>> As for the BLUE color for the silicone piece, we are going to make black and red also, since so many people have asked for it.<<

Woohoo!

 

>> Some cars, mainly NA cars, don't need the catch can, because the crankcase pressure is not very high. So less oil gets "blown" into the intake track.

Could you elaborate on this, specifically with regards to the Cooper's 10.6:1 vs the Cooper S's 8.3:1 compression ratios? Wouldn't this be more necessary for the Coooper than the Cooper S, or am I misreading you?

R

 

ALTA2 wrote:

The supercharger grabs gulps of air and sends them out its outlet. If the upstream air pressure is low, the number of air molecules passed to the intake manifold will be low. By starting off with pressurized air (you aren't gonna get much pressure from a intake scoop, but let's pretend you are going 300 mph and have quite a bit of pressure) the supercharger will dutifully pass those air molecules to the engine, resulting in higher boost.

 

I would like to see yellow as a color choice as well.

 

But Andy, I am planning on going three hundred miles per hour.....


I wanna see the speedo spin like the dial on Homer Simpson's scale.

_________________
Bradley

 

It is good to plan for those kind of speeds, rather than end up there accidentally.

 

OK, I've read all of your credentials and see that I'm not one to speak. But I must.

First, about this new misinformation, ram air induction makes an enormous difference -- far greater than the improvement offered by an oversize filter. Furthermore, ALTA2 is frighteningly off-base with the theory that it makes no difference on supercharged engines. Hmm... So a big air filter results in all this extra power but ramming the air through it is a waste of time?

Now that that is settled, I'm quite impressed that Andy took the time to measure the static pressure at the cowl vent. Although his results showed virtually no pressure (0.04psi), I am surprised nonetheless that it was positive. By any chance was the pressure being read using the cabin pressure as a reference? With the window down?

And finally my point: The 0.04psi from the cowl will not necessarily be added to the pressure from the scoop. At high speeds and low RPM, the ram air will dominate and overcome the cowl pressure to flow *out* the cowl and reduce the engine performance. Only if the engine attempted to draw more air than what would normally be rammed through the scoop would the cowl pressure be utilized for gains. The point at which that will occur is at idle on the dyno but at 50MPH it could be 3000RPM or 20,000RPM. There's no way of knowing without testing the engine's air demand at various states vs. the ram's ability to maintain excess pressure at different velocities. I don't think any meaningful conclusions can be made by testing the ram air pressure or the cowl pressure separately. I believe the only meaningful data would have to come from a test of the air pressure at the filter in either configuration, at a variety of speeds and RPM until a line can be drawn denoting the transition between cowl losses and cowl benefits.

 

>>>> Some cars, mainly NA cars, don't need the catch can, because the crankcase pressure is not very high. So less oil gets "blown" into the intake track.
>>
>>Could you elaborate on this, specifically with regards to the Cooper's 10.6:1 vs the Cooper S's 8.3:1 compression ratios? Wouldn't this be more necessary for the Coooper than the Cooper S, or am I misreading you?
>>
>>R
>>

Yeah you're misreading him. Compression ratio and crank case pressure arent the same thing. Compression ratio is in the CC and crank crase pressure is well, in the crank case. What happens is after the mix is ignited, some of the expanding gases sneak past the rings and pressurize the crank case. Your PCV valve is supposed to prevent this, and it does, but sometimes some oil sneaks out the PCV line as well.

You cant compare static compression ratios on different induction setups in this application. The supercharged mix has already been compressed 2:1 so its not a fair comparison.

--
Cheese

 

>>Andy,
>>That is great that you did the test of how much pressure actually gets pushed into the vent by the window. One thing people don't understand is that with turbo and supercharged cars, a "Ram" air intake won't make much of a difference, since the supercharger sucks in a fixed amount of air with RPM.

>> Jeff Perrin
>>http://www.Altaminiperformance.com


??? Eaton superchargers dont suck in a fixed amount of air, they displace a fixed VOLUME of air. So higher pressure air yields more power potiential from the same volume. In an ideal world, the intake kit is supplying a lossless supply of air and maybe yours is "ideal" I dont own one so I wont speculate but there are still potientially pumping losses in the TB and the TB-SC manifold. You can overcome these negative pressures with positive pressures from ram air.... or you can market and sell "ideal" ported throttle bodies and "ideal" manifolds too :smile:

--
Cheese

 

>>ALTA2 wrote:
>>
>>>>
>>The supercharger grabs gulps of air and sends them out its outlet. If the upstream air pressure is low, the number of air molecules passed to the intake manifold will be low. By starting off with pressurized air (you aren't gonna get much pressure from a intake scoop, but let's pretend you are going 300 mph and have quite a bit of pressure) the supercharger will dutifully pass those air molecules to the engine, resulting in higher boost.

Compression ratio isn't everything. Boosted engines will always produce more blow-by because the cylinder pressure is much higher. There is much more "gas" being blow past the rings because of the higher cylinder pressure, this is what causes the higher crank case pressure.

Andy i would agree that if you were going 300mph, that the ram air would make a difference. What i said was that it wouldn't make "MUCH" difference having the ram air in effect, esspecially at 100mph or less.

You would have to exceed the "vaccum" or neg pressure in the inlet before the SC to make a difference. So lets just say,at 11PSI at 4000, you would have to overcome the vacuum that it is already producing at the inlet. But i am not saying that having some ram air would help, i just don't think that it would be enough difference to actually feel while driving.

Either way having that extra .07psi that you measured in the vent helps with getting that cold air into the air filter.

 

>>>>ALTA2 wrote:

>>You would have to exceed the "vaccum" or neg pressure in the inlet before the SC to make a difference. So lets just say,at 11PSI at 4000, you would have to overcome the vacuum that it is already producing at the inlet. But i am not saying that having some ram air would help, i just don't think that it would be enough difference to actually feel while driving.


No you dont. Any postive pressure in the intake system may partially or fully negate the negative pressures (vac) (due to the intake system) causing less losses. Less losses = gains.

--
Cheese

 

Everyone should read this:

http://www.autospeed.com/cms/article.html?&A=0629

 

Some people should read it twice :smile: and thats not a knock, I've read it a few times in the past few years.

--
Cheese

 

It took me a while to read, but I learned a lot!

Thanks for the link Andy!

...now where's that article about creating the new boost control system that he was going to do?

 

I have plenty to add to this discussion, but I will hold my mouth this time and leave a simple question.

Is anybody interested in purchasing this kit without the air box (ie: just the ALTA silicone intake tube and the ALTA foam filter element) from me for $100?

 

I might be interested in just the tube for testing purposes :smile: The filter is no good to me. Anyone care to split it? :smile:

 

Interesting posts here, so allow me to throw in my 2c worth:
I really like what I can see so far of the Alta air box.
One thing I thought deficient in other designs was that the heat shield was not carried all the way around the intake, and there is a wide air gap (as far as I can tell) around the ECU box in eg the Madness intake. Around this area, the intake will suck in air from the engine bay, and this will be hot air (or at least warmer than ambient). The Alta is the first intake I have seen that properly deals with this problem, other than the BMP intake which however has a much smaller airbox.
Personally, of all the aftermarket units I have seen (but of course not tested or driven), I like the Alta best followed by the BMP one.
Just my humble 2c worth.
Cheers,
Markus

 

FWIW - no matter how scientific you want to get, there isn't any better evidence then doing trial runs and learning whats best. You can sit here run numbers all night, but one thing I have learned, and has my father, is to just shutup and try stuff. Some of the best engineers spend too much time running numbers and not enough time doing trial and error in a real life scenario.

Just my little contribution. One which probobly isn't very popular.

 

TomM - Amen brother!

MG-BGT,

Actually, the Rogue intake does create a heat shield around the entire filter elemnt. The ECU case itself acts as the other side of the shield. The intake of the filter is only coming from the snorkle and the rear cowl area (and that is even without the MINI-Motorsport airbox mod - the stock set-up has a hole at the lower part of the airbox to draw air from the cowl area).

That said, the ALTA or the Rogue/Madness with the partition drilled out will draw a good amount of air wihtout using the under bonnet air. I'll wait until it gets here to run all the tests and check the fit and finish before I make a final decision, but I like the design of the ALTA unit (now it will be next week before I get it - arrgh).

Hope that helps!

Randy

 

Let us know about sound levels also please. This is probably going to be the loudest of the bunch. Does look like the best design though.
Thanks
Wes

 

Anyone at all interested in the Alta Performance conical air filter element from this kit for $40? A comparable K&N filter goes between $45-60.

 

Pressure at the base of most windshields will be slightly positive. But not enough for any ram air effect performance inducing gain. The point is that it is relatively cool air which is good and will enhance performance over drawing in hot engine bay air.

The factory design, especially in MINI's infancy has a lot of room for improvement, but with out careful testing, the parts modifications may not work as you think. You all are to be commended for all efforts to date to find and document what works.

Engineers spend a lot of time crunching numbers AND verifying the results. They tend to treat powerplants as systems. Sometimes an "improvement" in one component will cause failures or problems in other components. The engineers are trying to get the best compromise possible. For example, BMW motorcycles are not the best in any one area, but they are very good in a lot of areas...more so than other manufacturer's products. A very good balance of clashing goals. I suspect BMW's design of the MINI engine had low cost and reliability higher on the value scale than performance. I am sure that the success of the car and everyone's attempts to get more performance will motivate BMW to engineer better engines for the cars. It will take time and many at this site will be responsible for pushing BMW engineers to build hotter MINIs.

Speaking of Engineers, Do you all know what they use for birth control? Their Personalities!