[QUOTE="Rich Euro M5"]It's always been my understanding the correct way to tune a suspension is increase spring rate to reduce roll, and then use antiroll bars to fine tune for oversteer/understeer.[/QUOTE]
You're right, Rich, but you know, I somehow doubt Raj is listening. He's already hell-bent on doing this 'upgrade' and no amount of logic is going to make him step back and devote that much thought to it. He wants Bigger Bars, and dammit, he's going to have Bigger Bars! :@
I hate to say this because there is such a high percentage of knowledgeable folks here who have done things like this because they know what they're doing and why they're doing it. Unfortunately, they often lose sight of the fact that not everyone who's asking about how to do things has given adequate consideration to the why they should do things. Simply enhancing the dynamic handling characteristics of the car is sometimes a foolish thing to do unless the driver is accomplished enough to skillfully use that enhancement. Is a Pentium 3GHz processor 'better' than a 4.77MHz Z-81 CPU? Not to a chimpanzee ... %)
reinforcing front sway bar mounts with 22/16 bars...
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C.R. Krieger
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You're right, Rich, but you know, I somehow doubt Raj is listening. He's already hell-bent on doing this 'upgrade' and no amount of logic is going to make him step back and devote that much thought to it. He wants Bigger Bars, and dammit, he's going to have Bigger Bars!
Huh? Hell bent on doing the upgrade? Have you even read the rest of the thread? I have had "bigger bars" (RD 22/16) on my car for about 4 years now, and I was just asking how to go about reinforcing the front mounts so that I dont break them off at an inopportune time (ie. during hard cornering). I already snapped off one of the sway link mounts on the strut at Willow Springs and was lucky not to go off when it happened. As it is, my suspension is very stiff, so I don't really need the bars to counter body roll...just to tune the handling balance of the car.
So how do chimpanzees feel about the Ford Mondeo...I mean Jaguar X-type?
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Guest
Raj,
Who's springs are you running ??
And how are you breaking parts off with 22/16 bars?? Sounds to me like your springs aren't as stiff as you think.
Even BMW didn't reinforce things until the 25/18 M5 bars came out. But the US/NA M5 uses stock 535i front springs with Boge Turbo gas shocks and the SLS rear stuff. This was obviously a compromise suspension system to maintain some level of ride comfort yet yield less body roll than the stock 535i setup. When you take this route, the swaybars are doing much more work than they would with a higher rate springs and the result is tearing out the mounts.
Rich
Who's springs are you running ??
And how are you breaking parts off with 22/16 bars?? Sounds to me like your springs aren't as stiff as you think.
Even BMW didn't reinforce things until the 25/18 M5 bars came out. But the US/NA M5 uses stock 535i front springs with Boge Turbo gas shocks and the SLS rear stuff. This was obviously a compromise suspension system to maintain some level of ride comfort yet yield less body roll than the stock 535i setup. When you take this route, the swaybars are doing much more work than they would with a higher rate springs and the result is tearing out the mounts.
Rich
Rich:
I am running H&R springs, which aren't that stiff. The only part I have broken so far was the left front sway link mount, on the strut assembly. At the time, I was running the H&R's with Bilstein Sports and the RD bars set on full stiff front, medium rear. Since then, I have replaced my rear shocks with re-valved Bilstein Sports that have the compression increased 25% and rebound increased 40%. Before, my suspension was firm, but compliant. Now, it's STIFF.
I am running H&R springs, which aren't that stiff. The only part I have broken so far was the left front sway link mount, on the strut assembly. At the time, I was running the H&R's with Bilstein Sports and the RD bars set on full stiff front, medium rear. Since then, I have replaced my rear shocks with re-valved Bilstein Sports that have the compression increased 25% and rebound increased 40%. Before, my suspension was firm, but compliant. Now, it's STIFF.
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Guest
9. H&R Springs - ~220-240 lb/in - 32mm drop, or 1.25 in. drop
10. Racing Dynamics - 274 lb/in - 32mm drop, or 1.25 in. drop
Raj,
H&R are still a little on the weak side per the info @ M535i.org. IIRC, they might also be a progessive rate spring, but I could be mistaken.
I have RD Sports for the M5, same drop as your H&R but with ~15-25% more rate than your H&R springs. I'll be running Koni SA Yellows and probably will purchase RD Sport swaybars.
Rich
H&R are still a little on the weak side
Yeah, they're a little softer than I'd like, but the suspension feels sooo much better since I installed the revalved Bilsteins. They should tide me over until it's time for some uber-stiff GCs with custom valved inserts/shocks.
I have RD Sports for the M5, same drop as your H&R but with ~15-25% more rate than your H&R springs. I'll be running Koni SA Yellows and probably will purchase RD Sport swaybars.
That's a very nice setup you'll have...think the Konis are worth the extra dough? I like the idea of adjustability (though they're not double-adjustable), but have heard from some driving instructors/racers that for track use, Konis generally have to be rebuilt 2-3 times as often as Bilsteins. Not sure how true that is, but that's what they told me.
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C.R. Krieger
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Sorry; that's not how it read. It looks (at least in your first message) like you're going to bigger bars. So my natural instinct is to say, 'Whoa; let's think about this process from the beginning.' Now it appears we're already in the middle. So I misunderstood. We get old ... we get foggy ... we get crotchety.Huh? Hell bent on doing the upgrade? Have you even read the rest of the thread? I have had "bigger bars" (RD 22/16) on my car for about 4 years now,
If you're getting that close, you probably ought to be thinking about adjustable bars. Also gove some serious consideration to the later posts suggesting that your springs maybe aren't as stiff as you might think. A shorter, but progressive, spring would tend to exert more force on those mounting points. Every time I have a wheel off, I have to shake my head and wonder why BMW put such cheesy bits on the way they did.As it is, my suspension is very stiff, so I don't really need the bars to counter body roll...just to tune the handling balance of the car.
Hey; you wanna come up here and race one? :@So how do chimpanzees feel about the Ford Mondeo...I mean Jaguar X-type?
If you do, don't forget your snow tires!
Truth is, it belongs to 'She Who Must Be Obeyed'. I drive Da Jeep ... %) Seriously, Ford or not (actually second generation Mondeo), it's a helluva fun car. Hammering it away from a snowy stop with traction control on AWD makes Da Red Dog's LSD seem positively primitive by comparison.
also, I don't see it listed here, but I just called the dealer to get the price for the frame brackets on the M5 for the front bar...
$11ea before CCA discount..... they are ubercheap... BMW has everything else you need exept the bars... unless you want to buy my bars with all the other stuff already....
but you better hurry because I might decide to actually put mine on the car.... a year later....
$11ea before CCA discount..... they are ubercheap... BMW has everything else you need exept the bars... unless you want to buy my bars with all the other stuff already....
but you better hurry because I might decide to actually put mine on the car.... a year later....
Sorry; that's not how it read. It looks (at least in your first message) like you're going to bigger bars. So my natural instinct is to say, 'Whoa; let's think about this process from the beginning.' Now it appears we're already in the middle. So I misunderstood. We get old ... we get foggy ... we get crotchety.
lol
If you're getting that close, you probably ought to be thinking about adjustable bars. Also gove some serious consideration to the later posts suggesting that your springs maybe aren't as stiff as you might think. A shorter, but progressive, spring would tend to exert more force on those mounting points. Every time I have a wheel off, I have to shake my head and wonder why BMW put such cheesy bits on the way they did
The RD bars are adjustable (2 way front, 3 way rear). The H&R's aren't as stiff as I'd like them (GCs in the future), but my suspension as a whole is pretty damn stiff now, mostly due to the rear shocks.
Hey; you wanna come up here and race one?...Hammering it away from a snowy stop with traction control on AWD makes Da Red Dog's LSD seem positively primitive by comparison.
I'd love to! Except I'd be driving my dad's QX4, with ATTESA AWD (similar to Skyline GT-R AWD system) and a limited-slip rear end. This thing is a drift machine in the snow...the LSD rear keeps the wheels spinning while the fronts just pull you through a 4-wheel drift. I need to find that video we made up in Tahoe...