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Old 01-13-2021, 07:32 PM   #21 (permalink)
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Quote:
Originally Posted by JulianEdgar View Post
BSFC is quite irrelevant.
It seems that a change in RPM at a given throttle position would affect BSFC, and therefore affect fuel efficiency.

The difference wouldn't matter much I wouldn't think, but it's an unaccounted for variable, which makes the throttle stop technique useful for average Joe, and not so useful to those in the industry that have access to more precise equipment and need to account for all the variables they possibly can.

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Old 01-13-2021, 07:32 PM   #22 (permalink)
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Quote:
Originally Posted by aerohead View Post
Store's closing in a few minutes. I'll be back Friday and pick up where I left off. We'll have some things to talk about.
In the meantime, you might want to reflect on all the possible variables which could be present during testing, which could color the data.

I suggest that you actually learn about what the technique involves, then you won't be arguing against some technique that appears to exist only in your mind (mpg, BSFC, etc).
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Old 01-13-2021, 07:34 PM   #23 (permalink)
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Quote:
Originally Posted by redpoint5 View Post
It seems that a change in RPM at a given throttle position would affect BSFC, and therefore affect fuel efficiency.

The difference wouldn't matter much I wouldn't think, but it's an unaccounted for variable, which makes the throttle stop technique useful for average Joe, and not so useful to those in the industry that have access to more precise equipment and need to account for all the variables they possibly can.
Why does fuel efficiency / BSFC matter? It doesn't at all. It's nothing to do with the technique!

Last edited by JulianEdgar; 01-13-2021 at 07:39 PM..
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Old 01-13-2021, 07:41 PM   #24 (permalink)
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Quote:
Originally Posted by JulianEdgar View Post
Why does fuel efficiency / BSFC matter? It doesn't at all. It's nothing to do with the technique!
I have to admit, it's been a while since I glossed over the technique. The overall concept was sufficient to me, which is that comparing the delta in max speed for a given throttle position, one could extrapolate out the difference in aero drag and efficiency.

I was going to read up in more detail when I actually employ the technique. Unfortunately I've lost most of my interest at the moment because I rarely drive, and when I do, my fuel is paid for by my employer. I'm not going to mod a company car.
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Old 01-13-2021, 07:49 PM   #25 (permalink)
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Quote:
Originally Posted by redpoint5 View Post
I have to admit, it's been a while since I glossed over the technique. The overall concept was sufficient to me, which is that comparing the delta in max speed for a given throttle position, one could extrapolate out the difference in aero drag and efficiency.

I was going to read up in more detail when I actually employ the technique. Unfortunately I've lost most of my interest at the moment because I rarely drive, and when I do, my fuel is paid for by my employer. I'm not going to mod a company car.
The technique has nothing whatsoever to do with fuel usage, thermal efficiency or BSFC. Nothing at all.

This thread is a good example of Aerohead just leading people astray and causing confusion - bringing in irrelevant concepts, not understanding what is being described (but at the same time being sure he is against it), citing irrelevant references.

If done carefully, the throttle-stop technique works extremely well in cars with manual throttles, and is light-years ahead of coast-down testing.
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Old 01-13-2021, 07:54 PM   #26 (permalink)
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Old 01-13-2021, 08:04 PM   #27 (permalink)
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Quote:
Originally Posted by JulianEdgar View Post
The technique has nothing whatsoever to do with fuel usage, thermal efficiency or BSFC. Nothing at all.

This thread is a good example of Aerohead just leading people astray and causing confusion - bringing in irrelevant concepts, not understanding what is being described (but at the same time being sure he is against it), citing irrelevant references.

If done carefully, the throttle-stop technique works extremely well in cars with manual throttles, and is light-years ahead of coast-down testing.
I arrived at confusion without the aid of anyone else.

The requirement of a direct throttle cable is a detail not known to me, as I assumed the technique could fairly well be applied to most any modern vehicle with "throttle by wire".

I understand the tendency to get irritated by the ignorance of others, but we can't really blame people for what they don't know. Everyone is ignorant of everything until they are not.
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Old 01-13-2021, 09:45 PM   #28 (permalink)
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Quote:
Originally Posted by redpoint5 View Post
I arrived at confusion without the aid of anyone else.

The requirement of a direct throttle cable is a detail not known to me, as I assumed the technique could fairly well be applied to most any modern vehicle with "throttle by wire".

I understand the tendency to get irritated by the ignorance of others, but we can't really blame people for what they don't know. Everyone is ignorant of everything until they are not.
I think you were helped into your confusion, since you picked up Aerohead's point and then ran with it. There's never been any mention of BSFC and throttle stop testing except in this thread.

I am never irritated by people who are ignorant. I am irritated when people refuse to improve their understanding, even when they are directed to sources that would allow them to do so. And I am more than irritated when people who are ignorant, and who refuse to improve their understanding, then lead others astray.
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Old 01-13-2021, 10:49 PM   #29 (permalink)
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Quote:
Originally Posted by JulianEdgar View Post
I think you were helped into your confusion, since you picked up Aerohead's point and then ran with it. There's never been any mention of BSFC and throttle stop testing except in this thread.

I am never irritated by people who are ignorant. I am irritated when people refuse to improve their understanding, even when they are directed to sources that would allow them to do so. And I am more than irritated when people who are ignorant, and who refuse to improve their understanding, then lead others astray.
I'll lay out the rough process my mind went through upon encountering this thread:

1. I found a provocative title saying I should question the throttle-stop method of testing mods.

2. The OP contained no information other than links, which I despise. Links should have commentary to a. take a position b. illuminate the relevant part of the link c. summarize the point

3. Someone posted an excerpt that was meant to be relevant, which I did not find to be relevant. I commented on that.

4. I glossed over and skipped most of the posts other than those in response to me.

5. I responded to your post since it was relevant to my misunderstanding.

I've got plenty of cause to dismiss aerohead, but I don't because I appreciate a good-faith representation of ideas. That isn't to say the idea is fully formulated, articulated, or even correct, but it comes from a place of candor. Candor I respect above all else.

I'm as irritated by others who don't agree with my careful illumination of the obvious, but even a refusal to "see the light" is baked into existence. Ultimately I have to end with saying I disagree, I have provided sufficient evidence to support my point of view, and you'll need to be specific with the thing you disagree with or don't quite understand.
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Old 01-13-2021, 11:58 PM   #30 (permalink)
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Quote:
Originally Posted by redpoint5 View Post
I'll lay out the rough process my mind went through upon encountering this thread:

1. I found a provocative title saying I should question the throttle-stop method of testing mods.

2. The OP contained no information other than links, which I despise. Links should have commentary to a. take a position b. illuminate the relevant part of the link c. summarize the point

3. Someone posted an excerpt that was meant to be relevant, which I did not find to be relevant. I commented on that.

4. I glossed over and skipped most of the posts other than those in response to me.

5. I responded to your post since it was relevant to my misunderstanding.

I've got plenty of cause to dismiss aerohead, but I don't because I appreciate a good-faith representation of ideas. That isn't to say the idea is fully formulated, articulated, or even correct, but it comes from a place of candor. Candor I respect above all else.

I'm as irritated by others who don't agree with my careful illumination of the obvious, but even a refusal to "see the light" is baked into existence. Ultimately I have to end with saying I disagree, I have provided sufficient evidence to support my point of view, and you'll need to be specific with the thing you disagree with or don't quite understand.
Skipping posts is always a problem in a thread, because (as in this case) your point was answered multiple times before you made it.

And I can't see how Aerohead can possibly be regarded as acting in good faith when he didn't understand the approach (or even try to understand, it appears - it's a pretty simple method) and then told everyone it didn't work, shouldn't be used, etc.

Good faith would have been to ask questions so that he could understand the method, and then perhaps test it for himself - not pass judgement in complete ignorance.

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