JC
New Member
Posts: 5
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Post by JC on Mar 31, 2005 15:39:59 GMT -5
I have bought the book and I want to adapt the design into a two seater. Are any plans avaliable of the Mk5? Also, what is the approx width (to outside of tyres) of the front end?
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Post by MiNiTiCi on Mar 31, 2005 16:00:11 GMT -5
Hi JC, Welcome to the forum. Yes, plans for the 'two seater' Mk5 are available from Allan. I got my set last week. The front track is approximately 52.5 inches with 6 inch wide rims. (but this could vary depending on wheel offset and width). Although the Mk5 is a 'two seater' the driver sits partially over the car centreline therefore there is not much room for a second seat. The cockpit transverse opening width is about 33 inches. Doug.
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JC
New Member
Posts: 5
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Post by JC on Apr 2, 2005 14:17:55 GMT -5
Next naive question from newby! how do you use a rose joint on the top of the hub? Do you replace the mini ball joint with a bolt?
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Post by stu on Apr 2, 2005 15:45:03 GMT -5
I turned up a shallow top hat shaped spacer and after grinding the small ball off the pin and turning the shaft down to the rose joint size, i tightened the large nut. Hasnt come loose in four years of racing BUT is regularly checked over. It was a simple solution to what could have been a complex situation. Glad to be of assistance cheers stu
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Post by MiNiTiCi on Apr 3, 2005 11:53:08 GMT -5
Hi Stu, Nice solution. I had wrongly assumed that the tapered part of the pin would be hardened. Anyway I went out to the workshop and tried one. Turned down a treat. What size of rod end joint did you use? I turned the pin down to suit a 1/2" dia rod end and this seems ok (but I suppose 7/16" could be used as the existing thread is 7/16" UNF). I left a small shoulder on the pin as a stop for the rod end, but I could have turned it all the way down and made a spacer to fit down onto the top surface of the ball. For security, do you think it advisable to fit a large washer under the 7/16 nut in case the ball tries to pull out of the rod end? Thanks for the tip. Doug.
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Post by MiNiTiCi on Apr 3, 2005 13:01:22 GMT -5
Hi again Stu, Just had a thought (dangerous this thinking thing!) As the top pivot point has been raised by installing a rod end joint (looks like about 1" higher pivot point), will the suspension and steering pickup points have to change accordingly? Doug.
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Post by stu on Apr 5, 2005 1:32:39 GMT -5
that is exactly as i have done with a shallow tophat turned up to fit beneath the area where the ball has been ground off. as to geometry, it does not appear to affect the handling but some experts may disagree. you are actually lowering the roll center i believe. good luck with the build and keep us informed. cheers stu
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Post by Terrapin on Apr 5, 2005 7:18:12 GMT -5
I utilised the Austin Metro hubs which are far more obtainable in UK. The difference from the mini in this area is the use of a "sealed for life" ball joint that screws into the hub. Hence, I machined adaptors to screw into the hubs which have a 5/8" unf thread in the centre for the SRE bolt. Safety washers are now fitted (not shown in this picture) Rob groups.msn.com/Locost/terrapinracecar.msnw?action=ShowPhoto&PhotoID=84
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JC
New Member
Posts: 5
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Post by JC on Apr 7, 2005 14:50:57 GMT -5
As I understood, the Metro Hub was slightly different to the Mini hub - the king pin inclination(?) was much greater as the tyres on the Metro had a large off set to give extra width. How does this affect the geometry/handling?
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Post by Terrapin on Apr 7, 2005 16:03:46 GMT -5
Yes, the Metro Hub is different and will give changes to castor and camber if fitted to a mini. On the Terrapin you have the ability to alter all these - castor by shimming the wishbone rosejoints fore and aft, upper & lower, camber by having rosejointed pivots at the hub and I have also made the steering rack mountings adjustable (up/down) to be able to counteract any bump steer. Keith Calver did a very good article in one of the mini magazines where he had a subframe set up and demonstrated the slight differences encountered when fitting metro hubs & discs to mini suspnsion / subframe - hence the surge in interest & production of mini adjustable tie rods and lower arms.
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Post by Terrapin on Apr 7, 2005 16:30:16 GMT -5
JC - I should also have mentioned that you will pick up from various sources warnings about fitting the metro hubs to mini's. This is good advice as some people will just bolt on the items and suddenly find the have odd handling due to the suspension geometry changes. Hence most are recomended to retain the mini disc hubs. There are others who have done the conversion with out incident but they have made sure that they set up the suspension properly, which usually involves modifications away from stock parts. 2 points also to note: The metro flanges have 4 protruding lugs that can foul the centre of some wheels - I like many others have machined these off in the lathe, I have also used the mini steering arms which are different to the metro ones (ultimately I will probable make billet arms & rosejoints to replace the track rod ends (rover gti metro with 14mm thread to fit my porsche 911 zf steering rack) One thing is for sure, building a Terrapin is a great learning experience. I have restored and rebuilt many cars over the years - I often reflect on what luxury there is to be able to buy performance parts where someone has done all the maths for you ;D No one said building a racecar from scratch would be easy & like many of you I have made mistakes ( or as I like to call them - opportunities to improve )
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JC
New Member
Posts: 5
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Post by JC on Jun 16, 2005 14:47:22 GMT -5
Terrapin/Rob
I now have my metro/rover 100 front hubs (have measured geometry and adapted design). Is there any chance you could post a diagram of the adapters that you made so that I can get some made up? Or could you make some more for me? If so, how much?
My Terrapin-esque plans are progressing - I'm about to order steel. It'll be nice to be putting things together, rather than pulling apart!
Thanks for the help
JC
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Post by Terrapin on Jun 23, 2005 19:19:48 GMT -5
JC, e-mail me direct and I'll discuss. cheers Rob
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Post by bigmal on Feb 19, 2006 4:45:26 GMT -5
Hello, please answer this question, fitting a rose joint to the top front upright to replace the ball joint, please explain the advantages of the rose joint over the Std ball joint? All the very best.
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Post by MiNiTiCi on Feb 19, 2006 4:59:08 GMT -5
Mini ball joints tend to have a lot of 'sticksion', they either stick or rattle! Rod end joints give much more precise control. Another advantage is that it is much easier to make a fine adjustment system for camber changes (compared to a welded on tapered bush in the wishbone).
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