Eacy

iTrader: (9)

Will U get all springs send to U, or will they be send to us

2pot

iTrader: (3)

They'll all be dispatched from the UK.

Eacy

iTrader: (9)

Hope they are on time
I am going to the Ring the 7 of May

mrgc8

Suspension noobie here.... I have a version 4 gc8 sti, the spring rates are 196/174 according to NorthUrsalia.

http://www.rs25.com/forums/f9/3266538-post7.html has the original listed as 194/157 for the p11.
What are the rates for the p11 L? Would this be a big upgrade to my version 4 springs? The wr15 r/t lowers the front and rear correct?

2pot

iTrader: (3)

Answered on RS25

qsl

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) +£50
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

In.

Also, how can you quote delivery time for the WR15 if the prototype hasn't been road tested yet, or is there some other news I'm unaware of?

2pot

iTrader: (3)

We've tested a 35N/mm rear spring, of the selected ride height.
It's free length was too short, to accommodate both previously and currently available rear dampers. That issue has now been solved.

We've also, now, found a stiffer, soft-nose twin-tube rear bump stop, that doesn't intersect the rate curve of the rear spring, in its normal operating range.

The front spring, that has been previously tested, was 37N/mm, but too low and, again, too short in its free length, for previous and current dampers.

Flat ride calculations dictate a baseline, front to rear spring differential.

The new, twin-tube, front stop is stiff enough, to protect the damper. And short enough, with soft-nose engagement, to preserve an effective damper travel, with the selected front ride heights.

The preferred balance is then going to be down to sta bar adjustments. As previously mentioned; probably, as intended, less rear bar.

Gear Head

iTrader: (2)

Sorry, silly question but are these available for the Blob WRX? (05)

2pot

iTrader: (3)

You need these:

https://www.scoobynet.com/group-buys...mited-run.html

HTH

RS Grant

I've got a V6 JDM STi Limited with standard 'pink' suspension.



I'd like a more compliant UK-friendly ride because I feel like the JDM springs struggle to cope with what a good Scottish back road has to throw at them. Also given that I'd like to increase my wheel size from 16" to 17" (maybe, but unlikely 18") then I'd like a drop in ride height too. What are my option(s) here??


Cheers,
Grant

2pot

iTrader: (3)

What are the front and rear bar sizes?
Are they 19mm front/20mm rear like a P1?
If they're the same bar sizes as the P1, then I'd find a second-hand 18mm rear bar and try that (18mm is what Prodrive used on the rear of the WR99 option suspension kit - almost identical in rear rate to the v6 sti). Just to get some more independence in the rear suspension, for your particular roads. You'd then know, for certain, if you're ever going to be happy with high spring rates.
I'd definitely change the internal kyb inverted bump stops, to the modern versions sold by pca dymamics.
If you're OK with your current brakes, I'd keep the 16" wheels for the extra sidewall compliance. Might even go 205/55 instead.
What's your wheel centre to arch measurement? - front and rear.

HTH, for a start.

piehole1983

iTrader: (7)

2pot, when the P11L springs arrive and ive fitted them to my inverted struts along with the PCA bump stops I've ordered today, is it reasonable to say that my standard UK Turbo bars may indeed be optimal for the crappy B roads I have around me? I did buy cusco 21 and 23mm bars to swap all at once, but reading this and other threads it seems bigger bars are no good for the road.

2pot

iTrader: (3)

The worse the roads, the smaller the bars. You want the tyre on the ground, not held up by an unnecessarily thick bar.
I'd get the geometry done, first. Then play with the tyre pressures. Start at 37psi front - and reduce, if required, from there. You'll probably end up between 32-36psi at the rear.
If Prodrive selected 19mm/20mm, as an average, for a P1, it's good. What are your bar sizes? I don't think 21mm front is unreasonable for a smooth road/track day car. If your geometry is right, a 20mm adjustable would be fine at the rear.
But, from what you've said, you haven't got smooth roads.

piehole1983

iTrader: (7)

I'm not sure what size my standard bars are, I'll need to measure them. The roads local to me are twisty with plenty of hills and dips and sometimes poor surfaces, some sharp corners in quick succession and so on. There's also plenty of dual carriageway but that's no fun.

The cusco bars I have are 21mm rear and 23mm front I believe. Maybe the other way round but defo 21/23mm.

2pot

iTrader: (3)

I think the uk turbo 2000 was f19mm/r20mm. From what you're describing, with P11L's, I wouldn't go bigger, than what you've already got - play with the geometry and tyre pressures.
If you haven't already, you could poly bush the bars and fit good quality end links.

Rob669

Is 37 psi really right, this sounds like a lot of pressure for most makes of tyre. OK for Toyos with their softer side walls, but that's quite a lot for other types of tyre.

2pot

iTrader: (3)

For the fronts, 37psi is a good (if harsh) starting point. What's max inflated pressure on a tyre? - 40/45psi
What's stock? f33/r32(31)psi - a compromise between handling and ride.
Increasing the pressure, within reason, biases more toward handling, also preserves the edges under heavy cornering. Although, as you rightly say, pressures are tyre dependent. Just check you're not too overly inflated, and wearing out the centre tread.

Sad Weevil

iTrader: (1)

I can confirm that UK turbo 2000 roll bars are indeed f19mm/r20mm, at least, they are on my '99 wagon. Polybushing them is well worth it. IMHO, you need the thinnest roll bars you can get away with on the sometimes bizarre surfaces we have to contend with. Understeer can be addressed with an alk plus alignment.
Stock tyre pressures on the wagon are f33psi/r28psi part laden, f33/r32 fully loaded according to the label on the door frame.

piehole1983

iTrader: (7)

Most folk seem to be of the opinion that standard bars are best for road use. I'll polybush them and keep them instead of the cusco bars. I have whiteline rear drop links and floflex front drop links ready to fit once I've got the P11L springs. Peter at PCA Dynamics has posted my bump stops today too.

2pot

iTrader: (3)

The FOURTH version of Whiteline's kca335 offset front top mount kit is nice.
Sealed bearings (6302z) and 10.9 grade studs - stamped on the stud head.
Avoid previous versions.

piehole1983

iTrader: (7)

Got my PCA Dynamics bump stops today

Rob669

Thanks for the reply on tyre pressures, I'll have a play about with some various options. On ARBs, I now have Whiteline 22mm on the front and 24 at the rear, both adjustable and I really like the slightly harsh feel it gives.

With my P11 L springs and new Excel G shocks, what else do I need to buy would you say - my bumpstops are original and so 15 years old?

piehole1983

iTrader: (7)

I think new bump stops are a must. Have you contacted Peter at PCA Dynamics?

Sad Weevil

iTrader: (1)

Thanks, I'll look into these. Are you using them?

bonesetter

iTrader: (9)

As far as tyre pressures are concerned, it is more beneficial to get to the situation where the temperature across the whole tyre is even

This will almost certainly be in synergy with the rest of your set-up.

Generally speaking though, I run stock pressures

The other important factor is to maintain the contact patch - too high or too low and the tyre will be compromised as will grip levels

'working temperature' is another consideration

You may set the pressure cold, but at full working temperature the psi may rise significantly, altering the contact patch. Think of track days and folk coming in after a few laps and reducing pressure

Some of my cars are dedicated hooners only so I set the cold pressures 'low' to allow for warm-up. Not so much in the colder months, but in summer certainly

These are good for seeing what's going on

Rob669

I'll do that, thanks.

2pot

iTrader: (3)

PCA do the bump stops for inverted dampers - internal bump stops

Your excel-g dampers are twin-tube - external bump stops

I've come up with a bump stop/dust boot kit (bump stop on show, to check for degradation) to match the P11 L to twin-tube dampers - £50

Let me know if you'd like them.

Re: your sta bars - the bump stops should allow you to run less rear bar, for the same balance. You may want remember that when you're re-adjusting/reconsidering your bars.

2pot

iTrader: (3)

Just bought a set of version 4.
Previously used camber plates, but never used the full, available, camber. So the increased NVH seemed an unnecessary downside.
The kca335 is still stiff rubber(group N?) though.

piehole1983

iTrader: (7)

2pot, you reckon I'd be wise to stick with my OE bars on my UK Turbo once I've fitted the inverted dampers, P11L springs and the PCA bump stops? If so I'll poly bush them and get rid of the Cusco bars I have sitting here. Might as well get some money back for them.

2pot

iTrader: (3)

Balance is such a personal thing.
I'd be inclined to start with the stock bars, and not sell on the cusco's, yet - they might suit you?

This sums up what I've discovered, and he's forgotten more than I'll ever know, about car set-up:

Originally Posted by johnfelstead
Setting a car up to handle is far more involved than just choosing the correct dampers and springs, you have to match everything else on the car so that it works in harmony. For example, having the spring rates low and damping high can lead to some very dangerous situations where the suspension jacks itself down onto the bump stops. You also need to choose the bump stops you use and how long they are, bump stops are not what most people think, a last resort to save the damper, they are a very important tuning device that alters your efective spring rates under higher load. My bump stops are used actively to give a rising rate of spring rate up at the upper end of suspension bump travel.

I also played around with suspension ride height and rake settings, the Impreza doesnt like low ride heights at all, it responds well to dialing in some positive rake, this especially improves front end bite on corner entry, it has less effect on set state cornering, changing as little as 3mm in rake makes a huge diference.

You also have to decide what you want from the car. I run my car with 22mm ARB's front/rear with the rear set to fully stiff. This works incredibly well in most circumstances, but on a very bumpy B road its more of a handfull than most people would like. Going back to a stock front and mid rear bar setting makes it much easier to drive on a bumpy road, the fastest aproach to ARB's on bumpy roads is actually to use stock STi bars, but that compromises the car on the smoother roads and track. You can help gain some control back by upping the damping rates, but that takes away some of the balance in other areas.

The point i am trying to make is there is no right or wrong (unless its seriously fubar'd), you need to know what you want and then design the suspension around that. Some things are certain, stiff wheel rates dont work in the UK, ride height needs to be sensible, you have to use positive rake and you must get your geometries setup acurately, running more rear camber than most people have and a very small amount of f/r toe-in to aid stability.

HTH