Munroe Gt Shocks Ke70

[ke70dave]

There is no reason why a car that low (the red one), shoudlnt handle well. but in order to get it that low you have to do a fair bit of work.

 

That red car has a nice arsenal of suspension bits last time i heard anything about it (like 3yrs ago....). Certainly better than the majority of ke70s on the forums (cut springs and wide wheels)

Edited May 9, 2013 by ke70dave

[altezzaclub]

The problem is that Aussie roads are quite 3rd-world, not nice smooth tarmac like V8Supercar tracks.. at least that's what I've found. Maybe living East of the Sandstone Curtain is different.

 

You need suspension travel to drive up the backbone of the Great Dividing Range, and there's no fun in driving along the flat coastline.

[ke70dave]

you remember my car yeah? My car was 120mm at the chassis rails, not quite as low as that red one, but pretty low.

 

Ii had about 100mm of rebound travel, and around 130mm of bump travel. (going on memories of 3yrs ago)

 

My front shocks were out of the rear of an SW20 MR2 in shortened shock tubes, and my wheels and tyres were such that i was able to utilise the whole suspension travel without them hitting anything, and i was using 5.9kg/mm springs in the front, and maybe 2-3kg/mm in back. which was a little high but not bad, if i did it again i might try 3.5-4kg/mm in front, and 2kg/mm in the back perhaps.

 

It handled great, and for an 80s corolla with "performance" orientated suspension, it reckoned it was quite comfortable. it was no mercedes benz, but i drove it daily with no dramas.

 

In my opinion and limited experience it is the shock absorber that dictates the ride comfort.

[altezzaclub]

In my opinion and limited experience it is the shock absorber that dictates the ride comfort.

 

Within the usual limits I'd agree. If you have a constant ride height between two springs but one is twice as stiff, the car will only go down half as far on a bump using the stiff ones. So that bump will feel more noticeable as the accelration is twice as much over half the distance travelled. But generally springs set the ride height and shocks set the ride comfort.

 

I do know you can see some horrible cars bouncing down the road on rockhard springs while the V8Supercars look amazingly pliant considering how low they are.

 

That 130mm of bump travel is pretty good, you must have had that well sorted.

[ke70dave]

So your wheel is going along the road, and you hit say a 10mm bump (a cats eye) at 70km/h. the wheel needs to move 10mm over say 0.02 seconds in order to absorb this input. It is the shock absorber that transfers this force through to the body of the car, not the spring.

 

The spring doesnt care too much, 10mm is hardly any movement for a spring to move. At 6kg/mmm spring, thats about 60kg of force needed to compress the spring, in a 900kg car, thats not much force from the vehicle moving at say ~70km/h hitting the above bump.

 

obviously make the spring stiffer and stiffer, and sure you will feel it. But in terms of controlling the wheel as it bumps up, then rebounds out, and not transfering any of this force to the body of the car (and the ocupants). so the body i reckon that is 90% shock absorber, that has been correctly chosen correctly for the spring rate.

 

I think...maybe...that just my experience with about 10 different springs/shocks in my ke70!

 

One of these days I'm going to read books about this stuff. One day.

[altezzaclub]

Oh no, you're dead right with that example, that's all shock work. I'm thinking of 75-100mm deep subsidences in the road surface, the 'potholes with slopes' that trucks leave, enough for the suspension to relax down into. When you hit the far side of it a stiff spring will push the body up harder than one of half the rate. ..and above that, a stiff shock will resist the strut compressing enough to give you a jolt.

 

The whole movement in manufacturing has been to soften springs, stiffen sway bars and make the shocks work harder over the last 30years. Modern cars combine handling with comfort in a way old cars can never match.

[rthy]

Before you guys start talking specs and parts, whats budget$$$$