Boost
 

You could ask a number of members on here to help further your knowledge. Brad Zastrow, Hot Pursuit, 40FlatDeck, many helpful members in the community

I have never seen a "boost" switch

Dont know if this helps but I will throw what little I know in here:
Boost is the measurement of resistance to airflow not the actual amount of air being "pushed". The harder it is to push thru the resistance the higher the boost reading.

Example: A blower that makes 10lbs of boost on a stock
motor with stock components will make probably only about 5lbs of boost if you put big heads,cam,intake and exhaust on the same setup because you have lowered the resistance to air flowing thru the entire engine.

another example: 5lbs of boost on a 502 big blocks requires almost twice as much air to be "pushed" than 5lbs of boost on a 350..
Take a turbo rated at 20lbs of boost off a a small engine like a 4cyl Import sportcar and put it on a 600" V8 and it may not even make boost because the engine requires more air than the unit can push.
CFM is a much better qualifier for a supercharger than boost.

I use one.

:eek:

So how does it work???????? I would guess some type of wastegate or pop off valve to relieve the extra boost????????

As far as I can tell Check 300 has the ECM pre-programed for differnent boost levels that are controled by how fast he is spinning the huffer via different pulley sizes. But thats just a guess ???

Not quite, thats likely a turbo app.

His deal is always making more boost than he is using, and the excess boost is electronically "bled" off.

This way you can regulate output, and adjust for fuel quality, and make a decisions between output level and component lifespan.

Mercs 6 and 700's bleed off more than they use as well but from a supercharged app. this is why they can deliver their rated (long story) power at any altitude or under any load condition.

Uncle Dave

He does have a turbo set-up .That sounds more realistic ...Thanks Uncle dave

electronic wastegate

Check300 is turbo:drink:

Check 300,

Does your switch change the fuel curve as well?

Yes, the fuel map is written for different boost levels so increasing the boost just uses a different area of the map. Hope that makes sense.

Yup,

Cheap processors / micros with allot of memory are sure nice to have, and we thought in the old days that computer controls were going to ruin our high performance fun.:cool-smiley-011:

So as the volume of available space for the air to take up increases the resistance decreases, but if that is the case, isn't the resistance fixed for each particular engine? And if that is the case how can you change it? If the engine can only hold so much how can you ram more in?

Any time I see a boost selector on just about anything I get a woody.



U.D

More boost means more pressure to push the air/fuel mixture in faster, getting more of it in on a given engine. More boost more power

The same way you can put more air into the same size tire or air tank. The pressure increases and more molecules are forced into the same space. Gases can be compressed. More boost forces more air/fuel in and pushes it through faster.

I need one of those on my boat!

engine uses certain amount of air per stroke.
If you increase the heads ports/volume,bigger cam,intake/exhaust
now the same size engine will use more air per stroke,
if the the blower was making x amount of boost before upgrading the engine now it will make less boost after adding the better parts even though engine size stayed the same.. In extreme cases the blower will not be able to feed the engine any longer and little to no boost so you step up to a bigger one
hp is made by air+fuel not engine size.
Just so happens the bigger the engine the more air+fuel it can use naturally aspirated but once you add forced air induction engine size can become much less important.

Formula style car race engines can make 1000+hp from tiny engines by running insane amounts of boost.
.

This is not taking into account heat either.
5lbs of nice cool room temp boost is not equal to 5lbs of boost of 200deg air which can happen when you overspin a blower with no intercooler.
As you heat the air it expands which will read as higher boost but in reality it is just hot air. :)

There is some good reading online if you search the phrase "Boost Vs Flow"

A very wise person once told me that Boost is your friend...

I didn't understand anything after " Don't know if this helps", but I am very convinced that you know your stuff

So if remember correctly it's PV=nRT, Ideal Gas law, pressure*volume = #ofmoles*constant*temp. Change the temp it will change the pressure.

Cool I have a pretty good understanding now, the bad news is now I want to go out and buy a blower.

"Simple terms"
Boost is like sex the more you get the more you want!!
The more you get the more it cost!!
That said I have run supercharged power for 25+ yrs and have broken every part man can make but would never go without. :D