Higgs Boson

Did you ever notice that everyone in every thread disagrees with everything you say and you never provide any real information at all?

Ignorance is bliss and you are one of the happiest people I have ever seen. Yours is a sad situation. I will pray for you.

Higgs Boson

you may be confusing the terms linear and flat.....

how can you have a flat curve?

a positive displacement blower like the E Force vs a centri power delivery is like this:

Higgs Boson

an NA motor like the LT1 has a power delivery much more like the PD blower (but less power)

an NA motor like a high revving small displacement honda makes power more like the Centri

Translator

^^^Higgs, maybe I did not come across as intended, but I did mean what I said. I have not seen any all NA heads/cam LT1's with a FLAT torque curve like the one that you manually drew on the previous page The only really flat torque curves that I have seen, have been the ones with the E-FORCE roots blower (specifically relating to the LT1). From the graphs that I have seen, the power delivery of heads/cam LT1's behave more like the curves from a centrifugal blower; with a more linear style of power delivery, versus flat. At least, that is my definition of linear/flat, when comparing TQ curves from a positive style displacement blower with a centrifugal; like the Whipple curve that you posted.

C7pimp

Ya, but this doesn't realistically display the power curve at all, it shows a boost curve.

RPM is horsepower's best friend, and if you're making 8 psi @ 2000 rpm, you're not making 100 more horsepower than an NA car @ 2000 rpm. HP increases most drastically with rpm, not boost level.

Both your chart examples are heavily exaggerated.

Higgs Boson

yes of course they are exaggerated, I was illustrating a concept, not giving an example.

I can personally attest to the concept myself as well. It is commonly referred to as Area Under the Curve.

I had a naturally aspirated 01 Z06 with motor work (490 rwhp) and ran on several occasions centrifugal powered LSx machines and flat out pulled them on the highway.

Needless to say, they thought I was spraying....however, no bottle in car anywhere! To make extra special extreme note, a nitrous car that makes 600 whp is going to torture and kill a 600 whp centri car.

It's a real thing. No question.

3 Z06ZR1

I think you need more than heads and cam. To keep up with Your 123mph trap tells the story.

TAK2TRK

Maybe I can help break this down a in a way that others can digest. I'll keep things as general as possible.

Power integrated over time = Work [And generally speaking--the car who can perform the most work wins.]

Cars do not make the same power at all engine speeds (RPMs).

So to determine what car is faster we cannot only look at peak power, but we need to look at the time spent at each power level.

This is visualized in the simplistic graphs already posted in this thread.

We can also approximate this by looking at the average power over time.

A car that makes less peak power can be faster if it can do more work.
That situation happens when Car 1's (lower peak) average power exceeds the average power of Car 2 (higher peak) over a given time.

Also remember that the cars' power is transferred through the transmission--that usually consists of more than one gear.

Here is an example with a few assumptions for simplicity:
Assume for Car 1 and Car 2 that each start in 1st gear at RPM X and end at RPM Y.

Car 1 makes 50 "hp" at X and 100 at Y (Lower Peak Power).
Car 2 makes 20 "hp" at X and 110 at Y (Higher Peak Power).

The simplistic model shows that Car 1 averages (50+100)/2= 75
And car 2 averages (20+110)/2= 65
In a race between the two, Car 1 wins because it was able to do more work over a given period of time.
[*If you assume they took the same time, Car 1 is moving faster and thus necessarily would have different gearing in the above example. If you assume they have the same gears, Car 1 would take less time to get from RPM X to RPM Y.*]

Now, because cars spend less time in lower RPMs in gears 2-X, higher peak power cars do better in gears 2+ than off the line. And this is why peak HP is a good overall indicator. Ideally, you want to run closer gear ratios as your power curve increases in slope in an attempt to put down more power.

So in addition to dyno charts, you would want to know gearing, shift points, and how fast the motor can change RPM (how fast it can rev) to get the entire picture.

I have hopefully explained why looking at peak power, or even a dyno charts alone, only paints part of the picture. Just let me know if anything is unclear.

randyn

Hey Chuck,

Not to hijack thread, but I noticed in previous post the car made 525 with the cam. I was looking forward to what the heads would add. Is this the same car with the addition of those new heads?

If so, 12 more HP seems a little low. Can you please comment. What was the chamber volume of the new heads vs old heads. Maybe you lost some compression.

Or maybe...the old heads are good enough for stock CI and stock compression.

Thanks

Sgoochds650

The only thing I haven't seen anyone bring up was the ability to put the power to the ground on one setup vs the other. My thoughts was as the rpm/boost/power climbs Ill have a slightly better chance to hook with the centri than if I were to have built a nitrous car. I'm sure with progressive controllers and such the hit of the bottle could be tamed down where the car wouldn't smash the tires quite so bad on the street but without it seems like it would be tough.

On that note I'm still trying to figure out which tire is going on my factory Z-51 wheels for my M7 416 ECS 1500 car....... I'll keep reading everyone's tire posts and hope for the best!

leadville1

I have some real world experience in this matter. I have a SC'd M3 that makes higher peak HP than my new C7 Corvette, but it only makes 378 ft/lbs of torque and has a centri supercharger.

The notion of the car's ability to make work is dead on. The Corvette with it's flat torque curve pulls away from the M3 in ever instance, on the track it is the same notion the Corvette with it's NA torque curve is getting the car up to speed much more quickly than the peaky CF supercharger in the M3.

I routinely race with cars like C5 and C6 Corvette's and Road America and the NA motors lay waste to my M3.

I would take a NA motor anyday at the race track, largely because it also doesn't heat soak as easily either.

0ChucksTuning

Bingo spaghetti-o.

As a tuner you see it all the time, but the internet only gets to see the best dyno run a car made (hey, it's advertising). But anyone who tunes will tell you that heat in a boosted car will take 600 rwhp down to 520-530 in a heart beat. And if tuned correctly, IAT timing corrections will add to this effect.

So at the end of the day, you aren't comparing apples to apples, you're comparing usable HP vs. usable HP.

0ChucksTuning

Went from 525 to 542. The stock heads are just so huge from the factory most shops are finding that there is little to nothing to be gained from porting the heads. Have heard reports of some shops losing power. Hoping the 460ci shortblock we're building will put my heads to use a little better.

0ChucksTuning

Here Higgs, we don't need a drawing.

0ChucksTuning

Here's a different angle, you all can be the judge. (skip to the 2:10 mark in the video)

https://www.youtube.com/watch?v=o43R...ature=youtu.be

3 Z06ZR1

Here's 8 psi for comparison.

3 Z06ZR1

Has more low end as well as top! 450 rwtq at 3000
Flatter curve. See Higgs your cartoons are for the little kids. Not adults.

3 Z06ZR1

Lets see the Procharged car dyno.
It may be less or the same as your car.

In that case your higher RPM would help

NoOne

What was the MPH between the two?

randyn

This entire thread is ridiculous.

It was a roll race. There is nothing to compare!! The car on the left was ahead to begin and got the jump anyways. Who knows if the car on the right had traction.

Point is nobody knows **** about what happened.

As, NoOne asked for MPH. If it was a real 1/4 mile from a light you would to just compare traps and this thread would be done.

Chuck you know this...you must be laughing at this stupid thread because you started a pissing match.

Have fun arguing about "Flat versus peak" curves when you don't even mention gear ratio in your argument.

Thanks for the confirmation Chuck about the stock heads, I'm sure that 460" motor will make better use of your ported heads of them. Or, a stock ci motor with a few additional points of compression and 2000 additional RPM.

have fun arguing!