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Triumph cutting coil springs??

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Wes, I thought this might be you. Nice to hear from you. Talk to Bruce S at BCD and he can give you a lot of advise on lowering. He's done it. I just don't recall what he did in the front and the back is easy with blocks.
 
Leaving the spacers out entirely will leave the suspension simply resting on the bump stop ...

CJD said:
...or, you could always lower the profile of your tires to keep the suspension travel the same. (but then the discussion will turn to your speedometer!?!)
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Ah, speedometer accuracy is much overrated anyway. Eventually, I'll put 3.45 gears in the diff, to just about compensate for my 205/55 tires (195/50 was definitely too short IMO), but in the meantime I use the tachometer to estimate speed.
 
the heat treat is why you pack the spring in the fiberglass and let it cool over the space of several hours. I'll let you know if the spring ever breaks.

We get leaf springs made for us that have a compression rating of 10 tons/inch, or thereabouts.
 
Willie_P said:
@foxtrapper:

that is very kind of you and extremely helpful. however, you forgot caveat #3: my car is completely disassembled and all I have are free springs.
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Ah, while that makes the cutting easier, it does make the measuring a good bit more difficult.

You could use someone elses car to measure, and then make your cuts based on that. But I wouldn't really recommend it. While it should work just fine, if there's enough difference between the cars, you'll get wonky results.

Were I in your shoes, I'd probably wait and put the car together. Then measure, remove and cut.
 
TR3driver said:
I'll put 3.45 gears in the diff, to just about compensate for my 205/55 tires (195/50 was definitely too short IMO), but in the meantime I use the tachometer to estimate speed.
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So that's what tires you are using! They look really good...worth the speeo error!

John
 
71MKIV said:
the heat treat is why you pack the spring in the fiberglass and let it cool over the space of several hours. I'll let you know if the spring ever breaks.
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Well...that's not heat treating. It's worth a try, but heat treating envolves exact temps and exact times, to reach an exact hardness...and the entire part needs to be treated, not just the last coil. The good news is the last coil is pretty much compressed completely, so I don't think breakage there will be a problem anyway.
 
Cooling it slowly like that is called annealing, which is indeed a form of heat treating. And it makes sense to me, since you don't want to leave the heated part so hard it will break. I'm not convinced it would wind up too hard even just letting it cool in air; but the fiberglass certainly won't hurt.
 
we do that to all kinds of things. We weld and braze all manner of iron parts and slow cooling is done all most all the time whether it's actually needed or not.

we have a heat treater that we use. the place is right out of Dantes. all kinds of flame and bubbling vats of God-knows-what in a cavernous dark building. With an oven big enough to stress relieve a middling size boiler. yea I know, stress relief isn't really heat treat, but we still wind up with a temp/time chart.
 
For steel, once it stops glowing the treating is already set. The rub comes when you only heat a section of a part, then the adjacent cold section cools the hot metal fast...and that hardens it, but only in a very localized area. You have no control over it. Using a blanket would help anneal the area you heated, while the unheated area of the part would be unchanged, and the area between the two would be hardened. It's that hardened boundary area that will cause trouble in a spring. It does 2 things...First, it is more brittle, making it easier to break when shocked. Second, because it is stiffer than the annealed portion of the metal, it stresses the adjacent metal more, making that area more susceptible to fatigue.

Some parts are over designed, and not very particular. Springs, however, are the highest stressed parts on a car...thus the treating and shot peening at the factory. Like you pointed out, it's not a simple process, so they would not do it if they thought it was not critical.

I have a 4 year degree in materials...and I personally would not use a torch anywhere near a spring...unless you take the whole spring to be treated and shot peened afterward. Then the problem is you don't really know what the material is and what hardness is optimum.

Bit long winded...but the bottom line is torches and springs just don't go together!

John
 
Torches and springs go together just fine.

You lose temper in the steel for about 2 inches beyond the cut. Nothing more.
 
CJD, take a piece of steel wire and cut it with a torch. It only takes a few seconds to make the cut. Because it's over so quick, the heat won't have time to travel along the wire. It'll barely be warm 4 inches from the cut.
 
That's not at all what I was referring to, this is what I am talking about as probably not being a good idea:


71MKIV said:
I shortened the springs of my Spitire that way. Warmed up the final coil with a torch while it was in the press. The final coil flattened down against the next one. Wrap the whole thing in fiberglass and let it cool slowly..
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I would still use a band saw...or hack saw if in a bind...to cut through any treated part. Right tool...so to speak. Now, if I want to cut wrought iron... Bring out the torch...burn baby burn!!!

John
 
I'm not familiar with the TR3 suspension, but I am curious, won't a 2" drop add a huge amount of negative camber to your wheels. That will add another set of problems just by itself.

My GT6 uses spacers for camber, but I don't think I could take out that much but even removing all of them.

I think removing the spacers would be best, even better, machine them down a bit and leave them in.

Cutting the springs will screw up the spring rate, unless you are a 16 year old driving a honda, I doubt you would be happy with the ride.

Mikey
 
CJD, I have a big lump of wrought iron here if you ever want to try to cut it with a torch. Plasma cutter maybe.

I will assume that with your degree that you are being tongue in cheek.

all I know is that I followed in the footsteps of people who have done it before, and have no complaints about the ride now that it is done, and the nose is down where it belongs, and the bump steer is almost gone.

If my springs break, I will post here immediatly with a Mea culpa.

(spring break? never got to do that, even in college)
 
I put GT6 springs on my Spit after cutting them down. The first time I neglected to bevel the ends and they squeaked something fierce. I took them off and hit the ends with a grinder and they work great.
 
Steve, Fox, I meant no offense.

I spent years in the AIr Force pulling plane parts out of the dirt, testing, analyzing and figuring out what went wrong...and even more years breaking metal alloys on hydraulic test machines and plotting the results. Surely, I should get credit for knowing something after all that work.

The beauty of this hobby is that, when it's all said and done, you can cut your springs any way you want.

John
 
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