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Discussion Starter · #1 ·
Has anyone tried different springs with their PSS9s?

I'd like to know if anyone has used smaller inside diameter springs. The stock PSS9 coils are 70mm (2.75") and I'd like to see if I can get down to 2.25 with some Swift springs of similar length and rating.

The reason is to try and get a 7" backspaced wheel in there. The wheels I want currently rub against the dividers or spacers between the springs and helpers. If I could reduce the spring diameters, I could get slightly better geometry for the front suspension by bringing the wheels inboard slightly while kicking the suspension itself out by installing the GT3 lower control arms.

thanks,

Ken
 

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I don't know the diameter but I believe that Tarret has alternate springs that were developed for the Spec Boxter class so I would check there.
 

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You need to machine new top hats/plates to get the parts to work.... That is what we do to our hot-rodded bilstein setup. Call the shop if you are interested.

Casey
 

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Hi, I was looking at replacing my springs recently on my pss9's to make them stiffer and complete race springs..

Well after about 50 calls on everything and about to pull my hair out, I concluded this.

As per Bilstien, they say that it can handle 500LBS springs.

I can replace the fronts with an id 60 from H&R or get helper250 adapter and springs from eibach.

The rears where another story completely.

To use the stock cayman tops they have an id 92.5 and 62.5 at the bottom, sort of like a honey comb shape. Well no one had adapters or a spring that would fit :-(

So instead of going with the revalve and spingngin ( about 1,800 ) I foudn it Much better to just buy a better shock with the spring rates I wanted to beggin with.

I went with the JIC Cross coilovers. They should be here today.

I hope this helps....
 

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Discussion Starter · #6 · (Edited)
Thank you FrankinCayman,

I'm hoping to get away with much less, but as you say, the ultimate option could be to just switch.

I'm just looking to modify the fronts and keep a similar rating... i.e. the Swift 7" are rated at 4kg (280 lb.) vs. my current 255 lb. I've only tracked a few weekends and am primarily an autocrosser, so the need to go to 450-500 lb. springs would be too stiff for my application.

My cheapest option is to machine down the current dividers (primary point of contact) and not get a wheel that goes that far inboard... I could get a 6.75 backspace in a narrower wheel. My searching has been to see if I can allegedly optimize the front end and make any 'excuses' for the car's occasional poor behavior fall squarely to me. :)

I do have a follow up question for some of you out there:

Bilstein mentioned my front springs were 7.1". The Spec guys are installing hefty 5" Eibachs or Swifts. I wonder if I got the right info. When I look at posted pictures, it doesn't look like they've jacked the perches up that much.... must be used as part of their lowering?

thanks,

kj
 

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7.1" is the main spring and there is a 3.3 inch tender spring ( helper ) spring as well.

That is the free length of the spring new. The bilstien springs Do settle and are less then that size. Good springs are pre compressed and will not sag or settle in. Even though H&R did the springs for these, they did not pre compress them :-(

Most people just change the main spring.. But you want to be sure if you go with a shorter spring that you have enough thread at the top of the thread area to make up for that shorter spring size..

On mine I was going to go with a 8" eibach ( 0800.250.0450 )

I mainly do AutoX as well. but I had a few pros drive my car and when we did the track portion of our event, my car was bottoming out on all 4 shocks :-(

From what I was told by them, for any competition the car just handles better 400-450 front and 500-550 rear spring rates. The car just stays more balanced. and if you ever decide to run slicks you need a stiffer spring then what you have now.

I also went with eh JIC so I can get more negative camber on the tires as well ( help on the turn in and corner speeds )
 
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