So how much boost can the stock internals take? I'm just assuming that everything isn't forged. Also, I read somewhere that the compression ratio is over 10:1. Surely you wouldn't want to try cramming too much boost in that engine? Please correct me if I'm wrong. I don't even own one yet and I'm already thinking about modding...

 

The motor is good for WAY more boost/power than the stock turbo can produce. The car has a twin scroll Borg Warner K03 on it. The efficiency range of that turbo maxes out somewhere around 16 to 18 psi. The stock injectors are big enough to provide the fuel for 18 psi. Chipping the car with unichip or alta's package does just that. It raises the boost level to add power. Mini was smart enough to put a turbo on the car that can not create enough boost/power to grenade the bottom end.

 

Well that's a good sign, even though throwing 18lbs of boost at cast pistons scares me more than a bit. I'm just assuming they're not forged. Is there any difference between the internals of an MC and an MCS?

 

Does fuel consumption increase if you increase boost pressure? How does one turn on the boost in an MCS?

 

I'm not sure about the differences between the MC and MCS motors, but I believe you would be comparing apples to oranges. I think that they are 2 totally different power plants.

Fuel consumption does increase with added boost pressure. Adding boost means that you are adding more air, so you have to add more fuel to make the air fuel ratio correct. As far as "turning" on the boost, you really can't. Our cars have too many electronic safeguards. In older turbo cars you could use a manual boost controller to turn up the boost and make more power, but our cars will not allow you to do that. This is why companies offer chipping. They electronically turn up the boost, more boost/air combined with more fuel equals more power!

 

The MCS does have forged pistons and a steel crank. Alta's unichip can up the boost to 20lbs if you also upgrade your intercooler etc. It goes like stink.

 

Thanks for the explanation? I have an MCS, but I was wondering if I can tell when my boost is activated while driving.

 

Get an alta intake and you will know.

 

You could get a boost gauge, or (an easier install) a ScanGaugeII.

 

Boost is "activated" any time you press the gas pedal. You need to first understand how the turbo works. Exhaust gas leaving the engine goes through the hot side of the turbo which has a "fan" blade in it. The exiting air spins the blades which are connected via a shaft to another set of blades on the other side of the turbo. These blades suck in fresh air and force it into the motor. The amount of force is represented by PSI. The more exhaust gas you make, the faster the fan blades spin thus pushing more air into the motor. When your engine is at idle, it does not create enough exhaust gas to force fresh air into the motor, so when you rev the engine up making more exhaust gas, you make more boost. The maximum amount of boost that your engine receives is electronically controlled. The computer in one form or another controls the waste gate which vents off pressure so that the turbo does not spool up and give the engine too much air.

 

so how come ALTA is bumping the boost up to 20psi with their piggy back chip?

 

Not true man.

The turbo on the MCS doesn't kick in until 2000 RPM or so, which means if you are "pressing the gas" below 2000 RPM, you have no boost.

 

I believe that since the car is direct injection, having more boost with higher compression isn't as much of a problem as it was with regular injected cars. I may be wrong though.

 

Is there any way to increase horse power or boost or whatever w/o sacrificing fuel mileage?

 

I'll have to disagree.

 

You have boost below 2000 RPM. That is what the twin scroll part of our turbos is for. This is why we have full torque at 1900 RPM'S. This means that the turbo is already spooled. As far as direct port injection goes, that has nothing to do with being able to run more boost with high compression.


The statement about the alta chip hitting 20 PSI, when I said it was efficient up to 16 to 18 that means constant boost. Yes the boost peaks to 20 but then immediately drops off. 20 psi is the peak boost. Our turbo is capable of peaking around 24 PSI, but at that point the air it is pushing is just so hot you have to worry about detonation.

 

let's not get vicious. it looks there are some newbs in here just looking for info.

russr/ if you increase boost you'll have to increase the fuel consumption. if you want more horsepower you'll have to increase consumption. so in short no. there really is no way to increase power without increasing fuel consumption.

that being said you can strip weight from the car to increase your power to weight ratio...
this is where you keep your stock engine but eliminate some weight. imagine you are pulling a rock up a hill that ways 200 pounds... then suddenly you only have to pull 5 pounds it will be noticeably easier.

if you are concerned about mileage try to decrease weight in the car. i'm not sure if there is a rear seat delete kit for the r56 yet but that will be a quick 100 lbs. or/= to a tenth of a second faster on the 1/4 mile.

 

If my comments come off as vicious, I am very sorry, my sole intention is to inform. If worked with/built many turbo vehicles in the last ten years and I just wanted to share what I know. I have a good deal of experience with the turbo that is on our cars because it is very similar to the one used on 1.8T VW's which I have owned and raced for years.

 

If you increase HP or boost you are generally making the engine system more efficient which usually does result in better MPG if you can refrain from driving with a heavier foot. With my mods, I've gained 2-3 MPG, even with a slightly heavier foot.

 

No matter what has, or has not been done to a car, the biggest factor affecting fuel milage is the driver's right foot. If it spends a lot of time deep into the throttle, the milage will go down. Restraint will result in better fuel economy, even if you have a high compression, high boost motor. One of the great things about the MCS is that you can zip about and still get overall milage in the high twenties or low thirties.

cheers,

Joe

 

ALTA CAI and exhaust increased my milage and horsepower simultaneously. Allows the engine to run more efficiently because of the increased flow. Most people just don't recognize this increase because they tend to drive with a heavier foot after mods.

 

How easy is it to install the Alta CAI? Is this something someone with no auto experience can do?