Weltmeister front sway bar install questions
11-11-2018, 04:25 PM
#1
Burning Brakes
Thread Starter
Weltmeister front sway bar install questions
Well, with a picture being worth a thousand words, I was going to post a few pictures describing what I want to ask, but the site isn't letting me upload pictures for some reason - I go to the download page, select my images (which I've shrunk down to size), but when I try to upload them, they disappear. I've gone through the procedure multiple times, and am getting frustrated because I don't have all afternoon to mess with. So, here's he best I can do - if anyone here has ever installed a Weltmeister adjustable front sway bar, please IM me, and I'll send you an email with the pictures.
But the bottom line is this - the bar I purchased (used) came with three pairs of metal plates: One is 6.5 inches long by 1-3/8 inches wide by 7/16" thick, with 5 holes drilled in it. This one I understand - it's the mounting plate of the hanger bracket for the sway bar. It's the other two that I can't figure out where, if anywhere (on my car) they belong. The first mystery plate is 3-3/4" long by 1.5" wide by 11/16" thick, with 3/8" diameter hols drilled neat its ends. The second mystery plate is 4" long by 2" wide by 1/8" thick, with a pair of 3/8" holds drilled a little off center. These holes are the same distance apart as the holds in the first plate for the bolts that attach the first plate to the chassis, so it looks like a reinforcement plate. But if I installed it against the chassis, the mounting plate for the sway bar hanger bracket would no longer be parallel to the ground. Man, I sure wish I could post those pictures... Thanks in advance for any help.
But the bottom line is this - the bar I purchased (used) came with three pairs of metal plates: One is 6.5 inches long by 1-3/8 inches wide by 7/16" thick, with 5 holes drilled in it. This one I understand - it's the mounting plate of the hanger bracket for the sway bar. It's the other two that I can't figure out where, if anywhere (on my car) they belong. The first mystery plate is 3-3/4" long by 1.5" wide by 11/16" thick, with 3/8" diameter hols drilled neat its ends. The second mystery plate is 4" long by 2" wide by 1/8" thick, with a pair of 3/8" holds drilled a little off center. These holes are the same distance apart as the holds in the first plate for the bolts that attach the first plate to the chassis, so it looks like a reinforcement plate. But if I installed it against the chassis, the mounting plate for the sway bar hanger bracket would no longer be parallel to the ground. Man, I sure wish I could post those pictures... Thanks in advance for any help.
11-11-2018, 08:58 PM
#3
Burning Brakes
Thread Starter
I'm having nothing but trouble with this forum today (although it could easily be on my end, as opposed to something with the forum). I wrote a fairly long response to your message, then got an error message, the wording of I can't remember, indicating things had shut down, before I had a chance to hit Submit. I've wasted too much time fighting with this today already, so I'll abbreviate and say that I've seen the thread your picture came from, but just now noticed what appears to the the first of two "mystery plates" - it looks like it's an adapter between the drop link and the control arm. I have Racers Edge arms, so I don't think I'll be needing this plate, which is good, because it's quite a heavy lump of metal!
11-12-2018, 02:07 AM
#4
Three Wheelin'
I can't help you with your installation, but I wonder how durable that setup is with the pair of spacer tubes for the forward mounting bolts of the center bushings. I ran in the POC "JI" class of time trials for a few years, which stipulated stock springs, but sway bars were free. I first ran 968 M030 bars (went to stock 968 front bar to quell understeer), then went to Tarett sway bars front and rear. Between the two I managed to tear out the front sway bar center mounts from the frame rails on both sides! This was because I was too dependent on heavy sway bars and stock springs. After welding reinforcements on the frame rails and running properly stiff springs, I have never had an issue since.
I only bring this up as food for thought for those thinking of running such sway bars on the track with soft springs . . . . .
I only bring this up as food for thought for those thinking of running such sway bars on the track with soft springs . . . . .
11-12-2018, 06:01 PM
#5
Burning Brakes
Thread Starter
Chris,
That sounds like a valid concern, but I may have a couple of factors that could mitigate it. First, I think one of the two "mystery plates" I mention in my first post is a reinforcement plate that goes between the spacer tubes and the frame rails. These should help dissipate the forces. Second, I'm running pretty stiff springs - probably too stiff, at 700 lb/in. For a suspension frequency of 150 cpm, I think I should be running closer to 450-500 lb/in. I plan to measure the unsprung weight soon to get an accurate assessment. I see you're running 500 lb/in. I have a whole project planned over the next few months to raise my front and rear roll centers, get my spring rates right, optimize my front/rear roll stiffness, etc.
That sounds like a valid concern, but I may have a couple of factors that could mitigate it. First, I think one of the two "mystery plates" I mention in my first post is a reinforcement plate that goes between the spacer tubes and the frame rails. These should help dissipate the forces. Second, I'm running pretty stiff springs - probably too stiff, at 700 lb/in. For a suspension frequency of 150 cpm, I think I should be running closer to 450-500 lb/in. I plan to measure the unsprung weight soon to get an accurate assessment. I see you're running 500 lb/in. I have a whole project planned over the next few months to raise my front and rear roll centers, get my spring rates right, optimize my front/rear roll stiffness, etc.
11-12-2018, 06:08 PM
#6
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11-12-2018, 07:25 PM
#7
Rennlist Member
I can't help you with your installation, but I wonder how durable that setup is with the pair of spacer tubes for the forward mounting bolts of the center bushings. I ran in the POC "JI" class of time trials for a few years, which stipulated stock springs, but sway bars were free. I first ran 968 M030 bars (went to stock 968 front bar to quell understeer), then went to Tarett sway bars front and rear. Between the two I managed to tear out the front sway bar center mounts from the frame rails on both sides! This was because I was too dependent on heavy sway bars and stock springs. After welding reinforcements on the frame rails and running properly stiff springs, I have never had an issue since.
I only bring this up as food for thought for those thinking of running such sway bars on the track with soft springs . . . . .
I only bring this up as food for thought for those thinking of running such sway bars on the track with soft springs . . . . .
I have had this sway bar on my car for 12 years with absolutely zero problems. The car is a dedicated track car and was raced during its career.
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11-12-2018, 07:32 PM
#8
Rennlist Member
Chris,
That sounds like a valid concern, but I may have a couple of factors that could mitigate it. First, I think one of the two "mystery plates" I mention in my first post is a reinforcement plate that goes between the spacer tubes and the frame rails. These should help dissipate the forces. Second, I'm running pretty stiff springs - probably too stiff, at 700 lb/in. For a suspension frequency of 150 cpm, I think I should be running closer to 450-500 lb/in. I plan to measure the unsprung weight soon to get an accurate assessment. I see you're running 500 lb/in. I have a whole project planned over the next few months to raise my front and rear roll centers, get my spring rates right, optimize my front/rear roll stiffness, etc.
That sounds like a valid concern, but I may have a couple of factors that could mitigate it. First, I think one of the two "mystery plates" I mention in my first post is a reinforcement plate that goes between the spacer tubes and the frame rails. These should help dissipate the forces. Second, I'm running pretty stiff springs - probably too stiff, at 700 lb/in. For a suspension frequency of 150 cpm, I think I should be running closer to 450-500 lb/in. I plan to measure the unsprung weight soon to get an accurate assessment. I see you're running 500 lb/in. I have a whole project planned over the next few months to raise my front and rear roll centers, get my spring rates right, optimize my front/rear roll stiffness, etc.
11-12-2018, 08:37 PM
#9
Burning Brakes
Thread Starter
11-12-2018, 09:04 PM
#10
Burning Brakes
Thread Starter
Spring rate = ((sprung weight)*(suspension frequency/π)^2)÷(motion ratio)^2
I'm going to use suspension frequencies of 2.5 cps for the front, and 2.25 for the rear, as these appear to be reasonable starting points for a non-aero car like mine. I haven't measured my car's unsprung weights, but using estimates, and knowing my car's total weight (2860 lb empty, so about 3035 lb with me in it), and making some assumptions (which may be way off) for the unsprung weight, I come up with estimates of front/rear spring rates of 531/795. I have coilovers all around, torsion bars deleted. So my current rear spring rate of 800 is probably close, by my 700 lb fronts are probably too heavy.
11-13-2018, 01:11 AM
#11
Rennlist Member
I'm going to calculate my front and rear spring rates using;
Spring rate = ((sprung weight)*(suspension frequency/π)^2)÷(motion ratio)^2
I'm going to use suspension frequencies of 2.5 cps for the front, and 2.25 for the rear, as these appear to be reasonable starting points for a non-aero car like mine. I haven't measured my car's unsprung weights, but using estimates, and knowing my car's total weight (2860 lb empty, so about 3035 lb with me in it), and making some assumptions (which may be way off) for the unsprung weight, I come up with estimates of front/rear spring rates of 531/795. I have coilovers all around, torsion bars deleted. So my current rear spring rate of 800 is probably close, by my 700 lb fronts are probably too heavy.
Spring rate = ((sprung weight)*(suspension frequency/π)^2)÷(motion ratio)^2
I'm going to use suspension frequencies of 2.5 cps for the front, and 2.25 for the rear, as these appear to be reasonable starting points for a non-aero car like mine. I haven't measured my car's unsprung weights, but using estimates, and knowing my car's total weight (2860 lb empty, so about 3035 lb with me in it), and making some assumptions (which may be way off) for the unsprung weight, I come up with estimates of front/rear spring rates of 531/795. I have coilovers all around, torsion bars deleted. So my current rear spring rate of 800 is probably close, by my 700 lb fronts are probably too heavy.
11-13-2018, 11:40 AM
#12
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That spacer was used on the kit for aluminum control arm cars...basically 1985.5 and later. The earlier cars that had steel arms didn't use the spacer.
11-13-2018, 03:29 PM
#13
Burning Brakes
Thread Starter
Also, my bar came with a thinner (1/8" thick) rectangular metal plate with a couple of holes that are the same distance apart as the threaded holes in the frame rails. I assume this is a reinforcement plate that goes between the sleeved mounting bolts and the frame rail, correct? Thanks.
11-13-2018, 04:03 PM
#14
Rennlist Member
11-13-2018, 08:51 PM
#15
Burning Brakes
Thread Starter
My bar came with a plate that I think is intended to serve the same function as the piece you made. It's only 1/8" thick, but its longer than the the one your made. I'd post a picture, but it still isn't working...