Open discussion on what's good and bad about them.

Create heat?
Increase usable rpm band?
More parasitic loss?
Increased air turbulence?

 

Well this went no where.

 

what would you like to know?
its goes in front of the blower.. so not sure why it would create heat.

Rpm band stays the same.. no loss and not sure why it would create any more turbulence then a regular filter..

You do relieze its just a piece of metal in front of your inlet of the blower with say a 2 inch hole instead of the 3.75 hole. All it does is restrict the amount of air going into the blower so to make less boost then you would normally.. the hole size will vary accordingly.

It great if you have a F1a on stock motor, that way you can make 15 psi at 4k all the way to red line instead of going up..

 

Question I ask it just trying to eliminate variables. Car is up and running w a upgrade from a p1sc to a f1d and 12 psi to 18 psi (restricted from 21) and the car is quicker but not even close to as much as I thought it would.

 

where you not over spinning the p1sc1 as appose to just pushing the new blower?

 

Was spinning the p1sc way under. The f1 is getting spun to 65k (spec) at 6600 rpm.

 

Restrictor plates really only work well in a small window, they do not work well in high boost scenario's in my experience. Capping a 13lb build to 10 lbs is fine, but a 20 lb build to 15 would be out of the "window of opportunity".

 

I had a 2.75, 3, and 3.25 built to cover a 4 in hole. The 2.75 netted me 15 psi, the 3 got me 18. In restricted I was 21by 5800 which is too high for a ls1 block what I was told even though I have head studs and ls9 head gaskets.

 

Have you dynoed this thing YET or just going by seat of the pants feel?

I'd make sure its even in the ball park of where you think it is going to be before you start chasing your tail.

I bet you end up pulling that restrictor.

 

Also why does this only work in a low boost senerio?

No Dyno yet. I am building a wastegate setup this week.

 

So its not cylinder pressure but amount of pressure in the intake that destroys the block. Good to know.

 

Car made 730 last year w the baby blower. Tell me again how air is not getting into the cylinders?

 

You were at 730rwhp with the p1sc correct? What is your current power level with the f1d? Are you going by seat of the pants feel? By restricting the blower, you are chopping off a lot the power that it would make from 5000 to 6500 rpm.

I try not to restrict anything related to going fast. I can't stand the way a restricted set-up feels. Everytime I get in a new sports car I am disappointed because you can tell that the manufacturers built in limits to keep it from performing to full potential.

 

I know that Im chopping boost off. Problem is I have the largest upper pulley I can get (4.5) on the a and a bracket now and its making 21 lbs (too much IMO) at 5800 rpm. Im just trying to knock off a few at the top to keep the heads from lifting. I also want the hit under the curve which is where the centi falls short.

 

What causes the heads to lift? Boost?

 

cylinder pressure aka psi right? how do you measure intake pressure different that cylinder?

 

Too rough of a finish on the head surface don't help

 

Cylinder pressure and boost pressure are not the same thing.

 

Compression Stroke

After the intake stroke, the intake valve closes to trap in the air and fuel. (The exhaust valve was already closed during the intake stroke.) Now the piston starts it's upwards stroke, compressing the air/fuel mixture to pressures of 100 to 200 psi or more. The actual pressure depends on when the intake valve closes, the pressure in the intake manifold (MAP or Manifold Absolute Pressure), Compression Ratio, and other details.

The compression of the air and fuel creates heat and somewhat helps vaporize the fuel. It also takes even more work from the engine to do this compression. So far, the engine is doing all the work and getting no power from the air/fuel mixture.

Combustion / Expansion Stroke

This stroke is where the spark plug ignites the air/fuel mixture, creating very high cylinder pressure which rise very quickly. Peak cylinder pressures near TDC (where spark occurs) will be in the range of 300 psi for engine's at light loads, to 1000 psi for production engines at full power to 1500 psi or greater for race engines. This is where the engine's power comes from, as it forces the piston down. As the piston goes down, the cylinder volume increases which reduces the cylinder pressure. When the piston gets to the bottom on the cylinder (BDC) there may only be 100 to 500 psi in the cylinder.
http://performancetrends.com/Definit...r-Pressure.htm

All I am trying to say is your ignition timing and a few other things have a much greater impact on longevity then a couple psi in the intake manifold. What is your power goal?

 

I see you said 850whp in the other thread. What heads do you have? What power are you making now at 5800?