Supercharger Efficiency and Weak Numbers

[05yellowgt]

Are you running a 6 or 8 rib pulley setup? You are almost certainly experiencing belt slip with the smaller pulley which is why you are seeing the boost drop to 7-8psi up top. Go look under your hood and look for black dust on the blower pulleys and around the general area where the blower pulley is.The more restrictions (stock heads,cams, exhaust manifolds, etc) you have the higher the boost pressure is going to be. The TVS blower that the E-Force setup uses is more than enough to push your motor to the 550-600rwhp range IMO. Stock heads and cams, though they don't give as much power as a good ported set with blower cams, won't reduce his boost pressure.

 

[Tommygun]

we have done 2 edelbrock cars with the 3.0 and both did not slip.

one with cams that made over 600rwhp and one stock that made almost 500rwhp

 

[05yellowgt]

6 rib or 8 rib?

 

[Tommygun]

6 rib

 

[05yellowgt]

Good to know. I don't know what else would be causing him to be losing that kind of boost. The TVS isn't like the M112 from the 03-04 cobra, its not going to drop boost pressure in the upper RPM's.

 

[stangzilla]

You think wrong. 4.10 gears will show less HP on the same car and dyno then if you had 3.73 and 4.56 will show less hp then 4.10 gears all other things being equal.

gonna thread jack for a second
for arguement's sake, heres a couple dyno's of similar corvettes with similar hp and tq
1 has 3.90 gears and the other 3.42's
when compared by rpms the power is very similar
when compared by speed the power is more with the 3.90's at any given speed
changing to higher gears may give you less top speed but your peak hp stays the same.
by changing out just gears your engine is putting out the same power, the load on the tires is the same, the only difference is the ratio at which the rear end turns the tires change. so speed is affected and power at a certain speed, but peak power is the same.

rpm chart:

speed chart:

 

[ZmanM3]

gonna thread jack for a second
for arguement's sake, heres a couple dyno's of similar corvettes with similar hp and tq
1 has 3.90 gears and the other 3.42's
when compared by rpms the power is very similar
when compared by speed the power is more with the 3.90's at any given speed
changing to higher gears may give you less top speed but your peak hp stays the same.
by changing out just gears your engine is putting out the same power, the load on the tires is the same, the only difference is the ratio at which the rear end turns the tires change. so speed is affected and power at a certain speed, but peak power is the same.

rpm chart:

speed chart:

I never said the power would change. The power will remain the same, i.e. if I have an engine that makes 450 on an engine dyno and say 400 at the rear wheels, then I change the rear gears from 3.55 to 4:10, the engine is still making 450, but what it is showing at the rear wheels will change. Peak HP might stay the same but it isn't going to be at the same RPM.

 

[stangzilla]

I never said the power would change. The power will remain the same, i.e. if I have an engine that makes 450 on an engine dyno and say 400 at the rear wheels, then I change the rear gears from 3.55 to 4:10, the engine is still making 450, but what it is showing at the rear wheels will change. Peak HP might stay the same but it isn't going to be at the same RPM.

ok, my bad.
i'm done beating the dead horse now. lol.

 

[Tommygun]

Chassis Dynos are a TUNING tool, nothing more, nothing less. I hate that people rely on what rwhp a car makes, how about seeing how it runs? how it drives? not just a number printed on a graph. We have some customers that are mad because they did not gain what they read on the internet with a mod, while others are more understanding and look at the af curve and see its making "safe" power and the car is more fun to drive.

 

[05roush0090]

isnt there some type of blow off valve built into the blower? isnt it possible that the valve may be malfunctioning under the increased load?