Originally Posted by Genesis_26317

Wow, what the hell it up with people bitching about peoples lack of knowledge?

I didn't know a CRX could go 9 seconds with a full weight street legal car. I saw a video, it did. Then I found out the engine was pretty much out of a fighter jet (twin engine style). In my opinion if any car can go 9 seconds or has 600-700 hp it really isn't the original car anymore (I'm talking inline 4's here).

Hell when you hear about people with 427 iron blocks or resleeved LS1's and 12 bolt rears it isn't a real Camaro (or LS1) anymore.

Anyway long story short MR2's don't make 600 hp the engine that the guy made a downpayment for a house to build makes 600 hp. Then they had to replace the transmission etc etc etc.

Originally Posted by Genesis_26317

In my opinion if any car can go 9 seconds or has 600-700 hp it really isn't the original car anymore (I'm talking inline 4's here).

Originally Posted by GMmexican

imagine that boost the 700horsepower MR2 is making on an LS-1 with supporting mods

Originally Posted by XakEp

You run what you brung. And that kind of boost on an LS1 is pretty much unstreetable - you'll just spin your tires or wrap yourself around a pole.

Originally Posted by Cop Car

i hate it when people just put up dyno sheets and dont actualy put up the cars best 1/4 mile et and trap.

once you start putting 500 hp through an MR2 wont it start to have transmission/halfshaft problems?

Originally Posted by Cop Car

i hate it when people just put up dyno sheets and dont actualy put up the cars best 1/4 mile et and trap.

once you start putting 500 hp through an MR2 wont it start to have transmission/halfshaft problems?

Originally Posted by GMmexican

alot of import guys that dyno around 500horses to the wheels only make half of that in torque to the wheels thats why they never post torque numbers........i seen a turbo crx making 450 at the wheels with only 260 pounds of torque,

Originally Posted by Sparetire

Dont forget though the high pressure created in the ex manifold and head due to the restriction of the turbine housing. That restriction creates back pressure which requires some boost to overcome. Aditionally, while the pressure in the intake might be above atmospheric still, the turbo will be past its max flow rating and efficency, and thus all the pressure is from very very hot air. That means that while you might still have some boost pressure, the density and thus the mass of air being moved is maxed out or decreasing.

Basicly, if you have a turbo blowing 200 degree intake air temps, you could have 10psi and not be flowing any more air because the density is crap. Remember pressure (or boost) does not equal flow. Flow is mass over time (lbs/min). Pressure is mass over area (lbs/in^2 or PSI). Hot air has more volume than dense cool air, and that volume in a fixed amount of space creates pressure (PSI). So 50lbs of cool air will create less pressure than 40lbs of hot air. The car with 40lbs/min of hot air flow will have higher boost PSI than the one with 50lbs of dense cool air flow. The 50lb of flow point in the cars rev range will make more power with the less boost on the same car and turbo. Flow determines power, not pressure.

So, that Viper with the turbo from a 1L might have 10 psi of boost at 6000rpm, yet be flowing less than if it was NA at 6000. This is due to the fact that that tiny turbo is heating the crap out the intake air and spining way out of spec rpm ranges to generate that pressure, while sacrificing flow and thus power. That heated air will cause the Viper to knock and pull ignition timing as well, which kills power. So you have less air mass being pumped, less ignition timing, all while dealing with an exsaust restriction. The Viper made its peak power on that weak turbo a long way back in the rev range and it was dissapointing, no matter if its still got boost. This is why turbo systems are so tuning sensitive. Its also a big part of why turbo choice depends of rpm range as much as displacement.

Cliffs Notes:
Pressure is not flow.
Flow determines power more or less. More flow=more power in the same setup.
Inefficent tiny turbo heats air up and creates pressure, while losing flow.
Losing flow means losing power, even with boost pressure in the intake mani.
Thus the Viper would make more power NA than with tiny turbo, even if tiny turbo is making boost.
Intake heat sucks.

Mods:
Should I repost this in FI? I'm sorry I hijacked this a bit, but its great info for guys going to FI.

Originally Posted by YlwGTO4m3

Ok you are so wrong about the pressure thing it is hurting my feelings. ONE, FLOW DOES NOT EQUAL POWER. If that were true, I could go get an industrial fan that flows 5,000cfm and strap it to the engine and be fast! But you know what, that won't work, why? because it won't build any boost!

TWO, heat is increased with pressure, thus they make innercoolers...

THREE, COOL AIR IS DENSER THAN HOT AIR. that's why they are HOT AIR balloons....

FOUR, the only thing you said that was even close to correct is matching the turbo to your application.

DO NOT LECTURE...you don't know what the hell you are talking about.

Originally Posted by XakEp

Youre an idiot. A fan wont be able to build boost because it cant seal to the intake at ALL. And yes, flow = power. I can personally attest to the fact that hot air (overworked turbo) from a turbo thats too small will create boost but flow buttall for air. Which is why so many ricers run 20 psi and make only make 150hp.

Originally Posted by YlwGTO4m3

Actually you CAN seal a fan, it won't build boost because the fan isn't powerfull enough to overcome the static pressure required to build boost. The force required to overcome static pressure is the whole reason why there is backpressure in turbo systems. the exhaust has to push the fan to overcome that force. Since there is this stupid idea called equal and opposite reaction, the force you are pushing with the fan is also pushing back on the fan. NOW, if your tiny *** turbo doesn't match your application (see FOUR from my last post) then that's your problem, but that doesn't necesarily mean it's not making more power than it would N/A or that it's a restriction, it's just inefficient. if your problem is flow, why don't you get the biggest turbo in the world? BECAUSE YOU WONT BUILD ANY BOOST. you have match your application. thank you. please go away until you have had fluid dynamics.