OK, gear-heads, this question is for you. So what is the safe amount of boost to run for our stock MCS engines?

• For a daily driver (keeping in mind longevity)
• For a weekend fun-run car (keeping in mind the pure enjoyment factor)
• For a race-only car (may require frequent engine rebuilds, but don't want to blow it up after a 1/8 mile)

 

Well since the Helix twincharged setup gives around 20 lbs of boost and that can be used as a daily driver, I'd have to say 20lbs for your first question. I can hit 18.5lbs no problem this time of year in my MINI and at 61k+ miles, it runs better than ever.

 

Oh sorry...I see now you asked this question of Gear-heads. Sorry! :smile:

 

You're forgiven :smile:

 

Hey Dom...Safe is a relative term...first off ...if yo uare using a turbo then you can have a boost controler....

The supras I have tuned run as much as 50 lbs of boost ...and they are "street cars"

YOur question cannot accually be answered at this time as no one as spent a night on a dyno willing to blow the motor...I.E. making pull after pull Turning up the boost untill the head gives or a piston shoots out through the roof of the facility...

SO...untill I get another MCS or Hubie decides to do it...We do not know...

 

Depends, 20lbs of boost from a twin charger set up is going to be a hell of a lot more power then 20lbs of boost from just the eaton. So in the end it really depends. Basically any of the pulley upgrades are proven safe and effective. I'd be more concerned with over spinning the charger then blowing the motor to be honest with you
Mike

 

Absolutley...however, I was calcualting in the fact that we are talking purley on boost...casue if you are going to try and get more boost other than just a pulley you should be willing to either eliminate the charger and go souly turbo...or upgrade to a twin screw etc etc....there is no free lunch...you wanna play you gotta pay...LOL

 

" There is no free lunch" LMFAO !!!

 

Interesting... Can you explain this further? I thought it didn't matter how the boost got to the combustion chamber, just that it got to it to condense the air so more fuel could be added which in turns makes for a stronger explosion. Can the combustion chamber really differentiate between 20psi from a turbo or 20 psi from a supercharger? No disrespect intended, I just want more of a explanation as to how. :smile:

 

Yep, hence my three "driving categories" to determine the max boost of each.


Call me first before this occurs. I'll make sure I get a vacation day :-) to come down and watch

 

The thing is, the supercharger is driven via a belt directly from the engine. So the engine has to work to create that boost. With a turbo, you're using exhaust gases so once that turbo gets spooled up, there's very little power lost.

At redline, our superchargers may be using 50hp to spin that supercharger at 15k RPMs - whatever the numbers may be. This is why in the Helix/PSI twin charge setup, they use the STOCK supercharger pulley for max HP gains. This way there is enough boost from the supercharger for low-end power yet there isn't as much supercharger DRAG at the high-end reducing max HP. :smile:

 

yes but again this is relative..for me...I will go as far as I can and keep the car streetable...LOL...why not...heh heh...and then get a race car and well that's another game cause power is not everything....

also if you are willing to put 101 or c16 in your car all the time ..then you can have as much boost as your engine can take on the street




you know it dood...LOL...gimme some credit

 

My comment about different boost is based mostly on the size of the blower or turbo. For example a small T3 turbo may be able to run 18lbs of boost, but because the turbo is so small and inefficient at the higher RPM's it may only make 250hp at the crank but have a boatload of torque down low. Whereas a larger turbo, say for examply a t3/t4 or a GT2871 will also be running 18lbs of boost but since the turbo is larger and much more efficient at the higher RPM's you'll be getting 350hp for example. Both are running 18lbs of boost yet you'll have drastically different power curves and power levels.

In the end the car may be able to handle 18psi with the smaller turbo but maybe with the bigger turbo the rods let go, the rod bolt fails, you crack a ring, etc. This is why it's not just based on the pounds of boost but more about exactly what components you plan on running.

But like I said before the 15%, 17%, 19% pulley's are all pretty safe on the MINI so I wouldn't worry to much.
Mike

 

IT's about the CFM that is moved! that's where the hp numbers for the turbo's come from, that's another way of look'n at it.
The larger the hp of a turbo normaly goes hand in hand with the turbo lag time. unless you have a aerodyne style turbo, that has the adjustable intake they ain't cheap! google it

 

OK, I get it, then to get 18 lbs of boost from a GT2871 the efficiency is 100 hp less of a parasitic drag on the expulsion of exhaust gasses, than the small T3.

OK, I get it. The engine with the smaller turbo producing 18lbs of boost is creating 100hp of more drag on teh expulsion of exhaust gasses which could cause too much back pressure to the engine, blowing it up. Whew! I get it now.