Anatomy on a supercharger and blower kit

[Dominic Torreto]

Just wanting to know some information that goes along with these forms of aspiration. I am familiar with turbos and how they work but a supercharger is different.

Can you control the boost psi on a supercharger?

Anything else to add I do plan on buying some books on these.

 

[Sixer]

Boost on a Roots type supercharger is controlled by pulley size-ie a 10% underdrive means the the blower pulley is 10% larger than the crank pulley-the opposite would be true for a 10% overdrive. Street engines are typically underdriven.A blower cam carries less lift and duration on the intake than the exhaust on street setups, as the blower provides for more intake charge, this is why street blown engines usually sound so mellow at idle. Intake valve spring pressures need to be higher at the seat than a similarly cammed unblown application, as the blower is always providing boost. Low compression pistons are a must, as are o-ringed heads at higher boost levels. Blowers do nasty things following a lean pop (backfire through the intake), you do not want to discover just how nasty. Blowers like alcohol-this would be a good time to investigate E-85 engine construction. There's a little bit for ya.

 

[RustyRatRod]

Turbos and roots blowers are both superchargers. Turbos were once called turbosuperchargers a LONG time ago. Through the years it was shortened to turbocharger and then turbo. The two blower types do the same thing through different means. The roots blower is belt driven while the turbo uses exhaust gasses to drive the impeller. I've built a number of roots engines over the years. They are fun and really have the wow factor. That said, I know which ones consistantly have the higher MPH at the strip. The turbo stuff. That means horse power. Turbocharging is somewhat more complex and has a learning curve....as does roots supercharging. But the latter is easier to set up and tune, while the former is easier to control and will ultimately produce more HP, IMO. Ommitting of course alcohol and nitro.

 

[Hemi Rebel]

Here is a good book for you, I have an older print, and will probably get this one too for any new info. http://www.allbookstores.com/Complete-Guide-Street-Supercharging-Pat/9781932494938
The typical thought when installing a blower is you need low compression and o-ringing the block. This does not necessarily hold true any more. There are a lot of factors that go into what is needed, but multi layer steel headgaskets negate the need for o-rings and depending on what material the heads and block are, you may find it better to run slightly higher static compression pistons and less boost. You will find that combo may make more power than the old way of low compression and higher boost. Definitely get as much info as you can get. And if and when you are serious, call someone. A quick conversation with someone at BDS or where ever.The blower shop. anyone of these places will be glad to get you what is right for your specific needs.
I will also add that there is more to just putting a blower or turbo on an engine an going to town. Any time you start getting into that kind of serious power you need to look at the whole package. Chassis and suspension. Brakes. The whole car front to back. Just throwing a blower motor in a stock body charger will twist it in half. It wont hook and you will probably not enjoy driving it. Worst case wreck it. So keep that in mind too

 

[rumblefish360]

While I am far from apt of knowledge on the subject…

There are two forms to supercharges. 1, the roots as
Entiomed and the second being a Paxton type, much like a turbo in size and such things.

The centrifical (Paxton style) can be set up much in the same way a turbo is, minus extra pipe. Though adding a inter cooler is fines, the units do not normally come OOTB needing one since there low pressure. Some where under 9PSI. This can bechanged with a pulley, just like the roots can.

Inter cooling a roots.ower adds height. The cooler Is installed under the blower and uses liquid (often water) to cool the charge.

BOOST CONTROL

Is done VIA pulley and/or blow off valve like a turbo except on a roots. The blow off valve is on the housing of the charger itself.

Extra stress is put on the crank. A quality crank solves this issue
If a high stress engine is built. Example? Funny cars.

 

[RustyRatRod]

Inter cooling a roots.ower adds height.

Which is why I always look for the tallest one. LOL Seriously....I am heavily considering running a 6.71 on my early Hemi. If I do, I WILL get the tallest intake I can find (Hot Heads) AND run either a 4" or 6" intercooler. Das wut I'm tawkin bowt. lol

 

[Hemi Rebel]

Which is why I always look for the tallest one. LOL Seriously....I am heavily considering running a 6.71 on my early Hemi. If I do, I WILL get the tallest intake I can find (Hot Heads) AND run either a 4" or 6" intercooler. Das wut I'm tawkin bowt. lol

:headbang:

 

[RustyRatRod]

That's a photochop. Only the ones in the middle are real. Just love blower surge. lol

http://www.youtube.com/watch?v=dkrgyfjJg3s

 

[RustyRatRod]

While we're on this roll.......man I love the Aussies. When they do somethin, they SLAP don't play.

http://www.youtube.com/watch?v=kiWUNdrQn6Y&feature=fvwrel

 

[Sixer]

That's a photochop. Only the ones in the middle are real. Just love blower surge. lol

http://www.youtube.com/watch?v=dkrgyfjJg3s

He can afford 2 blowers and an Auto Meter dash, but refuses to spring for some spray lube for the door hinges. Typical Poncho owner.:happy7:

 

[RustyRatRod]

He can afford 2 blowers and an Auto Meter dash, but refuses to spring for some spray lube for the door hinges. Typical Poncho owner.:happy7:

I thought that was funny, too. Sounds like a old truck when the door opens. lol