Jump to content

interesting response from QT


white90

Recommended Posts

The best thing any supplier can do IF it does turn out to be a design fault is to put their hands up, say "sorry we 'cked up" and sort it out. It usually does them great credit in the long term, but I suppose the issue for a small company is whether they can afford to do that or not :(

Link to comment
Share on other sites

Poor man's bling:

scan0001.jpg

The first time I saw the QT ones, I ran. In my humble opinion, you cant do it in the way it is done. Its too flimsy and the bottom bead is split up in pieces which are welded in places. The picture shows that it broke, yes, exactly on the weld. You can cause a lot of havoc if the other arm breaks also, which is now increasingly likely, by a factor of 2 almost.

I made my lightweight arms from oldspec rangy arms. These are 0.5 KG lighter to begin with, and after smoking a load of holes you take out another 1 kg, making the weightsaving 1.5kg per arm. I also polished the outside of the arms with a flapwheel to reduce the tendency to crack.

Then had it zinc plated for added bling :rolleyes:

I personally dont bother with castor correction, although the lift is only 1-1.5 inch on my car.

Daan

That looks very nice but how are the arms coping with holes drilled all over them ?

To my untrained eye the holes apear to be in a "non stressed" area of the arms but is this really so ?

I had standard ones on my Range Rover and after lifting it fitted QT ones but the vibrations from the propshaft weren't very nice.

Link to comment
Share on other sites

That looks very nice but how are the arms coping with holes drilled all over them ?

To my untrained eye the holes apear to be in a "non stressed" area of the arms but is this really so ?

I had standard ones on my Range Rover and after lifting it fitted QT ones but the vibrations from the propshaft weren't very nice.

I think it is ok this way, The idea is not new, and I went for it, having seen several rangerovers and defenders competing in the dakar rally using it and finishing. There is a logic to the diameter of the holes, in that the cross sectional area stays the same throughout the length of the arm. And as you say the centre does have very little effect on bending stress. They have seen some serious abuse for over 5 years. I havent done any stress analysis, maybe filthyboy can tell us more....

Daan

Link to comment
Share on other sites

I heard a clonk this morning on my way to the jet wash and this is what I found... :(

gallery_3150_282_592122.jpg

gallery_3150_282_1743377.jpg

This is my daily driver and my offroader so I was a little concerned. They have been on the car for about a year but I have no receipt for them. Looks like I'm going to have to fork out for some replacements.

Jeff.

kin hell jeff thats too much power and the lead boot

not a good combo

it aint a scania be nice :lol::lol:

Link to comment
Share on other sites

To me the design of the arms looks ok. They'll only be loaded in bending (either by cross axling or by acceleration/braking). The single nut at the chassis end means they can't be twisted (loaded in torsion) so the discontinuous welding between the two plates and the web shouldn't be a problem. Equally, the holes are along the neutral axis so shouldn't be in a stressed area or heavily affect the bending strength.

Since the failures pictured on here (I haven't seen the Pirate thread) are around the 'hockey stick' bit, I'd guess there's an abnormal loading around there, and that LR put enough (forged?) metal in there to resolve the situation.

As was said earlier, time to wait and see how QT respond on Monday.

Link to comment
Share on other sites

kin hell jeff thats too much power and the lead boot

not a good combo

it aint a scania be nice :lol::lol:

How ya doin Kelly, to be honest I still have standard CV's and shaft's so I would expect them to break before the radius arms and I do try not to abuse the motor too much.... ;)

Link to comment
Share on other sites

I think it is ok this way, The idea is not new, and I went for it, having seen several rangerovers and defenders competing in the dakar rally using it and finishing. There is a logic to the diameter of the holes, in that the cross sectional area stays the same throughout the length of the arm. And as you say the centre does have very little effect on bending stress. They have seen some serious abuse for over 5 years. I havent done any stress analysis, maybe filthyboy can tell us more....

Daan

Daan

We only looked at the standard part (when we were attempting to make hinged radius arms work) but I think you are absolutely correct when you say the holes are in the right place to not adversely affect the part.

We will soon be doing the stress and FE analysis on our new frame. Send me the CAD drawing of your radius arm and I will put it through at the same time :P

Just kidding!

Tim

Link to comment
Share on other sites

Any reduction in unsprung weight will improve the roadholding of a vehicle. (or something to that extent)

If this is done properly it will be a better vehicle.

Cutting notches in your seatbelts reduces the sprung weight and therefore do not make a vehicle safer. :P

Link to comment
Share on other sites

These arms are on no relevance to me as our only coiler is the wifes daily drive/caravan tug. But the first time i saw fabricated radius arms which were either QT or similar some years ago i thought yeeuugghh how weak and cheap looking.

But how many of you who have failures are running red polys(or equivalent) and how many running OEM rubber bushes. Less give in the polys might have a bearing on the cracking/failure.

Link to comment
Share on other sites

Why anyone would want to save 1.5 kilos a side on a 2 ton landrover is beyond me. I get more than 3 kilos of plop on my truck when i drive up a field. Why not cut notches out of your seatbelts to save weight... sounds just as safe.

Although the point is that lower unsprung weight helps, I have to agree that some of the things people buy (not just these arms) do make you wonder if they've got their brains fully engaged.

Link to comment
Share on other sites

Although the point is that lower unsprung weight helps, I have to agree that some of the things people buy (not just these arms) do make you wonder if they've got their brains fully engaged.

Don't be a Hater John :)

I wanted to sort out castor(steering self centering issue) the alternatives at the time were QT or Scrapiron

I went for QT, I may now regret this but still I did have my brain engaged.

Link to comment
Share on other sites

The Equipe ones are a little expensive though. I'm sure they are a great product but are they worth the money?

Can anyone justify spending that sort of cash on saving a kilo or 2?

Not that this affects me as I too have never been impressed with the concept of drilling holes in them - HOWEVER, hindsight is a wonderful thing, but I suspect the real question now is: ' is your or your familys life worth that sort of cash'!

Link to comment
Share on other sites

The Equipe ones are a little expensive though. I'm sure they are a great product but are they worth the money?

Can anyone justify spending that sort of cash on saving a kilo or 2?

Oh, the price has gone up since I looked ages ago, currently £1244.60 :o

175__orig.jpg

I've had QT arms in the past & they did the job but the welding & plating wasn't great, they were going rusty even before they were fitted & the welding was a bit messy.

Link to comment
Share on other sites

I will admit that the lower unsprung weight will benefit handling. It is how much that gets me. If a front axle assembly weighs 300kg (for arguments sake) and you lose 3kg, you have lost 1%. Sod all difference.

So if the handling or roadholding isnt much better, why fit them? Castor correction is the only other reason i can think of, but you can correct castor with modded standard ones from GL, or with eccentric bushes in standard arms.

I still dont get them. Is it just because people like the look of them?

Link to comment
Share on other sites

Oh, the price has gone up since I looked ages ago, currently £1244.60 :o

175__orig.jpg

I've had QT arms in the past & they did the job but the welding & plating wasn't great, they were going rusty even before they were fitted & the welding was a bit messy.

Lovely aren't they. IF i won the lottery i'd have a 90 with the full EQUPE set up on there!

Like i said the others seem a poor copy.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy