Random Thoughts - Part Deux [NO POLITICS]

[Ultramaroon]

OMG, that's horrible.

[Tcoat]

Originally Posted by Ultramaroon

OMG, that's horrible.

[Spuds]

Originally Posted by Tcoat

The problem with trying to do that is that such changes can actually be hard to quantify due to the number of variables involved. The engineers are going to hate this statement but math only works properly in a controlled environment. Not all modifications will fit into a nice easy equation that is applicable across the board. That is why the subject matter is debated because people want a nice clean X or Y answer when the reality could be something between A and Z.

@Notatroll ( obviously I remember his name wrong) had something that he was working on that was at least good in theory but he disappeared a while back.

I couldn't find anything on here, maybe I'll search again. I know there are websites that can help generically with the problem, but I figured I would make my own because I'm a control freak.

The universe behaves in mathematical ways. If you have enough data, you can predict pretty much anything. The problem is having enough data and processing power.

As far as the calculations, yes there will be things I do not have enough data (or time) to account for. Distribution of weight in a wheel is a biggie for example. That being said, you can get pretty close with assumptions and use empirical data to adjust accordingly.

And yes, environmental variables will have a huge effect on performance. But the point is to predict, all other things being equal, what the performance difference is by changing weights, diameters, etc. How much faster or slower would my car have accelerated if x were changed in y way.

Another thing that I cannot account for is differences in engine performance with a higher/lower angular acceleration. However, I feel this is negligible in any practical use of the tool. Same for friction and viscous forces.

[Tcoat]

Originally Posted by Spuds

I couldn't find anything on here, maybe I'll search again. I know there are websites that can help generically with the problem, but I figured I would make my own because I'm a control freak.

The universe behaves in mathematical ways. If you have enough data, you can predict pretty much anything. The problem is having enough data and processing power.

As far as the calculations, yes there will be things I do not have enough data (or time) to account for. Distribution of weight in a wheel is a biggie for example. That being said, you can get pretty close with assumptions and use empirical data to adjust accordingly.

And yes, environmental variables will have a huge effect on performance. But the point is to predict, all other things being equal, what the performance difference is by changing weights, diameters, etc. How much faster or slower would my car have accelerated if x were changed in y way.

Another thing that I cannot account for is differences in engine performance with a higher/lower angular acceleration. However, I feel this is negligible in any practical use of the tool. Same for friction and viscous forces.

Well this is all stuff that Stu had done. He had some program that would give the theoretical values for almost every moving part. He actually is a rocket scientist even if that is horribly cliche.

[Ultramaroon]

Originally Posted by Tcoat

The problem with trying to do that is that such changes can actually be hard to quantify due to the number of variables involved. The engineers are going to hate this statement but math only works properly in a controlled environment. Not all modifications will fit into a nice easy equation that is applicable across the board. That is why the subject matter is debated because people want a nice clean X or Y answer when the reality could be something between A and Z.

@Notatroll ( obviously I remember his name wrong) had something that he was working on that was at least good in theory but he disappeared a while back.

What? The engineers? All modifications? Are you saying it's difficult to quantify the effects of a change in inertia of a flywheel? That simple shit. Time-consuming? Yes. Difficult? Black magic? Hell, no.

[Tcoat]

OK who here knows the opening of T2? I know they are potato pics but any critiques on this? I attempted to match the scene lighting in paint as much as possible. The nuked playground equipment is had made the KK and T-800s are kits.

[Tcoat]

Originally Posted by Ultramaroon

What? The engineers? All modifications? Are you saying it's difficult to quantify the effects of a change in inertia of a flywheel? That simple shit. Time-consuming? Yes. Difficult? Black magic? Hell, no.

His criteria was "all rotating parts in terms of straight line acceleration". The variables that could be introduced in the possible combinations are probably in the hundreds of thousands. Stu had the numbers for the flywheel, all pulleys, etc. but I don't remember the thread. Even his hard numbers did not stop debate.

[humfrz]

Originally Posted by Sapphireho

So, I think I'm going to buy my dad's truck from my mom. It's a 2005 4 door 4x4 same as mine, the only difference is mine has 95k miles and my dad's has 43k. that and the back bumper needs to be replaced. I think my dad went to the same driving school as Humfrz. I was thinking selling mine after, but my 17yo will be getting his license this summer. I wonder what it would cost to insure a 17yo with a truck with a hemi?

Welp, back when your Dad and I learned to drive, when you saw a truck backing up ...... you got the hell out of its way .......

Insurance for a 17 year old ...... maybe you should delay your retirement till they are over 25 .....


humfrz

[Spuds]

Originally Posted by Tcoat

Well this is all stuff that Stu had done. He had some program that would give the theoretical values for almost every moving part. He actually is a rocket scientist even if that is horribly cliche.

Well, now I need to go find his to evaluate.

[Spuds]

Originally Posted by Tcoat

His criteria was "all rotating parts in terms of straight line acceleration". The variables that could be introduced in the possible combinations are probably in the hundreds of thousands. Stu had the numbers for the flywheel, all pulleys, etc. but I don't remember the thread. Even his hard numbers did not stop debate.

Still don't have halfshafts and pulleys. Wasn't planning on doing inertia of gears, since I doubt anyone going that far will care, and likely negligible as well. Also wasn't going to do bearings because it's a hobby not my job.

Most variables you are talking about are negligible. "Close enough for engineering" is a great saying.

[humfrz]

Originally Posted by Spuds

Wondering where to post a tool where one can put in any upgrades to rotatey bits of a car and get affected performance output in terms of straight line acceleration. Would also cover overall weight reduction/increase as a side effect. Tired of seeing debate on something that can be numerically solved. Pun intended.

I reckon someone already did that.

F=ma


humfrz

[Ultramaroon]

Originally Posted by Spuds

Wondering where to post a tool where one can put in any upgrades to rotatey bits of a car and get affected performance output in terms of straight line acceleration. Would also cover overall weight reduction/increase as a side effect. Tired of seeing debate on something that can be numerically solved. Pun intended.

Originally Posted by Tcoat

His criteria was "all rotating parts in terms of straight line acceleration". The variables that could be introduced in the possible combinations are probably in the hundreds of thousands. Stu had the numbers for the flywheel, all pulleys, etc. but I don't remember the thread. Even his hard numbers did not stop debate.

I disagree. Spuds, it's up to you. My take is that you want a model that demonstrates the change in straight-line performance given a change in one or more components.

That's easy. Remember that paint mixer? I did all the closed-form solutions to verify the important pieces of a dynamic model of the whole machine right down to the gyroscopic effects of the internal components of the reduction drive.

Getting the unwashed masses to believe in the model is a different story. That's why I don't waste my time with the bullshit.

[Ultramaroon]

Ok, so I took too long. Whatevs, man.

[Tcoat]

Originally Posted by Spuds

Still don't have halfshafts and pulleys. Wasn't planning on doing inertia of gears, since I doubt anyone going that far will care, and likely negligible as well. Also wasn't going to do bearings because it's a hobby not my job.

Most variables you are talking about are negligible. "Close enough for engineering" is a great saying.

Originally Posted by Ultramaroon

I disagree. Spuds, it's up to you. My take is that you want a model that demonstrates the change in straight-line performance given a change in one or more components.

That's easy. Remember that paint mixer? I did all the closed-form solutions to verify the important pieces of a dynamic model of the whole machine right down to the gyroscopic effects of the internal components of the reduction drive.

Getting the unwashed masses to believe in the model is a different story. That's why I don't waste my time with the bullshit.

LOL I don't think I was clear in what I was saying. His original statement was "all" changes. That is what I said would be impossible (Improbable maybe a better word?) a task to do all the math for each conceivable combination of components. If just looking at each individual part without adding the others then sure totally doable. The project is not how I first understood it to be.

I can not remember Stu's last user name. He was Stugray so some of it may be under that name. His work on this topic was impressive.