dj55b

iTrader: (2)

Another interesting point, koenigsegg (an exotic car if anyone doesn't know) is actually equiped with 2 of these types of superchargers ... must be a reason

dj55b

iTrader: (2)

May have found the best of both worlds ... this is the Antonov 2 speed version of the Rotrex supercharger ... this unit enables boost at low (about 1,500 rpm) and high, the kick switch between a high and a low is controlled via a solenoid, which can be adjusted for when to make it go high. this is graph from it.

http://www.antonov-transmission.com/graph.htm

Not sure yet on the cost of this unit yet though.

slo

iTrader: (1)

Not enough air, you would be better off to go with the largest S/C that would realisticly fit. as many have pointed out centrifugal designes require rpm to build power. But its still a supercharger, having a larger impeler won't increase the lag time, it should have just the opisite effect and decrease the rpm required for a specific mass of air.

look through the single turbo section, its not un-common to install t-60's gt 35s and gt 42's on 13b's.

There are several different design possibilies for implementing a supercharger, do some reaserch into how they are implemented on other cars.

dj55b

iTrader: (2)

hmm looking at prices .. the C38-81 which is the biggest one that they offer and delivers .55kg/s is only 100$ more than the other one, and it only about 3mm longer then the other unit.

edmcguirk

Actually the opposite is true.

Centrifugal SC have an island of efficiency just like turbo's. If you buy one that's too big, it can't reach that island.

If you are talking about only 210 HP you would actually want one of the smallest.

I don't know the exact numbers off the top of my head but 210 Hp is equivalent to a certain amount of CFM (I believe it's in the neighborhood of both 350CFM and 7PSI).

If the size Rotrex won't make 7PSI at 350CFM it won't work on your car.
If it makes more than 7PSI at 350CFM it won't work on your car.
If it needs more than 350CFM to make 7PSI it won't work on your car.

If you want a different HP number you need to match different CFM and PSI numbers.

Roots SC don't have this kind of matching problem but they are less efficient. It's all a tradeoff on what you want and what is actually available for purchase.

dj55b

iTrader: (2)

is there any websites that I can learn about all this stuff .... also is there a way of measuring how much air it going inside the engine?

84stock

iTrader: (5)

That antov 2 speed conversion would be perfect for a camden. Dan??????????

edmcguirk

You can multiply the size of an engine (cubic feet per revolution - not the same as displacement) by the RPM to get CFM.

Or you can use rough estimation based on HP. Efficiency changes the ratio but you can use a very rough estimate of 500 CFM = 300 HP.

Also you can use the HP ratio against the pressure ratio (again efficiency changes the ratio) HP1/HP2 = (P2- 14.7)/14.7

Where:
HP1 = Stock NA HP (145HP)
HP2 = expected HP
P2 = boost pressure

You can use similar equations to figure out how much HP you will get by raising the redline.


These kind of equations are not exact but they are in the ballpark and can be used to eliminate some of the ridiculously optimistic engine modifications.


There are web pages that let you just plug various engine measurements and get HP but some of them can get a little complicated.

http://www.not2fast.com/turbo/glossary/turbo_calc.shtml

dj55b

iTrader: (2)

thanks will be reading that site.