94bird

I think it's not that simple Steve. Remember, this street car owner who started this discussion has no intention of keeping stock rate springs. That will change your equation, as I pointed out in my previous post.

It is quite easy to have too big of a front sway bar for a production based race car, despite Herb Adams' quote. Ever seen a car riding on 3 wheels, like a Porsche 911? That's a car that's very likely using a large sway bar to counterract another suspension or chassis weakness and not achieving optimum handling because of it. That's fine if rules limit you to certain modifications, but when they don't, fix the root cause, don't just bandaid it. There are very few car preparation rules for a street car.

In the end, for a street car, I haven't heard anyone here justify why a 35mm bar will improve handling when the car owner is also running higher rate springs, well in excess of what you or I run. Come on guys, it's for the street. We're not talking race tires here that will demand more negative camber or sacrificing ride quality for that last tenth of a second. We're talking about advising someone on building a good handling combination that's predictable, safe, and still fast when it needs to be. You may rightfully put up a Herb Adams argument that stock spring rates are likely the best compromise, and that better shocks and bigger sway bars are the best way to approach your goals with a street car, but a lot of street car owners want to lower their cars more than an inch for looks, and also to achieve better handling. With that comes the need for an increase in spring rate, and unless someone goes with coilovers like we chose to, that will almost certainly mean higher spring rate than either one of us currently have. Once you decide you will take the hit on spring rate to get the looks and handling feel you want, why make the ride worse with a bigger sway bar?

bruecksteve

Maybe but like I said, I use the 35mm and 500# springs and I don't feel my ride has been compromised at all.

I think the Porche example might be a bad one simply because they have no weight in the front. Yes, it would be easy to go to stiff on that car. But we have almost 58% of our weight on the front. If you look at the spring rates from most of the aftermarket springs below, almost none of them are as stiff as what you and I run, yet I like how mine rides and I believe you like yours.

As you and I both know, it comes down to a matter of taste and what you're going to do with the car. I just feel like the big front bar allows for the best roll control without compromising ride quality. As you and I know also, this is an age old argument among the most accomplished race car drivers and designers, this doesn't put us in that catagory does it???

Spring Front (lb/in)- Rear (lb/in)- Ride Hight (in)
V6 223 95.4 N/A
Z28 (93 - 97) 292 114 N/A
Z28 (98+) 291 114 N/A
1LE (94+) / WS6 / 99+ Base SS 360 130 - 180 +0.5
SLP Level II "gray" (Eibach) / y2y SS 300 - 450 115 - 185 -0.75
SLP Race/Aimes "red" (Eibach) 337-674 83.4 - 138.2 -2
Eibach Pro (93 - 97) 377 - 600 94 - 160 -1.5
Eibach Pro (98+) 377-600 94-160 -1.25
Eibach Sportline 360 80-137 -2
Hotchkis 285 - 525 100 - 140 ?
Edelbrock 585 120 - 150 ?
Suspension Techniques 600 140-160 (?)

Sam Strano

Well, fixing the root cause requires serious modification to things like suspension pick-up points and so on. And the "band-aid" works pretty well. Unless you are smart enough and have enough money to redesign the whole suspension of the car you have to make the best of what you have. Hell, we'd all like to have Independent suspensions, and we *could* as it would be the fix of a root cause problem, but not practical.

In regards to the 3-wheeled thing. It doesn't hurt handling. As a matter of fact, when we started using the bigger bars on MR2's, the went faster, and pulled front wheels much more often. And Porsche has some pretty smart folks there. Believe that if that slowed the car, they wouldn't have done it. E36 BMW's, same way. RX7tt's, the fastest ones usually had a tire cracked off the ground. You don't want to be on 3 wheels, and certainly not getting big air under one, but it's not uncommon or definitely bad to be doing so.

To justify why the 35mm bar stiff helps street cars. Bars don't simply control angles. They also help the response of the car, they allow the car to be crisper feeling, which can make up in some regard for soft street tire sidewalls. Some folks like to have the car stiff. Steve for one, and myself for another have run all the different size bars available, we both like the 35mm even with stiffer springs (to a point). Stock springs make it a no-brainer. Of course the bars allow you to get the roll control you want, without having to run REALLY stiff springs. Bars have much less effect on ride than do stiff springs, and do more to control lean. Also, I've found that more bar allows me to run less damping since the bar helps the car's response. This is nice because I run the shocks as spring dampers again, and not have to run them "overly" stiff to get the car to react. Now, I could run the shocks stiffer, and a smaller bar if response was the whole thing (it's not). But then that's a compromise because on non-smooth surfaces it can cause the suspension to pack down.

There are lots of theories. Sometimes the math adds up, sometimes it doesn't. I'm not an engineer. I like that because I'm not afraid to think outside the box. I've had mechanical engineers tell me things won't work. Only once was I wrong, and that had nothing to do with an f-body. And it's fine I was, because I was still right more often than not. However the proof is in the pudding, lots of quick cars run the big bar. Again, all I can say to add is this. With only one exception, everyone who has run a 35mm bar has stayed with it. The one exception had be concerned from the start. He's running heavier front springs than I do, and teamed up with shocks that are too weak to properly damp them. As we know, springs, bars and shocks work together. When he bought the the bar, I was upfront and told him I was concerned it might be too big. He thinks it was, I think better shocks would go a long way toward curing that for him, but to each his own. Seriously, and not trying to be a pain, but you haven't tried it, a lot of us have been where you are. You're saying it might not work the best, but haven't given it a shake. And yes, if you are happy with the car, great. But most of us are always looking for a bit more. That might require changing other things in conjunction with the bar to make the setup work. But you never know until you try.

To close: You hear lots about how the 3rd gen is a "better" handler than the 4th gen is. Given the spring rate of a stock one, and the location of the spring, the wheel rates are similar when you add a big bar to a 4th gen vs. a stock 3rd gen. And the 3rd gen cars like late Z28's and 1LE's........ solid 34mm or hollow 36mm bars, stock.

TA Dreaming

i run LT1 prokit springs with off the shelf bilstien HDs. ive got the 35mm bar. camber is zero right now. the car rides very well. its not harsh at all. hell i drive almost 400 miles a week just to work. it handles great. it doesnt roll much any more. it turns in quicker and crisper. i had the 32mm hollow bar as my car is a WS6. the difference is night and day. i wont be switching back. my eagle F1s arent that great but they do the trick on the street and in the rain. im still learning a lot fo this stuff. i have no where near the knowlegde that steve or sam have, but ive got the car and i have the setup that your disputing. it works for me. i autox and have never been on a road course so maybe i would really hate it out there, but i like what i got now for the parking lots and the mountains. its works. trey

94bird

It's not a bad one. It's just one Herb Adams wasn't thinking about when he wrote that statement.

Actually, you just illustrated my point. The rising rate springs from the aftermarket are much stiffer than either mine or your spring rates at their highest point, and they hit that rate at very minimal compression.

94bird

Of course being on 3 wheels hurts handling. That's an example of using an extreme bandaid to try to make the best of what the factory gave you, and it is most definitely slower than making the car neutral with 4 tires on the ground.

Don't ever take it for granted that an OE does something because it's the best performance solution, including Porsche. There are always other constraints on a mass production vehicle.

Granted, but noone's answering my question about why on earth you'd want to run something like ProKit springs (with shocks properly valved for them, not like TA Dreaming is using) and still run such a huge sway bar. For street use I'd just use the 35mm ST bar with stock springs and Bilsteins, ala Herb Adams. Possibly I would go with 1LE front springs and lower the .5". However, if I lower the car much and therefore end up buying one of the kits that Steve so kindly detailed for us above, you just don't need such a huge front bar. All I'm getting from your statements is that for street use the big bar helps your steering response. As you say, steering response doesn't mean your car handles better. It just feels better, and will ride rougher because of it with minimal or no improvement in handling. If that's worth it to the car owner, then he's made his choice.

I think you're misunderstanding my reasons for not making the jump to the big bar.

1. You and the other people I've found who like the bar are not using the car for the same purpose I am.
2. You and the other people I've found who like the bar haven't taken over 500 lbs. out of the car (over 600 by the spring), effecting weight distribution quite dramatically, and thus the optimum setup.
3. You and the other people I've found who like the bar are more camber limited than me because of rules constraints. That's a huge reason such a big bar is an advantage in ESP and certainly FS.
4. You and the other people I've found who like the bar do not have the freedom in the rules to reduce weight as much as I have and still can. This winter I'll be spending about $400 for a glass hood to lose about 30 lbs. I'll be spending almost $400 for a lexan windshield to save a similar amount of weight. You better believe that if LG comes out with his new k-member and it saves me more than 20 lbs. that's going on the car too. Even then I'll be likely 250-300 lbs. heavier than a Fox body Mustang and we're both limited to the same maximum size tire and thus brake rotor diameter by the rules. My car handles very well right now, and weight is my greatest disadvantage. I'm going after that with a big amount of effort this winter and in '04. Once I get somewhat stable on weight then I'm sure I'll have to revisit suspension tuning. At that point, maybe I'll consider trying a bigger bar, but at that point I won't need near as much roll resistance as you do either. I'll have a significantly lower cg and significantly less weight.

However, I will state again, the original post was from a street car owner who doesn't race the car on a track at all and intended to change the springs also. Again, why make the ride harsher for just better steering response when that has minimum actual performance benefit? For racing I'll make the sacrifice, but for a street car, why? Heck, some of us live in pothole alley (ala Detroit).


Actually I never hear a 3rd gen is a better handler than ours. I just hear it's a lot lighter. Maybe they can afford some additional weight from a heavy bar since they don't have the disadvantage of weighing so much from the outset.

I'm also guessing that since a 3rd gen isn't a SLA front suspension like ours they have a much worse camber loss curve unless they run some extreme caster. In that case, you might want more roll stiffness to keep what camber you can get. I'm not sure that's a valid comparison point when you're only saying they have similar wheel rate so it should be a good setup for the 4th gen also.

TA Dreaming

youve answered your own questions. we are street cars you are not. we can not ride around with -2 camber and expect our tires to survive. adding the bigger bar does not affect ride quality. im sorry it doesnt. my car changed ride quality when i added the HDs. ive only known the car with the prokit on it and it had decarbons at the time. it was soft and bouncy at times. the HDs fixed that. didnt make it rough at all. the 35mm bar didnt change the ride quality and it handles better. i can rip through turns much better, quicker, and with less roll.

may car did perfectly fine with the current setup only using the 32 hollow bar. thats also why i said it would prolly work fine for him. however i wanted more so i switched to the 35mm bar. everything changed for the better ride quality didnt change. if youre having to live with potholes why expect a smooth ride with a fbody?

all im seeing is a debate over why two different applications require two different setups. on the street run the big bar and a good spring/shock combo. nothing wrong with my setup. its cheap works great and is easy to do. will it work for you and your application possibly not. will it work for nine out of ten people that say hey ive got a prokit on my fbody i want it to handle great. yes it will work, and work good too. trey

bruecksteve

The big bar does nothing in my opinion to make my ride rough. It never has on the last 4 F-Body's I've owned. But what it did was improve transients, sharpen the quickness of the steering, and reduce roll which reduces camber changes. I can guarentee I can run a slalom better with my big bar than the one your running.

And speaking of one wheel off the ground. Look at drag cars. They want to shift the weight to the wheels that matter. Ideally, the two front tires should be slightly off the ground for maximum weight transfer. It's really no different for handling. When cornering, the outside wheels are taking the brunt of the cornering forces, the inside wheels, especially the front will only have a very light load if you're cornering at maximum efficiency. In other words, it's not really doing much anyway. Keep in mind we're talking about production cars here, not designed from the ground up race cars.

Yes, your car is different. 99% of us can't gut our cars, they are either our daily street cars or dual purpose street/autocross cars that have to conform to class rules. We live with cars that have 58% of the weight on the front wheels and need a good way to help control how that weight is being thrown around. The 35mm bar is the ideal way to do that.

94bird

There's no slaloms on the street.

Very bad comparison. Drag cars have no use for traction with the front wheels when they pull them briefly off the line. You have a good use for all 4 of your wheels when cornering.


Not really. It's the combination that matters. A 35mm bar is only part of the equation. As I've stated many times above I agree with you if you keep the spring rate under control, but . . . (guess where I would go with this if I felt like keeping on typing)

94bird

Um, no, my questions are still waiting to be answered. You're the closest to an example of a real street car that has tried to respond, but as I see it, you are 1 F body owner who likes his combination for the street. Noone else is speaking from that perspective here. From your description of your combo I know it would ride even better and would respond better to transients if you had your fronts revalved for your spring rate. Tick off an improvement in transient response there. With Prokits I was running just over -1 camber. On street tires, given the conditions we see on the street (meaning trying to maintain some semblance of safe speeds), are you really telling me your car handles better with your combo? Define handles better and under what conditions you see the improvement if you don't mind. Ripping through turns better isn't quite the kind of description I'm looking for.



And you certainly don't need -2 camber on street tires for street use either, so what's your point?



That's because you're closer to matching the right damping for your big increase in spring rate now. It could get better if you revalved your front shocks.



Sorry, but need I bring up my unanswered question again? Why have a harsher ride just to get better steering response for a street car? Yes, I've gone up in sway bar size in every car I've owned and every time I've felt a ride harshness increase. If you don't, given the magnitude of your change my experience tells me you weren't paying enough attention.

bruecksteve

Mine is a street car. I drive it daily back and forth to work, right now it's the only car I have (divorce). And even if I had another vehicle, I'd still drive my Camaro daily, it's fun to drive. I wouldn't have it any other way.

No, but there are slaloms in an autocross.

What's harsh to you is obviously not harsh to hundreds of other people, otherwise they wouldn't be satisfied with the 35mm bar.

My combination is exactly what I was looking for. Could it be tweaked and refined?? Absolutely and it will be over the winter. But it won't involve removing one of the best items I've added to the suspension.

I'm willing to accept trade-offs in ride comfort to achieve the handling I'm looking for. When I spoke with Sam before I purchased my parts, I told him that my primary focus was a competitive ESP Camaro, everything else was second to me. I feel like I've achieved that in this suspension setup. The added bonus is that I feel it rides better than the stock suspension that came on the car.

TA Dreaming

i bought my HDs from sam. i decided to buy them as an investment. i didnt have nor want to spend the money on revalved ones. so i decided to try them out off the shelf. i really like them. i put them on months before i had my sway bar. so not only did i put my usual 400 miles a week on the car. i did two autoxs and went to missouri and back one weekend and i went through the dragons tail in tennessee three times. so yes i know what my car rode like before i put the bar on and it didnt change for the worse once i did put the bar on.

i realize getting revalved bilstiens will be better and im going to send them back to sam and have them revalved but they work great for now. the de carbons that were on there were shot. i needed an upgrade, HDs are what i chose.

my comment about the -2 camber was just to show the difference in our applications. you obviously are a race car. steve and I are not. we both drive many miles every week and then to the autox on the weekends. the only changes made are i check my tire pressure and steve puts on his hoosiers. i dont even take my sound system out. so yes we are street cars but we race them. racing a street car does not make it a race car.

how did my handling change? well by ripping through corners i mean i can go through them a lot faster and not have as much roll as i did with the 32mm bar. i can go easy through a turn and feel the car planted better. this is just simple driving through curves in the road. the front inside corner doesnt lift as much and it plain and simply feels better. yes it is safe on the street, but i dont push it as hard on the street as i do on the autox course.

i dont know any other way to describe it. the bar change made things much better and did not affect my ride quality at all. i know my set up is not optimal, but it works for now. besides i know im not that good of a driver. im sure that my car would post much better times with an experienced driver. im doing my best and enjoying every moment. Trey

94bird

That's precisely the reason why I'm interested in what you have to say, because your application more closely resembles what my Firebird used to be used for, but also precisely the reason why I don't think you're a good example for a car owner who doesn't race his car.

Wow, I have to say if your car rides better than stock with your setup you must not have to live with Detroit roads. I was running stock sway bars for awhile with 450 lb/in GC front springs and revalved Bilsteins from Sam and when hitting a pothole I can VERY easily tell it's rougher than stock. However, its' still better overall than when I had Pro Kits and HDs with no revalving.

BTW, I'm going to 600 lb/in springs over the winter and keeping my 1LE bars for now. I wanted to fine tune the roll resistance and dive when braking. I'm keeping the 450 springs though, just in case things change. They always do don't they?

bruecksteve

I'm not saying it's not rougher, but not nearly too rough. Talking about rough though... 600#!!!! I'd be willing to bet you'll need the Koni's instead of Bilsteins!!! And yes, they always change, always looking for every last bit of advantage you can get!!!!

I run against one of the best F-Body drivers in the county, Tommy Pulliam, so it's going to be a big challenge for me just to keep up. He drives an 01 Z28 so he already has me by about 60hp, he's been running F Stock but now Sam (thanks a lot Sam!!!! ) is throwing everything he can think of toward Tommy's car to make it ESP!!!

Oh well... Sam, I'm calling you in a week or two to get the T2R and torque arm. And while you're at it, I need an LS1 too....

And speaking of noticing a change, how much difference did you notice with the T2R??

94bird

Actually no, I'm not a race car, but I do own one. Now if I could be a race car, which one would I be? Sorry, but I couldn't let that one go. Now back to the fun.

Well, the difference is obvious, but you keep on comparing your car to mine. I was more interested in and kept trying to recenter the discussion on street performance, not autox performance. The main post that got you on this line of reasoning I think was when I responded to Sam about why I chose not to run the bar yet. I was only responding to his questioning.



Ah, now we're getting somewhere. One of the first points I was asking about was with street tires how much of a benefit do you see with a larger bar? Hoosiers will demand either more negative camber or more roll resistance since they will pull more lateral gs, and a change in tire like that can totally change the optimum suspension setup. You haven't made this change yet.

BTW, once you do go to race tires it's a slippery slope. Next you'll tow a tire trailer behind you like I did. Then you'll get the bright idea to tow your car to the race and prep it at home where you can take your time. Then that will open up doing track days. Then you'll catch that bug. Then you'll try your hand at road racing. Then . . .



Those are good comments, and this combination obviously suits you. I still say the best approach though is not to just jump straight to making everything stiff, but creep up on your optimum setup. Heck, SLP bars can be found very easily and I bought both front and rear bars, and converted my bushings for the larger diameters for less than I can buy just the 35mm bar. I will also be able to sell the parts for very close to what I paid for them later if needed. Since I'm happy with this combo I've decided to move on to more important matters. There's a LOT more F body owners out there with either stock sway bars or the SLP size that are perfectly happy with their handling on the street than owners of the ST bar, I can guarantee you that.

That's all any of us on this board are doing. It's all about having fun and learning at the same time when you can.