Track Suspension

[Loren]

Not sure how you'd attach something like that, especially at the top.

The bottom perch you can definitely bolt something to, the K-Sport kit does that, too.

[Tamago]

Originally Posted by Loren

Not sure how you'd attach something like that, especially at the top.

The bottom perch you can definitely bolt something to, the K-Sport kit does that, too.

WINDO-WELD AT THE TOP?

[Loren]

Originally Posted by Tamago

WINDO-WELD AT THE TOP?

I wouldn't expect that to hold against a stiff spring that's being bent in it's perch. Maybe if you happened to have a completely loose spring it would keep things aligned as the car came down?

If you want simple... old swing-axle cars (like my Spitfire, old VW bugs and Corvairs) sometimes used "droop limiters". They used them for a different reason, on those cars, when the axle droops, camber goes positive, and if you come down on it quickly while the camber is way positive... it's not pretty.

But, all you need is a strap or cable or chain or something to keep the axle assembly from falling low enough to unseat the spring. Sort of the same thing we're already doing with the shock. That's exactly what the shock does at full extension, it limits the droop of the axle. Adding a droop limiter takes that load off of the shock, which is probably a good thing.

[Tamago]

Originally Posted by Loren

I wouldn't expect that to hold against a stiff spring that's being bent in it's perch. Maybe if you happened to have a completely loose spring it would keep things aligned as the car came down?

If you want simple... old swing-axle cars (like my Spitfire, old VW bugs and Corvairs) sometimes used "droop limiters". They used them for a different reason, on those cars, when the axle droops, camber goes positive, and if you come down on it quickly while the camber is way positive... it's not pretty.

But, all you need is a strap or cable or chain or something to keep the axle assembly from falling low enough to unseat the spring. Sort of the same thing we're already doing with the shock. That's exactly what the shock does at full extension, it limits the droop of the axle. Adding a droop limiter takes that load off of the shock, which is probably a good thing.

1/8" cable + a turnbuckle would do this quite nicely. that's a good idea.. i think i'll just do this lol

oh, and panel bonding epoxies are EXTREMELY strong, in most cases is replacing welding for bodymen.

[largeorangefont]

I already brought this up a couple weeks ago in the Tokico HTS thread.

You can use a tow strap to limit down travel, and it will be lighter than all that extra crap to hold the spring in. Pro Comp makes straps in various lengths for off road trucks.

I was also thinking of a bolt in perch on the torsion axle, but since there is a hole in the middle, make the lower perch adjustable.

[kngrsll]

Originally Posted by Loren

But, all you need is a strap or cable or chain or something to keep the axle assembly from falling low enough to unseat the spring. Sort of the same thing we're already doing with the shock. That's exactly what the shock does at full extension, it limits the droop of the axle. Adding a droop limiter takes that load off of the shock, which is probably a good thing.

great idea, someone brought it up last week i think

Originally Posted by largeorangefont

I already brought this up a couple weeks ago in the Tokico HTS thread.

You can use a tow strap to limit down travel, and it will be lighter than all that extra crap to hold the spring in. Pro Comp makes straps in various lengths for off road trucks.

I was also thinking of a bolt in perch on the torsion axle, but since there is a hole in the middle, make the lower perch adjustable.

LOL yep, thanks for the suggestion!

so now, we can use a shorter spring for a higher rate, as long as we use a strap to shorten the droop! 400 lb rear springs, here we come?

[largeorangefont]

Originally Posted by kngrsll

great idea, someone brought it up last week i think



LOL yep, thanks for the suggestion!

so now, we can use a shorter spring for a higher rate, as long as we use a strap to shorten the droop! 400 lb rear springs, here we come?

If you can find a 400# spring of the right diameter and length, you could do it now with no perches. You will definately need straps for those HTS shocks.

Assuming the spring can sit on the stock perches,you can roughly figure out the length needed measuring the length of your current spring with the car on the ground. Then take the weight of the car, and the weight distribution, and figure out roughly how much weight is on the rear tires. Remember you have 2 rear springs so you want to devide this weight by 2. You know it takes 400lbs to compress the spring 1 inch. Do the math and you will have your approximate free length. It should only be around an inch more than the measurment of the compressed spring. There is not a lot of weight back there.

Strap placement will be tricky, so you will need to figure that out. You would set the droop so that the spring could never fall out if the rear suspension were to become unloaded or if an inside rear tire left the ground in a corner. That type of full articulation is actually more droop than if both rear wheels were off the ground. If you set the droop such that the spring is unloaded, but still touching the perches, you should be fine. You have the "dome" of the perches to hold the spring in and give you a little extra buffer in a 3 wheel situation.

Unfortunately with stiff spring like that you wont be left with much rear droop. This is fine for the racetrack, but may be a little harsh on the street.

[Tamago]

Originally Posted by largeorangefont

There is not a lot of weight back there.

say what, 40% of 2300lbs? 920lbs total, split that and you have 460 lbs each spring.

so you'd get 1.15" of compression at rest..

[Tamago]

Originally Posted by largeorangefont

Unfortunately with stiff spring like that you wont be left with much rear droop. This is fine for the racetrack, but may be a little harsh on the street.

if i cross from a parking lot to the street at a diagonal angle, i'm two-wheeling every time. i've gotten used to it, but have had strangers at the gas station comment on it lol

[Loren]

I'd add the caution here that this might not be the smoothest riding street suspension over big bumps. With a 400# spring, you're not going to have much more than 1" of compression under the weight of the car. That means that your droop limiter has to retain the spring at a mere 1" of droop. Fine for competition, but possibly rough for the street.

[Loren]

Funny... Big Orange and I are saying the same things.

[Tamago]

Originally Posted by Loren

I'd add the caution here that this might not be the smoothest riding street suspension over big bumps. With a 400# spring, you're not going to have much more than 1" of compression under the weight of the car. That means that your droop limiter has to retain the spring at a mere 1" of droop. Fine for competition, but possibly rough for the street.

i should have kept the motion ratio in mind when doing my calcs.

rough motion ratio is .7, so you'd actually compress 1.64" at static.

[largeorangefont]

Originally Posted by Loren

Funny... Big Orange and I are saying the same things.

We generally do.

[largeorangefont]

Originally Posted by Tamago

say what, 40% of 2300lbs? 920lbs total, split that and you have 460 lbs each spring.

so you'd get 1.15" of compression at rest..

Yea if that...

[largeorangefont]

Originally Posted by Tamago

if i cross from a parking lot to the street at a diagonal angle, i'm two-wheeling every time. i've gotten used to it, but have had strangers at the gas station comment on it lol

It is not that, it is dips at speed we are talking about. Potholes are a good example. At speed a softer, longer travel suspension would allow the wheel to drop into the hole and on hole exit the suspension would absorb the impact with bump travel.

Lets say you hit a pothole with yout right rear. With no droop the entire weight on that wheel falls into the pothole, you feel the car drop into the hole. Upon exit of the pothole, that wheel would reload the left front wheel, and you would feel the wheel and car lifting up and out of the hole. It would feel very jaring.

[Tamago]

Originally Posted by largeorangefont

It is not that, it is dips at speed we are talking about. Potholes are a good exampl. A softer, longer travel suspension would allow the wheel to drop into the hole and on hole exit the suspension would absorb the impact with bump travel.

Instead the entire weight on that wheel falls into the pothole, and pushes that weight back up upon exit of the pothole. It would be very jaring.

just drive really fast and float over the potholes? ;)

[Loren]

Originally Posted by largeorangefont

if an inside rear tire left the ground in a corner

If? This is a situation that anyone who's going this far with their suspension needs to PLAN on. The young guys working course at the BMW club autox I went to last weekend were calling me "tripod" at the end of the day!

The inside rear wheel will be in the air more than it's on the ground unless you're going straight.

[Tamago]

Originally Posted by Loren

If? This is a situation that anyone who's going this far with their suspension needs to PLAN on. The young guys working course at the BMW club autox I went to last weekend were calling me "tripod" at the end of the day!

The inside rear wheel will be in the air more than it's on the ground unless you're going straight.

which is kind of unfortunate as it leaves you with 3/4 of your total grip..