Engine Masters. Daily report.

[rmcomprandy]

NO ... he probably took it as a personal attack when I told him to quit changing the subject to fit his own agenda and this was because he simply didn't understand WHY the EMC scored the way they do.

When I showed him with actual numbers he became all defensive and was doing everything he could to get away from the original subject.

[F1Fever]

No, it was the tone of these posts...

viewtopic.php?t=18457&p=206073#206073

viewtopic.php?t=18457&p=207993#207993


but for the record I do agree with you here:
viewtopic.php?p=208313#208313

[A Atwood]

In every form of racing / motorsports that I know of, whether it be drag racing, truck pulling, offshore boat racing, etc., the team that can produce the most power, has an obvious advantage over the other teams. I don't care how the team produces it. It could be a nitrous assisted bigblock, or a turbocharged 4 banger. It simply doesn't even matter the torque of the given engine. The one that can produce the greatest level of horsepower will have the greatest level of acceleration / hardest pulling / fastest top speed, you name it. Of course there are exceptions suuch as additional weight of the engine, higheset average power applied, and such.

This does NOT imply that the team will win, it just means they have an advantage in ONE aspect of the competition. If a team is circle track racing, and they are not applying the highest level of horsepower to the ground (also know as highest axle tq potential), there would have to be a totally different reason for it (such as traction), as it would be slowing them down otherwise.

I believe Darin Morgan stated that pro stock engines have not gained 1 ft/lb tq in the past ten years, yet hp has increased over 100. ET's have went down along with the increase in hp..

It always has been, still is today, and always will be about producing the highest HORSEPOWER you can achieve if you want to have the advantage in THAT aspect of the competition. More horsepower=greater potential for acceleration, top speed, and pulling force. If you do not understand this, you are in the wrong business.

ARN

[mbrooks]

horsepower falls off where the torque falls off. horsepower is a calcuation computed off of torque. the 100hp increase you refer to means the torque curve has been sustained at higher rpm.

i'm not talking about peak torque falling off, look where the hp falls off and then below to what the torque curve does. where hp falls, torque falls, they are related.

[rmcomprandy]

A Atwood:
In ANY case, if you need to give-up too much torque below its peak in order to gain a little more horsepower at or above the peak AND it needs to run in a wide a 4000 RPM band where, (as you say), you can not take ADVANTAGE of that additional peak horsepower then it will also NOT be advantagous in the end results.

The key here is the WIDE band of power an engine NEEDS to continuously exhibit in the EMC.

With a NARROW band of power, as in using a transmission, it's a completely different story.

[David Redszus]

So lets compute some G force vs MPH curves for engines actually used in the EMC competition.

If someone has the torque curves for an engine and the specs for a car to put it in, I'll do the computations if Stan will post the resulting graphs.

The needed data is torque curve, tire size, vehicle weight, frontal area, drag coefficient (or estimate), gear ratios and rear end.

We could put two different engines in the same car to see the difference in acceleration and speed.

[Stan Weiss]

In every form of racing / motorsports that I know of, whether it be drag racing, truck pulling, offshore boat racing, etc., the team that can produce the most power, has an obvious advantage over the other teams. I don't care how the team produces it. It could be a nitrous assisted bigblock, or a turbocharged 4 banger. It simply doesn't even matter the torque of the given engine. The one that can produce the greatest level of horsepower will have the greatest level of acceleration / hardest pulling / fastest top speed, you name it. Of course there are exceptions suuch as additional weight of the engine, higheset average power applied, and such.

This does NOT imply that the team will win, it just means they have an advantage in ONE aspect of the competition. If a team is circle track racing, and they are not applying the highest level of horsepower to the ground (also know as highest axle tq potential), there would have to be a totally different reason for it (such as traction), as it would be slowing them down otherwise.

I believe Darin Morgan stated that pro stock engines have not gained 1 ft/lb tq in the past ten years, yet hp has increased over 100. ET's have went down along with the increase in hp..

It always has been, still is today, and always will be about producing the highest HORSEPOWER you can achieve if you want to have the advantage in THAT aspect of the competition. More horsepower=greater potential for acceleration, top speed, and pulling force. If you do not understand this, you are in the wrong business.

ARN

The first graph is of an early '90s Pro Stock engine that larry M posted. The second is the same torque curve moved 1300 RPM higher.

[F1Fever]

So lets compute some G force vs MPH curves for engines actually used in the EMC competition.

If someone has the torque curves for an engine and the specs for a car to put it in, I'll do the computations if Stan will post the resulting graphs.

The needed data is torque curve, tire size, vehicle weight, frontal area, drag coefficient (or estimate), gear ratios and rear end.

We could put two different engines in the same car to see the difference in acceleration and speed.

sounds good, to keep in the spirit of the competition the weight of the vehicle should be set with the CI of the engine, ie 1 lb per ci

[rmcomprandy]

So lets compute some G force vs MPH curves for engines actually used in the EMC competition.

If someone has the torque curves for an engine and the specs for a car to put it in, I'll do the computations if Stan will post the resulting graphs.

The needed data is torque curve, tire size, vehicle weight, frontal area, drag coefficient (or estimate), gear ratios and rear end.

We could put two different engines in the same car to see the difference in acceleration and speed.

Will this car have a direct drive to the rear end, with no transmission what-so-ever; a la a sprint car...? That is what an entry is up against in the EMC.

[Stan Weiss]

Once someone posts a rpm / torque listing with engine size. A number of different graphs can be produced by adjusting parameters until we have a good standard, then we can move on and do other engines.

[A Atwood]

In ANY case, if you need to give-up too much torque below its peak in order to gain a little more horsepower at or above the peak AND it needs to run in a wide a 4000 RPM band where, (as you say), you can not take ADVANTAGE of that additional peak horsepower then it will also NOT be advantagous in the end results.

I agree with you here completely.

That is why I said this in my post:

Of course there are exceptions suuch as additional weight of the engine, higheset average power applied, and such.

What you are referring to is highest average power applied.
I have referred to maximum average horsepower applied at least a couple times during these discussions.

ARN

[Stan Weiss]

OK I will start it off. Using the torque curve that David posted. I graphed G's against RPM and also against time.

RPM = 10000
Tire Diameter = 24.0
Car Weight = 200.0
Rear Gear Ratio = 4.11
T Gear1 = 1.0
T Gear2 = 0.0
T Gear3 = 0.0
T Gear4 = 0.0
T Gear5 = 0.0
T Gear6 = 0.0
T Gear7 = 0.0
; Acceleration and Top Speed
Coefficient of Drag = 0.35
Frontal Area = 16.0
Percent Drive Train Power Loss = 0.0
Percent Rear End Power Loss = 0.0
Tire Rolling Radius = 12.0
Dyno Correction = 1.00
Launch RPM = 5200
RollOut = 12.0
Automatic Trans = No
Hood Scoop = Yes
; User Selected Options
Grid Switch = 1
Solid Switch = 1
Graph Line Width = 3
; Data for Acceleration / Top speed calculator
; The following parameters must stay in this order
Acceleration = 5200 92
Acceleration = 5400 94
Acceleration = 5600 99
Acceleration = 5800 100
Acceleration = 6000 101.5
Acceleration = 6200 102.5
Acceleration = 6400 110
Acceleration = 6600 119.5
Acceleration = 6800 122.5
Acceleration = 7000 126
Acceleration = 7200 131
Acceleration = 7400 135
Acceleration = 7600 138
Acceleration = 7800 139
Acceleration = 8000 140
Acceleration = 8200 138
Acceleration = 8400 136
Acceleration = 8600 136
Acceleration = 8800 136
Acceleration = 9000 134.5
Acceleration = 9200 131.5
Acceleration = 9400 129
Acceleration = 9600 127
Acceleration = 9800 122
Acceleration = 10000 119.5
; Added by me
Acceleration = 10500 109

[F1Fever]

stan, the thing to do probably would be to have a start RPM of 3000 and an end RPM of 7000 with something like a 5.0 gear, direct drive transmission
vehicle weight 10 lb per CI (or 7.5 lb per ci.. as long as it is constant per engine)
and measure the time it takes to get from 3000 rpm to 7000 rpm

[Stan Weiss]

OK, I had to redo the graphs. When I increased the power by 10 times and the weight by 10 times I got much different results. I needed to set Coefficient of Drag = 0.0 for them to be the same. New graphs follow. Any EMC contestants want to post their torque curve?

[David Redszus]

Will this car have a direct drive to the rear end, with no transmission what-so-ever; a la a sprint car...? That is what an entry is up against in the EMC.

The program allows the use of a single gear (and rear end gear), or any number of gears (up to 6), any tire diameter, frontal area and drag Cd.

What I failed to include is the traction limit based on G forces. It makes no sense to design a car that can do 3.5Gs and have tires limited to 1.2Gs.
Also, aerodynamic downforce (or lift) has not been included.