craig1410
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| posted on 30/6/03 at 09:21 PM |
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Which steering rack for +4" chassis?
Hi,
I've picked up bits of the answer on other threads but can't decide what to do for the best. The question is:
Which steering rack is best for a +4" chassis with standard wishbones and Cortina uprights? I have various books about suspension design and
know all about bump steer etc but I still can't decide which way to go. I have both an Escort rack and a Sierra rack which both need
reconditioned so I can go either way but need to take the plunge! The Sierra rack is about 4 inches too long and the escort one is 4 inches too
short.
If I go the escort route then I think the rack itself is too narrow and I was wondering if anyone makes rack extensions which screw into the ends of
the rack between the rack and the inner balljoint. I think it would only require a piece of metal with a male thread on one end and a female thread on
the other. The rubber gaitor should have enough length to cover the whole smash.
Rough measurements show that I need about 4 inches of extra length from T.R.E. to T.R.E. and I think that bump steer would be less likely if this was
added to the rack instead of between the track rod and T.R.E.
Has anyone tried this? I'd rather stick with the escort rack if possible since I can get a very cheap quick rack and don't want to have to
cut a reconditioned Sierra rack in half and weld it back together... 
Cheers,
Craig.
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Stu16v
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| posted on 30/6/03 at 09:51 PM |
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A couple of workmates built Locosts +4" and they fitted Capri racks, which fitted perfect, and (decent) quick rack kits are available for them
too. The downside is that the TRE adjustment threads are in UNF, cnat remember how they got over that, I think they used Capri balljoints too...
TRA extensions are available, a local engineering shop could probably knock you a pair up, or try PROCOMP (advertise most months in Kit-Car mag).
HTH Stu.
Dont just build it.....make it!
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craig1410
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| posted on 30/6/03 at 10:02 PM |
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Thanks Stu,
Never thought of the Capri. Can I assume that the Capri rack is mounted forwards of the front axle line then? Also, do you happen to know if the taper
on the TRE is the same for the capri as it is for the cortina?
Cheers,
Craig.
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Rorty
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| posted on 1/7/03 at 01:16 AM |
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If cost/availability isn't an issue, you could cut and shut two Escort racks to make one the correct length.
It's simple to do, and you'll have a relatively stock looking Escort rack, and without stressing the gaiters.
Cheers, Rorty.
"Faster than a speeding Pullet".
PLEASE DON'T U2U ME IF YOU WANT A QUICK RESPONSE. TRY EMAILING ME INSTEAD!
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bob
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| posted on 1/7/03 at 09:33 AM |
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Is capri rack not the same as cortina rack ?
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Simon
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| posted on 1/7/03 at 09:35 AM |
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Craig,
I did this:
http://forum.locostbuilders.co.uk/xmb/photos/cgi-bin/showpic.pl?10000022.jpg
Shortened Sierra rack!!
Hope this helps!
ATB
Simon
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craig1410
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| posted on 1/7/03 at 06:58 PM |
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Thanks guys!
Rorty, are you suggesting welding two rack bars together and housing them inside a cut and shut rack housing? That sounds a bit scary to me...
Don't get me wrong, I'm sure you have more faith in your welding than I have but that would scare me a bit. I don't mind a cut and
shut rack housing as it isn't so critical, but the rack, track rods and TRE's would have to be joined with threads for my piece of
mind.
Simon, did you do the welding yourself and if so, is it difficult? How many amps would I need from my welder to weld this thickness of Ally? I gather
that I need pure Argon, a teflon liner and Ally wire, is that it? Oh yes and some practice... 
Can I assume that your rack is just cut at the end and a new thread cut into the end of the rack? Any problems?
The good thing about the shortened Sierra rack is that I don't need to worry about the splines not fitting between the steering column and rack
as I'm using a Sierra column.
Anyone else got any bright ideas?
Cheers,
Craig.
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Viper
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| posted on 1/7/03 at 07:34 PM |
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Craig.
don't even think about ali welding with your mig, find someone at a local engineering co to TIG it for you, It is difficult to tell from Simons
pic but that weld looks very porous hence very week is that what you want?
Simon
i understand that the outer casing of the rack is not under a massive load BUT if your welding is noticed by the sva man then it will most likely make
the man look closer at the rest of the construction, i know it would make me look, your choice of course.
(just going to get my flack jacket again  0
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craig1410
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| posted on 1/7/03 at 09:22 PM |
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Viper,
Yes I take your point and to be honest I wasn't all that keen to start messing about with Ally welding if I could help it. I have enough trouble
with steel welding at times...
Does anyone sell reconditioned, shortened Sierra racks on an exchange basis?
Or, does anyone up here in the Glasgow area know of a reputable engineering company who could Tig my Sierra rack for me?
Thanks for the advice,
Craig.
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Rorty
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| posted on 2/7/03 at 02:03 AM |
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craig 1410:
quote:
Rorty, are you suggesting welding two rack bars together and housing them inside a cut and shut rack housing? That sounds a bit scary to me.
Yes, butt-weld/thread-and-weld the two rack sections together. It's quite common practice, but would have to be done properly.
If you're in any doubt at all, as to your abilities, then pass it to someone who has the skills to do it.
Same goes for any part of the car for that matter.
I once had an old Hillman banger, which I welded the rack in. That particular rack had two rack and pinion sections welded together, so I had two
steering wheels in the car! Great for teaching driving skills, or just great fun with two idiots behind the wheels!
Cheers, Rorty.
"Faster than a speeding Pullet".
PLEASE DON'T U2U ME IF YOU WANT A QUICK RESPONSE. TRY EMAILING ME INSTEAD!
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bob
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| posted on 2/7/03 at 08:46 AM |
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Just spoken to a couple of people not on the list that have made +4 chassis,one used a capri rack and the other used a cortina mk4.
MK will sorten sierra racks as they do this for the indy kits
Hope this helps
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Simon
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| posted on 2/7/03 at 08:50 AM |
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Viper,
Don't worry - I have absolutely no intention of using it on the road like it is - I only did it so it can be pushed around!
When time comes, I'll be buying a new/recon rack and getting it prof modded to the size of my modded one
(I've already approached Gerry Hawkridge of Hawk Cars (Cobra/Stratos etc fame), and he quoted me £70 ish, and he's v local.
It's gonna be expensive, but that's the way it goes.
Craig,
I'm fortunate in that my father has an AC/DC welder for ally, but the casting is absolutely appalling and difficult to weld - you can see how
crap it looks in piccy. Fortunately there is a big mounting bolt on both sides of weld.
Someone else on here shortened (IIRC)rack as follows:
Cut case, machine outside and cut thread both sides. Another ally tube threaded inside. Screw case halves into tube and weld up.
Shorten rack to required length and tap end for steering arm.
Simple (ish)
ATB
Simon
[Edited on 2/7/03 by Simon]
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James
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| posted on 2/7/03 at 10:19 AM |
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quote:
Originally posted by Simon
<snip>
(I've already approached Gerry Hawkridge of Hawk Cars (Cobra/Stratos etc fame), and he quoted me £70 ish, and he's v local.
It's gonna be expensive, but that's the way it goes.
<snip>
ATB
Simon
[Edited on 2/7/03 by Simon]
MK will chop a Sierra rack for a barry bargain of £30! I think it's then about £10 for delivery.
Or, you can do what I did and get them to hand deliver it all the way to LeMans for you!
They don't weld the outer casing at all. The two halves are made about 1" shorter than they should be and then about .5" (each end)
is turned down. A 2" ali sleeve is then used to hold them together. The mount bolts do the rest.
I'm not sure exactly what they to do to the rack- presumably just chop a few inches off the 'bank' end and re-thread it.
Cheers,
James
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bob
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| posted on 2/7/03 at 12:32 PM |
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Thats North South divide prices for you on engineering a rack
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