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TheHammer said:
yes I am...stated this earlier on in this thread

=)
oops, i missed that. i guess i will limit my posting when i am busy at work:p

edit: :censored: , i just found you as the second poster in the thread...how embarassing:lol:
 

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After driving on the RCE's for a couple months, I really am thinking of going with the prodrives or even back to stock because of the harsh ride. I thought it wasn't that big of a deal at first but after a few 3hour drives, i've decided that the ride comfort was much more important than some lift/dive action.
 

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Parker said:
After driving on the RCE's for a couple months, I really am thinking of going with the prodrives or even back to stock because of the harsh ride. I thought it wasn't that big of a deal at first but after a few 3hour drives, i've decided that the ride comfort was much more important than some lift/dive action.
i love my prodrives! less bouncing and overall the ride is slightly better than stock on all surfaces except really bad bumps, then the stockers are 5% better at best.
 

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Parker said:
After driving on the RCE's for a couple months, I really am thinking of going with the prodrives or even back to stock because of the harsh ride. I thought it wasn't that big of a deal at first but after a few 3hour drives, i've decided that the ride comfort was much more important than some lift/dive action.
yeah, on long car trips or in areas where the roads are crappy, it just got to be too annoying. on med/large bumps and cracks, the jarring can be just too much for both the driver and chassis itself.

For the daily commute and shorter trips, the ride comfort with the RCE's was just fine.
 

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9 years ago, the Holy Grail was a cross between the ride height of the rce's and the ride quality of the Prodrive s05/d5/001
9 years later, did a spring set ever achieve this?
 

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Not that I am aware of.


Sent from my iPad using Tapatalk
 

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Handling and comfort is a very subjective matter. RCE with bilstein, it's a bit harsh but something I can tolerate. All my passengers complain about it, I complain about it too whenever I drive other cars.

Sent from my SM-N9005 using Tapatalk
 

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Finally, received a suitable design for a new, front, gd/gg sti dual-rate spring - 245lb/in linear, in its normal operational range.
8mm lower front ride height, than 05-07sti Prodrives - same as an RB320.
Longer front spring, free length, to properly accommodate Koni inserts and other non-inverted.
Matching bump stops - front and rear - for inverted and non-inverted.
Working on the dual-rate rear design.
Looking to maintain a degree of forward rake - similar to the RB320.

Watch this space.
 

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Doesn't that make them close to stock stiffness?
Aren't GDs better off with stiffer front than rear.

So really they will be "linear lowering springs"

Perhaps not, the many available choices are progressive and the highest rate is what is listed, correct? But we really don't know what exactly what they are through their range of motion. They wouldn't be difficult to model though. If I had a spring I believed in and wanted to sell them, I'd make valid comparisons available for the RCEs, Swifts, Eibach, Tein . . . You really need to account for the bump stops too.

Actually after all theses years I'm surprised I have seen this done. The serious people really aren't playing with stock fitment springs anymore though.
 

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245lb/in front, 223lb/in rear
They are linear from 15mm above ride height to coil bind.
Ground top coil front and rear.
65mm front coil bind, 90mm rear coil bind.
The inverted sti struts had a 60mm, rock-hard, front bump stop that was used as a form of pitch control - OK on smooth roads - understeer and bobble-head on uneven roads. Which is why Prodrive included a more progressive, soft-nose, 50mm bump stop, with their '05 sti springs.
Additionally, stiffening the rear bump stop helps contain understeer, without automatically using a bigger rear bar.
You want the smallest bars possible, on a road car, to avoid 'roll-rock'.
If the spring rate is relatively low and the bar is too stiff, a suspension movement, initially, occurring on only one side of the vehicle, will be transmitted to the other side, inducing an unsettling 'roll-rock' motion and destablizing the tyre contact patch.
The RB320 (and P1) had a, relatively, higher rear ride height - this moves the roll centre upward, increasing rear roll resistance.
That, in turn, makes the front end roll more - helping turn-in response and reducing understeer, without the use of stiffer bars.
The new springs offer reasonable ride-heights 14.3" front, 14.6" rear (work with wagons) and are not overly stiff on undulating/uneven roads.
 

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Sounds good!
 

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And still the best thread, for this discussion.Took 2 years to design/re-design the springs.
After pre-production machine stress testing: 0.25mm increase in wire diameter. Slight increase free spring lengths. 0.65 more coil at the front: coil bind now at 74mm.
Reducing the number of coils does reduce the coil bind/weight. But, increasing the coils, increases elasticity. The spring has to reach coil bind and return to its specified free length.

If the design/material exceeds its elastic limit, then the spring won't reach coil bind, or will take a set, and not return to the specified minimum free length.

The WA/A2 springs have an increased free length, compared to a stock STI spring - to accommodate longer length, non-inverted, struts - koni inserts, AGX etc. As well as inverted struts.

Now due, into the UK, week commencing 19 March.
 
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