I think they use some type of lockup on the supercharger. Its locked up at low rpm low boost, then it unlocks when boost reaches a set level.

 

I see, I see. Guess they would just have to make sure the lockup wouldn't be prone to failure or bad things could happen, like limited flow to the engine and higher pressures in the turbo region. Just thinking off the top of my head...

 

theres always someone who has to build it to prove people wrong and say it can be done for all the people who say " you cant build that". just like putting a p-pump on a 3rd gen, guys have proved you can do it. I would like to ride in a supercharged/turbocharged cummins I bet it would be interesting

 

The old Detroits had a roots style supercharger for scavaging since it's a two stroker. And with a turbo.
Not sure how it would work on a 4 stroke with a turbo.

MikeyB

 

Think something like on the A/C compressor. When you give it some juice it locks up take it away and it spins free.

 

No need for a lock up at lower rpms. The parasitic drag on a supercharger is in direct relationship to the rpms of the engine and the psi it is being asked to produce... superchargers are nice because they provide air to that relationship... if anything the clutch would serve to disconnect at higher boost; (not necessarily higher rpm) it depends on engine load.

 

At lower RPMs,(like idle), superchargers have very little drag, and very little boost, on the engine.

 

Do some research on the new VW TDI engine...it uses this technology to get higher mileage and less emissions. If our trucks had a super charger to take us to 15psi and the turbo charger took over after that...you could run a massive main turbo....not unlike a set of big twins....as you would be guaranteed to achieve liftoff spool from idle to WOT....the only limitation on this has been the cost but with belt driven 2nd pumps and lift pumps...this is a no brainer....the only thing is that you need a huge gear up from the low revs of the engine so that the belts don't last long....I was racing a supercharged mustang at the track.....yep he won the first race I took the second when he took out the belt...without the belt he was down. It sounded awesome though as he pulled away....about an hour to change a belt...I wouldn't have my supercharger belt driven. KS

 

I dunno Kerry, I've got a powerdyne 8psi supercharger on my Bronco that has a lightning 351 on it... I have over 70K on the same belt that drives the charger... no problem at all and it sees 6500 engine rpm all the time.

 

Sounds like a reliable supercharger there....8psi on 5.7Litres....no bad...This guy seemed like he was really used to changing the belt...I would think it would be the quick acceleration at the track that would be hardest on the belt. I have belts on some of my large grinders and they are 20+years old and have thousands of hours on them... but I bet I could shred them in am minute if I dropped the clutch at 2500rpm's on the pto. The only thing with the belt driven models is they take up a lot of space in the engine bay where you don't have alot of space if you have dual pumps and a mitusa. KS

 

That is a point, I do have an auto, (ate 5 so far) and not a manual in the Bronc... and our discussion is about 15psi as opposed to 8... so about triple the belt load... I think if the alternator was repositioned where the second cp3 is, eliminate 2nd cp3... run a grand poo-bah...put the supercharger where the alternator is roughly... might not be so bad!!

 

belt should hold up if it's designed right. Think about the primary on the Harley drag bikes and custom choppers. They tend to hold up rather well.

 

My primary belt on my chopper IS a BLOWER BELT! LOL.