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fleagle
Samba Member
Joined: October 10, 2012
Posts: 17
Location: Michigan
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 Posted: Wed Jul 01, 2015 11:50 am Post subject: School me on R&P steering for my Berrien chassis Manx... |
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Hi All,
I'm working on a buggy that's has a Manx body & Berrien Nostalgia
chassis. I'm considering a rack and pinion set-up for the ball joint beam.
I need to wrap my head around the bump steer problem and how to layout
the R&P unit and tie rods. Any guidance would be appreciated.....Thx!! |
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didget69
Samba Member
Joined: July 22, 2004
Posts: 4927
Location: Raleigh, North Carolina
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| Posted: Wed Jul 01, 2015 12:46 pm Post subject: |
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Is the reason for R&P steering simply to be different?
bnc
_________________
I never found the need to impress people with any mechanic certifications, trophies or track wins... unless it was for Mom to post on the refrigerator door. |
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fleagle
Samba Member
Joined: October 10, 2012
Posts: 17
Location: Michigan
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| Posted: Thu Jul 02, 2015 4:57 am Post subject: |
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| Uhhh, no. I don't have any steering parts, so I'm considering a R&P set-up.... |
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jspbtown
Samba Member
Joined: January 27, 2004
Posts: 5156
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| Posted: Thu Jul 02, 2015 6:15 am Post subject: |
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Lots of work for very little benefit.
I think Intermeccanica uses a Rabbit rack if I am not mistaken. |
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streetbuggy8804
Samba Member
Joined: August 25, 2009
Posts: 652
Location: Placentia,ca
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| Posted: Thu Jul 02, 2015 7:25 am Post subject: |
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I put a Saco unit on my last project. Best 300 I could have spent on the steering set up. I set it up at about 7* after a bunch of research. Bump steer was a concern for me to, but I guess I got it right as I never felt anything like described when you read about bump steer. The one negative was that I had to modify the gas tank and also the frame head to accommodate the rack. Mine was a left hand mount and you may not have this issue if you use a center mount.
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Iguana
Samba Member
Joined: April 19, 2008
Posts: 922
Location: SOCAL
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| Posted: Thu Jul 02, 2015 8:09 am Post subject: |
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StreetBuggy - how much driving did you do with the rack in your buggy ?
Putting a center steer rack off to one side on that angle as shown in the pictures will have lots of bump steer and handle like crap, this is geometry not opinion.
People are using Daewoo Racks, SAAB Racks, Gold / Rabbit Racks BUT most are pretty quite on the actual numbers they are getting.
Have a read of - http://www.thesamba.com/vw/forum/viewtopic.php?t=610959 Todd is working on a bolt on setup for Ball Joint Beam.
Is this a street buggy or an offroad ? The less wheel travel you have the easier it is to get it close to acceptable. |
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didget69
Samba Member
Joined: July 22, 2004
Posts: 4927
Location: Raleigh, North Carolina
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| Posted: Thu Jul 02, 2015 8:16 am Post subject: |
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Replacement Bug steering box / tie-rods & ends / steering damper will most likely be cheaper price than going R&P route. Bolts on, fits, & little headache.
bnc
_________________
I never found the need to impress people with any mechanic certifications, trophies or track wins... unless it was for Mom to post on the refrigerator door. |
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ellobo
Samba Member
Joined: December 18, 2004
Posts: 286
Location: O.C. California
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| Posted: Thu Jul 02, 2015 3:31 pm Post subject: |
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I don't know how well this works. It's a picture I have for reference. It uses a rack and pinion from a 79 Rabbit.
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streetbuggy8804
Samba Member
Joined: August 25, 2009
Posts: 652
Location: Placentia,ca
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| Posted: Thu Jul 02, 2015 7:07 pm Post subject: |
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| The rack is an off center rack. Designed to be mounted in that orientation. It handled 100 times better thank the stock set up. Actually a great product and well worth the money. |
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streetbuggy8804
Samba Member
Joined: August 25, 2009
Posts: 652
Location: Placentia,ca
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Iguana
Samba Member
Joined: April 19, 2008
Posts: 922
Location: SOCAL
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| Posted: Fri Jul 03, 2015 12:25 am Post subject: |
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You do realize that these setups refer to the fact the pinion is offset to left on the center not that you can set the entire rack of to the left of center ?
These are all Center Mounted Racks designed to be set in the center of the beam with equal length tie rods.
How much driving did you do with the rack you show mounted in the buggy with the clamps ?
Don't get me wrong you can mount the rack anywhere you want I would just hate to think you are handing out advice to people without actually testing it and adding to the rapidly growing internet collection of incorrect advice which people may actually follow.
The stock VW Steering Box has ZERO bump steer when in the factory position, some damn smart German dude did very well to design the pitman arm and rotation of the box etc to achieve this. When it comes to putting a R&P into a stock width BJ Beam it becomes very hard to get it located in such a place that bump steer is even close to zero (This is what Todd at SubaruGears is currently working on) .
When we looked at doing this we had the entire front end modeled to achieve it and then had jigs cut to allow the rack to move in the correct place.
We installed it on a widened BJ beam in my Iguana Buggy and managed to get it to have around 5mm of bump at full travel (9 inches) with a center mount setup and measuring with a wheel alignment jig.
You may want to turn the sound down as the sound track is some what annoying lol .
Link
The DSBE has a Center Mounted Fortin 2.0 Buggy Rack which is a center mount and got it to around 5mm bump at full cycle ( 15").
I would be asking why bother on a stock style buggy where a stock steering box and some HD Tie rods will probably serve you very well. In my experience most of the benefit of going R&P is in getting P/S and a stronger setup for offroad abuse. If you get the setup wrong it will drive like crap. |
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didget69
Samba Member
Joined: July 22, 2004
Posts: 4927
Location: Raleigh, North Carolina
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| Posted: Fri Jul 03, 2015 6:08 am Post subject: |
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^^^ School's out for Summer - class dismissed!
bnc
_________________
I never found the need to impress people with any mechanic certifications, trophies or track wins... unless it was for Mom to post on the refrigerator door. |
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streetbuggy8804
Samba Member
Joined: August 25, 2009
Posts: 652
Location: Placentia,ca
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| Posted: Fri Jul 03, 2015 7:30 am Post subject: |
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| I think you tend to forget Brad, that not everybody is on here to try and put on a college level class on everything. Some people are here to share EXPERIENCE not advice. I did enough driving to know it worked well. For all your knowledge, you wouldn't know that because you never drove it. Your opinion is just speculation. |
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Iguana
Samba Member
Joined: April 19, 2008
Posts: 922
Location: SOCAL
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| Posted: Tue Jul 07, 2015 11:44 pm Post subject: |
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| streetbuggy8804 wrote: |
| I think you tend to forget Brad, that not everybody is on here to try and put on a college level class on everything. Some people are here to share EXPERIENCE not advice. I did enough driving to know it worked well. For all your knowledge, you wouldn't know that because you never drove it. Your opinion is just speculation. |
I think you are mistaking me trying to limit the amount of incorrect advice given to people based on what I clearly know to be wrong with something else.
If you ever drove your buggy with that setup I would be amazed as it is simply wrong. I did not invent bump steer and there is a very good reason people set out to limit it in most applications. Your installation of a center mount rack will have excessive bump steer, this is not opinion it is geometry.
As for my opinion being speculation that doesn't even make sense, I never said I drove your buggy, I can say if you ran it as shown then your bump steer would sux, plain and simple.
As for experience and advice, I would suggest I have more than enough experience to quantify my advice as experience based on fact, geometry and results not an ass pluck from some half mock setup which would not work. If you feel any of this is unfounded I am more than happy for you to prove me wrong with your DualSport Build and look forward to seeing what you come up with and how it performs. I have put my money where my mouth is and my last build is just about to complete over 6000 miles of road driving which followed racing Baja etc so I must have an idea or two about how to build reliable vehicle which actually get used and perform.
How much driving did you do in your buggy with that setup ?? |
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glassbuggy
Samba Member
Joined: June 02, 2005
Posts: 897
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| Posted: Wed Jul 08, 2015 6:17 pm Post subject: |
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| I dabbled with putting a rack in my buggy and some years back I worked at an auto parts store so I had books with pictures and I came across the VW Quantum rack. This is what it looks like after minimal arrangement and I felt it would give both tie rods equal billing. I haven't got any further on it but hey - knock yourselves out. I believe it has a non power counterpart but you might have to look into that [img][/img] |
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glassbuggy
Samba Member
Joined: June 02, 2005
Posts: 897
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| Posted: Wed Jul 08, 2015 6:17 pm Post subject: |
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| [img][/img] |
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