[RS Barn]

BTW, Bob's car is fantastic under pretty smooth driving conditions.

One of my major problems in spring discussions are actual rates. The "STD" progressive springs are somewhere in the 180-220 range if you convert N/mm but that may not tell the whole story. Progressive spring rates are measured differently than linear rates. They measure with zero preload and then measure every 1/2" until coil bind. Linear springs are quoted at a 1/2" preload and then measured.

I did the tests on a spring dyno with my Turbo Cup car to verify the 180-410 rate.

I believe the std springs would measure around 260 in/lbs. I've run 250 linear and they are softer than stock. 275 feel almost like stock, maybe a tiny bitt stiffer. I like 300 in/lb as a slight increase. From my calculations that is 13% stiffer than stock springs. MO30 spring is 15% stiffer but feel like more. The 4" barrel spring Porsche uses feel way different than 2 1/2" linear. I like Eibach vs Hyperco too. They just feel smoother.

if you lower car from stock ride height the spring rate needs to go up to maintain same ride quality as stock. So if you lower car 1/2" you may need to up 5% . Take the math from there

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[flash]

for what it's worth, 7 years ago, when i was trying to figure out my springs the first time, i measured the rates of the stock springs, as well as the porsche motorsport tech art/eibach springs. i got the numbers that are published in the workshop manual for the stock springs.



fortunately i have a set of extremely low mileage standard springs here on which to base the initial rate for the new progressive springs,and will report back with all of the preloaded and inch by inch rates of that spring, as well as the new ones.

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[DaveN]

[quote name='RS Barn' timestamp='1317395396' post='116081']

I like Eibach vs Hyperco too. They just feel smoother.

[/quote]



My mechanic refers to H&R springs as "Hard & Rough" and prefers Eibach. I thought he was just being opinionated but it's nice to see someone else think they may be a bit harsh. I watch with interest as I get closer to my decision.

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[Lim Yong]

Just chiming in.....I would prefer stock ride height with softer initial damping progressive springs. So, maybe 150 - 220.

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[flash]

it just isn't going to be cost effective for me to wind 2 different springs, and in fact, i have to do a LOT of them just to get it done at all,and will probably be sitting on quite a few for a very long time.

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[RS Barn]

I think one of the most important improvement in newer Porsches handling is spring rate and damping. They are "Really Good" at matching ride quality and body roll with Spring Rates and then damping rates.

I've worked with Honda HRC Racing and KTM Motorcycles on shock valving for Ohlins and White Power gas shocks. This was long ago but the principals haven't changed much. Much of 90's racing technology is now coming to production high end autos.

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[Qfrank]

Chudson,

I might have some hyper coils to sell, if I cannot get this car the way I want. <acronym title='previous owner'>PO</acronym> installed them on stock suspension.

I auto crossed again this weekend, and I feel the car is to low under heavy braking and cornering, to the point I am scrubbing speed due to all the weight transfer, look at my picture, I can almost scrub front bumper.



I measured ride height on level surface, and it is off from left to right.



I measured from the ground, to the bottom of the fender, following the center cap as center line.



LF- 25.25"

RF- 24.75



LR- 25.50

RR - 25.25



I am on stock shock struts, with 83000 miles. New dampers are coming soon, I just need to see what else I need to due. Not sure I want a lowered spring, unless a good alignment can correct some of the height issues. The alignment seems aggressive on the negative camber on all 4 corners due to tire wire on the insides. I would consider a 200-250lb spring to help in the corners and would love sway bars as well. Anybody have any?





What do you guys think about thee ride height?

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