Hilltop Eu4

[neoviper]

relate the drag figures to the power required to overcome them. If we add rolling resistance and air resistance together we get total drag in pounds. Power required is then calculated as:
Power (bhp) = Total drag x mph / 375
We could if required split the power into the amounts needed to overcome each drag separately. The equations would then become:
Power to overcome rolling resistance = weight x 0.013 x mph / 375
Power to overcome air drag = fA x Cd x 0.00256 x mph cubed / 375
Hopefully something of major importance should be clear from the above. We already know that it is air resistance that is the major element in this equation and we can see that we need to incorporate mph cubed in the power equation for air drag. As a simplification therefore we can say that power required is closely related to mph cubed - i.e. to double the speed of a vehicle we need 8 times the engine power. Alternatively we can express this as top speed is a function of the cube root of engine power. This means that engine modifications will have a much greater impact on acceleration (which is directly related to power) than top speed. Also that is why an old engine which is down on power might accelerate slowly but still have close to its original top speed

Roger I am curious to see your mathematical equations how you come to this conclusion since you are not calculating drag weight and distance just so I understand can you explain the formula that you're using to come to these conclusions I am extremely curious

Sent from my iPhone

 

[CPJS]

Is yours a GS or GSA? And, yes, you're probably right about the top speed not being any different.

2014 GS TE

 

[Nutty]

relate the drag figures to the power required to overcome them. If we add rolling resistance and air resistance together we get total drag in pounds. Power required is then calculated as:
Power (bhp) = Total drag x mph / 375
We could if required split the power into the amounts needed to overcome each drag separately. The equations would then become:
Power to overcome rolling resistance = weight x 0.013 x mph / 375
Power to overcome air drag = fA x Cd x 0.00256 x mph cubed / 375
Hopefully something of major importance should be clear from the above. We already know that it is air resistance that is the major element in this equation and we can see that we need to incorporate mph cubed in the power equation for air drag. As a simplification therefore we can say that power required is closely related to mph cubed - i.e. to double the speed of a vehicle we need 8 times the engine power. Alternatively we can express this as top speed is a function of the cube root of engine power. This means that engine modifications will have a much greater impact on acceleration (which is directly related to power) than top speed. Also that is why an old engine which is down on power might accelerate slowly but still have close to its original top speed

Roger I am curious to see your mathematical equations how you come to this conclusion since you are not calculating drag weight and distance just so I understand can you explain the formula that you're using to come to these conclusions I am extremely curious

Sent from my iPhone

Brilliant!

 

[Roger 04 RT]

relate the drag figures to the power required to overcome them. If we add rolling resistance and air resistance together we get total drag in pounds. Power required is then calculated as:
Power (bhp) = Total drag x mph / 375
We could if required split the power into the amounts needed to overcome each drag separately. The equations would then become:
Power to overcome rolling resistance = weight x 0.013 x mph / 375
Power to overcome air drag = fA x Cd x 0.00256 x mph cubed / 375
Hopefully something of major importance should be clear from the above. We already know that it is air resistance that is the major element in this equation and we can see that we need to incorporate mph cubed in the power equation for air drag. As a simplification therefore we can say that power required is closely related to mph cubed - i.e. to double the speed of a vehicle we need 8 times the engine power. Alternatively we can express this as top speed is a function of the cube root of engine power. This means that engine modifications will have a much greater impact on acceleration (which is directly related to power) than top speed. Also that is why an old engine which is down on power might accelerate slowly but still have close to its original top speed

Roger I am curious to see your mathematical equations how you come to this conclusion since you are not calculating drag weight and distance just so I understand can you explain the formula that you're using to come to these conclusions I am extremely curious

Sent from my iPhone

Hi Geoff,
Yes we're on the same page regarding the calculation of required horsepower.

I've used the RB-Racing Aero HP Calculator posted here on their web page: https://www.rbracing-rsr.com/aerohpcalc.html.

If you unpack the HTML code and search for the formula, then search for the javascript, the code they use is:

function bonneville2(form, cd, a, w, v) {
a2 = a * 0.09290304;
v2 = v * 0.44704;
w2 = (w / 2.2);
e1 = Math.pow(v2 / 100, 2.5);
e2 = Math.pow(v2, 2);
rx = (0.01 + (3.24 * 0.005) * e1) * w2 * 9.81;
drag = (0.592 * cd * a2 * e2) + rx;
power = Math.round(10 * drag * v2 * 1.34 / 1000) / 8.5;
powerlost = Math.round((cd * a) * (v * v * v)) / 150000;
form.hp.value = power;
form.hplost.value = powerlost;
}

​

If you follow it through, they take Cd, Frontal Area, Speed Cubed and Weight into account. I've measured effective frontal area of a few bikes and estimated it's around 8 sq-ft, larger on some R1200s than on others. I've also estimated Cd based on my own acceleration and coast-down tests. The figure I've come up with is somewhere between 0.7 and 0.8 depending on model. Since the math is a*Cd, the key is that the product of area and Cd is in the ballpark.

My questions at the moment are not about your customer's satisfaction with their bikes after your tuning but some of the "before" figures, which look low to me. As a cross-check, either an acceleration test or a top speed test can get you in the ballpark of before HP. I've used street acceleration as a torque and HP calculation device, others of my friends use top speed.

One area where the dyno diverges from the real world is the load on the engine. On the dyno, the load doesn't increase with the cube of rear wheel speed because the bike is sitting still and the moment of inertia of the roller is constant. Therefore the road loads the engine more heavily than the dyno.

Another area is starting condition. On the road if you cruise along at 1800 RPM and then open the throttle fully, the AFR ahead of the catalytic converter is always lambda=1 (14.7:1 for gasoline) unless you've used a lambda-shifting device. I've noticed on many of the charts that your customers post that AFR starts very high. I assume that's due to the dyno wheel driving the engine into Overrun Fuel Cutoff.

As a businessman, I know that protecting intellectual property is vital, especially for small businesses. I do have some questions but I'll leave it to you which you believe it's in your interest to answer.

Should you ever wish to include lambda-shifting the closed loop area into your product portfolio I'd be happy to put you in touch with the Nightrider folks. I've always believed lambda-shifting and a re-program have great potential.

 

[batman1]

I'm out!

 

[R1200GSAPilot]

I got as far as (️ x ️) / .... what I do know is my bike is now smoother and gets there quicker.


Sent from my iPhone using Tapatalk

 

[Toddmeister]

I got as far as (️ x ️) / .... what I do know is my bike is now smoother and gets there quicker.


Sent from my iPhone using Tapatalk

You did well

I managed to get to "fat blokes are slower"

 

[Nutty]

I couldn't care less how it works, as long as it doesn't wreck my bike. Which it won't.

 

[neoviper]

Hi Geoff,
Yes we're on the same page regarding the calculation of required horsepower.

I've used the RB-Racing Aero HP Calculator posted here on their web page: https://www.rbracing-rsr.com/aerohpcalc.html.

If you unpack the HTML code and search for the formula, then search for the javascript, the code they use is:

function bonneville2(form, cd, a, w, v) {
a2 = a * 0.09290304;
v2 = v * 0.44704;
w2 = (w / 2.2);
e1 = Math.pow(v2 / 100, 2.5);
e2 = Math.pow(v2, 2);
rx = (0.01 + (3.24 * 0.005) * e1) * w2 * 9.81;
drag = (0.592 * cd * a2 * e2) + rx;
power = Math.round(10 * drag * v2 * 1.34 / 1000) / 8.5;
powerlost = Math.round((cd * a) * (v * v * v)) / 150000;
form.hp.value = power;
form.hplost.value = powerlost;
}

​

If you follow it through, they take Cd, Frontal Area, Speed Cubed and Weight into account. I've measured effective frontal area of a few bikes and estimated it's around 8 sq-ft, larger on some R1200s than on others. I've also estimated Cd based on my own acceleration and coast-down tests. The figure I've come up with is somewhere between 0.7 and 0.8 depending on model. Since the math is a*Cd, the key is that the product of area and Cd is in the ballpark.

My questions at the moment are not about your customer's satisfaction with their bikes after your tuning but some of the "before" figures, which look low to me. As a cross-check, either an acceleration test or a top speed test can get you in the ballpark of before HP. I've used street acceleration as a torque and HP calculation device, others of my friends use top speed.

One area where the dyno diverges from the real world is the load on the engine. On the dyno, the load doesn't increase with the cube of rear wheel speed because the bike is sitting still and the moment of inertia of the roller is constant. Therefore the road loads the engine more heavily than the dyno.

Another area is starting condition. On the road if you cruise along at 1800 RPM and then open the throttle fully, the AFR ahead of the catalytic converter is always lambda=1 (14.7:1 for gasoline) unless you've used a lambda-shifting device. I've noticed on many of the charts that your customers post that AFR starts very high. I assume that's due to the dyno wheel driving the engine into Overrun Fuel Cutoff.

As a businessman, I know that protecting intellectual property is vital, especially for small businesses. I do have some questions but I'll leave it to you which you believe it's in your interest to answer.

Should you ever wish to include lambda-shifting the closed loop area into your product portfolio I'd be happy to put you in touch with the Nightrider folks. I've always believed lambda-shifting and a re-program have great potential.

Oh dear what have I done I foolishly attempted to explain in the hope that you would see obviously this is not possible you continue to make comments regarding load and dyno set ups and how my software works where in reality you have absolutely no idea I make a very quick reference to the dyno the dyno is a load cell dyno I'm not going to explain what that is because it's a waste of time so on that note I'm off to eat another big Mac and possibly a banana milkshake

Sent from my iPhone

 

[Stevie4scoops]

Hi Geoff,
Yes we're on the same page regarding the calculation of required horsepower.

I've used the RB-Racing Aero HP Calculator posted here on their web page: https://www.rbracing-rsr.com/aerohpcalc.html.

If you unpack the HTML code and search for the formula, then search for the javascript, the code they use is:

function bonneville2(form, cd, a, w, v) {
a2 = a * 0.09290304;
v2 = v * 0.44704;
w2 = (w / 2.2);
e1 = Math.pow(v2 / 100, 2.5);
e2 = Math.pow(v2, 2);
rx = (0.01 + (3.24 * 0.005) * e1) * w2 * 9.81;
drag = (0.592 * cd * a2 * e2) + rx;
power = Math.round(10 * drag * v2 * 1.34 / 1000) / 8.5;
powerlost = Math.round((cd * a) * (v * v * v)) / 150000;
form.hp.value = power;
form.hplost.value = powerlost;
}

​

If you follow it through, they take Cd, Frontal Area, Speed Cubed and Weight into account. I've measured effective frontal area of a few bikes and estimated it's around 8 sq-ft, larger on some R1200s than on others. I've also estimated Cd based on my own acceleration and coast-down tests. The figure I've come up with is somewhere between 0.7 and 0.8 depending on model. Since the math is a*Cd, the key is that the product of area and Cd is in the ballpark.

My questions at the moment are not about your customer's satisfaction with their bikes after your tuning but some of the "before" figures, which look low to me. As a cross-check, either an acceleration test or a top speed test can get you in the ballpark of before HP. I've used street acceleration as a torque and HP calculation device, others of my friends use top speed.

One area where the dyno diverges from the real world is the load on the engine. On the dyno, the load doesn't increase with the cube of rear wheel speed because the bike is sitting still and the moment of inertia of the roller is constant. Therefore the road loads the engine more heavily than the dyno.

Another area is starting condition. On the road if you cruise along at 1800 RPM and then open the throttle fully, the AFR ahead of the catalytic converter is always lambda=1 (14.7:1 for gasoline) unless you've used a lambda-shifting device. I've noticed on many of the charts that your customers post that AFR starts very high. I assume that's due to the dyno wheel driving the engine into Overrun Fuel Cutoff.

As a businessman, I know that protecting intellectual property is vital, especially for small businesses. I do have some questions but I'll leave it to you which you believe it's in your interest to answer.

Should you ever wish to include lambda-shifting the closed loop area into your product portfolio I'd be happy to put you in touch with the Nightrider folks. I've always believed lambda-shifting and a re-program have great potential.

I have no interest in any equations etc because in the same way as employing an accountant or lawyer as and when I need one because I have no interest in the complexitys of their professions just the end result.

Like many others who have had their bikes Hilltopped, I'm very pleased with the results.

We can't all be wrong?

 

[Roger 04 RT]

Oh dear what have I done I foolishly attempted to explain in the hope that you would see obviously this is not possible you continue to make comments regarding load and dyno set ups and how my software works where in reality you have absolutely no idea I make a very quick reference to the dyno the dyno is a load cell dyno I'm not going to explain what that is because it's a waste of time so on that note I'm off to eat another big Mac and possibly a banana milkshake

Sent from my iPhone

You asked the question what formula I was using, and you introduced all the V-cubed and Cd technical stuff. Hope you enjoyed the Big Mac.

 

[Tripleblack13]

The BMW spec on the R1200GSW is for a top speed in excess of 125 mph, I'm not sure which gear that's in or at what RPM but with the gearing ratios it can be figured out. If the before power is 97 HP or lower as many have reported, that says the bike would struggle to reach even 120 mph.

The other test that can be done, and I've used a GS-911 to do it, is to measure rate of acceleration--before and after. With more torque and HP, the rates will increase.

As Geoff pointed out a couple posts back these tests should be done at the same air temperature (or compensated as the dyno does), on the same road, into the same wind conditions. Wind is a significant factor in top speed testing.

Oh dear. I'm speech less. Time to close the thread.
I opened this thread with a simple question. In amongst the bullshit I got the answer.
Geoff, You did a great job. I'm very happy.
Those who doubt - it's a free world.
Those of use who've had the remap are riding around happy on great bikes that go even better.
My pcp deal ends in 2 years. I'll no doubt ask the same question of the new euro'whatever compliant engine and I'm sure my 19 plate GSA will be introduced to Geoff.
Chaps thanks for your input. Nice to meet those that I did at Hilltop. Geoff you're a star - cheers.

 

[Tripleblack13]

Thread closed.
Cheers guys.