Prodrive P1 Lowering Springs - Rare Purchase opportunity.
08 February 2015, 04:43 PM
#271
Part of the process of having the front tyres loose grip, before the rears, is to have the front bumpstops engage before the rears and/or at a higher rate.
We, as self-proclaimed driving Gods, normally get around this, intentional, in-built understeer, by fitting a stiffer rear bar (reducing rear grip), to neutralise the handling.
A stiffer rear bar reduces the independence of the rear suspension - on anything less than a very smooth road surface, that equals a loss of traction and comfort.
If you can use the bumpstops, to get a neutral baseline starting point - you can use less rear bar.
However, balance is personal. On a track day car, once you've changed the bumpstops, you may prefer a larger front bar to get back to neutral, rather than reduce the rear bar. A stiffer front bar would reduce loss of camber on turn and limit front suspension travel.
I don't know why you would need more, than a 20mm adjustable rear bar, on the road - but it's very personal.
£50/$75 for front and rear bumpstops and dust boots. Bumpstops to be on show, to check for degradation, with the dust boot attaching to the bumpstop.
Does that help?
09 February 2015, 07:18 AM
#272
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Hello,
I was more under the impression that a bumpstop was just protection to keep the car from bottoming out than an active part of the suspension. I stand corrected. It does make sense now that I think about it. You essentially have a secondary spring that is activated under increasing load.
Aftermarket sway bars at least in the US will be interesting. Most were tuned I suppose for a stock suspension, with 22mm through 27mm being common.
I was more under the impression that a bumpstop was just protection to keep the car from bottoming out than an active part of the suspension. I stand corrected. It does make sense now that I think about it. You essentially have a secondary spring that is activated under increasing load.
Aftermarket sway bars at least in the US will be interesting. Most were tuned I suppose for a stock suspension, with 22mm through 27mm being common.
09 February 2015, 07:58 AM
#273
Hello,
I was more under the impression that a bumpstop was just protection to keep the car from bottoming out than an active part of the suspension. I stand corrected. It does make sense now that I think about it. You essentially have a secondary spring that is activated under increasing load.
Aftermarket sway bars at least in the US will be interesting. Most were tuned I suppose for a stock suspension, with 22mm through 27mm being common.
I was more under the impression that a bumpstop was just protection to keep the car from bottoming out than an active part of the suspension. I stand corrected. It does make sense now that I think about it. You essentially have a secondary spring that is activated under increasing load.
Aftermarket sway bars at least in the US will be interesting. Most were tuned I suppose for a stock suspension, with 22mm through 27mm being common.
If you wanted to keep the stock dust boots, the P11-6, on a twin-tube damper, could use the standard rear bumpstop with the smallest section removed. Again, if you wanted to keep the stock boots, on a twin-tube, rather than cut down the front stop, I'd use Febi 27848 - dome side up (in the US search 13189414 which is the GM equivalent)
Last edited by 2pot; 09 February 2015 at 08:17 AM.
09 February 2015, 12:53 PM
#275
No, they wouldn't need trimming, but I would get new, updated bumpstops for them. I think they're £57 a set of 4
peter@pcadynamics.com
10 February 2015, 12:54 AM
#279
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http://www.superstreetonline.com/how...mp-stops-here/
If you wanted to keep the stock dust boots, the P11-6, on a twin-tube damper, could use the standard rear bumpstop with the smallest section removed. Again, if you wanted to keep the stock boots, on a twin-tube, rather than cut down the front stop, I'd use Febi 27848 - dome side up (in the US search 13189414 which is the GM equivalent)
If you wanted to keep the stock dust boots, the P11-6, on a twin-tube damper, could use the standard rear bumpstop with the smallest section removed. Again, if you wanted to keep the stock boots, on a twin-tube, rather than cut down the front stop, I'd use Febi 27848 - dome side up (in the US search 13189414 which is the GM equivalent)
And if you already have a largish front and rear sway bars, what adjustments could be made to bump stops to lean more towards neutral?
10 February 2015, 10:43 AM
#280
Maybe, you've spent, almost, all you can afford on the P11-6 springs? Then, assuming the dust boots (front and rear) and the rear bumpstops are in good condition, you could cut down the rear bumpstop by one section - and re-use. Then, just buy a couple of the febi stops for the front.
I'd spend the extra £50 and get the new, alternative bumpstop set.
Or, maybe, you like the original look under your car? All sorts of differing people in the world.
I assume those who have gone to the expense of stiffer, adjustable, front and rear bars, have now achieved a balance they like. Changing the bumpstops, when changing the springs, should allow them to run less rear bar, for the same balance - which has the benefits already discussed.
My question would be: If they're running lowered springs, what did they do, if anything, with their OEM bumpstops?
10 February 2015, 11:38 AM
#281
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Ah, gotcha. I figured in for a penny, in for a pound at this point.
The US 2.5 RS came with tinnie-tiny sway bars (19mm/13mm) and such questionable choices as hard rubber endlinks. Consequently, the most popular modification was new sway bars all around (I have 22mm/22-26mm) and better endlinks, even without thinking of lowering the car.
The balance is quite good, with very controlled rotation at medium speed.
But now is the option to increase the absolute grip in the rear while still keeping the same balance. The question is given the other changes, what range for the rear sway bar?
Since I don't know what UK spec GC8 sway bars were, it is hard for me to gauge.
The US 2.5 RS came with tinnie-tiny sway bars (19mm/13mm) and such questionable choices as hard rubber endlinks. Consequently, the most popular modification was new sway bars all around (I have 22mm/22-26mm) and better endlinks, even without thinking of lowering the car.
The balance is quite good, with very controlled rotation at medium speed.
But now is the option to increase the absolute grip in the rear while still keeping the same balance. The question is given the other changes, what range for the rear sway bar?
Since I don't know what UK spec GC8 sway bars were, it is hard for me to gauge.
at Eibach.
10 February 2015, 05:33 PM
#284
Ah, gotcha. I figured in for a penny, in for a pound at this point.
The US 2.5 RS came with tinnie-tiny sway bars (19mm/13mm) and such questionable choices as hard rubber endlinks. Consequently, the most popular modification was new sway bars all around (I have 22mm/22-26mm) and better endlinks, even without thinking of lowering the car.
The balance is quite good, with very controlled rotation at medium speed.
But now is the option to increase the absolute grip in the rear while still keeping the same balance. The question is given the other changes, what range for the rear sway bar?
Since I don't know what UK spec GC8 sway bars were, it is hard for me to gauge.
The US 2.5 RS came with tinnie-tiny sway bars (19mm/13mm) and such questionable choices as hard rubber endlinks. Consequently, the most popular modification was new sway bars all around (I have 22mm/22-26mm) and better endlinks, even without thinking of lowering the car.
The balance is quite good, with very controlled rotation at medium speed.
But now is the option to increase the absolute grip in the rear while still keeping the same balance. The question is given the other changes, what range for the rear sway bar?
Since I don't know what UK spec GC8 sway bars were, it is hard for me to gauge.
I think you'd have fit the springs and bumpstops, and adjust the balance back to your personal taste through the bars.
If the rear bar is adjustable, I might be inclined to start at its softest setting.
10 February 2015, 06:13 PM
#285
Eibach have re-designated the P11-6, the P11 L
I've now increased the order of P11 L's to 50.
So, a price break kicks in - £235 delivered mainland UK
twistybits - P11 L
topshot - P11 L
Scooby Wagon - P11 L
piehole1983 - P11 L (NI)
Rob669 P11 L
Sad Weevil P11 L
OBSTi P11 L (US)
Laupy P11 L
Donkey Dave P11 L
2pot WR15 R/T
Scott.T WR15 R/T
qsl WR15 R/T (US)
Geddesk2_2 WR15 R/T (US)
HighRevimpreza WR15 R/T (US)
Eacy WR15 R/T (Denmark)
Scoobyedge WR15 R/T
bonestter P11
Vee P11
Mtb_ed P11
P1 Steve73 P11
rusty&dusty P11
KRob P11
allsop83 P11
I've now increased the order of P11 L's to 50.
So, a price break kicks in - £235 delivered mainland UK
twistybits - P11 L
topshot - P11 L
Scooby Wagon - P11 L
piehole1983 - P11 L (NI)
Rob669 P11 L
Sad Weevil P11 L
OBSTi P11 L (US)
Laupy P11 L
Donkey Dave P11 L
2pot WR15 R/T
Scott.T WR15 R/T
qsl WR15 R/T (US)
Geddesk2_2 WR15 R/T (US)
HighRevimpreza WR15 R/T (US)
Eacy WR15 R/T (Denmark)
Scoobyedge WR15 R/T
bonestter P11
Vee P11
Mtb_ed P11
P1 Steve73 P11
rusty&dusty P11
KRob P11
allsop83 P11
10 February 2015, 08:24 PM
#287
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Hi I'm glad I found this thread on Google while searching for springs. I live in Canada how much would it be for shipping?
I imported a MY98 v4 GF8 sti, would any of the 3 springs improve on rear sag? I don't know much about suspension but I want to get a set since these are rare.
Could anyone recommend one for a daily driver, spirited highway driving, slight lower, and no track? I'm guessing the p11-6? Is it too late to order?
Also how can you tell if its an early or late Bilsteins?
I imported a MY98 v4 GF8 sti, would any of the 3 springs improve on rear sag? I don't know much about suspension but I want to get a set since these are rare.
Could anyone recommend one for a daily driver, spirited highway driving, slight lower, and no track? I'm guessing the p11-6? Is it too late to order?
Also how can you tell if its an early or late Bilsteins?
10 February 2015, 09:24 PM
#288
Hi I'm glad I found this thread on Google while searching for springs. I live in Canada how much would it be for shipping?
I imported a MY98 v4 GF8 sti, would any of the 3 springs improve on rear sag? I don't know much about suspension but I want to get a set since these are rare.
Could anyone recommend one for a daily driver, spirited highway driving, slight lower, and no track? I'm guessing the p11-6? Is it too late to order?
Also how can you tell if its an early or late Bilsteins?
I imported a MY98 v4 GF8 sti, would any of the 3 springs improve on rear sag? I don't know much about suspension but I want to get a set since these are rare.
Could anyone recommend one for a daily driver, spirited highway driving, slight lower, and no track? I'm guessing the p11-6? Is it too late to order?
Also how can you tell if its an early or late Bilsteins?
Prodrive Bilstein WR97/98
2030055120 (7114262M000) 2030055130 (7114261M000) 2220055120 (7104264M000) 2220055130 (7104263M000)
Prodrive Bilstein WR99 professional
F4VE34625M0 F4VE34626M0, F4VE34627M0 F4VE34628M0
There were some Japanese Bilstein variants:
Bilstein/eibach soft 171/140
front pair strut and spring 2000055020
rear pair strut and spring 2000055030
rear pair strut and spring wagon 2000055040
Bilstein/eibach hard 196/168
front pair strut and spring 2000055050
rear pair strut and spring 2000055060
The P11 L (previously P11-6) and the WR15R/T both accommodate the GF8
From your description P11 L would be suitable
PM me an address and post/zip code and I'll check delivery costs. To the US its $120 US - 3-5 day delivery.
HTH
Last edited by 2pot; 10 February 2015 at 09:55 PM.
12 February 2015, 04:13 PM
#289
Eibach have re-designated the P11-6, the P11 L
I've now increased the order of P11 L's to 50.
So, a price break kicks in - £235 delivered mainland UK
WR15 R/T - currently £290 delivered mainland UK
Please add below, if your dampers are inverted (in) or twin-tube (tt).
If twin-tube, do you want a matched bumpstop/dust boot kit? +£50
If inverted, and you want bumpstops - contact peter@pcadynamics.com www.pcadynamics.com
£62.40 UK delivered - kits for early Bilstein, late Bilstein and inverted KYB.
twistybits - P11 L
topshot - P11 L
Scooby Wagon - P11 L
piehole1983 - P11 L (NI) in
Rob669 P11 L
Sad Weevil P11 L in
OBSTi P11 L (US) in
Laupy P11 L
Donkey Dave P11 L in
2pot WR15 R/T tt +£50
Scott.T WR15 R/T in
qsl WR15 R/T (US)
Geddesk2_2 WR15 R/T (US)
HighRevimpreza WR15 R/T (US)
Eacy WR15 R/T (Denmark) tt+£50
Scoobyedge WR15 R/T
bonestter P11
Vee P11
Mtb_ed P11
P1 Steve73 P11
rusty&dusty P11
KRob P11
allsop83 P11
I've now increased the order of P11 L's to 50.
So, a price break kicks in - £235 delivered mainland UK
WR15 R/T - currently £290 delivered mainland UK
Please add below, if your dampers are inverted (in) or twin-tube (tt).
If twin-tube, do you want a matched bumpstop/dust boot kit? +£50
If inverted, and you want bumpstops - contact peter@pcadynamics.com www.pcadynamics.com
£62.40 UK delivered - kits for early Bilstein, late Bilstein and inverted KYB.
twistybits - P11 L
topshot - P11 L
Scooby Wagon - P11 L
piehole1983 - P11 L (NI) in
Rob669 P11 L
Sad Weevil P11 L in
OBSTi P11 L (US) in
Laupy P11 L
Donkey Dave P11 L in
2pot WR15 R/T tt +£50
Scott.T WR15 R/T in
qsl WR15 R/T (US)
Geddesk2_2 WR15 R/T (US)
HighRevimpreza WR15 R/T (US)
Eacy WR15 R/T (Denmark) tt+£50
Scoobyedge WR15 R/T
bonestter P11
Vee P11
Mtb_ed P11
P1 Steve73 P11
rusty&dusty P11
KRob P11
allsop83 P11
Last edited by 2pot; 12 February 2015 at 10:29 PM.
12 February 2015, 10:27 PM
#297
Twin-tubes with the P11 L, optimally, you should use the matched bumpstop set for £50.
However, if your existing rear dust covers and rear bumpstops are OK, you could cut the smallest section off the bumpstop, gaining you 15mm.
If the front dust covers are OK, use Febi 27848 or Optimal F8-7662 (£15/25 delivered) dome side up, instead of your existing 60mm long front bumpstops.
If you've got buy OEM replacement new rear stops and boots, then that's going to cost £26. I know the link says wagon, but they're correct for classic wagon and saloon.
http://www.spring-loaded.co.uk/prodd...rs~-~AK-735144
So, maybe £41 in total - you might as well have the inherently better balanced, £50 matched set. The matched set also have bumpstops visible to more easily check for any degradation.
HTH you decide.
Last edited by 2pot; 13 February 2015 at 08:45 AM. Reason: Add alternative/info
13 February 2015, 10:36 AM
#298
The P11 L are arriving in 5/6 weeks. Let me know if you want to go on the list, with or without, matching bumpstops and dust boots.
I will not be collecting any monies, until they are at Eibach UK.
20 February 2015, 11:32 AM
#300
Eibach have re-designated the P11-6, the P11 L
I've now increased the order of P11 L's to 50.
So, a price break kicks in - £235 delivered mainland UK
WR15 R/T - currently £290 delivered mainland UK
Please add below, if your dampers are inverted (in) or twin-tube (tt).
If twin-tube, do you want a matched bumpstop/dust boot kit? +£50
If inverted, and you want bumpstops - contact peter@pcadynamics.com www.pcadynamics.com
£62.40 UK delivered - kits for early Bilstein, late Bilstein and inverted KYB.
twistybits - P11 L
topshot - P11 L
Scooby Wagon - P11 L
piehole1983 - P11 L (NI) in
Rob669 P11 L
Sad Weevil P11 L in
OBSTi P11 L (US) in
Laupy P11 L
Donkey Dave P11 L in
awdftw P11 L (Can) tt +£50
2pot WR15 R/T tt +£50
Scott.T WR15 R/T in
qsl WR15 R/T (US)
Geddesk2_2 WR15 R/T (US)
HighRevimpreza WR15 R/T (US)
Eacy WR15 R/T (Denmark) tt+£50
Scoobyedge WR15 R/T
bonestter P11
Vee P11
Mtb_ed P11
P1 Steve73 P11
rusty&dusty P11
KRob P11
allsop83 P11
I've now increased the order of P11 L's to 50.
So, a price break kicks in - £235 delivered mainland UK
WR15 R/T - currently £290 delivered mainland UK
Please add below, if your dampers are inverted (in) or twin-tube (tt).
If twin-tube, do you want a matched bumpstop/dust boot kit? +£50
If inverted, and you want bumpstops - contact peter@pcadynamics.com www.pcadynamics.com
£62.40 UK delivered - kits for early Bilstein, late Bilstein and inverted KYB.
twistybits - P11 L
topshot - P11 L
Scooby Wagon - P11 L
piehole1983 - P11 L (NI) in
Rob669 P11 L
Sad Weevil P11 L in
OBSTi P11 L (US) in
Laupy P11 L
Donkey Dave P11 L in
awdftw P11 L (Can) tt +£50
2pot WR15 R/T tt +£50
Scott.T WR15 R/T in
qsl WR15 R/T (US)
Geddesk2_2 WR15 R/T (US)
HighRevimpreza WR15 R/T (US)
Eacy WR15 R/T (Denmark) tt+£50
Scoobyedge WR15 R/T
bonestter P11
Vee P11
Mtb_ed P11
P1 Steve73 P11
rusty&dusty P11
KRob P11
allsop83 P11
Last edited by 2pot; 20 February 2015 at 08:02 PM.