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DISCUSSION => General Topics => Topic started by: romkasponka on November 28, 2006, 08:10:07 AM

Title: coil-over
Post by: romkasponka on November 28, 2006, 08:10:07 AM
what do you think? F500/R450 lbs/in

(http://img134.imageshack.us/img134/6207/surinkimasvh2.jpg)
Title: coil-over
Post by: Gunni on November 28, 2006, 09:10:44 AM
according to the internet the ratio of the rear springs is .65
100lbs work as 65lbs and so on,

500front and 292lbs doesn“t sound right,
What are you basing the numbers on?

Also if the sleeve is more then 51mm it will fit, I had a 51mm sleeve opened up by 1mm the other day to make things fit
Title: coil-over
Post by: romkasponka on November 28, 2006, 09:14:03 AM
The rear will be direct fit on the damper. So the ratio will be ~1,1 or more.

suspensio frequency wiil be F 163 cpm, R 186 cpm.
Title: coil-over
Post by: Gunni on November 28, 2006, 09:25:14 AM
Well in that case,
I belive I read on the gustave site or elsewhere that the rear needs a little more stiffness then the front to neutralize understeer tendency
Title: coil-over
Post by: romkasponka on November 28, 2006, 09:31:34 AM
In my case efective stiffnes is    F500/R540
Title: coil-over
Post by: D. Clay on November 28, 2006, 02:36:55 PM
What about the upper shock mounting area. You're gonna need beef! 500+ pounds/inch into that? Get out the welder!
Title: coil-over
Post by: romkasponka on November 28, 2006, 03:30:59 PM
I'm thinking about rear strut bar.........
Title: coil-over
Post by: romkasponka on November 28, 2006, 03:34:28 PM
Quote from: D. Clay;14597
What about the upper shock mounting area. You're gonna need beef! 500+ pounds/inch into that? Get out the welder!


What do you mean by saying beef? Sorry for my poor english.
I found that M3 had 685/1027.  :D
Title: coil-over
Post by: Gunni on November 28, 2006, 03:34:41 PM
Quote from: romkasponka;14571
In my case efective stiffnes is    F500/R540


Could you explain why you get that effective ratio?
Title: coil-over
Post by: romkasponka on November 28, 2006, 03:37:08 PM
rear shock is mounted behaind halfshaft, so the shock lever is bigger than wheel lever.
Title: coil-over
Post by: Gunni on November 28, 2006, 03:40:57 PM
could you explain the painting a little bit more?
where exactly are you thinking about mounting the rear shock?
Title: coil-over
Post by: romkasponka on November 28, 2006, 03:54:10 PM
(http://img105.imageshack.us/img105/7303/strutbarsb5.gif)

(http://img105.imageshack.us/img105/485/scanneditems034oa1.jpg)

(http://img163.imageshack.us/img163/5337/rearcoilover1ld9.jpg)
Title: coil-over
Post by: Gunni on November 28, 2006, 06:59:10 PM
If you use a strut brace in the back you will probably need to add strenght from it to the body with welding,
Title: Where's the beef?
Post by: D. Clay on November 28, 2006, 09:12:42 PM
Quote from: romkasponka;14605
What do you mean by saying beef? Sorry for my poor english
As in the expression "beef it up". Meaning to reinforce, brace, and  strengthen. It may be a US expression. All of the rear suspension load will be entering the structure at the upper shock mount. It was designed for the shock only and not the shock and spring load.
Here's a link to a picture and text explaining some of the ratios discussed above:
http://e30m3performance.com/tech_articles/susp-tech/eff_rate/eff_rate2.htm
This is the best article I am aware of. Note on the first page the author indicates that his earlier determination was in error. Suspension is art, craft,  science, and voodoo.
Title: coil-over
Post by: romkasponka on November 29, 2006, 07:35:17 AM
Quote from: D. Clay;14642
http://e30m3performance.com/tech_articles/susp-tech/eff_rate/eff_rate2.htm
This is the best article I am aware of. Note on the first page the author indicates that his earlier determination was in error. Suspension is art, craft,  science, and voodoo.


Yes, I know this article.

I would like to be a woodoo master :)
Title: coil-over
Post by: 2002maniac on December 04, 2006, 11:39:23 AM
sounds good! My effective spring rates are 400/422 (using the .65 calculation for the rear) and I think the balance is perfect!  are you going to build the setup yourself?

What about valving?

If I had the money, I know my car would bebefit by revalving the shocks.
Title: coil-over
Post by: romkasponka on December 17, 2006, 09:59:59 AM
front 300/300 rear 200/200, or 150/300 100/200. I will ask bilstein for best setup.
Title: coil-over
Post by: D. Clay on December 17, 2006, 01:12:58 PM
The short track stock car racers now use Penske adjustables.  They  put the car on a skid pad (a big circle) and spring it for desired wheel travel and neutral handling at max lateral G's. This results in a slight under steer in the real world. Then they use the shocks to fine tune the car. They now change springs 2-3 times a season instead of 6-8 times. In real terms, front engine sedans are almost always stiffer in the front than the rear. A 2600# stock car usually runs 400# front and 200# rear springs. A TransAm Camaro or Mustang. will run 500#-700# front and 250#-400# rears. E30's usually run with 15" wheels and tires with a soft spring rate. E30 types in general use springs to control body roll in place of sway bars. They put stiff springs on the rear and take off the rear bar.
Title: coil-over
Post by: romkasponka on December 17, 2006, 02:31:29 PM
How much cost penske adjustable shocks?
Title: Not cheap.
Post by: D. Clay on December 17, 2006, 08:07:05 PM
Quote from: romkasponka;15742
How much cost penske adjustable shocks?
http://www.lefthanderchassis.com/107.html
http://www.lefthanderchassis.com/108.html (http://www.lefthanderchassis.com/107.html)
http://www.lefthanderchassis.com/109.html (http://www.lefthanderchassis.com/107.html)
$200 to $1000 each depending on the model. I don't know of any adjustable valving strut inserts.
Title: coil-over
Post by: romkasponka on December 18, 2006, 03:43:42 AM
http://www.avouk.com/pm/123 (http://www.avouk.com/pm/123)
Title: coil-over
Post by: dino245 on December 18, 2006, 09:13:49 AM
The AVO struts are nice but the E30 has an itegral hub and strut so you would need to build a strut assy. with the axel stub onit.
Title: coil-over
Post by: romkasponka on December 18, 2006, 09:16:46 AM
AVO inserts nice too ;)

(http://www.avouk.com/mediastore//IMG/10138.jpg)
Title: coil-over
Post by: romkasponka on December 18, 2006, 09:19:18 AM
Quote from: D. Clay;15739
A 2600# stock car usually runs 400# front and 200# rear springs. A TransAm Camaro or Mustang. will run 500#-700# front and 250#-400# rears. E30's usually run with 15" wheels and tires with a soft spring rate. E30 types in general use springs to control body roll in place of sway bars. They put stiff springs on the rear and take off the rear bar.


Spring mean nothing, you should say frequency.
Title: coil-over
Post by: Gunni on December 18, 2006, 09:31:00 AM
could you explain why frequency make more sense then spring stiffness?
Title: coil-over
Post by: romkasponka on December 18, 2006, 09:48:07 AM
because to make setup you selecting suspension frequency which you want to have, after calculation you get wheel ratio, and only after you calculate spring ratio. Your wheel rate could be affected by suspension type and geometry, so spring doesn't mean nothing if we are talking about various cars, because you dont know what you get on the wheels.
Title: coil-over
Post by: Gunni on December 18, 2006, 10:10:49 AM
Can you give me an example of how you calculate diffrence frequencies using 2 E30“s? only diffrence beeing wheels and spring rates.

Thanks
Title: coil-over
Post by: romkasponka on December 18, 2006, 10:39:08 AM
http://hometown.aol.com/EURORALLY/Suspension1.htm (http://hometown.aol.com/EURORALLY/Suspension1.htm)
Title: coil-over
Post by: romkasponka on February 22, 2007, 02:45:47 AM
update :)

(http://img140.imageshack.us/img140/7429/img0001mediumrd0.jpg)

(http://img266.imageshack.us/img266/3579/img0002mediumfu3.jpg)

(http://img266.imageshack.us/img266/4111/img0003mediumyc8.jpg)
Title: coil-over
Post by: romkasponka on June 29, 2007, 08:56:41 AM
almost done :D

http://romkasponka.blogspot.com/2007/06/tuoj-bus-surinkimas.html
Title: coil-over
Post by: romkasponka on July 01, 2007, 04:14:16 PM
(http://bp3.blogger.com/_MjQwpLOTuIM/RogW58XeqfI/AAAAAAAAAEw/A3_zlbYrV5Q/s1600/IMG_0081%2B(Large).JPG)
Title: coil-over
Post by: romkasponka on October 02, 2008, 07:05:20 AM
Very happy with this setup. Brakes require more time to make good setup, because it is quite easy to lock front wheels. 195 tires are too narrow for this brakes setup. :D
Max camber is about -4,5 deg. Will try setup with bigger caster and less camber. Rear springs are to long for propper clearance so new shorter springs will be fitted.
It feels very stable, no dive and body roll. Front wheels are with 28mm spacers and steering wheel became less loaded during cornering, not bad without power steering. Will try to make few pictures/video on the racetrack. Front stabilizer mounting places are changed and it became more rigid.

(http://www.ipix.lt/thumbs/66163085.jpg) (http://www.ipix.lt/desc/66163085)(http://www.ipix.lt/thumbs/40768408.jpg) (http://www.ipix.lt/desc/40768408)(http://www.ipix.lt/thumbs/70687025.jpg) (http://www.ipix.lt/desc/70687025)(http://www.ipix.lt/thumbs/24055284.jpg) (http://www.ipix.lt/desc/24055284)

(http://www.ipix.lt/thumbs/10991650.jpg) (http://www.ipix.lt/desc/10991650)(http://www.ipix.lt/thumbs/76593672.jpg) (http://www.ipix.lt/desc/76593672)(http://www.ipix.lt/thumbs/56858890.jpg) (http://www.ipix.lt/desc/56858890)(http://www.ipix.lt/thumbs/89281287.jpg) (http://www.ipix.lt/desc/89281287)
Title: coil-over
Post by: JuniorM42 on October 02, 2008, 05:38:06 PM
nice, but GAZ can do you a fully adjustable coilover setup for around £650 (strut exchange) thats included rear strengthend shocker mounts, bump,rebound,damping,height adjustable, its called the "Gaz gold" range, for track and road usage, but you can specify what you want with custom springs rates and what sort of motorsport you will be doing ;)

and if any of you watched the top gear when they entered the BMW Diesel into the 24hr brit-car, they set that up with their coilover systems