Newage WRX suspension on an STI?
16 April 2015, 02:10 PM
#1
Newage WRX suspension on an STI?
This might sound crazy to some - but for my needs, compliance is everything.
I had a 93 WRX RA (softer spring rates than later GC8 cars) which was simply sublime in its ability to devour bumpy country roads where my Imprezas spend almost all of their time. My MY99 WRX RA had P1 springs with Bilstein Prodrive dampers - a well-known combination which was equally excellent.
I am looking to replicate this handling on my 2004 (non widetrack) STi which currently has Eibach Pro Street S coilovers fitted which are much too stiff and bouncy for the average B-road. I doubt that any coilovers would be suitable, hence looking at fixed-perch options.
I have a set of RB320 Eibach springs which I've considered fitting with KYB AGX dampers (with the use of Scooby921 spacers).
I've also been considering fitting WRX springs/dampers for the softer spring rates, with larger ARBs to minimise roll.
Any thoughts on the Eibach/AGX versus WRX solutions would be welcomed.
I had a 93 WRX RA (softer spring rates than later GC8 cars) which was simply sublime in its ability to devour bumpy country roads where my Imprezas spend almost all of their time. My MY99 WRX RA had P1 springs with Bilstein Prodrive dampers - a well-known combination which was equally excellent.
I am looking to replicate this handling on my 2004 (non widetrack) STi which currently has Eibach Pro Street S coilovers fitted which are much too stiff and bouncy for the average B-road. I doubt that any coilovers would be suitable, hence looking at fixed-perch options.
I have a set of RB320 Eibach springs which I've considered fitting with KYB AGX dampers (with the use of Scooby921 spacers).
I've also been considering fitting WRX springs/dampers for the softer spring rates, with larger ARBs to minimise roll.
Any thoughts on the Eibach/AGX versus WRX solutions would be welcomed.
17 April 2015, 09:14 AM
#3
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Not crazy at all, compliance is the reason I just bought a 2005 WRX rather than an STi (I'll be refreshing the suspension with PCA Dynamics springs and some fresh dampers but I'll not be making it all stiff).
I don't know what rims you run, but a good place to start might be to look for the lightest of lightweight rims that you can reasonably find and run some very good road tyres (not semi slicks or track day tyres) with a bit of sidewall. And if you're running a huge BBK with big calipers and fat single piece discs etc, there might be some weight to shed there too.
On my other car, I tend to find it a relief to swap back from 9kg 17s and AD08s to 6½kg 16s with Bridgestones at the end of the track season. It's only 2½kg per corner but it really helps when not on the track.
I don't know what rims you run, but a good place to start might be to look for the lightest of lightweight rims that you can reasonably find and run some very good road tyres (not semi slicks or track day tyres) with a bit of sidewall. And if you're running a huge BBK with big calipers and fat single piece discs etc, there might be some weight to shed there too.
On my other car, I tend to find it a relief to swap back from 9kg 17s and AD08s to 6½kg 16s with Bridgestones at the end of the track season. It's only 2½kg per corner but it really helps when not on the track.
17 April 2015, 11:08 AM
#4
Great reply. I am running forged JDM BBS 17s which are as light as 17s get, with STi Brembos.
I hear what you say on the sidewalls, but I want the compliance to come from the suspension not the tyres as I'm not wanting to sacrifice turn-in or overall response. To clarify I am looking for performance not comfort - IMO the received wisdom that stiffness equals high performance is the total opposite of my own experience driving fast road on British country lanes. Soft springs + thick ARBs are the way forward in this environment.
I hear what you say on the sidewalls, but I want the compliance to come from the suspension not the tyres as I'm not wanting to sacrifice turn-in or overall response. To clarify I am looking for performance not comfort - IMO the received wisdom that stiffness equals high performance is the total opposite of my own experience driving fast road on British country lanes. Soft springs + thick ARBs are the way forward in this environment.
Last edited by plenty; 17 April 2015 at 11:15 AM.
17 April 2015, 11:19 AM
#6
I agree
I have my bc's set at the softest setting and although it's bouncy at times it's a lot more drivable through the twisties than when it's on a harder setting.
I'm considering Jdm shocks with eibach springs but that would mean second hand probably and a backward step.
Siv
I have my bc's set at the softest setting and although it's bouncy at times it's a lot more drivable through the twisties than when it's on a harder setting.
I'm considering Jdm shocks with eibach springs but that would mean second hand probably and a backward step.
Siv
17 April 2015, 11:36 AM
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17 April 2015, 11:50 AM
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If the KYB AGX dampers are adjustable, and you have a decent set of well matched springs, then perhaps that's the best combination you're going to get, with stock (or otherwise softish) bump stops. I'd also be inclined not to add a bunch of poly bushes to the suspension, or aftermarket top mounts. Maybe just bush the engine and gearbox to keep it under control over the bumps.
And as I'm a newbie to Imprezas, what combination of ARBs and drop links would you be running? Do all Subaru's need the 'stout mounts' to get the ARBs to work? Does anyone soften off the front bar in the search for compliance instead of stiffening both bars/just the rear? (I've found that a stiff rARB and no front bar worked well on my other (FWD) car.)
And as I'm a newbie to Imprezas, what combination of ARBs and drop links would you be running? Do all Subaru's need the 'stout mounts' to get the ARBs to work? Does anyone soften off the front bar in the search for compliance instead of stiffening both bars/just the rear? (I've found that a stiff rARB and no front bar worked well on my other (FWD) car.)
Last edited by MaxA; 17 April 2015 at 11:55 AM. Reason: ARBs
17 April 2015, 01:49 PM
#11
And as I'm a newbie to Imprezas, what combination of ARBs and drop links would you be running? Do all Subaru's need the 'stout mounts' to get the ARBs to work? Does anyone soften off the front bar in the search for compliance instead of stiffening both bars/just the rear? (I've found that a stiff rARB and no front bar worked well on my other (FWD) car.)
Some people uprate the rear bar only (which goes a long way to countering the understeer that Imprezas come with out of the box), while 22F/24R and 24F/24R are also popular options.
This thread is worth a read.
17 April 2015, 02:03 PM
#14
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i have heard conflicting information about rear ARB sizes - some say anything bigger than 22 on the back can actually have an adverse effect on how twitchy the back end feels and went back to the stock 19mm bar instead
but they did have coilovers fitted rather than a decent shock/spring combo
but they did have coilovers fitted rather than a decent shock/spring combo
17 April 2015, 02:41 PM
#15
I never went down the coilover route for this very reason.
I'm still using my hawk WRX shocks with Tein lowering springs. Handling is fantastic, holds like no business and lovely and predictable and has the added benefit of not shaking my spine out of my arsehole every day on my road car!
OEM struts with decent lowering springs on a road car every day!
I'm still using my hawk WRX shocks with Tein lowering springs. Handling is fantastic, holds like no business and lovely and predictable and has the added benefit of not shaking my spine out of my arsehole every day on my road car!
OEM struts with decent lowering springs on a road car every day!
17 April 2015, 02:57 PM
#17
Going 24mm rear without changing the front to at least 22mm WILL give you a brown trouser moment and WILL see you facing the other way or worse !
I know, I've done it and got away with it.
22mm front and rear suits my driving just fine and I find the oversteer can be controlled with the throttle.
Don't get me wrong coilovers are excellent on smooth surfaces but in the real world of British roads they will rattle your feckin teeth out.
Siv
05 October 2015, 01:53 PM
#20
I posted the following on another thread - pasted below:
I thought I would add my own experience to this excellent thread as I too have been looking to create a compliant road setup for my 2004 JDM.
When I acquired the car it was fitted with coilovers which (as with with all coilovers in my experience) were too firm and crashy for the road. My benchmark was the P1/Bilstein setup I had on my classic which was absolutely spot-on.
After reading up on the matter my initial actions were to fit a set of KYB AGX with Prodrive Red 05+ springs. I would have liked a set of Prodrive 04 springs which have a slightly softer rate but these are more difficult to source at least at the time of my buying. As the AGX are twin-tube not inverted dampers I needed new bump stops and fitted a set of WRX bump stops (used on the front and new on the rear).
It was apparent that this setup wasn't what I was looking for either as the car was still too jittery on B-roads. I was considering trying Prodrive Blue (WRX) springs or even P1 springs but following the tips on this forum particularly from 2pot and InTurbo, as well as advice from Peter Cambridge of PCA Dynamics, I chose to (a) downgrade my 22F/24R ARBs to 19F/20R OEM items, and change my front bump stops to shorter Febi items to allow more travel. (Rear bump stops unchanged.)
I also replaced the front springs with RB320 items to create a small amount of front rake which as documented on this thread works well on the newage and reduces the amount of understeer allowing you to run a smaller rear ARB.
WOW - what a difference. The jitteriness is gone and I have achieved what I was looking for, i.e. the ability to soak up the bumps and confidently press on down a country road...the balance is fundamentally neutral, the rear is utterly planted and there is only a very small amount of understeer when really pushing on in wet conditions, all characteristics which suit my style of driving.
There is of course more lean when cornering but nothing unmanageable, and I would say it's not quite up to the standard of my P1/Bilstein setup which was truly legendary in its ability to "float" across poor surfaces, but after 800+miles hooning around Wales this past weekend I pronounce it 95% as good and I'm satisfied with it.
If I were to do it again I would probably try Koni inserts rather than the AGX which is an old design and has only coarse adjustment (four positions). I am running position 1 (softest) on the front and 2 on the rear.
Thanks to 2pot, InTurbo, Peter Cambridge and others for contributing valuable information - it's gratifying to know that there are still people out there who are interested in tuning Impreza suspension for optimal handling (as opposed to simply aesthetics).
I thought I would add my own experience to this excellent thread as I too have been looking to create a compliant road setup for my 2004 JDM.
When I acquired the car it was fitted with coilovers which (as with with all coilovers in my experience) were too firm and crashy for the road. My benchmark was the P1/Bilstein setup I had on my classic which was absolutely spot-on.
After reading up on the matter my initial actions were to fit a set of KYB AGX with Prodrive Red 05+ springs. I would have liked a set of Prodrive 04 springs which have a slightly softer rate but these are more difficult to source at least at the time of my buying. As the AGX are twin-tube not inverted dampers I needed new bump stops and fitted a set of WRX bump stops (used on the front and new on the rear).
It was apparent that this setup wasn't what I was looking for either as the car was still too jittery on B-roads. I was considering trying Prodrive Blue (WRX) springs or even P1 springs but following the tips on this forum particularly from 2pot and InTurbo, as well as advice from Peter Cambridge of PCA Dynamics, I chose to (a) downgrade my 22F/24R ARBs to 19F/20R OEM items, and change my front bump stops to shorter Febi items to allow more travel. (Rear bump stops unchanged.)
I also replaced the front springs with RB320 items to create a small amount of front rake which as documented on this thread works well on the newage and reduces the amount of understeer allowing you to run a smaller rear ARB.
WOW - what a difference. The jitteriness is gone and I have achieved what I was looking for, i.e. the ability to soak up the bumps and confidently press on down a country road...the balance is fundamentally neutral, the rear is utterly planted and there is only a very small amount of understeer when really pushing on in wet conditions, all characteristics which suit my style of driving.
There is of course more lean when cornering but nothing unmanageable, and I would say it's not quite up to the standard of my P1/Bilstein setup which was truly legendary in its ability to "float" across poor surfaces, but after 800+miles hooning around Wales this past weekend I pronounce it 95% as good and I'm satisfied with it.
If I were to do it again I would probably try Koni inserts rather than the AGX which is an old design and has only coarse adjustment (four positions). I am running position 1 (softest) on the front and 2 on the rear.
Thanks to 2pot, InTurbo, Peter Cambridge and others for contributing valuable information - it's gratifying to know that there are still people out there who are interested in tuning Impreza suspension for optimal handling (as opposed to simply aesthetics).