Hotchkis is a brand I carry, and in fact those particular bars are on my website as well. I cannot recommend them. It's not because of quality, or anything of the sort...they are very nice. And they are complete overkill.
It is my opinion, based on my use of these cars that you don't need or want a 1" rear bar on the car. Yeah, their rear is adjustable... but only stiffer, not softer than the 1". Up front, 1.5" is 38.1mm. And yeah, it's adjustable too, but considering that I run the 35mm adjustable on the Shelby in the middle setting most of the time, my 35mm isn't even as stiff as the soft setting on that bar would be.
I personally think they are just too damned much, and an adjustable 35mm front and a 22mm rear is a great combination of sizes for the car. I've done with my test fitting and such for a set of Strano Performance bars, which will not only be those sizes, but the front will be adjustable, and the rear will be hollow (why carry the weight?). And can also be gotten with our adjustable bar endlinks and upgraded from mount brackets, which is a weak spot and even more reason why you don't need or want a 38mm front bar on the car.
Hotchkis is a brand I carry, and in fact those particular bars are on my website as well. I cannot recommend them. It's not because of quality, or anything of the sort...they are very nice. And they are complete overkill.
It is my opinion, based on my use of these cars that you don't need or want a 1" rear bar on the car. Yeah, their rear is adjustable... but only stiffer, not softer than the 1". Up front, 1.5" is 38.1mm. And yeah, it's adjustable too, but considering that I run the 35mm adjustable on the Shelby in the middle setting most of the time, my 35mm isn't even as stiff as the soft setting on that bar would be.
I personally think they are just too damned much, and an adjustable 35mm front and a 22mm rear is a great combination of sizes for the car. I've done with my test fitting and such for a set of Strano Performance bars, which will not only be those sizes, but the front will be adjustable, and the rear will be hollow (why carry the weight?). And can also be gotten with our adjustable bar endlinks and upgraded from mount brackets, which is a weak spot and even more reason why you don't need or want a 38mm front bar on the car.
Sam, I'm curious. What's the percentage of increase the bar on the Shelby has over stock in the middle position? You're saying it's not even 20% over stock? I mean, the diameter really doesn't matter if the rates are comparable. If the 38mm bar is only 20% over stock at the softest setting, is that in your opinion "overkill"? Have you compared the rates on these two bars (the one on the Shelby and the Hotchkis) and if so, can you share that info? As for the rear, at 50%, it seems to be a big increase over stock, but it's common knowledge that these cars need more of a rear bar upgrade than front due to a bad case of push from the factory. If you're going to upgrade the front bar, then to increase the bias would dictate you're going to have to upgrade the rear even that much more, so at a 20% upgrade on the front, (given that's an acceptable amount) what would you say is a good percentage of increase for the rear, and again, how does that compare with the Hotchkis rear (at 50% on the softest setting)? Is a 30% bias increase too much? What's the increase over stock with the 22mm bar you're running? Are you running the FR3 bars? Thanks.
< Message edited by steelcomp -- 5/5/2008 8:20:25 PM >
Thanks for the input, I too would be interested in your analysis per Steelcomp's post. Additionally, do you think that the shock/strut combo you are running could play a significant part in your analysis over the stock pieces?
Thanks again, Matt
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How do you figure size doesn't matter? That's like saying it doesn't matter if you run 250/200 springs or 1000/800 springs. Swaybars are springs, they add wheel rate, and like coil springs if you "too much" it's not good. And like coil springs you won't get a 100% consensus.
To begin with the front and rear suspensions are not the same--at all. So if you just look purely at numbers your aren't considering that you are dealing with two completely different setups on ends of the car that also weight different amounts.
Setting aside adjustment, going from stock bars (34/20) to Hotchkis bars @ 38/25 bumps front roll stiffness by about 35%, but the rear by around 60%. Bars torsion springs and their OD effects their stiffness. 1mm makes a huge difference as you take the OD of the bar and multiply to the 4th power, the increase in size is exponential.
Also you must consider how bars work. The bigger the bar, and the higher the grip the more the inside tire is unloaded. I.E. mongo rear bars for instance can cause the inside rear wheel to come up off the ground which is not ideal.
This is a case where someone is thinking that if a little is good then a lot must be better. Hotchkis historically makes the biggest bars around. That's just their thing. I also will use some big bars, but on pony-cars it tends to be big on the front, and more moderate on the rear because the rear axle needs no help in controlling camber loss (it doesn't lose any when the car rolls), and huge bars transfer more impact energy to the other side of the axle. One thing solid axle cars don't need is for the rear to be more jumpy on bumps.
Speed comes from mechanical grip and balance. Mechanical comes from the softest wheel rates you can run (and bars add wheel rate) without compromising camber curves or balance. Ever wonder why a car without a rear swaybar won't turn? Because the lack of the rear bar adds a lot more grip. Add more bar than you need in the rear and the car becomes an oversteering mess. Neither are fast.
There are different ways to skin a cat, and it's true that the Hotchkis bars are the biggest and stiffest around. The question is, what do you gain from that? And how are they setting up a car around those bars? Most folks don't know about negative camber for front grip. Most folks don't understand chassis dynamics. They want the car to roll less because it's perceived that roll is nothing but bad. Ironically, most of the hate put on the springs of bars fault is actually a lack of roll rate control (shocks). Can't tell you how many times that we've done performance shocks on a car and the owner say "I love it, it doesn't roll anymore", when in fact the amount of roll did not change... the speed of it's generation did and that fools people who don't know any better.
If I want to balance car, I try and fix the end lacking grip first. I don't start taking grip from the other end to balance it. And you have to when to say when, I spend a lot of time looking at pictures of cars in action so I can get a look at the camber curve in front. When the car doesn't roll into positive camber it doesn't need to be any stiffer in roll in front, so I don't add more. All more does it more heavily load the outside tires. The higher the load, the lower grip limit is. Call me crazy but that's not really what I'm after. Sometimes it take big bars, sometimes it doesn't.
thank you for your coments on the hochkis swaybar set. i do alot of track competiion and autocross events so i was looking for something that i could adjust acordingly. i have alot of road race experance so i understand exactly what you are saying about suspention dynamics. you sad these bars would be over kill most of the time but understand that i do take my car to a bunch of road corses throught out the year would they work for me?
I don't believe these are the best bars, I think they are too big. I think they are overkill period, road course and otherwise. Hotchkis also makes massive bars for the F-body. I make my own for that car as well. We run much more similar fronts, but very different rear bars. This is just a case of more of the same. A well thought out setup of springs, bars, and shocks, alignment should not require masssive amounts of adjustment from the bars. Further, both bars generally do not need be adjustable if you are in the ballpark overall on setup, as an adjustment at one end will effect the car as a whole.
But it's a personal decision, and if you'd like some we can certainly help you out. I run a fine line with selling parts. I'd still like them to be my customers just so long as they know that I'm only trying to do my best by them.
I cannot offer any greater discount, being a small business is tough sometimes. I try and sell for the best price I can all the time. I'm not always as cheap, but that's usually the case with any business that's not the 800 pound gorilla. You can find the bars we have here: http://www.stranoparts.com/searchbymodel.php?CategoryID=80&ModelID=5
I feel the Eibach bars are not only a better value, but since I actually use them and do very similar things to what you do with your car I can more than comfortably recommend them.
If you'd like to talk details more in depth, I invite you to call me. Of note, due to the passing of my Mom, I will be closed this Thursday and Friday.
How do you figure size doesn't matter? That's like saying it doesn't matter if you run 250/200 springs or 1000/800 springs. Swaybars are springs, they add wheel rate, and like coil springs if you "too much" it's not good. And like coil springs you won't get a 100% consensus.
To begin with the front and rear suspensions are not the same--at all. So if you just look purely at numbers your aren't considering that you are dealing with two completely different setups on ends of the car that also weight different amounts.
Setting aside adjustment, going from stock bars (34/20) to Hotchkis bars @ 38/25 bumps front roll stiffness by about 35%, but the rear by around 60%. Bars torsion springs and their OD effects their stiffness. 1mm makes a huge difference as you take the OD of the bar and multiply to the 4th power, the increase in size is exponential.
Spring rate can differ depending on material, heat treat, and if tubing- then the wall thickness. The way the bar is bent can effect rate as well. Hotchkiss says their front bar is 20% stiffer on the softest setting. (also depends on where the hole is drilled) so by your "analysis" are they lying? (you calim 35%) It seems you haven't actually comapred the bars except to sy they don't "look" like the ones you use, so they can't be right.
< Message edited by steelcomp -- 5/7/2008 7:37:19 AM >
Spring rate can differ depending on material, heat treat, and if tubing- then the wall thickness. The way the bar is bent can effect rate as well. Hotchkiss says their front bar is 20% stiffer on the softest setting. (also depends on where the hole is drilled) so by your "analysis" are they lying? (you calim 35%) It seems you haven't actually comapred the bars except to sy they don't "look" like the ones you use, so they can't be right.
The modulus of elasticity for most steel types and treatments falls within a narrow range - IIRC it's about 10% wide from low to high. Since there aren't too many really different steels that are appropriate for this use, the range gets a bit tighter. Heat treatment has much more to do with raising the allowable stress than increasing the modulus. IOW, you can ignore differences in material and treatment for the purposes of comparison here. Maybe you'd be pickier if you were specifying a bar for Tony Stewart's race car, but that's a different story.
The stiffness of a bar can either be measured (if you're set up to do so) or calculated knowing the full geometry of the bar (I've got both spreadsheet/basic structural formulas and finite element methods available). The bars can't be hugely different, else they wouldn't fit as bolt-ons. I get different numbers than 35% and 50% with just the simple math (higher in both cases), so I suspect that Sam's 35% and 50% may be considering the total roll stiffness at each end including the spring stiffness contributions (and not swapping the springs, which is consistent with SCCA F-Stock limitations). FWIW, the relation for tubular bars is closer to the 3rd power as long as the wall thickness is held constant (IOW, comparing identically bent/supported/drilled 34 mm and 38 mm tubular bars, with each having, say, 6 mm walls).
Sam and I haven't always seen eye to eye on the details of technical issues, but I see what he's saying. At some point the next increment of additional stiffness will pass the point where diminishing returns turn around and become a net loss even though the car remains flatter and gets rolled over to equilibrium quicker. The contact patch load variation effects will cost you more than the ever lessening amount of additional camber control will gain back for you, even if you dial out some static negative to help the braking out and add that benefit as well. Plus or minus some unknown and driver-specific amount to better match driver preference on how fast the car reaches equilibrium.
Unless you're trying to keep something under control that's mostly unrelated to lateral load transfer (such as aero on the NASCAR Cup cars), it is entirely possible to overdo the bars. For example, too much bar and not enough spring can make the inside wheel slightly "lazy" in following the back sides of bumps encountered while cornering. On either axle.
Edited
Norm
< Message edited by Norm Peterson -- 5/8/2008 3:50:33 AM >
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steelcomp... who pissed in your Wheaties? If you want to think I'm a complete moron, that's fine but it won't stop me from posting.
As for bar comparisons, most folks use 1045 spring steel. The bar has to fit in the stock location and you can see by looking that it clearly does. The front bar has the same endlink position too. While I agree that if a bars shape or length changes in any tangible way it will effect the stiffness, the fact is that doesn't apply to these bars. Further the front bar stock from Ford is hollow, as is the Hotchkis so there are no worries about "one is solid so what about the big of stiffness that adds". And all you have to do is sit down, and do the math. D to the 4th power. Compare what 34 to the 4th is vs. 38 to the 4th and tell me you come up with 20% difference.
And regarding endlink holes or adjustment. Changing lever arm length is no way equivilent to a 4mm change in diameter. Example, two like size bars, one with a 10" arm the other with a 5" arm. The 5" arm will offer you twice the roll stiffness as the 10" bar with the same diameter... but here we aren't talking about cutting the arm in half, nowhere near that. In fact, having just measured a stock bar the lever arm is about 15" long, and the most you can shorten it without the endlinks getting too far from vertical is about 2.5" at best, or about 16-17%. So no I don't buy that the bar is only 20% stiffer than stock on the softest hole.
And what's more, I've played with bars on these cars already. And in fact a hollow 35mm bar with the softest hole about 1/4" further back is indeed stiffer than the stock 34mm bar. How do I know? I've tested it, and the response rate was up in the car, as was at the limit understeer (I tested that front with a stock GT front bar at first, and later wtih a hollow rear bar we're working on of 22mm diameter).
Ford hit the relative bar balance pretty close to on the head with this car. Some what stiffer, and that's fine, some some more rear bar vs. front, and that's fine, but they are damned close and not at all small bars. I don't really feel this car needs massively differnet bars, and historically I would change bars on a lot of cars, including other Mustangs right away. Not here. If more roll stiffness is warranted, that's fine and it can be used, but you seem to think that 38/25 is not a massive increase, and you're wrong. Further, you seem to think that as long as you look at the bars front to rear and keep their relative increase of roll stiffness the same that the balance will remain the same when it fact it will not due to the fact a solid rear axle acts nothing like the front end dynamically.
To each his own. If I told you the sky was blue you'd say I was lying and tooting my own horn. I can't please everyone, and I'm not going to try. And fwiw, why would I tell folks this considering I sell the very bars in question? You think I'm some sort of snake oil saleman I guess. I could have popped in and said "those bars are perfect, run them" and tried to make the easy sale you seem to think I'm after by having the nerve to pay to advertise on this site. But in reality.... I don't think those are the right bars, period. And because I sell those bars I'd hope folks would realize I'm saying that becaue that's how I feel, and not because I don't carry the line.
Nothing is absolute. Hotchkis's thing is massive bars. Always has been, pick a car they make bars for and you'll find they are way bigger than anyone else's. That's just their MO. That's fine and I don't know why, nor do I really care because they also think that regular off the shelf Bilstein HD's are fine for lowering springs, when in fact for years Bilstein own documention said there weren't. I guess Bilstein was lying? I guess that nobody could do any better.
Might I ask that you jump down off you high-horse and if you wish to discuss something to do so in a way that better hides you disdain for me? If you want to discuss, we can discuss.
Jeez man, who pissed in who's Wheaties? Maybe you're having a bad week, or maybe you just don't like being questioned, but I made no personal references to you, why the personal attack? I was hoping to elevate this thread to a more technical discussion, as in Norm's response, not just a "Sam Strano says..." thread. Get over yourself, man. Your attitude sucks. You're obviously not a complete moron, but you are a self congratulating ass to the n'th proportion, on your own high horse. Unlike you, I have no agenda here, contrary to your opinion. Oh, and please don't stop posting. Some of these guys really think you're something.
quote:
ORIGINAL: Sam Strano
steelcomp... who pissed in your Wheaties? If you want to think I'm a complete moron, that's fine but it won't stop me from posting.
As for bar comparisons, most folks use 1045 spring steel. The bar has to fit in the stock location and you can see by looking that it clearly does. The front bar has the same endlink position too. While I agree that if a bars shape or length changes in any tangible way it will effect the stiffness, the fact is that doesn't apply to these bars. Further the front bar stock from Ford is hollow, as is the Hotchkis so there are no worries about "one is solid so what about the big of stiffness that adds". And all you have to do is sit down, and do the math. D to the 4th power. Compare what 34 to the 4th is vs. 38 to the 4th and tell me you come up with 20% difference.
And regarding endlink holes or adjustment. Changing lever arm length is no way equivilent to a 4mm change in diameter. Example, two like size bars, one with a 10" arm the other with a 5" arm. The 5" arm will offer you twice the roll stiffness as the 10" bar with the same diameter... but here we aren't talking about cutting the arm in half, nowhere near that. In fact, having just measured a stock bar the lever arm is about 15" long, and the most you can shorten it without the endlinks getting too far from vertical is about 2.5" at best, or about 16-17%. So no I don't buy that the bar is only 20% stiffer than stock on the softest hole.
And what's more, I've played with bars on these cars already. And in fact a hollow 35mm bar with the softest hole about 1/4" further back is indeed stiffer than the stock 34mm bar. How do I know? I've tested it, and the response rate was up in the car, as was at the limit understeer (I tested that front with a stock GT front bar at first, and later wtih a hollow rear bar we're working on of 22mm diameter).
Ford hit the relative bar balance pretty close to on the head with this car. Some what stiffer, and that's fine, some some more rear bar vs. front, and that's fine, but they are damned close and not at all small bars. I don't really feel this car needs massively differnet bars, and historically I would change bars on a lot of cars, including other Mustangs right away. Not here. If more roll stiffness is warranted, that's fine and it can be used, but you seem to think that 38/25 is not a massive increase, and you're wrong. Further, you seem to think that as long as you look at the bars front to rear and keep their relative increase of roll stiffness the same that the balance will remain the same when it fact it will not due to the fact a solid rear axle acts nothing like the front end dynamically.
To each his own. If I told you the sky was blue you'd say I was lying and tooting my own horn. I can't please everyone, and I'm not going to try. And fwiw, why would I tell folks this considering I sell the very bars in question? You think I'm some sort of snake oil saleman I guess. I could have popped in and said "those bars are perfect, run them" and tried to make the easy sale you seem to think I'm after by having the nerve to pay to advertise on this site. But in reality.... I don't think those are the right bars, period. And because I sell those bars I'd hope folks would realize I'm saying that becaue that's how I feel, and not because I don't carry the line.
Nothing is absolute. Hotchkis's thing is massive bars. Always has been, pick a car they make bars for and you'll find they are way bigger than anyone else's. That's just their MO. That's fine and I don't know why, nor do I really care because they also think that regular off the shelf Bilstein HD's are fine for lowering springs, when in fact for years Bilstein own documention said there weren't. I guess Bilstein was lying? I guess that nobody could do any better.
Might I ask that you jump down off you high-horse and if you wish to discuss something to do so in a way that better hides you disdain for me? If you want to discuss, we can discuss.
Since this has turned into a techincal discussion about sway bars I have a question. Explain why a larger rear bar is often recomended when you start running a staggered wheel set up? To be more specific I am now running 255/45r18 up front and 285/40r18 in rear. I have vogtland gt500 spec springs, koni yellow's, lower control arms, adjustable panhard rod w/ brace. caster camber plates up front. upper rear control arm. The car was feeling good with the stock tires and the front struts set at one turn in from full soft and the rear set at 1.5 turns in from full soft. when I added the new wheel and tires the ass end started to feel different. I do not have a lot of seat time behind the new wheels and tires and I realize that it will take some getting used too. I have read on other posts in the past about rear sway bar recomendations for those doing the staggered wheel thing. If any one can educate me on the this area and make some set up recomendations to me it would be great. Also would I benefit from a steeda x5 ball joints and do you have to tun them with a bumbsteer kit?
What you're trying to do is re-balance the slip angles (which is a definition of either understeer or oversteer that can actually have a number attached to it - in vehicle dynamics there is something called "understeer budget" that slip angles are one component of).
When you put larger tires on the rear the usual effect is that the rear tires will now need less slip angle during any given corner. Meanwhile the front tire slip angles remain unchanged. More slip angle up front relative to the rear (or less slip angle in the rear relative to the front in this case) means that the front wants to run wide more than the rear does, which is an understeer effect. So you want to make the rear a little "looser" to put the balance back where it was. One way to do this is by making more of the lateral load transfer happen out back, because the more unequally either pair of tires are loaded the less total grip they have - and since this is true at any slip angle, the rears will always slip a little more with the larger bar in place.
You do have to be a little careful with this sort of tuning - all the usual caveats about "everything else remains the same" apply. It's most applicable when the larger rear tires are simply wider sizes in the same tire make/model as before (which were hopefully the same make/model as the fronts). And when the wider tires are mounted on comparably wider wheels.
It may demand more from the driver, since the extra lateral load transfer that helps your steady-state cornering means that you won't be able to add throttle on corner exit quite as soon or quite as fast as you might have been able to with the smaller bar. IOW, faster but less forgiving up around the limits.
Norm
< Message edited by Norm Peterson -- 5/9/2008 6:26:21 AM >
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Can't make any specific suggestions until I have some measurements. For a guess, I'd say whatever amount more bar gives additional wheel rate equal to about what 10% of the rear spring rate would do and go from there.
Right about here I'll grumble a bit about most S197 sta-bar adjustabilities being on the front bars only, as it just isn't as logical to tweak the bar that's primarily responsible for limiting roll for balance while leaving the rear bar that's on there for balancing the roll couple in the first place alone. I'd like to see an infinitely-adjustable rear bar, but that's probably a separate rant.
Missed the X-5 balljoint item earlier - anything you do to a strut suspension that affects the inclination of the LCAs relative to the tierods means that the bumpsteer will be affected, so yes.
Norm
< Message edited by Norm Peterson -- 5/9/2008 8:39:02 AM >
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Hotchkis Sport Sway Bars 2005+ Ford Mustang - 
