Since picking up my 2007 MCS, I've been considering a Hybrid or JCW turbo upgrade.

The hybrid turbo, and to a lesser extent the JCW turbo, upgrades seem to maintain boost (and thus torque) through the RPM and increases the overall area under the curve. It's just a question of how much of a hit in spool up you want to take to reap the benefit of that sustained boost in the upper rev range.

Am I think about this correctly?

 

This thread of a Hybrid turbo was very informative:

https://www.northamericanmotoring.co...o3-review.html

 

Yep your thinking correctly...sort of. There's several things to consider. With a JCW or hybrid turbo the exhaust turbines are the same size its the compressors that are larger. All things being the same a larger compressor will have greater mass and take more energy to spin up to the same RPM as a smaller one.

However, this is offset by the fact that a larger compressor will move more air at a lower RPM. In point of fact my hybrid provided more boost at lower RPM while testing on the stock tune prior to re-installing the JB+. In addition at identical boost levels the larger compressor will be spinning at a lower RPM (reducing bearing wear) and will transfer less heat energy into the intake. The intake charge will still be heated due to compression but to a slightly lower degree. Plus you benefit from being able to carry high boost into the upper RPM range.

One of the things that caught me off guard when I installed mine was the difference in sound between the stock and hybrid turbos. Once I installed the aftermarket intake I could always hear the turbo spooling. With the stock unit it was a high pitched noise that varied depending on boost level. Now with the hybrid installed its more of a growl a lower boost that scales up to a minor roar lol. (for lack of a better way to describe it.)

 

So then is it safe to say, your engine can only handle so much before excessive heat and detonation, but in your case you are getting to that point quicker and able to hold it there for longer... so no more power, just better sustainability and area under the curve?

 

Exactly its all in the tune. With stock tune and humongous turbo 14 psi is all your going to get period. You might get it sooner and/or hold it longer but that's it. With a larger turbo and cranked up (i.e. poorly written) tune you can hit 28 psi and crazy power levels....once . That's why it so important to choose someone with a great deal of knowledge and experience when getting a tune. Pushing the envelope is one thing but I'd rather have it done by someone that's already done it many times.

My engine is a long way from reaching its potential and around 230 to 240 is a reasonable number to expect to hit without sacrificing reliability too much on stock internals. Especially since the higher boost tune on mine will only be activated with the sport button and I doubt I'll be using it that much. It's enough for me knowing its there if I want it. Besides even at 205 it's loads of fun to drive.

 

So big turbo doesn't mean you'll blow it up, but bad tune can no matter if stock or hybrid turbo. For me it may be about cost, u can get a new jcw turbo for 1100. And even without a 360 beating like a jmturbo, it's 500 less. So if it dies earlier, the replacement cost is less.

Also with some of the tuning companies, they charge more to tune a hybrid I believe.

And a last thought, there something I love about the power of the mini I that you don't have to be scared of applying the power. I don't want to deviate to much from that.

 

I don't agree with some of this.

I am running an 09 JCW all stock with a 42 mm jmtc turbo and I can get 17 psi anytime and have pushed it to 20 a couple of times before I backed off. Just how fast do I need to go on a public road!!

Your mileage may very.

113k miles.
No tune.
Stock IC.
JCW airbox.
JCW exhaust.
Catless dp.

 

I've seen 21.8psi with stock S turbo using torque app, car is running fine.

 

IMO, it's not about the boost, it's about the load in the cylinders. An ECU starts pulling timing and saying "too much!" when it hits a certain load in the engine. A larger turbo will flow more CFM at a given PSI, so CFM is really what it's about as opposed to PSI. A larger turbo can certainly max out an engine at a lower PSI. So if you can get a larger turbo to spool relatively quickly, then the ECU saying "ok captain, I'm giving her all she's got!" an the ECU flatlines the load to the engine through the rev range and at higher RPMs the smaller turbos tail off whereas the larger ones can sustain.

(certainly open to better educated opinions here, trying to learn)

 

Interesting. I've heard of the ECU allowing more boost at elevation due to the air density being lower. IIRC according to the specs the factory S ECU should be programmed to be limited to 14 psi in over boost at sea level and the JCW kit ups that to 17 or 18 psi.

 

That's an interesting insight. I think it's reflective of a number of MINI owners' perspectives.