6 psig: 342 RW ft-lbs, 286 RWHP
12 psig: 415 RW ft-lbs, 373 RWHP

Nice bell shaped curves, no spikes. It is a perfect street car match.

Scan of Dyno Sheet will follow today. The car is a bullet.

 

Hi John,

>6 psig: 342 RW ft-lbs, 286 RWHP
>12 psig: 415 RW ft-lbs, 373 RWHP

Cool, congrats! At 12psi that 928 has to be a HOOT!!!

>Nice bell shaped curves, no spikes. It is a perfect street car match.
>Scan of Dyno Sheet will follow today.

Can't wait to see them!! HURRY UP!

>The car is a bullet.

No doubt, great job!!

 

Great job! Is that the highest dyno result anybody has had on a 4.5L?

 

Forgive my ignorance, but is 12psi boost from a turbo provide the same kind of stress on the engine/internals as 12 psi from a centrifugal supercharger? I would assume so but thought I'd ask.

 

VERY NICE!

 

Not again


John - I might have missed this bit of info, but what CR is this car? Still the US intake and TB?

Awesome numbers!

 

Engine torque is expressed as lb-ft not ft-lb. I thought you were an engineer?

Work = Force * 2 * Pi * radians = (in english units) 1 lb * 2 * 3.14 * 1 ft = 2 * 3.14 lb-ft = 6.283 lb-ft

Power = Work / time = 6.283 lb-ft / min

1 hp is defined as 550 lb-ft / s = 33,000 lb-ft / min (from James Watt's measurements)

So, if 1 lb-ft of torque is applied in one minute (1 rpm) = (6.283 lb-ft / min) / (33,000 lb-ft / min) = 1 / 5252 of 1 hp.

 

From a previous thread:
Jim, ft-lb = lb-ft.

 

The only flow increasing mod on the engine internals is the stock 79 camshafts. No head porting, no euro intake or TB....it is all stock except for the Niaksil, JEs and 79 cams...and of course all of the "jewelry" I hung off the heads.

When you see the dyno sheets you will understand this turbo match is really great for the 4.5 liter.

 

Honestly, I'm really not trying to stir up a ****storm here; I just figured that the CS is pretty much a belt-driven turbo and was the closest approximation.

If he's comfortable using 12PSI boost with a turbo, I don't get why a lot of folks on the SC bandwagon are fearful of going above 7. Although an 8:1 CR is a lot different than 10 or 10.5:1.

Jeez.

 

I'm with Brian on this... How does this compare from a engine stress standpoint. Does 12psi on a turbo equate to roughly 6 or 7 psi on a CS? I dunno, so I ask.

Impressive #s John!

 

Lord, this must be a true funride! That's serious, neck-snapping torque.

 

Jim, that is semantics. The units are interchangable, multiplication is commutative. Any engineer should know that.

As far as stress on engine goes turbo vs SC, thats complicated. In the end the turbo is gentler, because you dont have a high tension belt pulling on the crankshaft. Combustion chamber stress itself should be identical, assuming identical engines with the same pressure and temperature air going in.

 

I know that it doesnt change anything but saying ft-lbs sounds so redneck. I was just messing with John to get his goat. That's some serious power either way. Good work John!

 

Good job John..!


To address the other's question on boost of CS/TS/Turbo......

As far as boost of Turbos vs CS vs TS, boost is pressure, or resistance to flow.. where is comes from is not as relevant. However, the charge volume or mass is important. as more mass at same pressure with have more total heat, but same relative heat in terms of heat created by the relative pressure. Actually, the density ratio is the most important....

In other words, more air + more fuel = more power. More air does not mean more pressure.. The correct way to evaluate, is to look at the amount of air (MASS/CFM/#'s of air) moved into the system instead of what pressure the system is operated at...... You guys should please try and understand this to understand meaningful fact from snake oil...

On another note, injecting methanol etc can be less efficient depending on where it is injected in the system.......

Just my $.02