Bilstien Sports and M5 Thrust Arm Bushies installed

My fears over these being too stiff are gone. They are perfect,I love them. But even after;New Tie Rods,new Lemforder M5 upper control arm/ Thrust arm bushings,new hub-centric rings all around one wheel trued and balanced on the right rear and two front wheels balanced i can still ever so slightly detect around 55 MPH an occasional steering wheel connected wobble.Only at certain times but i really feel it and i don't believe i should. can the Lower C/A's allow for this? What else up front need i inspect and or replace? Sway bar bushings? Sway bar links? Lower control arms? what else is there? Rotors aren't even a year old (Brembo slotted with Akebono proAct pads still with plenty of meat) The shop who did the suspension had to apply weights to the outer lip on my Rondell 58's to get them to balance... its an abomination to say the least but i thanked him for actually getting them balanced. I suggested if they needed that then they must be bent and he said they weren't( he did balance them ,i guess he'd have seen if they were) anyway like i say maybe I'm being extreme and failing to distinguish road ripples from wheel wobble but i am pretty sure i can still sometimes detect it slightly.. maybe his balance job wasn't as good as he believed. Should i try it on a Road-force balancer? can they reveal anything beyond wheel balance?

A road-force balance might help. What they do is de-mount the tire, put the wheel on the machine and measure the runout with a dial indicator which the computer stores runout vs. azimuth info. Next they mount the tire and a 5" +/- dia. pinch wheel applies the appropriate force to the tire to simulate actual ground contact. This measures stiff & soft spots in the sidewalls, stores that info also. Then they push the tire beads off the rim and rotate the tire to the optimum position on the wheel such that the stiffest part of the sidewheel coincides with the lowest spot on the rim. They road force it again and confirm that the reading is within an acceptable amount usually 15% or less. A good tire will usually fall within 5-10%. If it passes that stage, they balance it and call it good. They'll be able to tell at the 1st stage if the wheel is bent.

Maybe have the alignment checked if they didn't do that with the suspension repairs. That much tampering can upset it.

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Originally Posted by Jehu

My fears over these being too stiff are gone. They are perfect,I love them. But even after;New Tie Rods,new Lemforder M5 upper control arm/ Thrust arm bushings,new hub-centric rings all around one wheel trued and balanced on the right rear and two front wheels balanced i can still ever so slightly detect around 55 MPH an occasional steering wheel connected wobble.Only at certain times but i really feel it and i don't believe i should. can the Lower C/A's allow for this? What else up front need i inspect and or replace? Sway bar bushings? Sway bar links? Lower control arms? what else is there? Rotors aren't even a year old (Brembo slotted with Akebono proAct pads still with plenty of meat) The shop who did the suspension had to apply weights to the outer lip on my Rondell 58's to get them to balance... its an abomination to say the least but i thanked him for actually getting them balanced. I suggested if they needed that then they must be bent and he said they weren't( he did balance them ,i guess he'd have seen if they were) anyway like i say maybe I'm being extreme and failing to distinguish road ripples from wheel wobble but i am pretty sure i can still sometimes detect it slightly.. maybe his balance job wasn't as good as he believed. Should i try it on a Road-force balancer? can they reveal anything beyond wheel balance?

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So now you have m5 thrust arm bushings BIlstein sport shocks and it isn't too stiff or rough? I've been thinking about these. How does it handle? and what springs are you using?
Thanks
-Mike

the heavier the wheel/tire the harder it is to shake the shimmey, 15s and 16s are fairly easy to get to run true but bigger then that and the weight is harder to control, stiff thick sidewalls and bigger rims gets the mass farther from the hub, and that shows the flaw in the suspension design, if you think a e34 shimmeys you outta check out a e38 with 19"s, you'd think the car was coming off the ground

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Originally Posted by Sam-Son

So now you have M5 thrust arm bushings BIlstein sport shocks and it isn't too stiff or rough? I've been thinking about these. How does it handle? and what springs are you using?
Thanks
-Mike

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I have the stock BMW lowered "M Sport" springs which came as an option from the factory;704 M SPORT SUSPENSION . I have to say first i haven't really driven any other sport cars. I test drove an E36 328 for about ten minutes and was a passenger for about that long in an E28 M5 so i don't really have any real sense of what this is like compared to anything else. For most of the past ten years i drove a Chevy cargo van as my daily driver... that being said the car handles incredibly well. It is very stable on the highway at high speeds and corners with ample bite but i will be buying a welded steel strut brace soon and we'll see what that can do. I have 17" wheels and newish within two months Bridgestone Turenza's rated to 164 MPH. I had it up to 120 MPH today a few times and it was just awesome, really without any real persistent hint of looseness or vibrations anywhere at this speed my only distractions were the limits of the road from other cars and that always nagging concern of being spotted by the Constabulary and getting the book thrown at me. I was really worried when the guy who put these on,in my phone conversation with him after he had installed them before i picked it up said it was "stiff" but when i got in it was really just wonderful. If this is stiff i like stiff. Even over the roughest messed up pavement and multiple train tracks it ( the suspension) defeats the surface irregularities with authority and does nothing like i imagined such as crush my spine and rattle my skull. Its not to me in any way a disappointment i even slightly consider undoing.. I;d go for it.

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Originally Posted by winfred

the heavier the wheel/tire the harder it is to shake the shimmey, 15s and 16s are fairly easy to get to run true but bigger then that and the weight is harder to control, stiff thick sidewalls and bigger rims gets the mass farther from the hub, and that shows the flaw in the suspension design, if you think a e34 shimmeys you outta check out a e38 with 19"s, you'd think the car was coming off the ground

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yah i had that explained today with my huge lipped Rondells. I could tell he felt while they may look good they aren't a great design from a technical perspective . I am being very strict about what i think i'm feeling maybe most people would just consider it " normal" and not even think it something you could or should worry about but i know the thing can run with an absolutly solid, smooth, quiet ride where even the most violent road conditions are defated absolutley and induce no persistant infirmity for a driver to feel once over them . In other words if i can feel the steering wheel even sligjhtly shake even on very smooth pavement at 55 mph i have to believe something can still be tuned and the rims are beginning to appear the likley culprit even thogh so far all the diagnostics come back as "accapetable" . I've tasted perfection before in this thing so I know its possible..

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Originally Posted by gale

A road-force balance might help. What they do is de-mount the tire, put the wheel on the machine and measure the runout with a dial indicator which the computer stores runout vs. azimuth info. Next they mount the tire and a 5" +/- dia. pinch wheel applies the appropriate force to the tire to simulate actual ground contact. This measures stiff & soft spots in the sidewalls, stores that info also. Then they push the tire beads off the rim and rotate the tire to the optimum position on the wheel such that the stiffest part of the sidewheel coincides with the lowest spot on the rim. They road force it again and confirm that the reading is within an acceptable amount usually 15% or less. A good tire will usually fall within 5-10%. If it passes that stage, they balance it and call it good. They'll be able to tell at the 1st stage if the wheel is bent.

Maybe have the alignment checked if they didn't do that with the suspension repairs. That much tampering can upset it.

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Good idea. The shop who did the Tie Rods did a laser alignment so i supose they can check it again as part of the original job last week.

you can always swap the wheels front to back if they are the same size and see if that changes anything, occasionally you will get a slightly out of round tire that won't show up on a less sensitive suspension

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Originally Posted by winfred

you can always swap the wheels front to back if they are the same size and see if that changes anything, occasionally you will get a slightly out of round tire that won't show up on a less sensitive suspension

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Wow, as a matter of fact before i had this done last week,before the suspension and before the tie rods there was no hint of the steering wobble i mention .... its so simple and yet i just guessed the rear tires would be fine since they were on the rear but when they came up front that's when all this happened but becasue one of the hubcentric rings was left off then a tie rod end looked bad i put the idea it could be the Tire out of mind partly i think becaseu i didn't wnat to seem like a pain in the ass to these guys but i'll return the fronts to the rear again and see if that does it.. it really was just fine before but for a slight high speed vibration not the wobble and i attributed that to a slightly bent rim which I assumed was on the front but i guess it could have been on the back just as well. God knows it was the solution once before..

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Originally Posted by Jehu

I have the stock BMW lowered "M Sport" springs which came as an option from the factory;704 M SPORT SUSPENSION . I have to say first i haven't really driven any other sport cars. I test drove an E36 328 for about ten minutes and was a passenger for about that long in an E28 M5 so i don't really have any real sense of what this is like compared to anything else. For most of the past ten years i drove a Chevy cargo van as my daily driver... that being said the car handles incredibly well. It is very stable on the highway at high speeds and corners with ample bite but i will be buying a welded steel strut brace soon and we'll see what that can do. I have 17" wheels and newish within two months Bridgestone Turenza's rated to 164 MPH. I had it up to 120 MPH today a few times and it was just awesome, really without any real persistent hint of looseness or vibrations anywhere at this speed my only distractions were the limits of the road from other cars and that always nagging concern of being spotted by the Constabulary and getting the book thrown at me. I was really worried when the guy who put these on,in my phone conversation with him after he had installed them before i picked it up said it was "stiff" but when i got in it was really just wonderful. If this is stiff i like stiff. Even over the roughest messed up pavement and multiple train tracks it ( the suspension) defeats the surface irregularities with authority and does nothing like i imagined such as crush my spine and rattle my skull. Its not to me in any way a disappointment i even slightly consider undoing.. I;d go for it.

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Thanks that helps