hi my name is idan i'm going to finish my last year at practical vehicle engineer course/studies in israel.
my graduation project is going to be an explanation of different types of shock absorbers over the years, springs (leaf,spiral,torsion and air) and some explanation about bumpstops. that will be some history lesson and filling pages... the fun part is going to be an explanation about the setup of the springs/shocks on a car... i'm not going to build a rally car, i have Kia Sportage MK1, its a very small SUV that i want to setup for some "fast" offsroad trail... think about what ford did with f150 -> f150 raptor. I need some bacis steps to start with... like which measurements i need ? and basically how do i chose valving and spring for those measurements... the rear shock is easy to replace with some 46MM bilstain (bilstain 5125/5165) at the front its a bit weird very short shock with fork (like old civics) and i need to see how i Shove some bilstain 5125/5165 there... btw: its body on frame front is double wishbone rear is solid axle ty |
tdrrally edward mucklow Senior Moderator Location: charleston,wv Join Date: 05/31/2011 Age: Possibly Wise Posts: 763 Rally Car: ford mustang LX 5.0, 1973 VW Beetle |
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If you want the engineering/design theory behind shock selection and dampening, look into Tune to Win and Engineer to Win by Carroll Smith for a very basic and easy to understand suspension theory. If you want more info, and to melt your brain, look into Racecar Vehicle Dynamics or listen to some Claude Rouelle seminars (highly recommended). The FSAE and BajaSAE forums also have some serious knowledge on shocks and vehicle dynamics.
http://books.google.com/books/about/Race_Car_Vehicle_Dynamics.html?id=opgHfQzlnLEC https://vimeo.com/41854831 http://www.carrollsmith.com/books/tune2win.html Then once you have a basic understanding of those concepts and measurement, contact Chris Billings at The Shock Shop and try to pick his brain. He's usually friendly... unless you're Robert Gobright http://www.shock-shop.com/ |
user440 Mike Davis Senior Moderator Location: St Louis Join Date: 06/09/2014 Posts: 12 Rally Car: Porsche 944 S2 |
Good suggestions above.
Also check out this thread on good books on the subject: http://www.corner-carvers.com/forums/showthread.php?t=3817&highlight=Suspension And this one as well: http://www.corner-carvers.com/forums/showthread.php?t=27574&highlight=Suspension Mike Davis St. Louis | KD0WTN | Co-Driver #951 Porsche 944 S2 Rally Badger Racing Team | http://instagram.com/rallybadger Edited 1 time(s). Last edit at 04/02/2015 07:21AM by user440. |
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john vanlandingham John Vanlandingham Elite Moderator Location: Ford Asylum, Sleezattle, WA Join Date: 12/20/2005 Age: Fossilized Posts: 14,152 Rally Car: Saab 96 V4 |
Bullshit. John Vanlandingham Sleezattle, WA, USA Vive le Prole-le-ralliat www.rallyrace.net/jvab CALL +1 206 431-9696 Remember! Pacific Standard Time is 3 hours behind Eastern Standard Time. |
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corax Keith Fritzinger Senior Moderator Location: Portland, OR Join Date: 01/20/2011 Age: Midlife Crisis Posts: 53 |
about 15 years ago, Curt LeDuc build a few Sportages for desert use - Darren Skilton and LeDuc both drove them in The Dakar
a quick internet search found some info, might be worth looking a bit harder to see what they did Class 3 for sale or rent
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i read some guides and articles, all was about sports cars, so im not sure if im in the right way...
all started with calculating suspension frequency. so lets start with some numbers: vehicle weight about 1320kg (2910lbs), front 720kg (1588lbs) rear 600kg (1322lbs) the vehicle is a body on frame and have double wishbone at the front and solid axle with LSD at the rear. my vehicle is lifted ~1.5" with springs, the springs are about the same length as stock but a lot stiffer 250lbs/in to 400lbs/in at the front, I bought it like that. I used this page to calculate suspension frequency (ATM front only): http://eibach.com/america/en/motorsport/products/suspension-worksheet hope that I measure right d1=26cm (10.23in) d2=38cm (14.96in) so MR = 0.685 ACF= cos 19 degrees = 0.945 so if i calculated right: WR: was 110lbs with stock springs and 177lbs with the spring i have now. suspension frequency: ~1.25HZ stock and ~1.6HZ with the spring i have now. now, how do i know what suspension frequency i should aim to ? |