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small SUV/pick up build help

Posted by idan 
idan
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Join Date: 04/01/2015
Posts: 3


small SUV/pick up build help
April 01, 2015 03:16PM
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
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tdrrally
edward mucklow
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Re: small SUV/pick up build help
April 01, 2015 04:03PM
i like the way this is sounding!



I would rather drive a slow car fast as a fast car slow!
first rule of cars: get what makes you happy, your the one paying for it!
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Robert Culbertson
Robert Culbertson
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Re: small SUV/pick up build help
April 01, 2015 05:17PM
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 smiling smiley

http://www.shock-shop.com/
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user440
Mike Davis
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Porsche 944 S2


Re: small SUV/pick up build help
April 02, 2015 07:20AM
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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idan
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Join Date: 04/01/2015
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Re: small SUV/pick up build help
April 02, 2015 10:36AM
any one here have seen vids from this guy ?




what u think ?
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john vanlandingham
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Re: small SUV/pick up build help
April 02, 2015 10:52AM
Quote
idan
any one here have seen vids from this guy ?




what u think ?

Bullshit.



John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

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CALL +1 206 431-9696
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is 3 hours behind Eastern Standard Time.
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Robert Culbertson
Robert Culbertson
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Re: small SUV/pick up build help
April 02, 2015 12:15PM
I about lost it when we was explaining suspension jacking.
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corax
Keith Fritzinger
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Re: small SUV/pick up build help
April 03, 2015 01:35PM
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
Quote

-Full floater 9 inch Cone rear ends
-Three link with 3" coilovers and bump stops in rear
-Coilover and bypass in the front
-Howe ram assisted steering
-Richmond 5 speed race trans
-Fuel Safe cells
-Autometer gauges
-Chase boxes and many spares included
-race prepared motors
-many spare parts and chase boxes

Will sell them "as is" for $20,000 each vehicle or $35,000 for the pair.

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idan
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Join Date: 04/01/2015
Posts: 3


Re: small SUV/pick up build help
April 04, 2015 01:22PM
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 tongue sticking out smiley

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 ?
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