SScam68

iTrader: (20)

Oh???? Do you have the name of the papers? I would love to read them

I'm and engineer and science geek

CamKing

I have the original copies in a box somewhere around here.
Do you know if they can be looked up by author?
That may be easier.

oneBADDz

iTrader: (26)

Texas DA varies across the state drastically. In lubbock we raced at a DA of 5900 a few weeks ago

SScam68

iTrader: (20)

Author would be easiest

CamKing

See what you can find under "Richard M Jones"
You could also check "Dick Jones" "Champion spark plug co"

BawlsZ28

iTrader: (11)

Ya, I wish I would have gone w/more compression. I guess more boost may help me out in the mean time!!

FieroZ34

iTrader: (1)

To make the same amount of power as an average high-tuned N/A engine, you are correct, the turbo motor will make the same amount of power with smaller lifts, intakes, etc. But this is because even though the restrictions are more, it is still boosting it. You'd need to block CFM quite a bit to get the N/A motor to outperform the turbo motor. However in terms of max performance for forced induction, generally speaking the bigger the better. The bigger your intake ports, the shorter the runners, the bigger the valves and valve lift, the more power you'll make. It's all about CFM. Since acoustic tuning doesn't matter anymore, the only reason to use 'small' parts is for spooling faster, less lag, and faster timing.

Here in Colorado Springs the DA right now is around 9400ft. No wonder my car runs over 1.5 seconds slower than at sea level. Gas is 85, 87, and 91 for the ballas. Generally speaking for an average 14-16 sec car, the highest output engine (LS1 for a Z28), will feel like the base model engine up here (3.8l). Hard to imagine, but it sucks.

hammertime

iTrader: (1)

Well, since no one else tried this one, it just occured to me what you were getting at: orbit velocity and escape velocity, right?
Not sure why that didn't come to me the first time I read it this morning.

CamKing

Nope.
The biggest mistake engine builders make is believing bigger is better.
The second biggest is looking at air in CFM. You need to look at it in Lbs/Hr.
You also need to look at pressure differentials on both sides of both valves. That is what makes Turbo engines so much different then NA and Blower engines.

FieroZ34

iTrader: (1)

I said generally, and it holds true for forced induction engines. Heads that flow 280cfm at .5 will make more max power than 225cfm at .5, max power on a forced induction motor, assuming head flow is higher throughout the lift range with the 280 heads. Yes, intake to exhaust ratios do change with forced induction, and this isn't to say you should have 2.02 intake AND exhaust valves, but generally speaking, and not defying common sense, bigger is better. More head flow, shorter and larger intake runners, etc. I didn't mention exhaust, as it still follows most of the rules of N/A, considering you still should keep it proportionate with the intake and dynamic compression ratios your getting, and bigger is better doesn't apply since the outgoing exhaust isn't under constant pressure, and you lose exhaust energy with heat. Also, intake plenum volume also doesn't follow the rule. The opposite is true so long as you don't lose intake flow, smaller is better (Less volume to fill).

CamKing

You can not lump Turbo and Blower engines together. They are two different animals. The exhaust side of a turbo engine is nothing like an NA engine.

FieroZ34

iTrader: (1)

You can lump turbo and supercharged engines together on the intake side. The same doesn't hold true for exhaust obviously, as the S/C motor will tend to navigate more with a N/A, just with more exhaust gas to deal with.

The exhaust side of a turbo engine is very much like that of a N/A engine. The design is still very similiar. The only difference is that there is probably more exhaust gas on the FI motor. But equal lengh and scavaging still plays a big role in the design, just primary length takes a back seat because it is more critical to keep exhaust temperature high. The optimum turbo manifold is still equal length though.

CamKing

Not in any form of racing I've seen.
NA engines don't have pressure differentials anywhere near that of a Turbo engine.

Think about what happens when you've got a turbo evacuating 8,000lbs/hr of exhaust, and the exhaust valve closes.

FieroZ34

iTrader: (1)

Of course they are going to be different sizes and flowing different amounts, that is again common sense. My point was that the overall design or the port and the manifold/headers are only slightly different than N/A, whereas on the intake side it is very much so different.

SScam68

iTrader: (20)

FieroZ34

You're arguing a point and physical phenomena that you don't completely understand yet.

cantdrv65

iTrader: (3)

Orbit and lost in space.

Old SStroker

Well put!