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Discussion Starter #1
Thought you might like to see this.
 

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Discussion Starter #4
Thx guys...:cheers:
 

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When you going to let us see the new dyno with the other motor and new mods???? How far are you from being done with the swap?
 

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Discussion Starter #8
I am running an 8# pulley, accufab sbtb, very conservative SCT tune. There are more ponies in there but i am very hearing impaired so i have a very conservative tune with 11.7 a/f ratio.

When my new motor gets here in a week or so and I get the new blower and all the widgets on, i'm going conservative again but it will be in the 600/700 club easily. I'll be switching to Sniper tuners after my breakin and i'm going to turn the b*tch up!
 

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Can you explain why this dyno does not cross at the corect points. Too me....the numbers are not fully valid.

If the Dyno is calibrated right...the dyno should cross at 5252.

Man your on the rich side....pretty safe...but there is more power in there if your that rich.
 

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Discussion Starter #10
dawgs77 said:
Can you explain why this dyno does not cross at the corect points. Too me....the numbers are not fully valid.

If the Dyno is calibrated right...the dyno should cross at 5252.

Man your on the rich side....pretty safe...but there is more power in there if your that rich.
I don't understand the question. There are no correct points. Why would they cross at 5252? Remember, this is NOT a NA motor...this has a blower. If you tune it at say 12.5 to 1 af then cold weather will stuff more air in and lean you out. There has to be some room on the tune for variables. Heat, cold etc.
 

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HP= a measure of forced over time, where 1 hp is equal to 550 lbs lifted one foot in one second. Expressed in terms of torque, 1 hp equals 550 ft/lbs per second. Noticed this measurement is time based.

Torque= the measure of instantaneous rotational force an engine can produce. Notice this measurement is not time based.

hp= torque x RPM / 5252
torque= hp x 5252/ RPM


With these two basic equations, you can figure out how much hp or torque you have at a given RPM with either measurement. Notice that because of this equation, an engine can NEVER make as much hp before 5252 RPM as it can torque, and the opposite is true above 5252 RPM. Any dyno chart you ever see where the two plotted curves don't cross at 5252 RPM is a bogus dyno chart.

What's important to understand as this pertains to vehicles is that hp is not a direct determinate to accelerative ability. Horsepower is more a way of easily summarizing the abilities of a car, but not an exact or necessary thing. Horsepower is basically a way of stating torque with gearing already taken into account, which makes the pain of figuring out torque multiplication factors less needed for generalized performance figures. Here's the three most important factors in determining how fast a car can accelerate...

-effective torque at the wheels
-overall vehicle weight
-available traction
-total drag (constituted mainly of aero drag at speeds above 50mph)

Since we are just talking about differences in power and how it effects acceleration, we can basically toss out everything except torque since the others can be assumed to remain constant(please remember this is just a simple hypothetical). So now you need to understand what torque multiplication is, and here's an excerpt from an older post I made on the subject...

"What this all means comes into focus when you understand the concept of torque multiplication.
Torque is the only productive force that an engine creates, so when talking about acceleration
relative to gearing this is all that matters. Torque multiplication takes the torque output of the
engine at any specific RPM and multiplies it by the overall gear ratio (think of this as gear
reduction) to show us how much torque is actually being transmitted to the wheels at any given
speed and in any given gear. An example:

Engine A is making 150 ft/lbs of torque at 3000 RPM, and is in our earlier hypothetical 1st gear
which has a ratio of 3.42:1 and a final drive of 4.27:1.

Effective torque at the wheels @ 3000RPM = 4.27 x 3.42 x 150...
which equals 2,190 ft/lbs of torque to the wheels! Ever wonder why acceleration is always better
in lower gears than higher gears? That's why. The true accelerative ability of a car is defined by
these laws, and in the most pure sense torque at the wheels is all that matters (meaning HP is
not directly important or a determinate of potential speed). "
 

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Another point...how did you start that dyno at 2,000 rpms????? Do you have the ability to lock your transmission in your 1:1 gear on a automatic tranny?
 

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Discussion Starter #14
dawgs77 said:
Another point...how did you start that dyno at 2,000 rpms????? Do you have the ability to lock your transmission in your 1:1 gear on a automatic tranny?
No, they allow it to shift into 3rd gear with od off and roll into it WOT so it doesn't downshift. I have no idea about all that math stuff. It makes what it makes. It runs strong and beats many people. :rolleyes:

My rear gears are 3.73 if that is important.
 

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fepony said:
No, they allow it to shift into 3rd gear with od off and roll into it WOT so it doesn't downshift. I have no idea about all that math stuff. It makes what it makes. It runs strong and beats many people. :rolleyes:

My rear gears are 3.73 if that is important.
I don't doubt that that engine makes that amount of power but something wasn't set up correctly. Dawgs is absolutely right, all dyno runs should have the hp and tq curves cross at 5252 rpm because that is hp is a function of tq, and when plotted on a graph, two numbers that are functions of each other will cross at the divisor.

Here are a few dyno graphs showing a proper crossing:











Each of the dynos is completely different cars (and non-cars) with completely different engines, trannies, gears, etc. Your gears have nothing to do with the math. Google image "dyno sheet" for yourself if you still have doubts.

Andrew
 

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The plot thickens...

I googled "HP Performance" and on their web page, they have several dyno sheets. This one is not incorrect as far as I can tell, there is no tq curve plotted:



But these are definitely not right:





Anybody care to speculate as to what is going on here? :huh:

Found here:

http://images.google.com/imgres?imgurl=http://www.turbochargedpower.com/images/Page%20Dyno%20HP%20Corrected.jpg&imgrefurl=http://www.turbochargedpower.com/About%20HP.htm&h=720&w=540&sz=43&hl=en&start=3&um=1&tbnid=4oRuh05d4vojpM:&tbnh=140&tbnw=105&prev=/images?q=hp+performance+dyno&svnum=10&um=1&hl=en&rlz=1T4TSHB_enUS222US223&sa=N
 

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Discussion Starter #17 (Edited)
ablexus said:
The plot thickens...

I googled "HP Performance" and on their web page, they have several dyno sheets. This one is not incorrect as far as I can tell, there is no tq curve plotted:



But these are definitely not right:





Anybody care to speculate as to what is going on here? :huh:

Found here:

http://images.google.com/imgres?imgurl=http://www.turbochargedpower.com/images/Page%20Dyno%20HP%20Corrected.jpg&imgrefurl=http://www.turbochargedpower.com/About%20HP.htm&h=720&w=540&sz=43&hl=en&start=3&um=1&tbnid=4oRuh05d4vojpM:&tbnh=140&tbnw=105&prev=/images?q=hp+performance+dyno&svnum=10&um=1&hl=en&rlz=1T4TSHB_enUS222US223&sa=N
Google this... Call Tony and ask him... http://www.hp-performance.com/ BTW he is the guy doing my motor swap. Feel free to call him. That is also the very same dyno i was dynoed on.
 

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The dynos above do not show the full plot. On the newer machines you can tell it what to show...JUST HP...Just TQ..or the entire plot.

Something as simple as not hooking the dyno up the the Number 1 plug can throw the dyno off.

But HP/TQ is constant. HP does not exist...it is a calculation of Torque. This calculation does NOT CHANGE!!!! Not for N/A....not for forced induction..and they WILL ALWAYS CROSS AT 5252.

Now I'm not saying your not putting some good power down to the ground man...that 13 second 1/4 mile run shows your putting some good power down.

You'll have good numbers....but that dyno's not corect. Not slamming you...just stating....something is out of whack.
 

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Dyno 1 up there shows HP and the AFR..not Torque

Dyno 2 shows two HP curves with different mods

Dyno 3 shows a MAJOR mod and change in HP.
 

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