Thoughts on the new Odin TVS blower making less then Whipple TQ?

[SolarFlare]

Yea yea, Im sure those diesel trucks making 1100wtq are just dying of fun with the way all that tUrkZ feels on its way to a 12.5sec pass at 108mph. As Ive already picked up my 9sec slip, pulled up to my spot, turned it off and popped my hood.

Sponsored

 

[80FoxCoupe]

Yea yea, Im sure those diesel trucks making 1100wtq are just dying of fun with the way all that tUrkZ feels on its way to a 12.5sec pass at 108mph. As Ive already picked up my 9sec slip, pulled up to my spot, turned it off and popped my hood.

But does your car throw you back in the seat???

 

[SolarFlare]

But does your car throw you back in the seat???

No, which allows me to lean forward on launch to bring the nose back down like bikes do.

 

[80FoxCoupe]

No, which allows me to lean forward on launch to bring the nose back down like bikes do.

Innovative. That's what I like about you bro!

 

[Bear_Stang]

Cool, I love a challenge.

Here’s a dyno chart showing two different blowers.

Ignore the fact that it’s Whipple and Edelbrock, it’s irrelevant to the argument.
(For those who are going to insist that it matters, the Edelbrock car was pre modular inlet and running the stock TB. Whipple was Gen 2 or maybe Gen 3, 132mm TB, rest of the basic setups unknown)
Apologies for the metric units, Again, it’s irrelevant to the point of torque being the dictator of acceleration rate.

Below the dyno charts are the raw numbers used for the plots (for those who really care)

Below that are the acceleration curves.

And finally, the raw numbers for acceleration.

In closing, there’s 50rwkw (65rwhp) separating those two vehicles.
The one with the higher hp wins the race but at NO POINT whatsoever does it produce as much push in the back as the “slower” car.

You’ll also notice that peak acceleration occurs at peak torque, Hp having absolutely nothing to do with it.
Hence, a good race car will produce its maximum torque toward peak rpm (creating more Hp) while a good street car doesn’t need to, preferably it will be easily accessible without you having to look like a boy racer trying to find it.

@gimmie11s
@engineermike

Anyone want to try and argue with physics or are we done here?

Burkey went science in a mustang forum... Dangerous gamble my friend... Dangerous gamble....

#numbersferlyfe

 

[SolarFlare]

How many pushes ya'll making at them wheels boys!!?!?!

 

[Burkey]

There is no “try” because you bungled the physics. First of all the correct equation is Acceleration=Force/mass not weight. You seem to have substituted mass for weight so the two errors actually cancelled each other out. Secondly, you substituted “moment” for “force” into your equation. Unfortunately these are not the same thing so the result is incorrect. Finally, the units for acceleration are m/s^2 not m/s. If you had kept track of units in the equation you would have arrived at m^2/s^2 for acceleration which would have been a clue that something in the math was erroneous

Another issue is that you assume only one gear is available. These aren’t boat motors so we have 6-10 different gears available. If your foot is to the floor with an A10 the engine speed stays above 5500 rpm nearly the entire time. The only place your assumptions would be technically valid is if you had an M6 and refused to downshift. But at least you listed your assumptions.

Ok, my apologies on this one. Unfortunately I allowed someone else to do the math. He was pretty busy at the time and I didn’t bother to check his work (given his previous history and his field of employment). At the end of the day, it’s on me. I made the claim, didn’t check the math, I’ll wear it.

 

[80FoxCoupe]

Ok, my apologies on this one. Unfortunately I allowed someone else to do the math. He was pretty busy at the time and I didn’t bother to check his work (given his previous history and his field of employment). At the end of the day, it’s on me. I made the claim, didn’t check the math, I’ll wear it.

Good man.

 

[Burkey]

Good man.

Meh. Ya gotta take a hit every now and then...

 

[80FoxCoupe]

Meh. Ya gotta take a hit every now and then...

Yep, you went real big on that one too.

 

[engineermike]

Very big, much respect.

 

[Burkey]

@engineermike

All good.
Can you explain this to me better to me then?

The dyno charts were produced on a Dynapack about 7 years ago. The estimates are created by the dyno after inputting weight, final drive ratio and tyre diameter (or radius, whatever).
The traces go off the top of the chart because the dyno can’t cope with the way the car delivers its oomph.

If we look at the red trace (because it’s more visible), we can see clearly that the prediction is that g’s will double with a doubling of torque but will not double with a doubling of horsepower.

Torque = 300 @ 2500 and 600 @ 3500 (Torque doubled at those points)
g’s were 0.375 @ 300 and 0.75 @ 600.

When we look at power (PS in this example)
Power is 150 @ 2500, 300 @ 3350 (again, double the output)
G’s were 0.375 @ 150 but didn’t make it to even as much as 0.55 at 300.

My question to you is, what gives?
Why do g’s double with a doubling of torque but not with a doubling of power? We can see quite clearly that G’s are about the same at 5500rpm as they are at roughly 3500rrpm. In my mind, this quite clearly shows that peak acceleration occurs at peak torque.
I don’t understand what’s missing here.
I realise that we aren’t allowing for aero drag here, but that’s just going to make the situation worse as rpm increases, making the relationship even worse for the power side of the ledger.
Please explain what I’m doing wrong here.
My assertion was that peak acceleration will occur at peak torque. I can’t for the life of me see how I’m doing it wrong.
I need to LEARN.

.

 

[80FoxCoupe]

Back again!!!!

 

[Burkey]

Back again!!!!

Lol.
I’m just trying to learn something new.

 

[engineermike]

Lol.
I’m just trying to learn something new.

I think that statement is a bit disingenuous since it’s clear every comparison you “set up” is an attempt to demonstrate some perceived superiority of the Edelbrock unit.

Anyway, I went ahead and applied some physics and even used the torque curves you posted in post #35. My assumptions were 3.55 gear, 4200 lb total weight, no aerodynamic drag, maximum sustainable acceleration is 1.0 g (generous on street tires), WOT is used, and the 10r80 ratios. The attached is the Whipple vs Edelbrock acceleration in G’s vs speed. This is what pushes you back in the seat.

It was actually a fun exercise and I plan on refining the model and adding more capabilities.

Sponsored