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500 lb coil springs

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M

mightymidget

Jedi Knight
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There is a set for sell on ebay.

I was thinking of my V-8 Bugeye rebuild later, the Ford motor weighes more than the orignal motor and I was wondering if the 500 lb racing front coil springs may be something that would help.

When I get around to rebuilding this Bugeye I plan on doing the MGB triumph brake modification to help in the brake area.

Presently the car seems to have stock suspension and is setting pretty straight. But I was thinking the beefier springs may help.

Does the spring rate help with the load from the top, or does it just help with loads from the bottom.
 
Billm said:
KG- don't you have another forum to haunt?? :smile:
BillM
Click to expand...

Et tu, Brute?!?!?!
grin.gif
 
I'm running 500# springs in my racer. They're not really that stiff (I ran them on the street too, along with poly bushings).

You can buy 520# from Spridgetmania (a BCF advertiser) for about $160/pair. They have 400# for $99/pair.
 
Thanks for that information.

Still trying to understand if the 500# springs will benifit supporting the extra weight of the V-8 motor. The weight will be from the top of the spring instead of being pushed from the bottom.

I realize that may be a no brainer, but one thing I have learn about cars is never assume
 
I don't see a problem with the heavier front spring for car with a heavier engine, we run pretty heavy front coil springs on the race cars, I even had a set on a race car that was 650 one time, and it handled like a dream.
 
mightymidget said:
......Still trying to understand if the 500# springs will benifit supporting the extra weight of the V-8 motor. The weight will be from the top of the spring instead of being pushed from the bottom....
Click to expand...

I can't say I understand what you mean? Are you making a radical change in the suspension design?

The "moving" side of the spring is the bottom (at least on a normal Spridget).

Even if you add more mass to the car, the spring forces respond to motion of the lower control arm. Although, to be honest, I don't think the spring cares if the load comes from above or below....the actual pressure (load) on each side of the spring is equal.
 
A different way

Bugeye purchased with a Ford V8 C4 A/T done I believe in the 60s because motor has a generator.

The suspension seems to be completly stock in the front (rear suspension has a 57 olds rearend)

The added weight of the V-8 has not been compenstated for. I have never driven the car. just hauled in on trailer.

When I rebuild this car I would think the front suspension would need to be "beefed Up" for the extra weight of V-8 (estimating about 250 lbs)
So I thought the heavier 500# spring would handle the weight added.

Also this is why I mentioned the B-Truiumph brake upgrade

So will the heavier spring help with the added weight of Motor?
 
I believe they should. Correct me if I'm wrong but I was taught that every action has an equal and opposite reaction so it doesn't really matter 'where' the added weight is. It all travels THROUGH the spring.

Now the raised rate of the spring means that it takes more weight to compress the spring an equal amount. If a stock spring is 320# then that means it takes 320#s to compress that spring one unit of measure, say one inch. A 620# spring (that's what I'm running on my street car) then takes 620#s to compress one inch. That means to me that a 4 cylinder is not going to compress the spring as much as an 8 cylinder on stock springs. That also means that heavier springs are going to resist the compression of a heavier engine.

So examples: My 4cyl with 620# springs is much stiffer than it was with stock 320#. The extra weight to compress the spring now has to come from inertia and cornering forces. That keeps it flatter in the corners because the spring is resisting compression and therefore corners better. The trade off is that the spring is also stiffer on bound and rebound which means that standard bumps and potholes will jar you teeth loose.

So an 8 cylinder car on stock springs is going to squish them much flatter with the additional weight and cycle them all over the place. They won't be able to handle the load and will lean and roll to the will of the v8. But if you bump them up to whatever 500-600# springs you found the springs are going to compensate somewhat for the weight. You'll still have the added weight acting on those upped springs and so the net gain could be back to close to neutral. That is to say, they will try to resist body roll in the corners just like it does for my 4cyl but with the added weight you'll still lose that fight a little. It'll probably be back to a bit of roll and a lot of understeer. Bound and rebound will likely feel like a muscle car: ie. the suspension will be slow to react and instead of being jarring to you the passenger, it will probably just be jarring on all of the unsprung weight; wheels, bearings, bushings, mount bolts.

I don't know what else I'm leaving out here but I think that's pretty much it.

JACK
 
Seems you preaty well covered it. Anything you can do to get weight out of the front will help of course, Alm. heads, manifold, what ever.

When I long long ago was autocrossing, I replaces stock springs with cut down plymouth ones, made em same length but they were tougher. Boy was cornering different and better.

Oh yea, raced for almost 4 years every month. Had two seconds, otherwise it was catch me if you can. Sigh, good times.
 
Your explanation was much appreciated. Common sense told me basically the same that you have explained. But suspension is quite a science and the more I try to study it the more it goes over the top of my understanding. So I rely on proven methods by others.
Thanks again
 
My question is, how well will the lower control arm mounts handle the extra force? If it's not uncommon to pull sway bar mounts loose with a heavier bar, what about control arm mounting tabs with a V8 and heavier spring?
 
That would depend how the car is driven. Street or racetrack.
I am not too concerned since it will not be a great handleing car, with way too much power. It was a oddity deal that I ran accross and it will be used as a Saturday night cruise car.

When you break down the weight difference for each wheel over stock. I don't beleive it will be as much as you would think. maybe 75 lbs more on each corner at the front. so this would equall taking a curve in a street Bugeye.
 
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