Re: Bigger tie rod ends for 71-74 B-body?
[Re: jcc]
#554623
12/16/09 03:28 PM
12/16/09 03:28 PM
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Joined: Nov 2004
Posts: 9,319 SoCal
68HemiB
master
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master
Joined: Nov 2004
Posts: 9,319
SoCal
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Close. 1. You still have "then" instead of than. 2. The member name is 68Hemi B.
Down to just a blue car now.
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Re: Bigger tie rod ends for 71-74 B-body?
[Re: jcc]
#554625
12/16/09 03:56 PM
12/16/09 03:56 PM
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Joined: Aug 2003
Posts: 11,179 Atco NJ
DJVCuda
I Live Here
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I Live Here
Joined: Aug 2003
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Quote:
The heavy braking flex is an interesting concept, and likely very valid, especially with a lot of wheel offset, however in your case, are you pretty confident that was soley responsible for your improvement?
I did an entire suspension overhaul, but i had poly - went back to poly, I had KYB's and went with new ones
stock upper control arms
I did upgrade the strut rods to oversize, and t-bars, but they would have minimal effect on braking stability IMO - i wont get into the calculations...lol
The car has 17x7's and 225 50's up front with the 11 3/4" rotors - so it can pull pretty hard brake wise.
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Re: Bigger tie rod ends for 71-74 B-body?
[Re: jcc]
#554627
12/16/09 09:31 PM
12/16/09 09:31 PM
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Joined: Aug 2003
Posts: 11,179 Atco NJ
DJVCuda
I Live Here
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I Live Here
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Re: Bigger tie rod ends for 71-74 B-body?
[Re: rtidd440]
#554629
12/17/09 05:12 AM
12/17/09 05:12 AM
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Joined: Dec 2003
Posts: 23,299 Here
jcc
If you can't dazzle em with diamonds..
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If you can't dazzle em with diamonds..
Joined: Dec 2003
Posts: 23,299
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1. I wonder why the TR are offset as an oem design 2. To your main point, the issue is the design rigidity of the adjuster tube, not the size of the TR, 9/16 vs 11/16"? 3. I will later try to calculate the amount of deflection the adjuster needs to move in the center to some determined value of compression ( ie toe out), unless someone wants to beat me to it, assuming what, a 14"? length? 4. Not sure what force is going to induce that deflection other then braking with a non oem offset wheel/hub 5. Not sure how much the force above would be 6. Not sure when that compression is calculated/guessed at, how much it would effect stability under braking 7. Would seem the idler arm would allow a significant more deflection under compression (ie toe out) then any adjuster deflection would contribute, and few seem to be concerned with it.
" All sorts of things can happen when you are open to new Ideas" Inventor of Kevlar
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Re: Bigger tie rod ends for 71-74 B-body?
[Re: jcc]
#554630
12/17/09 11:57 AM
12/17/09 11:57 AM
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Joined: Feb 2005
Posts: 283 N.E. England
Roppa440
super street
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super street
Joined: Feb 2005
Posts: 283
N.E. England
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Lets see if I get shot in the back of the head... I think bigger tie rods are just another one of those "must have" things that you really do not need. In fact you are adding to the unsprung weight a little so you are actually going the wrong way for an improved steering/suspension system. I have even seen people boxing their LCAs (adding more weight) and then using stock pivot bushings. What is that about?
2002 Chevrolet Corvette 5.7 LS1
2011 Alpha Romeo Giulietta Veloce 1.6 JTD
Because running a Mopar in the UK is getting TOO expensive!!
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Re: Bigger tie rod ends for 71-74 B-body?
[Re: Roppa440]
#554631
12/17/09 03:14 PM
12/17/09 03:14 PM
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Joined: Dec 2003
Posts: 23,299 Here
jcc
If you can't dazzle em with diamonds..
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If you can't dazzle em with diamonds..
Joined: Dec 2003
Posts: 23,299
Here
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So I did some quick calculations on tie rod assembly flex. If we assume the assembly is 14" (?), and it flexes in one direction 1/4" off center, the change in length (toe out) is approx .012" at the tie rod. If both assemblies L & R wheel flex the same, that totals .024" and with a 1/16" being .031", I would say that brake induced flex resulting in a change in noticeable handling is "busted". And anyone that thinks a 1/4" of flex in a tie rod assembly is normal or OK, should seriously reconsider.
" All sorts of things can happen when you are open to new Ideas" Inventor of Kevlar
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Re: Bigger tie rod ends for 71-74 B-body?
[Re: RokketRide]
#554633
12/17/09 03:30 PM
12/17/09 03:30 PM
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Joined: Dec 2003
Posts: 23,299 Here
jcc
If you can't dazzle em with diamonds..
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If you can't dazzle em with diamonds..
Joined: Dec 2003
Posts: 23,299
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That's a hit and run comment, care to point out any assum,ptions you disagree with and try to debunk them so we all can learn? In engineering, nothing is "free".
" All sorts of things can happen when you are open to new Ideas" Inventor of Kevlar
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Re: Bigger tie rod ends for 71-74 B-body?
[Re: rtidd440]
#554635
12/18/09 08:00 AM
12/18/09 08:00 AM
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Joined: Dec 2003
Posts: 23,299 Here
jcc
If you can't dazzle em with diamonds..
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If you can't dazzle em with diamonds..
Joined: Dec 2003
Posts: 23,299
Here
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Quote:
Quote:
So I did some quick calculations on tie rod assembly flex. If we assume the assembly is 14" (?), and it flexes in one direction 1/4" off center, the change in length (toe out) is approx .012" at the tie rod. If both assemblies L & R wheel flex the same, that totals .024" and with a 1/16" being .031", I would say that brake induced flex resulting in a change in noticeable handling is "busted". And anyone that thinks a 1/4" of flex in a tie rod assembly is normal or OK, should seriously reconsider.
I'm not an engineer, nor do I play one on TV. I do see a few things i would like to comment on. 012" at the tierod, would be more than that at the tire because the pivot point is at the end of the steering arm at the point where the ball joints pivot. Also a larger diameter tube is more resistant to flex than a smaller diameter one. The increasing size of motorcycle fork tubes are a prime example of this. I would be more interested in the forces needed to turn the wheels off center at speed rather than braking forces. That nasty gyrosope effect and all. Lastly and most importantly if the smaller size was adequate why did Ma Mopar bother to update it to the larger size even on the a body sized Volares and Aspens?
Well technically, regarding what really matters regarding Toe in is angle, not a distance, since as you mentioned, the distance would change depending on where you measure, but the angle always stays the same, and the diameter of the tire then comes into play, and measuring at say the leading edge of the tire is only a relative measurement since it only contacts air.
Stating a larger tube likely flexes less then a smaller one is a no brainer argument.
Determining the steering forces at speed is something that would likely have to be measured/tested to get an accurate measurement with tire scrub, gryro, hub, rotor, aero, etc forces involved, I would guess. However those forces would put one tie rod in compression, and the other in tension, where tube diameter plays little importance. No one ever complains their car is harder to steer at high speed vs low speed.
Not sure why Mopar would have later have (which I have no experience with) used a larger Tr, maybe to cut inventory in half, maybe as others have stated they are cheaper, maybe someone hit a kids foot when striking a curb and some SA lawyer wanted to know why moapr used such a small puny 9/16" TR, and nobody spoke up. Anybody know why Ford used a similiar sized TR on millions of Fox bodies in the 80's. I think these questions lose focus on the original question of why is a 11/16" "needed" in place of a 9/16" TR.
Regardless, you OK with a TR flexing 1/4" in compression to give .012" change in toe? I really don't think that is likely.
" All sorts of things can happen when you are open to new Ideas" Inventor of Kevlar
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Re: Bigger tie rod ends for 71-74 B-body?
[Re: jcc]
#554636
12/19/09 03:57 AM
12/19/09 03:57 AM
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Joined: May 2003
Posts: 819 Central Ohio
rtidd440
super street
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super street
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Central Ohio
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Quote:
Quote:
Quote:
Well technically, regarding what really matters regarding Toe in is angle, not a distance, since as you mentioned, the distance would change depending on where you measure, but the angle always stays the same, and the diameter of the tire then comes into play, and measuring at say the leading edge of the tire is only a relative measurement since it only contacts air.
Stating a larger tube likely flexes less then a smaller one is a no brainer argument.
Determining the steering forces at speed is something that would likely have to be measured/tested to get an accurate measurement with tire scrub, gryro, hub, rotor, aero, etc forces involved, I would guess. However those forces would put one tie rod in compression, and the other in tension, where tube diameter plays little importance. No one ever complains their car is harder to steer at high speed vs low speed.
Not sure why Mopar would have later have (which I have no experience with) used a larger Tr, maybe to cut inventory in half, maybe as others have stated they are cheaper, maybe someone hit a kids foot when striking a curb and some SA lawyer wanted to know why moapr used such a small puny 9/16" TR, and nobody spoke up. Anybody know why Ford used a similiar sized TR on millions of Fox bodies in the 80's. I think these questions lose focus on the original question of why is a 11/16" "needed" in place of a 9/16" TR.
Regardless, you OK with a TR flexing 1/4" in compression to give .012" change in toe? I really don't think that is likely.
You are correct that toe is an angle, not a distance, but small differences in toe make a difference that people can detect in the way the car drives. The only way we can set toe is at the outer edge of the tires. If you are saying that a 1/4" of flex results in a change of length of 012" for the rod sleeve assembly, I'm saying that the difference in the toe measurement would be a larger number.
At high speeds most steering input is very small so effort is really not the issue so much as the feel or precision of the steering.
Chuck a sleeve rod assembly in a vice at one end. I bet you can deflect it a measureable amount with just pressure from your hand.
I dont mess around with Fords, but dont Fox body cars use a rack? If so the inner rod is a ball inline with the sleeve which would take 50% of the offset force out of the picture.
I dont think its a question of "need" at all. People who make this upgrade are looking to improve how their car drives. This upgrade goes with poly bushings, bigger wider tires, braced k frames, firm feel steering boxes etc. If you dont do a least some of these other upgrades than you are correct. It would be a waste, if there were much of a price difference.
My guess as to why Ma did this would be the difference in tires. Narrow 14's with traction close to pressed cardboard as opposed to wide 15" radials.
Rob
70 Swinger 340 4spd FC7 4 sale
69 Charger auto Q5
14 Challenger SRT8 Core 6spd black
Deposit on Hellcat
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Re: Bigger tie rod ends for 71-74 B-body?
[Re: rtidd440]
#554637
12/19/09 07:55 AM
12/19/09 07:55 AM
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Joined: Feb 2005
Posts: 283 N.E. England
Roppa440
super street
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super street
Joined: Feb 2005
Posts: 283
N.E. England
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So in a nutshell... What you guys are saying is that if I fitted my car with every conceivable performance suspension upgrade, including very high quality low profile race tyres on large diameter alloy rims, then I would be able to fit bigger tie rods and cut my drive time to my next car show by an amazing 3/100s of a second. Wow!
2002 Chevrolet Corvette 5.7 LS1
2011 Alpha Romeo Giulietta Veloce 1.6 JTD
Because running a Mopar in the UK is getting TOO expensive!!
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Re: Bigger tie rod ends for 71-74 B-body?
[Re: Roppa440]
#554638
12/19/09 10:33 AM
12/19/09 10:33 AM
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Joined: Sep 2007
Posts: 14,889 up yours
Supercuda
About to go away
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About to go away
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Well, you can definately pick out the people who ponder the little details and those who take that as a personal attack.
They say there are no such thing as a stupid question. They say there is always the exception that proves the rule. Don't be the exception.
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Re: Bigger tie rod ends for 71-74 B-body?
[Re: rtidd440]
#554639
12/19/09 10:57 AM
12/19/09 10:57 AM
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Joined: Dec 2003
Posts: 23,299 Here
jcc
If you can't dazzle em with diamonds..
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If you can't dazzle em with diamonds..
Joined: Dec 2003
Posts: 23,299
Here
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Quote:
Chuck a sleeve rod assembly in a vice at one end. I bet you can deflect it a measureable amount with just pressure from your hand.
Even though your example would correct about bending, I don't think that test represents the situation. A TR assembly is not really being bent, it is only distorting from a compressive force applied in line with its almost center axis. I hate to use this example because others will try to use it incorrectly, but it you take a straw and put it in a vice, yes you can bend it easily, but if you take your flat hand and compress it in a straight line along its long axis, it will take considerable more force before bending and buckling, which describes the hypothetic mentioned 1/4" deflection. A slightly more accurate test would be to take a TR assembly and put each end in a vise/fixture and use your hand (or anything) to push against the center of the assembly, not likely IMO to get a 1/4" deflection.
I thought the mustang TR has the exact same issues, except it is front steer, and the issue as others desrcibed would then be tension, not compressive under braking. My main point with the 5.0 was the TR outboard end is a single shear design, with a lot of offset, and likely way worse then mopar ever designed, regardless it seems to be accepted and work.
Hope no one mistakes being thorough as being personal
Last edited by jcc; 12/19/09 11:51 AM.
" All sorts of things can happen when you are open to new Ideas" Inventor of Kevlar
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Re: Bigger tie rod ends for 71-74 B-body?
[Re: jcc]
#554640
12/20/09 04:02 AM
12/20/09 04:02 AM
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Joined: May 2003
Posts: 819 Central Ohio
rtidd440
super street
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super street
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Central Ohio
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I'm not taking anything personally. I thought forums like this were the place to trade ideas. It occured to me today that perhaps we are looking at this literally from the wrong end. looking at the front end as whole assembly in mechanically optimal condition. We know that some components have some give or flex. Besides the tierod assemblys, jury still out on those, the pitman arm, the lower ball joint between the pivot point and the tr socket, possibly the spindle to a small degree. Any part that has a rubber bushing might have some effect even if not directly in line with the steering force. The one component that I have seen for myself is the k member. You can watch it move as you turn the wheel. As you said in a previous post we cant really know what amount of force it would take to turn the wheels off center in a moving vehicle. The variable such as speed, side loading in a corner or from road crown or other factors is really beyond this conversation. I think its safe to say it is probably a significant number. So if we can say there is some motion in the system before the wheels turn then what is the affect on the interface between the system and the driver. Lets say that at the sector shaft this results in a movement of 2 degrees before the tires change direction. I cant recall offhand the ratio of a manual steering box, I want to say 24 to 1 but lets go with 20 to 1. This would translate to 40 degrees of movement at the steering wheel. While not a huge amount I would say this is something that a person familiar with their own vehicle would notice a change in. Sadly this still leaves us with the original question of do the smaller units flex or give enough to make a difference. I have no personal experience with this as all but one of my cars have been off the road for over ten years, and even before that had much more pressing problems than tie rods. I have in the past on this board read post from people who say that it made a difference that they could notice. My other evidence would be Mopar Actions Rick Ehrenburg who seems to have done these sorts of things many times. My own eperience with motorcycles is that anything you do to make the link between you and the tire more rigid results in beter steering "feel". One way to test this might be to take a car with the small assemblies, and measure steering wheel movemt and tire movement, then repeat with the larger parts and see if there is a difference. As all of you can tell I have a lot of time to think while at work. Hopefully Mr Ehrenburg or some of the front end guys could put some real numbers to this topic.
Rob
70 Swinger 340 4spd FC7 4 sale
69 Charger auto Q5
14 Challenger SRT8 Core 6spd black
Deposit on Hellcat
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