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Discussion Starter · #1 ·
How much boost is the stock turbo on the Juke putting out? Does anyone know what size turbo the Juke is equiped with?
 

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I've been curious about this aswell. We traded in my wifes '01 Jetta 1.8t to get her the Juke. I noticed that the turbo on the Juke is smaller than the KKK K03 on the 1.8t. Given that the Juke has 38hp more than the stock, K03 equipped, 1.8t with smaller displacement AND smaller turbo, I'd really like to know how much psi it's pushin'.
 

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If it's running high compression (most direct injection gas engines do) say 10-12:1 I dare say no more than 6-8psi.

It's easy to check.

Un-plug a vac line on your juke, T in a boost guage and take it for a spin....
 

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Discussion Starter · #5 ·
I've been curious about this aswell. We traded in my wifes '01 Jetta 1.8t to get her the Juke. I noticed that the turbo on the Juke is smaller than the KKK K03 on the 1.8t. Given that the Juke has 38hp more than the stock, K03 equipped, 1.8t with smaller displacement AND smaller turbo, I'd really like to know how much psi it's pushin'.
The physical size of the turbo isnt what determines its flow potential, its the size of the intake/exhaust wheel area thats important. A lot of times a turbo may be a little smaller in actual physical size, but that dosnt mean it flows any less.
 

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A pnumatic actuator is not a simple open/shut operation. 'Cracking' pressure is 9psi however things like engine speed, backpressure, intake temp, turbine speed, load etc are all contributing factors to exactily how much boost is produced.

Cheers

Justin
 

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I'd dare say a decent intake and exhaust will see you hit the 'boost/airflow cut' and result in 'limp' mode or at least a protection (retard ignition- rich mixture) map.

Just pull the wastegate reffrence line... ha ha ha.
 

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The physical size of the turbo isnt what determines its flow potential, its the size of the intake/exhaust wheel area thats important. A lot of times a turbo may be a little smaller in actual physical size, but that dosnt mean it flows any less.
Yeah, I'm aware of that, but like the lady says, size does matter.

As soon as our Juke is broken in, I'll T-in a pressure gauge and put our collective curiosities to rest.
 

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The Juke is actually build at 26psi of boost, factor in atmospheric pressure already of 14 lbs, subtract and you get the factory reading of 12 psi. A lot of older cars you can play around and increase it, 2011 technology, the ECM has other ways to find out if boost is going past that to shut it down, already researched into it
 

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The Juke is actually build at 26psi of boost, factor in atmospheric pressure already of 14 lbs, subtract and you get the factory reading of 12 psi. A lot of older cars you can play around and increase it, 2011 technology, the ECM has other ways to find out if boost is going past that to shut it down, already researched into it

....................:(
 

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So xrated, are you saying that a CAI and a 2.5" cat-back will actually hurt my performance? This is my first turbo vehicle.
 

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You realize this thread was from 2 years ago? I haven't seen that guy at all in the 5 or so months I've been on here.

And to answer your question, a CAI and 2.5 catback will get you a nice bit of performance upgrade.

As well and slightly increase gas mileage. I would suggest reading some posts around here since there are all over the place.
 

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So xrated, are you saying that a CAI and a 2.5" cat-back will actually hurt my performance? This is my first turbo vehicle.
The thing about turbo vehicles and larger exhausts is this: The larger your exhaust, the lower your backpressure. Lower backpressure allows for quicker turbo spooling. You increase your horsepower, but lower your torque in the mean time.
Torque is what gives you your off the line acceleration, but horsepower is what gives you better at speed acceleration (60-100 for example)

With the Juke being either AWD or FWD, you don't need to worry about torque numbers as much as if you were in a RWD vehicle. Too much torque with FWD and you simply spin the tires (this goes for any set-up, with enough torque.)

...Least, this how its been explained to me by other, far more experienced, AWD guys; one being a Subaru technician.)
 

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The thing about turbo vehicles and larger exhausts is this: The larger your exhaust, the lower your backpressure. Lower backpressure allows for quicker turbo spooling. You increase your horsepower, but lower your torque in the mean time.
Torque is what gives you your off the line acceleration, but horsepower is what gives you better at speed acceleration (60-100 for example)
You want your exhaust back pressure in turbo'd applications to be as low as possible ...The best possible case is having no exhaust pipe off the turbo outlet port at all!!! And I've also found this to be the case with our Jukes!...Opening up the exhaust as much as you possibly can off the turbo outlet will serve to quicken boost spoolup response resulting increasing an overall increase in hp across the entire power band as well as improve low end torque response....

Now where you might decrease low end torque is if you dramatically increase both piping dia size and length from the turbo intake end through the IC to the intake manifold and care need to be taken as not to increase the length or diameter of this intake portion of piping too much as to introduce lag and therefor impact low end torque...

Once I have my 3" turboback fully installed and dyno i'll be able to show this better on a before and after dyno plot
 

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You want your back pressure to be as low as possible in a turbo'd application....best possible case is having no exhaust pipe off the turbo outlet port at all!!! And I've also found this to be the case with our Jukes!...Opening up the exhaust as much as you possibily can off the turbo outlet will serve to quicken boost spoolup and response resulting increasing an overall increase in hp across the entire power band as well as improve low end torque response....

Once I have my 3" turboback fully installed and dyno i'll be able to show this better on a before and after dyno plot
Sounds good, You using the Injen downpipe or having one custom built? I'd like a better downpipe but would like to keep a cat-converter... And are you doing any sort of muffler/resonator? I really like the Injen 3" sound, but can't justify paying $750 for it if a local shop can do all the same bends and such for $100 and I just provide the muffler to use...

I'd love to hear yours once it is done too!
 

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Injen doesn't offer or make a true downpipe for the Juke...they only offer a 2nd cat delete pipe that they call a downpipe....I'm going with 3" pipe from the turbo exhaust port to tip only using a magnaflow 3" 5x8x14 race muffler...

I will be posting another dyno after install in the next few weeks and post ...
Ahh, didn't realize it was simply a 2nd cat delete. Looking at the service pictures for the OEM cat, it didn't seem like the Injen "downpipe" would line up correctly. Please put a video up for the exhaust once its done, I'm very curious as to what the difference is!
 

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You increase your horsepower, but lower your torque in the mean time.
Torque is what gives you your off the line acceleration, but horsepower is what gives you better at speed acceleration (60-100 for example)
THis isn't accurate. YOu can't decrease torque while increasing horsepower.



As you can see, if torque goes up or down, horsepower also goes up or down at a fixed proportion.

What you likely meant to say is that increasing to a larger diameter pipe will decrease low rpm torque while increasing high rpm torque.

I will agree though that putting too large a diameter pipe on a turbo car is hurtful, unless your only concern is maximum power. If you are looking for a normal car that drives well on the street you need to find a balance, this is even more important if you own a CVT equipped model. For those manual guys, you can let out your clutch at a higher rpm, or downshift to keep the revs higher and the boost on. With the CVT it's a bit more of a pain in the ***. The CVT seems programmed to drop as low as it can as often as it can. This will make driving in the sub boost region increasingly painful. The CVT in sub boost is already painful as it is, reducing low end torque further will make this even more pronounced.

The torque curve is also something that should be considered. Going after that peak HP up at 5800 rpms is silly. What you really want is to get as broad of a powerband as possible. The more area under the curve the better all around performance you will have. Given we drive street cars no track cars, shooting for maximum horsepower is not the wisest of moves. The better approach would be to find mods that balance each other so that you increase total torque, without favoring on end of the rpm band over the other.

If you want to see what I'm getting at, go find a friend with a boosted honda. They just love putting in those 8:0-1 compression pistons in there and then pushing 20 lbs of boost. Sure they make 300-400 HP, but try taking off from a light without reving the piss out of it. They have zero torque without the turbo spooled and it makes for a Sh*t ride. With our little 1.6L motors, the last thing you want to do is reduce low end torque. It's low enough as it is.
 
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