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View Full Version : I was just told I need to pick up a physics book...



Luni
06-08-2008, 09:43 AM
On DSMTalk they were talking about how to torque the exhaust mani bolts and I said since you cant get the torque wrench in there without an extension to just use an extension, you wont lose torque through the extension, and like 3 of em came out and said I was wrong.

Of course I know Im right. You dont lose torque through an extension thats 90 degrees perpendicular to the handle (which is the source of the torque itself). Doesnt matter if you have a 1 inch, or a 1 foot extension, your torque reading will be the same.

Sometimes peoples ignorance kills me.

yankee7568
06-08-2008, 11:30 AM
hmmmmmmmmm really? My old boss I worked for told me that it does and he went to a trade school and has 18 years exp. in the auto mobile world.

I always thought that my old boss was a know it all bull shiter.

I dislike my old boss a lot if you can tell lol.

PhillyDRFT
06-08-2008, 03:48 PM
Tell em' to take their cranks for a walk.

When talking about math on paper the extention can loose a little bit of torque. but on the same perfect environment keeping it at a perfect 90* will negate that. Then backto the real world, were talking about an extreamly low fraction of loss by the flex of the extension and other factors inside the tool.

It's a bullshit nerd pissing contest to see who knows more. But in the real world your exhaust manifold stays put ither way. When the torque wrench clicks, You've put that much power into the bolt. It's a DSM not a Boeing.

19celica90
06-08-2008, 04:06 PM
http://i241.photobucket.com/albums/ff87/19celica90/crankwalk.jpg

Mr Celica
06-08-2008, 05:50 PM
http://img.photobucket.com/albums/v284/CapnNismo/Motivational%20Posters/dsm1.jpg

Colossus20v
06-08-2008, 06:50 PM
so which one are you going to buy?

T-spoon
06-08-2008, 08:12 PM
Technically there is theoretically some minute twisting flex in the extension, but technically there is also a minute variation from one torque wrench to the next in terms of how flexible the long lever of the typical off the shelf wrench is. It's kind of a ridiculous argument IMO because the change would have to be a fraction of a ft/lb if that either way. Some people have nothing better to argue about :lolhittin

The Captain
06-08-2008, 09:23 PM
Honda owners will be so confused reading this thread.

3SmeCaptain
06-08-2008, 10:35 PM
there is some lose, but like everyone else says, not enough to piss and moan about. different metal strengths will yield different flex and thus different loses from one another. but it's like finding a needle in a hay stack for something like this, no need to freak out about it. this is just where you ask you self, if there was a lose worth worrying about, then why does EVERYONE still do it anyway? and why do they never have a problem? cause it doesn't really matter.

Galcobar
06-08-2008, 11:16 PM
On that basis, using a deep socket loses torque over a shallow socket, and any socket loses torque over a flat wrench.

Somehow I doubt these twits ever claim you cannot use a deep socket to torque a bolt.

andy
06-08-2008, 11:22 PM
there will be more loss the thinner and longer the extension, if its the same diameter as the bit there shouldnt be any. using a 3/8'' 1 foot extension on a 1'' wrench will mess up all your reading yo.

VikingJZ
06-09-2008, 04:01 AM
Hey John Honda owners are confused anyway. :D



That's BS though Robb, fo serious. That's like saying that using a cheater pipe won't help you get a stuck part unstuck.

Slider
06-09-2008, 04:40 AM
http://img.photobucket.com/albums/v284/CapnNismo/Motivational%20Posters/dsm1.jpg

:lolhittin I think that's my buddy's car, exact same rims and color.

Galcobar
06-09-2008, 05:18 AM
What are the wheels, actually?

KoreanJoey
06-09-2008, 07:25 AM
It's a goddamn exhaust manifold bolt!!! OMFG, specified torque:

Tight...

Friggin morons w/ DSMs.

CriScO
06-09-2008, 08:04 AM
^ That's what I was thinking, glad one of the resident Toyota mechanics feels the same. Especially one that schools me a lot. :) I'd been trying to figure out why they cared so much in the first place.

See what happens when you leave your flock Rob? :hehe:

CHRiS'_CeLiCa
06-09-2008, 06:02 PM
Our teacher at school tells us that you it distorts it a little bit but the extension you need to remove a manifold isn't gonna be big enough to make that much of a difference anyways...

Conrad_Turbo
06-09-2008, 06:59 PM
If it was 500ftlb or greater and they were using a standard 3/8" extension then they would be correct, however the extension twisting due to the torque being applied thorugh it is sooooooooooo minimal for an exhaust manifold nut. Ask them if they calibrate their torque wrenches a minimum of once a day and tighten the bolt(s) in a temperature controlled environment and freak out if they don't. :lolhittin

healy_gts
06-09-2008, 07:53 PM
ok....i work in a tire shop and unproper torque is the number one cause of wheels coming off so i know torque....it doesnt matter how thick your extention is you will loose 5% torque value for every 6 inches of extention

Conrad_Turbo
06-09-2008, 08:16 PM
ok....i work in a tire shop and unproper torque is the number one cause of wheels coming off so i know torque....it doesnt matter how thick your extention is you will loose 5% torque value for every 6 inches of extention

At what specified torque though? I can guarantee at 5ftlb, you won't see a variance of 5% torque using one extension. But using 200ftlb I can bet you will see more than 5% variance.

Rules of thumb are great, but you always have to consider the source of where that info is coming from.

Shadowlife25
06-09-2008, 09:14 PM
Improper torque, as in insufficient torque, is what will cause a wheel-off.

Over-torquing will cause the studs to snap during removal.

Lastly, why in God's name, would you need to have such a long extension to torque manifold bolts anyhow? Unless these fellas are working in a shop environment, I highly doubt that their tools are even properly calibrated. It's all fine and good to talk theoretically, but to basically call someone out because their friend said...... completely pointless. It's already been said that the flexion in the extension and variances in torque are minimal, so who cares. Did they even bother to specify whether they are using 1/2" or 3/8" drives? I didn't think so...

'Nuff said.

Shadowlife25
06-09-2008, 09:17 PM
By the way... A 3ft breaker bar tends to end an argument quickly, with no one left wondering "who was right?" :hehe:

Luni
06-09-2008, 09:31 PM
Well on a DSM, you cant get a torque wrench onto the manifold bolts, unless you use at least a couple inches of extension or a really deep socket.

Point is, the shit modern tools are made of, the wrench will flex as much as the damn extension.

T-spoon
06-09-2008, 11:43 PM
ok....i work in a tire shop and unproper torque is the number one cause of wheels coming off so i know torque....it doesnt matter how thick your extention is you will loose 5% torque value for every 6 inches of extention


If you think about that logically, it can't be true. At the very least it has to be a ratio between the length, the amount of flex in a given extension and the length of the extension. It's obvious that the amount of force you are applying will effect how much flex there is additionally. Wheel studs are what? 60-80ft/lbs or something? A 3 inch long 1/2 inch drive is not going to lose 2 ft/lbs for an 80 ft/lb target torque, but even if it did, holy crap, a 2 ft/lb variance is not going to make the wheel fall off. The biggest reason there are problems with wheels is people forgetting to tighten them, or tightening in the wrong pattern, and even then warped rotors are more common than wheels falling off. You're going to run into more problems firing on two studs at 135 ft/lbs using an air tool and the others at 90 than you are having them all within 10 ft/lbs of each other doing it completely by hand without a torque wrench.

Honestly, I bet more heads are stripped by introducing angles with extensions that there are problems associated with missed torque values on an extension.

black94t
06-10-2008, 12:17 AM
Quick test: take a 3/8" drive impact wrench and put a socket on the end. Try breaking a 60-70ft lb bolt from the xmember. now, take a 6" extension and do the same. It wont happen 6" from point of torque. Trust me. It just happened to me LOL.

It's pretty basic, the further distance from the point of rotation, the more energy required to pivot. Think of it in blown up proportions. Think of taking a 12' extension using a 6" rachet. Aint no way you're going to be able to break a bolt loose or properly torque because the rachet axis and the extension axis are directly related. I cant remember the simple function, physics 101 was a loooooong time ago.

It's the inverse relationship of increasing the distance of force from the point of pivot. The relationship of a 12' extension to a 1" long socket will increase the amount of torque applied.

The problem with extensions is that it's hard to keep the head of the socket directly at the center of rotation without holding the rachet at the center (which is another element that would make achieving torque more difficult.

but ya...who cares....I dont think this topic has ever cross my mind or baffled me since asked on the exam, 10 years ago.

Luni
06-10-2008, 01:46 AM
Oh my god, the amount of misinformation out there on the internet is mind blowing.

Look guys, you cant change the dynamics of physics. Physics are pretty set in stone.

And what do you honestly think is going to torque and twist first? The soft ass aluminum, or the bolt itself, or the forged hardened extension/socket.

Seriously guys. Ive performed this test with both a 3/8 extension with adapter to 1/2 and just a 1/2 inch extension on my 1/2 torque wrench and Ive not seen any difference at the torque I use to tighten my lugs on (I torque to 78ft lbs).

T-spoon
06-10-2008, 01:49 AM
Oh my god, the amount of misinformation out there on the internet is mind blowing.

Look guys, you cant change the dynamics of physics. Physics are pretty set in stone.

And what do you honestly think is going to torque and twist first? The soft ass aluminum, or the bolt itself, or the forged hardened extension/socket.

Seriously guys. Ive performed this test with both a 3/8 extension with adapter to 1/2 and just a 1/2 inch extension on my 1/2 torque wrench and Ive not seen any difference at the torque I use to tighten my lugs on (I torque to 78ft lbs).


I think a lot of the perceived difficulties is in keeping the ratchet at perfect right angle to the bolt, but that doesn't have anything to do with twisting forces, it's just that we're not robots and have trouble applying the force as precisely as we should.

Luni
06-10-2008, 02:59 AM
Heres the thing about the twisting force lost through the extension; yeah the extension will spring and twist, however the force required in the mechanism of the torque wrench to click, or for the gauge to read a given value doesnt change as long as you dont mess with the "distance" part of the torque equation. So, if you dont increase the wrenches handle size, and you stay perpindicular to the center of the wrench where the force is applied, it wont change. So, while your arm might have to apply more force on the wrench for a given torque value, the value the wrench reads or clicks at will not change. This is why even though you use an extension it might require more force from you, and that force maybe be applied in a twisting motion along the extension, but the end result will be a static torque value achieved on the torque wrenches click mechanism. (or whatever kind of wrench you use)

So, if youre NOT using a torque wrench, how hard you turn will affect your bolt force at the end, because theres nothing telling you to stop applying force. But using a torque wrench, the wrenchs calibration isnt affected if you dont mess with the length of the wrenches handle. (change the amount of "distance the force you apply travels")

The torque your wrench reads is how much torque the bolt or nut you are torquing is springing back against you. For every action theres an equal and opposite reaction. Force applied is applied back against its origin if theres nowhere for it to go. Since it requires x amount of force to make your wrench mechanism click, your arm might be pushing 80 ft lbs at one side, but only 75 makes it through to the bolt. The wrench will "click" at 75, not 80, because only 75 of it pushed back against you.

Luni
06-10-2008, 03:02 AM
One word of note, this does NOT work in conjunction with an impact gun.

you WILL lose forces through an extension using an impact gun. Your impact gun has a STATIC force value in it, it wont compensate and increase force just because the extension flexes and springs and absorbs the forces.

Again, I restate the only reason why this works with a torque wrench is because you will compensate and add more force to get the desired amount of force on the far side.

Slider
06-10-2008, 05:32 AM
What are the wheels, actually?

5zigen inperio m-05 , don't believe they are produced anymore

ciento44
06-10-2008, 05:16 PM
Honda owners will be so confused reading this thread.


Srsly.... how many horsepowers or vtecs will it take to turn the wrench?

This whole torque thing..... i dunno man.

ciento44
06-10-2008, 05:22 PM
ok....i work in a tire shop and unproper torque is the number one cause of wheels coming off so i know torque....it doesnt matter how thick your extention is you will loose 5% torque value for every 6 inches of extention

If it clicks, then it's the same torque reading. End of story. I don't care if it's a 12 foot cheater bar on that torque wrench. If it clicks, it's seeing whatever specified torque reading you set.

All that the flexing is doing is making you use potentially more energy to get the same torque. End result at the end of that wrench will NOT change if you're using a torque wrench.