Spring rates
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Spring rates
OK can some one give me the basics. I am looking at a set of coil overs for a new car I am setting up. The company that makes them is telling me I can get any spring rate I want.
I was informed that its based off the strut. So If I am going with Bielstien sports, is that all I need to consider. Or does the car weight also come into play?
Im jsut trying to get every ones input on this, because there is a bit of contradiction of Info out on the net..
B
I was informed that its based off the strut. So If I am going with Bielstien sports, is that all I need to consider. Or does the car weight also come into play?
Im jsut trying to get every ones input on this, because there is a bit of contradiction of Info out on the net..
B
Turn 7 at Sebring
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yes, there are many things to consider. Weight of the car, strut type, drive set-up and road/track conditions. I would ask some people that race/drive your car which spring rate works for them. I run 8/6 on my 240sx at Sebring and really like them, but I could probably move up to a 10/8 at a smoother track like Homestead.
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Yep, best bet is to find people who know your particular car and have set them up for your particular purpose. (autox spring rates won't be the same as track spring rates, for instance)
In the Miata world, there are lots of engineers who have taken all of the critical measurements and made it easy for non-engineers (like me) to calculate things like the "front roll couple percentage" (a good indicator of the car's balance... takes into account front and rear spring rates, motion ratios, swaybar rates, etc) and the total roll resistance (a good indicator of transitional response, turn-in... and ride harshness). I would be surprised if such info was not available in the BMW community.
With that, you can make a decision, such as... "I want to run 550 pound front springs, stiffer than that would be too much for some of the rough surfaces that I have to run on"... and then you can determine what rear spring rates and swaybar rates you would need to balance the car.
Or you could just call somebody like Ground Control and get their suggestions. (heck, call several places and see if you get similar suggestions) Or you could just guess and do your own experimentation... there is much to be learned by experiencing what "wrong" feels like... though it does waste time and money.
In the Miata world, there are lots of engineers who have taken all of the critical measurements and made it easy for non-engineers (like me) to calculate things like the "front roll couple percentage" (a good indicator of the car's balance... takes into account front and rear spring rates, motion ratios, swaybar rates, etc) and the total roll resistance (a good indicator of transitional response, turn-in... and ride harshness). I would be surprised if such info was not available in the BMW community.
With that, you can make a decision, such as... "I want to run 550 pound front springs, stiffer than that would be too much for some of the rough surfaces that I have to run on"... and then you can determine what rear spring rates and swaybar rates you would need to balance the car.
Or you could just call somebody like Ground Control and get their suggestions. (heck, call several places and see if you get similar suggestions) Or you could just guess and do your own experimentation... there is much to be learned by experiencing what "wrong" feels like... though it does waste time and money.
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Oh, to answer your question about shocks... you need shocks to match your springs. (or, I guess you could do it the other way around)
If you put more spring rate on your Bilsteins than their valving can handle, the car will be "floaty" or "bouncy". How much spring your particular shocks can handle is another question the BMW experts should know the answer to.
Unless you just want to experiment, you may find that it's less expensive in the long run to just buy a complete kit with matched shocks and springs specifically designed for your car. (for a BMW... maybe not)
If you put more spring rate on your Bilsteins than their valving can handle, the car will be "floaty" or "bouncy". How much spring your particular shocks can handle is another question the BMW experts should know the answer to.
Unless you just want to experiment, you may find that it's less expensive in the long run to just buy a complete kit with matched shocks and springs specifically designed for your car. (for a BMW... maybe not)
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Yea how did you know its a BMW?I'm getting 318ti, I like the way the 4 cyl cars handle . I'm going to do an M50 engine swap on the black car and set it up for track events.Russ's 318 is set nice so ill check to see what he is running re springs. plus call around. thanks for the info..
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Heh, I just skimmed your message and assumed you were talking about the black bimmer. D'oh!
Just remember that it's important to have sufficient dampers to go with your springs. I wouldn't be surprised if you ended up with some VERY stiff springs, especially on the track car. (800's?) Typical shocks won't like that very much. The good news is that Bilsteins are revalvable, so you can have them custom valved to match your spring rates and your intended use.
Just remember that it's important to have sufficient dampers to go with your springs. I wouldn't be surprised if you ended up with some VERY stiff springs, especially on the track car. (800's?) Typical shocks won't like that very much. The good news is that Bilsteins are revalvable, so you can have them custom valved to match your spring rates and your intended use.
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The Fat Cobra
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I have talked to Russ several times about his car. I believe he is using the Bilestien PSS coilovers.
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You need to grab ahold of that line between speed and chaos, and you need to wrestle it to the ground like a demon cobra.-Talladega Nights
You need to grab ahold of that line between speed and chaos, and you need to wrestle it to the ground like a demon cobra.-Talladega Nights
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I hear Bilstein tech support is top notch. I bet a phone call would get you the info you are looking for. They could tell you what would work best with the shocks you have.
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Drew Scoda
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Ksport USA - Performance Suspension - Contact Us
don't be ashamed. Loren and myself are so impressed by this kit, yea the spring rates are not perfect for an all out track beast but they did a very nice job of choosing springrates that work awesome on the track and the dampers allow you to adjust the slightst bit of understeer all the way to oversteer oh and this weekend we were faster then ALOT of all out race cars.
Their MSRP numbers look real high but mine MSRP for $1500 and I paid $700 shipped so I assume the BMW ones can be had for under $1000 I did talk to them and for not much more (an extra $100 street price) they will match the valving and spring rate to suit your needs, however I was very satisfied with their off the shelf setup. little things like they include top mounts (which on E30 cars are infamous for failing) and camber plates. these things were never availble to me when I was a BMW nut, and NO WAY at these prices.
They are monotube high pressure gas and identical in design to Bilstein.
as a past E36/7 owner (Z3)
your Ti is an E36/5 and identical in suspension design.
I spent WAY too much money trying to make off the shelf bilsteins work. and when I finally got them revalved. it cost me more then a set of Coilovers... just a warning.
there is a Dealer right on hillsborough avenue too that sells them at bargian basement prices. even the custom valved/sprung RR models.
Good luck.
don't be ashamed. Loren and myself are so impressed by this kit, yea the spring rates are not perfect for an all out track beast but they did a very nice job of choosing springrates that work awesome on the track and the dampers allow you to adjust the slightst bit of understeer all the way to oversteer oh and this weekend we were faster then ALOT of all out race cars.
Their MSRP numbers look real high but mine MSRP for $1500 and I paid $700 shipped so I assume the BMW ones can be had for under $1000 I did talk to them and for not much more (an extra $100 street price) they will match the valving and spring rate to suit your needs, however I was very satisfied with their off the shelf setup. little things like they include top mounts (which on E30 cars are infamous for failing) and camber plates. these things were never availble to me when I was a BMW nut, and NO WAY at these prices.
They are monotube high pressure gas and identical in design to Bilstein.
as a past E36/7 owner (Z3)
your Ti is an E36/5 and identical in suspension design.
I spent WAY too much money trying to make off the shelf bilsteins work. and when I finally got them revalved. it cost me more then a set of Coilovers... just a warning.
there is a Dealer right on hillsborough avenue too that sells them at bargian basement prices. even the custom valved/sprung RR models.
Good luck.
Last edited by treekiller; Feb 12, 2007 at 07:32 AM.
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Well I have been speaking with other drivers and have also heard that I may want to go with an adjustable shock so that I can tweak the reabound setting if I were to change springs.
So Konis have come into the picturre.
Seems the 318ti is a e36 front and a e30 rear suspension. So they are a little differnt.
I also have seen Ciol overs/ adjustable pearch set ups for 400 to 700, with pretty much any sping rate I need. So Im still going to do a little more research and decide.
Thanks for all the data..
B
So Konis have come into the picturre.
Seems the 318ti is a e36 front and a e30 rear suspension. So they are a little differnt.
I also have seen Ciol overs/ adjustable pearch set ups for 400 to 700, with pretty much any sping rate I need. So Im still going to do a little more research and decide.
Thanks for all the data..
B
