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12:45 AM
@ᴘᴀᴜʟsᴛᴇʀ2 How have ya been bud?
 
@DucatiKiller I'm good, kind sir.
 
glad to hear it
I've been chasing harley's with my friend
 
everytime he comes to town he has to look at every FXR that's for sale
he buys and sells them
 
12:47 AM
so, I have to go look at Harley's with him for a few days. Which he absolutely loves.
 
Does he do the "fix-n-flip" on them?
 
he buys them for builders
 
I'm really not all that in love with HD's ... is that sacrilegious?
 
not at all
I'm not in love with them
 
Okay, I feel better now.
:D
 
12:48 AM
lol
here's one that I do like though
 
That is a great looking bike!
It's clean ... just beautiful.
 
I like the builder. He puts modern tech on his builds.
brb phone
 
1:06 AM
I'm in the process of downloading about 50GB worth of game.
It's gunna take a while, lol
Even at 50MB-U/50MB-D, it still takes a little bit.
when I get done, my SSD is gunna be "FULL" ... I'll have about 2-3GB of space left on it.
Not a good thing. Looking at larger SSDs
I don't know that I have the money for a new one though.
@DucatiKiller - Have you ever heard of: ibpublishing.com
 
1:34 AM
@ᴘᴀᴜʟsᴛᴇʀ2 I have not
 
@DucatiKiller I signed up with them today to do freelance articles for LS1Tech
"How to" and "diagnostic" articles between 400-700 words pay $25. "Modification" and "brand review" articles of 600-1000 words pay $50.
I'm kind of surprised. I got a response back in two days time telling me I was accepted. I used what I've done here as a reference of sorts.
They asked for a writing sample, so I sent them a small article I wrote on how to hot rod a lawn mower ... basically it talked about how HP is figured and by increasing your RPMs you would in effect raise the HP output of the engine.
 
wow, that's pretty coool
good job
@ᴘᴀᴜʟsᴛᴇʀ2 Do they have a list for you to write? How does that work?
 
It could be
Yah, one second.
Same link I posted above.
They have Auto Specialty: HD on there.
 
1:51 AM
7
Q: Brake fluid doesn't move in the master cylinder container

MDrazorI have done a clutch bleed on my toyota corolla e120 2006 because I had some difficulties shifting out of 1st gear, I bled it through the slave cylinder and I noticed the fluid was dark black, I was checking the fluid level of course, after clear fluid was coming without air I closed the valve an...

weird
The user that posted this question has two identities because he's not registered.
 
That is really weird.
I see what they are saying it doesn't flow into the master side reservoir ... I know some vehicles use the brake reservoir for the clutch circuit ... I don't know if that's a good idea or not, though.
 
yeah, I've seen that too. I've also seen reservoirs that are duel use but have a single cap and with two caps. That one doesn't seem to have two caps?
IDK
weird
 
I'm wondering if there is a split under the cap?
as in technically two reservoirs?
 
it's possible
I saw that on a datsun b210 I think.
I'm going to have a PTSD moment if I talk about Datsun's too much though.
 
I'm trying to get a better picture of the reservoir.
ROFL!
 
 
1 hour later…
3:26 AM
Whoever sees this... Any idea if I'll see a price difference between checking alignment of one wheel and actually performing front end alignment? You think a shop would even have a price for just a check?
Had a blowout on the way home, but can't tell if it's from alignment or driving too long on a very low tire. The inside edge wore down to the belts.
 
@JPhi1618 I asked that of a shop once my gal drove over the medium of an expressway. They wanted to charge for an overall alignment and not of one wheel. Definitely not saying someone wouldn't, a shop just wouldn't do that for me. They said, "same thing"
Is the car damaged ?
 
No, a strip of rubber came loose and started making a slapping noise so I could safely pull over.
The tire is down to the wear strips, so they needed replacing anyway.
 
but the slapping rubber didn't mess up your wheel well or anything?
 
Nah, it's fine. Suspension feels tight - not worn.
So, it really could be alignment or me abusing a low tire.
 
yeah. thank god it didn't tear up a bunch of body and brake lines. After you get the new tires you'll know if you need an alignment
 
3:35 AM
I had a pretty major (not at fault :) ) accident a year or so ago, and no telling if they checked alignment.
Yea, I'll be keeping a close eye on it for sure. Tires are too expensive not to!
It was only a 1/4" strip, so it was a perfect warning sound.
 
super lucky you weren't hauling ass. :-) there's some mystery meat in alignment for me. I'd get the new tires and take it from there. If it's pulling after that then an alignment is probably in order.
 
Cool, thanks man. Oh, I was going 75 on the tollway! That loose strip saved my ass. And the toll road has free roadside assistance , so another bonus.
 
Free roadside assistance. The benefits of toll roads. Those things don't exist out here but I think I want some.
 
Well, pay $200/mo just to get to work and you might change your mind :P
 
I've changed my mind
 
3:43 AM
Ha, yea.
 
Your a closer. You changed my mind pretty quickly.
Seemed effortless.
 
Well, gotta finish watching TV with the wife. Cya tomorrow. Thanks again.
 
take care, catcha then.
 
 
8 hours later…
11:58 AM
@JPhi1618 - Agree with @DucatiKiller on this. I don't think you're going to find too many places which will do an alignment check for free, unless you purchase tires from them. You may just want to get your front end inspected to ensure there's no mechanical issues, though.
If you do end up getting an alignment, getting a "good for xx year(s)" type deal is not as bad as it sounds. You have to use it, but it can pay off if you buy one for a year and get your alignment checked three times during that period.
 
 
1 hour later…
1:01 PM
Neat. My first out of context downvote on a five year old answer in a long time.
I guess someone doesn't agree with my point "fuel is heavy".
 
Wasn't me
 
@ᴘᴀᴜʟsᴛᴇʀ2, Thanks. It's not so much that I want a check for free, but it'd be great if they would (prices made up) check the alignment of the one wheel for $30 instead of me having to get a $120 alignment.
And I've certainly used the "good for xx years" before when I knew I was about to replace the suspension. It can be a good deal indeed.
 
How can you just check the alignment for one wheel? It will be relative to the other wheels
 
Yea, I don't know...
I'm not sure how the machine works, but that's a good point.
 
I'm putting together a wiki for the tag
> Use this tag for questions related to tools, techniques and generic methodologies for diagnosing problems. For diagnosing case-specific problems, please use the tag instead.
Seem reasonable?
 
1:15 PM
Sounds good to me.
 
"Case-specific" seems so vague
Is there another way to refer to specific cases?
 
system-specific? I guess that doesn't really mean the same thing.
 
Doesn't work for me
I've left it as case-specific for now
It's a wiki, so it doesn't have to be perfect from the first take
 
 
2 hours later…
3:22 PM
@BobCross, do you have a handy "convert to comment" button or is a manual process?
 
It's manual. I have to jump out of the app on my phone and do it in chrome
I can't see the mod tools in the app.
It's a pain because chrome renders the page with leeeetle weeeee links on the phone. I feel like I'm trying to type with segments of bratwurst.
 
Ha, that's funny.
 
I live to bring you joy. :-)
 
Reminds me of an article I saw... In Japan, meat sticks in the winter are popular. People use the sticks as styluses because they have gloves on.
 
Fortunately compiling time allows for lots of little time slots that I can fill with exactly this sort of nonsense.
A meat stick stylus is both cool and gross at the same time. I need to swipe to the next screen but it's cold so I'll use bacon. Yum and Ick.
 
3:44 PM
Ok, so they were Korean...
http://www.engadget.com/2010/02/11/south-korean-iphone-users-turn-to-sausages-as-a-cold-weather-me/
 
My diagnosis stands. The Ick factor increased after I saw the picture of the sausages. Ew ew and ew.
 
 
2 hours later…
5:37 PM
@ᴘᴀᴜʟsᴛᴇʀ2 one interesting follow up to your AR question is the popularity of twin scroll turbos
 
5:50 PM
Hello everyone
 
@cloudnyn3 Hello
@BobCross Variable-geometry turbos, my cup of tea :)
2
 
6:32 PM
@Zaid those are also interesting but I've never heard that twin scrolls are coming with variable geometry
 
6:49 PM
@BobCross twin-scrolls are considered to be a type of VGT
Alongside variable-stator-vane (like on the new Porsche 911 Turbos) and devices which alter the effective cross-sectional area available to the incoming exhaust gases
With twin scrolls, you don't alter the geometry of the turbo internals. You alter the flow by changing the flow velocity and angle characteristics by splitting the plenum into two and controlling how much flow goes through chamber A vs chamber B
 
7:20 PM
In mainstream twin scrolls, is the flow really controlled? For example in a four cylinder, we might see two cylinders sending exhaust gases down one scroll and the other two down the other. The manifolds that I've seen online don't look controlled as such. Just funneling the gas that comes in whenever.
I've never disassembled such a manifold so I only have book learning about them.
 
Same here
I guess I spoke too soon when I said that the flow between the two is controlled
 
I would really like to know how they handle twin scrolls on the new WRX. The runners are long: exactly how do they neck together?
 
You're right. They usually rely on exhaust pulses from certain cylinders to tune the pulses
Trust an engineer to cut costs when asked :)
 
I'm willing to accept them as a subset of VGT, just trying to make sure I understand
 
Some people do. At least at work they do
It gets really fun when you start to see why VGT's work
It's got to do with velocity triangles and (of all things) trigonometry
 
7:25 PM
I believed it before. They just looked complicated and expensive.
Velocity triangles?
 
Yessir... welcome to the wonderful world of turbomachinery
Where flow can be relative and absolute at the same time...
It's a black art, I tell ya
 
Doesn't sound complicated. I've ridden in helicopters. I believe in both kinds of flow. Otherwise the rotors don't work. Then bad stuff happens.
My favorite part is the initial hover test. "Well, I wonder if the rotors will pop off when we use them. We better check before we fly way over there."
 
Lol
Better safe than sorry, I suppose
 
It would be like jacking up the car, running the engine up to speed to see if the wheels shoot off. Not the worst idea but kind of disconcerting.
 
I'm thinking testing rockets is probably the worst case.
Maybe big firey death, and maybe it works!
 
7:35 PM
I have Kerbal space program. Testing rockets is easy. Just click "revert to launch" when things start spiraling. ;-)
 
@JPhi1618 Musk seems to have the right idea - announces an RUD and start again :-)
The Pod Bay
 
No, never been over there.
I visit the space site from time to time.
 
If you have any interest in rockets, satellites, SpaceX, Virgin Galactic, ISS etc, it's well worth hanging out there
 
Cool, thanks.
I love all that stuff that SpaceX is doing.
When I lived in central Texas, we heard one of their early rocket tests, and it felt like there was an earthquake or aliens were invading.
 
7:58 PM
Question for you programmers
I'm trying to generate a list of all possible firing orders
(for a flat-plane V8)
I have 4 buckets
[ 1, 4 ]
[ 5, 8 ]
[ 2, 3 ]
[ 6, 7 ]
What's the least painful way to generate all possible combinations?
For example, one possible firing order is 1-5-3-7-4-8-2-6
 
Is it always bucket 1-2-3-4-1-2-3-4 ?
 
yes
Obviously you can't select the same cylinder second time round
 
Well, you have a binary list since there's just two in each bucket.
 
uh huh
I like where this is going
 
So, And there will be 2^4 combinations (16)
Trying to see why I might be wrong...
 
8:04 PM
Take the example of two buckets
 
I think you can just use a for loop from 0-15, call it "fire=0; fire < 16; fire++"
 
1-5-4-8
1-8-4-5
4-5-1-8 (dupe)
4-8-1-5 (dupe)
 
Why dupe?
 
The second and third rows are the same
Just that you started from a different cyl
 
Ok, didn't think of that requirement.
 
8:07 PM
So when the engine runs it'll be 1-8-4-5-1-8-4-5...
That's not a biggy
So you reckon it'll be 2^4 = possibilities?
 
It seems like if it will always start in bucket 1 you don't have that issue.
What language are you using?
 
I was hoping for some fancy string combinatorics but whatever
I think I'll use Perl
Either that or Excel
I think this is what I'll do
 
Ew, ok. Hmm.
 
I'll cycle through all possible 4-bit strings:
0000
0001
0010
0011
...
 
Yea, that's where I was going.
She second 4-bit string is the first one negated.
 
8:10 PM
For each one, take the complement and append it
 
Yea, sounds good.
 
Yes, I got it
Then the hard part... splice in the cylinder value for the relevant bucket
 
8:28 PM
For future reference:
use strict;
use warnings;

my @buckets = ( [ 1, 4 ],
[ 5, 8 ],
[ 2, 3 ],
[ 6, 7 ],
);

for (0..15) {
my $combination = sprintf "%04b", $_;
$combination .= $combination =~ tr/01/10/r;
my @options = split //, $combination;
print $_, "\n" for join '-', map { $buckets[ $_ % 4 ]->[ $options[$_] ] } 0 .. $#options;
}
Now for the fun part... figure out which ones are dupes
Lol, that print ... for join ... map ... @stuff is sloppy
 
Are you going to have dupes tho if the buckets are always in the same order?
 
We saw it for the two-bucket scenario, right?
 
Yea, I guess so.
Sorry, was thinking the wrong way.
 
Here's the list of possibilities, btw
1-5-2-6-4-8-3-7
1-5-2-7-4-8-3-6
1-5-3-6-4-8-2-7
1-5-3-7-4-8-2-6
1-8-2-6-4-5-3-7
1-8-2-7-4-5-3-6
1-8-3-6-4-5-2-7
1-8-3-7-4-5-2-6
4-5-2-6-1-8-3-7
4-5-2-7-1-8-3-6
4-5-3-6-1-8-2-7
4-5-3-7-1-8-2-6
4-8-2-6-1-5-3-7
4-8-2-7-1-5-3-6
4-8-3-6-1-5-2-7
4-8-3-7-1-5-2-6
 
Yea, so first and last are dupes.
 
8:36 PM
I think I can safely ignore the second half of this list
 
Looks like it.
That's a great programming interview question, lol.
 
At Hennessey, lol
Confirmed
Here is the code:
use strict;
use warnings;

my @buckets = ( [ 1, 4 ],
[ 5, 8 ],
[ 2, 3 ],
[ 6, 7 ],
);

my @combinations;

for (0..15) {
my $combination = sprintf "%04b", $_;
$combination .= $combination =~ tr/01/10/r;
my @options = split //, $combination;
push @combinations, join( '-', map { $buckets[ $_ % 4 ]->[ $options[$_] ] } 0 .. $#options ), "\n";
}

my @twice = map { $_ .'-'. $_ } grep /^1/, @combinations;

my %seen;

for my $combination ( @combinations ) {

for my $twice ( @twice ) {

if ( $twice =~ /$combination/ ) {
And here is the output:
4-5-2-6-1-8-3-7 already seen in 1-8-3-7-4-5-2-6-1-8-3-7-4-5-2-6
4-5-2-7-1-8-3-6 already seen in 1-8-3-6-4-5-2-7-1-8-3-6-4-5-2-7
4-5-3-6-1-8-2-7 already seen in 1-8-2-7-4-5-3-6-1-8-2-7-4-5-3-6
4-5-3-7-1-8-2-6 already seen in 1-8-2-6-4-5-3-7-1-8-2-6-4-5-3-7
4-8-2-6-1-5-3-7 already seen in 1-5-3-7-4-8-2-6-1-5-3-7-4-8-2-6
4-8-2-7-1-5-3-6 already seen in 1-5-3-6-4-8-2-7-1-5-3-6-4-8-2-7
4-8-3-6-1-5-2-7 already seen in 1-5-2-7-4-8-3-6-1-5-2-7-4-8-3-6
4-8-3-7-1-5-2-6 already seen in 1-5-2-6-4-8-3-7-1-5-2-6-4-8-3-7
@LynnCrumbling how do you format chat messages for code?
 
I know you can enclose stuff in backticks ( ` )
Not sure if that works on multiple lines.
`test
test
test`
 
It doesn't scale well across multiple lines
 
Nope, it doesn't
 
8:51 PM
So here's the list of possible firing orders

1-5-2-6-4-8-3-7
1-5-2-7-4-8-3-6
1-5-3-6-4-8-2-7
1-5-3-7-4-8-2-6
1-8-2-6-4-5-3-7
1-8-2-7-4-5-3-6
1-8-3-6-4-5-2-7
1-8-3-7-4-5-2-6
 
There's this, but not helpful:
http://chat.stackexchange.com/faq#formatting
 
Question is, why does Ferrari use 1-5-3-7-4-8-2-6?
And not one of the other 7
 
@zaid are you including degrees of rotation from TDC cylinder 1 into the mix?
 
Yessir
 
I researched a heck of a lot on the Yamaha flat plane. That was only a 4 and it spun me a bit
 
8:53 PM
I'm looking at a Ferrari-style flat-plane (UDDU)
 
they were firing 3 and 4 only 90 degrees off. They went with the 'big bang' methodology
 
I think my thought experiment could yield some interesting findings for your big-bang question
I just need a way to evaluate the impact of these different firing orders
 
@Zaid I had a bunch of people telling me once about how the Ferrari V8 flat plane solution would vibrate too much...blah blah blah....and how it wouldn't work.
@Zaid Oh yes, indeed. I think it will.
 
Yes... that's what I need to work into the mix somehow
The net forces on the journals
(and mains)
 
@Zaid Did you figure it out? (formatting chat messages as code)
Control-K
 
8:56 PM
@LynnCrumbling thanks
 
Test:
use strict;
use warnings;

my @buckets = ( [ 1, 4 ],
                [ 5, 8 ],
                [ 2, 3 ],
                [ 6, 7 ],
              );

my @combinations;

for (0..15) {
  my $combination = sprintf "%04b", $_;
  $combination .= $combination =~ tr/01/10/r;
  my @options = split //, $combination;
  push @combinations, join( '-', map { $buckets[ $_ % 4 ]->[ $options[$_] ] } 0 .. $#options ), "\n";
}

my @twice = map { $_ .'-'. $_ } grep /^1/, @combinations;

my %seen;

for my $combination ( @combinations ) {
Groovy
 
Control K how?
 
Select the code
Ctrl-A, Ctrl-K
 
In the edit window?
 
8:57 PM
Type (or paste) your code, and before hitting enter, hit control-K
 
Cool.
 
@Zaid The yamaha flat plane firing order was 1, 3, 2, 4 w/ crank at 0, 270, 450, 540 degrees. Interesting that 2 and 4 fire 90 apart but 1 and 3 fire 270 apart.
 
This is an inline, right?
 
correct
 
@DucatiKiller You sure about the 270°? No cylinder is at TDC at 270° (I'm assuming one of your cylinders is at TDC at 0°)
Same comment applies to the 450°
 
9:12 PM
270 relative to 0 when 1 is at TDC. 270 degrees of crank rotation from that point
they are all 90 apart
 
Do you have a picture of the crankshaft?
 
one sec
 
Sorry to hijack... Are there car engines where two or more cylinders fire at the same time?
 
none that I'm aware of
your not hijacking
 
@DucatiKiller that's a cross-plane
 
9:15 PM
yes
 
not a flat-plane
ok... makes sense now
 
whoops
 
let me update my model...
 
I typed flat up there
I'm sorry
my bad on the typo.....spun you into the abyss....my bad
yes, it's cross plane and I'm a dbag :-)
 
No problemo
How can I show you what I see?
 
9:18 PM
hmmmm
not sure
 
Here you go
Ignore the numbers on the y-axis
Obviously you want to have ignition at TDC
 
I'm adding some bangs to the graph
Here you go
@DucatiKiller Can you see the second graph?
 
@JPhi1618 I understand your position, but there is no way to check the alignment of one wheel as you have to check them against the other ones in order to get it right (I'm sure someone might have said this already).
 
@DucatiKiller you should be able to see it now
And yes, it's very interesting
 
9:27 PM
@Zaid & @DucatiKiller If you are talking about the image above, it is not a cross plane crank ... you need to look at where the pins are at and you'd know ... Maybe I'm coming into the conversation late, though?
 
Clearly you can't have 180° spacing
@ᴘᴀᴜʟsᴛᴇʀ2 I think it's cross-plane. Look at the heights of the pistons
Plus what Ducati said about the ignition events wrt crankshaft angle makes sense when it's cross-plane, not flat-plane
 
@Zaid Look at where the rod ends are at ... I don't know where they are degreed to (exact location), but they are not 180° out from each other.
 
@Zaid yes, it is
 
The first two appear to be about 60° out from each other.
 
@ᴘᴀᴜʟsᴛᴇʀ2 it's a cross plane
 
9:31 PM
@DucatiKiller What is the layout of a cross-plane crank?
 
depends on the amount of cylinders
 
No, not really.
 
@ᴘᴀᴜʟsᴛᴇʀ2 The way I see it, #1 is at TDC, #2 is 90° offset, #3 is 180° from #2 and #4 is BDC
 
on a 4 cylinder and 9 cylinder it's 90 degrees off
8 cyl
 
@Zaid - Okay, shoot me now ... It must have been a long day.
 
9:33 PM
<bang>
:)
 
I TOTALLY was getting flat plane and cross plane screwed up in my head.
Thanks for bearing with me whilst I let this brain fart escape from my ear.
 
Anyway... @DucatiKiller I can see a few other possible firing orders
 
LOL! I quit! You all have a great evening :D
 
wow, that was fast
 
9:34 PM
For example 1-4-3-2
(the classic)
It's just the nature of the inline-4. You can't have even firing
 
yes, it's not possible
which is why you can wind up with the 90 off firing
 
Can a I4 use a flat plane crank?
 
which is why yamaha chose it. Closest to the 'big bang' with a flat plane
 
Yes...
 
@ᴘᴀᴜʟsᴛᴇʀ2 Yes you can. Most MC's are this config and so are many cars
 
9:36 PM
Now you are talking motorcycles ... I do quit this time.
I'm totally not making it, lol!
 
@ᴘᴀᴜʟsᴛᴇʀ2 According to this, yes : what-when-how.com/automobile/…
 
there is only 1 production MC with inline 4 and crossplane AFAIK
 
There can be only one.
 
And here you were telling me that the only one out there was a flat-plane :)
 
lol
yes, my dyslexia...not
 
9:43 PM
It's fascinating
But I've really got to sleep now
 
indeed
 
.
 
@ᴘᴀᴜʟsᴛᴇʀ2, Yea, I think Zaid said that... I'm at 85K, so I don't think an alignment would be a bad thing.
 
So the argument is the power pulses being close together allows the tire a moment to 'unload' in order to take the next pulse which allows a higher level of mechanical grip on the road surface
This IS the reason that Yamaha claims they went with this config
an homage to the 'big bang' flat plane configuration of the late 90's
 
@DucatiKiller if I have time I'll look at a flat-plane I4
Tomorrow
 
9:51 PM
sure. deconstructing isn't trivial
 
In the mean time, could you gents please illuminate me on what factors influence choice of firing order
0
Q: What made Ferrari choose this particular firing order for their flat-plane V8's?

ZaidIn other words, what factors influence an engine designer's decision to go with a certain firing order? I had some free time today to investigate what kinds of firing order are possible on a flat-plane 90° V8 and calculated that there are 8 feasible firing orders: 1-5-2-6-4-8-3-7 1-5-2-7-4-8-3-...

 
I'll respond tonight after my work chaos
 
I imagine bearing loads have a role to play
 
I've been on con calls this whole time and I'm frequently saying, "excuse me, can you repeat that?" AND "Pardon?"
@Zaid I imagine your correct
When I think of Ferrari the first thing I think of is mechanical grip. Not sure why, perhaps it's their competitive heritage.
 
10:20 PM
@zaid here's an interview with one of the Yamaha engineers, the engineer starts at 2:23....everything before it is low signal to noise.
 
 
1 hour later…
11:50 PM
@Anarach Congrats on 4K!
@ᴘᴀᴜʟsᴛᴇʀ2 Looks 50K today. Super huge. Congratulations in advance. Amazing.
 
@DucatiKiller - Haha, 4 points short ... thank you kind sir. I appreciate the acknowledgement.
 

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