Help me choose sway bars
05-15-2013, 02:22 PM
#21
There's a local guy selling a "wonderbar" off an 86 iroc. It's 24mm diameter. Only thing I don't know is if it's a solid or hollow piece.
Also, my moser 9inch doesnt have the mounts so I need to add those. I thought about just fabbing some up from scratching using some 3" exhaust clamps, 1" cold rolled steel flat stock 0.125" and just some off-the-shelf bushings. Thoughts?
Also, my moser 9inch doesnt have the mounts so I need to add those. I thought about just fabbing some up from scratching using some 3" exhaust clamps, 1" cold rolled steel flat stock 0.125" and just some off-the-shelf bushings. Thoughts?
In my last post, I erroneously called the iroc bar a wonder bar. Lol.
I picked up the iroc bar and it measures out to 23mm diameter, solid. Right now I have no bar. The car handles like a drunken rhinoceros. My poly bushings are on order and I hope to have that bar mounted up in a day or two. I'll report back with handling results though.
Currently, I have a non staggered tire setup. Eventually I'll be going wider in the rear when I find a deal on some 305's.
I picked up the iroc bar and it measures out to 23mm diameter, solid. Right now I have no bar. The car handles like a drunken rhinoceros. My poly bushings are on order and I hope to have that bar mounted up in a day or two. I'll report back with handling results though.
Currently, I have a non staggered tire setup. Eventually I'll be going wider in the rear when I find a deal on some 305's.
This is just on the street. Without the rear bar, my car just wallows around the corners. I felt like I was driving a minivan. I would hesitate to take any turn with any amount of speed, let alone try to accelerate through it. I would literally slow down for every turn (not sweepers or fast bends), coast thru the turn and accelerate after the lateral g subsided. For higher speeds, I jus wouldn't attempt fast corners at all.
I put on the iroc 23mm solid today. I used 3" exhaust clamps. I welded 1.25"x0.125" flat stock to the back of the clamps to serve as the backing for the bushings. I ordered energy suspension black poly bushing kit for the 3rd gen iroc 23mm bar. I needed the elongated bolt holes on the new bushing shells because the Oem iroc shells were too small to clear my axle tubes. With the mounts fabbed and painted, it all bolted up like stock. My only issue is that my bar literally rides against the diff housing. If it becomes a problem, I'll have to fab up thicker backing plates on the mounts.
The car is so firm and planted now. I can easily push the limits of my tires... Michelin pilot sport cup 2 which are pretty good tires. It pushes editing the turn and the rear steps out after the apex of the turn. I currently have only 245s out back. Once I get my 17x10 bbs and 305s on there, the handling will even out very nicely. But that this point, I'm second guessing my need for a front bar.
Btw, the iroc bar was $60. Pretty good score IMO.
I put on the iroc 23mm solid today. I used 3" exhaust clamps. I welded 1.25"x0.125" flat stock to the back of the clamps to serve as the backing for the bushings. I ordered energy suspension black poly bushing kit for the 3rd gen iroc 23mm bar. I needed the elongated bolt holes on the new bushing shells because the Oem iroc shells were too small to clear my axle tubes. With the mounts fabbed and painted, it all bolted up like stock. My only issue is that my bar literally rides against the diff housing. If it becomes a problem, I'll have to fab up thicker backing plates on the mounts.
The car is so firm and planted now. I can easily push the limits of my tires... Michelin pilot sport cup 2 which are pretty good tires. It pushes editing the turn and the rear steps out after the apex of the turn. I currently have only 245s out back. Once I get my 17x10 bbs and 305s on there, the handling will even out very nicely. But that this point, I'm second guessing my need for a front bar.
Btw, the iroc bar was $60. Pretty good score IMO.
C'mon man. Don't hijack someone else's thread. I don't understand your posts. You are happy with your 30/23 setup? Seems like too much rear bias which will result in oversteer.
06-28-2013, 11:59 AM
#22
I think we had gone back and forth on another thread and I just didn't get a chance to respond... but help me understand what your reasoning is for why adding a 25mm bar is going to help combat the understeer and all of a sudden make the car neutral. I'm not seeing it.. maybe you understand and I don't, so that's why I'm asking the question.
This is what I see happening if you put on the 25mm bar with the offset tire setup. With more roll resistance combined with that wider tire.. all I see is a really fine line between traction and no traction. Aka your car will hold really well and understeer.. or once you break free, you will break free pretty suddenly. I'd think I'd have a nightmare on my hands if I took that combo to my local circle track events...
I think you were arguing that a softer bar will add snap oversteer. I can see this happening if you think that the compression of the suspension approaches the bumpstops too quickly. Is this what you are thinking will probably happen with a 315 in the back? If that's the case.. then will it really matter? 315 or 275 in the back.. your unsprung weight stays the same regardless.
I don't think I have the answer here nor am I claiming to. But if I don't, then I'd like to understand why so that I know in the future
This is what I see happening if you put on the 25mm bar with the offset tire setup. With more roll resistance combined with that wider tire.. all I see is a really fine line between traction and no traction. Aka your car will hold really well and understeer.. or once you break free, you will break free pretty suddenly. I'd think I'd have a nightmare on my hands if I took that combo to my local circle track events...
I think you were arguing that a softer bar will add snap oversteer. I can see this happening if you think that the compression of the suspension approaches the bumpstops too quickly. Is this what you are thinking will probably happen with a 315 in the back? If that's the case.. then will it really matter? 315 or 275 in the back.. your unsprung weight stays the same regardless.
I don't think I have the answer here nor am I claiming to. But if I don't, then I'd like to understand why so that I know in the future
There are a couple of ways to balance this. One is to increase tire pressure up front and lower it in the rear. The other is to run a stickier front tire (say R888s up front an a regular road tire in back). This link also gives you a good idea of ways to fix understeer and oversteer: http://www.nyracer.com/overunder.htm
Or you can stiffen the rearend to balance the setup. Swaybars increase the effective rate at the tire with grip. Since most run Strano or BMR spring setups, you have a 550/150 or 160 front to rear spring rate. And then you put a 35mm front bar which is like 480lbs up front and the rear 22 is around 190-200. A 25 is closer to 320 or so IIRC. What you're doing is creating more balance with additional rear spring rate assuming front and rear tires are the same compound.
Like I said, a 22mm is fine for the 315. You're just going to get more push. It's safer. The 25 helps balance it out. A 22mm adjustable that gives more rear rate is also a good idea.
06-28-2013, 04:16 PM
#24
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The added tread and wider track in back causes the car to understeer. That's just what's happening - it's physics. You have more grip in the rearend now, and you're going to scrub some speed when you try to turn since the front isn't gripping as well as the rear.
There are a couple of ways to balance this. One is to increase tire pressure up front and lower it in the rear. The other is to run a stickier front tire (say R888s up front an a regular road tire in back). This link also gives you a good idea of ways to fix understeer and oversteer: http://www.nyracer.com/overunder.htm
Or you can stiffen the rearend to balance the setup. Swaybars increase the effective rate at the tire with grip. Since most run Strano or BMR spring setups, you have a 550/150 or 160 front to rear spring rate. And then you put a 35mm front bar which is like 480lbs up front and the rear 22 is around 190-200. A 25 is closer to 320 or so IIRC. What you're doing is creating more balance with additional rear spring rate assuming front and rear tires are the same compound.
Like I said, a 22mm is fine for the 315. You're just going to get more push. It's safer. The 25 helps balance it out. A 22mm adjustable that gives more rear rate is also a good idea.
There are a couple of ways to balance this. One is to increase tire pressure up front and lower it in the rear. The other is to run a stickier front tire (say R888s up front an a regular road tire in back). This link also gives you a good idea of ways to fix understeer and oversteer: http://www.nyracer.com/overunder.htm
Or you can stiffen the rearend to balance the setup. Swaybars increase the effective rate at the tire with grip. Since most run Strano or BMR spring setups, you have a 550/150 or 160 front to rear spring rate. And then you put a 35mm front bar which is like 480lbs up front and the rear 22 is around 190-200. A 25 is closer to 320 or so IIRC. What you're doing is creating more balance with additional rear spring rate assuming front and rear tires are the same compound.
Like I said, a 22mm is fine for the 315. You're just going to get more push. It's safer. The 25 helps balance it out. A 22mm adjustable that gives more rear rate is also a good idea.
That is a good link you sent. Though I would choose other options from that list before going to a big rear bar. Adjust camber.. match the tire sizes up front.. adjust tire pressure. Just my .02
During autox, I actually try to create understeer conditions with my power 400 rwhp in order to put full power down. Otherwise my tires always break free, and that just causes a huge loss of momentum.
06-28-2013, 04:25 PM
#25
I like a neutral balance with just a hint of throttle-induced oversteer. For a mostly stock vehicle, I'd recommend a 35/21-22 solid, or the equivalent hollow bars with a similar rate... something like a 36.5/25 hollow with the correct wall thickness. If you lower the rear roll center then you can run a bit bigger bar, on the order of 24mm solid. The 25mm rear bar was always too lively for me in my autocross/street driving; I always use the same wheel/tire combo at all four corners, anywhere from 265 to 315 over the years.
06-28-2013, 04:54 PM
#26
I plan on running a staggered 275/315 setup with the rear tire being softer than the front. For me, killing off a little traction in the corner is fine with a bigger bar. I need the softer tire so I don't blow the tires off in a straight line (which also the 25mm helps with).
It's hard to get best of both worlds.
But you're right that oversteer to balance understeer isn't ideal. That's why I said an adjustable 22mm bar is the best solution. Throttle oversteer is easy to modulate and creates a safer condition.
But on street tires, 315s create a lot of push... even more if you have a sticky tire out back.
It's hard to get best of both worlds.
But you're right that oversteer to balance understeer isn't ideal. That's why I said an adjustable 22mm bar is the best solution. Throttle oversteer is easy to modulate and creates a safer condition.
But on street tires, 315s create a lot of push... even more if you have a sticky tire out back.
