glgorman

1.5" Tubular Front Bar, 4 Way Adjustable. Rate increase vs stock +20%, +29%,+38%,+50%
1" Tubular Rear Bar, 3 Way Adjustable. Rate increase vs stock +50%, +70%, +100%.
http://www.lightningforceperformance...c2a68d30b751af

just wondering if any one has used these before.

I do a lot of autocross and track days so the adjustability would be nice.

any feed back would be nice

thanks

Sam Strano

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.

steelcomp

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 woulddictate 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 ofincrease 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.

Fullsayl

Sam,

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

Sam Strano

How do you figure size doesn't matter? That'slike 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 springsyou 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 numbersyour 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. Mechanicalcomes 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.

glgorman

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?

and do you give a discount to forum members?

you can pm me with the later if you prefer.

Glenn.

Sam Strano

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, asan 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 bestby 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/searchbym...&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.

steelcomp

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 seemsyou haven't actually comapred the bars except to sy they don't "look" like the ones you use, so they can't be right.

Norm Peterson

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, witheach 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 backfor 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

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 whatstiffer, and that's fine, some some more rear bar vs. front, and that's fine, butthey are damnedclose 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 theeasy 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'sare fine for lowering springs, when in fact for years Bilstein own documention saidthere weren't. I guess Bilstein was lying? I guess that nobody could do any better.

Might I ask that youjump down off you high-horse and if you wish to discuss something to do so inaway thatbetter hides youdisdain for me? If you want to discuss, we can discuss.