make a good amount of power (thats if your not beating the crap out of it) it is possible to get better fuel efficienty out of a turbo car.

when i got my SRT-4 it was getting 23-25mpg highway
now that i modded it, it now get 35mpg highway. So i got an increase of 10 mpg now do that with a supercharger.

our Cruiser was getting 19mpg when we got it in May
with the mods so far its now getting 25mpg and were not even done modding it yet.

[nevinsrt]

Originally Posted by bobs turbo pt

hey nevin the srt looks really nice !!

Thanks bob!!!

[Cal Cruzer]

The PT has a very small turbo which spins up quick so you get full boost at a low RPM. I could be wrong but I think I remember reading when they first came out that full boost was available at 2200 RPM. However, full boost does not mean peak torque or horsepower. Like any other engine, it has a power curve. That is where you will really feel the turbo push you into the seat. On mine it starts about 3000 RPM and keeps going from there.

The turbo's spin speed is directly related to the amount of exhaust gases passing over the blades, so the turbo spins all the time that the engine runs, it just doesn't spin fast enough under low acceleration to create boost. Boost is directly related to how hard you push the go pedal