Understeer caused by 22mm Front roll bar?
#1
Understeer caused by 22mm Front roll bar?
I'm not sure what a standard MY98 WRX saloon setup is for the suspension but this is what I have got
Standard dampers with Eibach springs with 35mm drop.
Rear powerflex solid drop links.
Rear Whiteline haevy duty anti roll bar mounts and bushes.
Front Whiteline bushes.
Alloy bottom arms with solid links.
Front 22mm Anti roll bar by zerosports.
Rear 22mm Anti roll bar by zerosports.
Front upper Cusco strut brace.
Prodrive geometry by scoobyclinic
Now, what I am getting is a lot of understeer in the wet and fair bit in the dry. This isnt just when under power, its all the time
Is there anything in my setup that would promote these symptons?
Standard dampers with Eibach springs with 35mm drop.
Rear powerflex solid drop links.
Rear Whiteline haevy duty anti roll bar mounts and bushes.
Front Whiteline bushes.
Alloy bottom arms with solid links.
Front 22mm Anti roll bar by zerosports.
Rear 22mm Anti roll bar by zerosports.
Front upper Cusco strut brace.
Prodrive geometry by scoobyclinic
Now, what I am getting is a lot of understeer in the wet and fair bit in the dry. This isnt just when under power, its all the time
Is there anything in my setup that would promote these symptons?
#2
Scooby Regular
I would've expected the rear ARB to be stiffer (i.e. thicker) than the front. Other than that the spec list looks fine on paper. What are you geometery settings?
Stefan
Stefan
#5
Scooby Regular
iTrader: (2)
Join Date: May 2000
Location: Class record holder at Pembrey Llandow Goodwood MIRA Hethel Blyton Curborough Lydden and Snetterton
Posts: 8,626
Likes: 0
Received 0 Likes
on
0 Posts
To be fair if the OE ARB's are the same thickness, then understeer sould be the same as before. It would be reduced if you kept the uprated one on the rear and OE on the front.
However, I'd get the bumpsteer mod done and keep the uprated ARB on the front. Bye bye understeer
However, I'd get the bumpsteer mod done and keep the uprated ARB on the front. Bye bye understeer
#6
Originally Posted by Jay m A
To be fair if the OE ARB's are the same thickness, then understeer sould be the same as before. It would be reduced if you kept the uprated one on the rear and OE on the front.
However, I'd get the bumpsteer mod done and keep the uprated ARB on the front. Bye bye understeer
However, I'd get the bumpsteer mod done and keep the uprated ARB on the front. Bye bye understeer
How does it help understeer?
#7
The fact that the fr/rr bars are the same diameter is not the point. The arm length on each is the critical bit here. The longer the 'arm' the more twist is loaded into the main 'straight' of the bar.
The Whiteline rear 22mm bar has 3 setting on the arms (3 drop link bolt holes).
After endless juggling on hill climbs in competition i find the middle hole just about right FOR MY SET-UP which is a bit extreme (it is a 3000 miles/yr road car too)
I'm not too sure, but arn't the Prodrive settings a bit of a safety/road/tyre wear compromise? I think people are now going a bit more radical, Power Station are on the Type 25?
For advice go to www.whiteline.com.au and chase their threads.
911
The Whiteline rear 22mm bar has 3 setting on the arms (3 drop link bolt holes).
After endless juggling on hill climbs in competition i find the middle hole just about right FOR MY SET-UP which is a bit extreme (it is a 3000 miles/yr road car too)
I'm not too sure, but arn't the Prodrive settings a bit of a safety/road/tyre wear compromise? I think people are now going a bit more radical, Power Station are on the Type 25?
For advice go to www.whiteline.com.au and chase their threads.
911
Trending Topics
#8
Scooby Regular
iTrader: (2)
Join Date: May 2000
Location: Class record holder at Pembrey Llandow Goodwood MIRA Hethel Blyton Curborough Lydden and Snetterton
Posts: 8,626
Likes: 0
Received 0 Likes
on
0 Posts
911, its a zerosports ARB, not sure if that is adjustable, but what I was getting at was if all things were equal bar the thickness.
Bumpsteer - you are correct in what you say, and what happens when the car dives under braking (or goes over a bump) is that the front wheels toe out as the suspension compresses.
So if you imagine the car going round a corner loading up on the outer suspension, the wheel thats trying to point round the bend is getting pushed straight ahead as the suspesion compresses on the outer side, hence understeer.
Bumpsteer - you are correct in what you say, and what happens when the car dives under braking (or goes over a bump) is that the front wheels toe out as the suspension compresses.
So if you imagine the car going round a corner loading up on the outer suspension, the wheel thats trying to point round the bend is getting pushed straight ahead as the suspesion compresses on the outer side, hence understeer.
#9
Jay, I've been through all this on my hill climb Sti v3 used in serious competition.
The wat I finally killed understeer and got the chassis to be 'right' was to follow Whitelines spec, and a bit further.
WL anti roll bars @ 22mm Fr and Rr (rear on mid setting)
AVO coil overs with 300 lb fr and 250 rr + 30 mm lower
MRT top mounts
Camber bolts
WL rear ower track bars
Full Powerflex bushes
Whiteline Radical set-up geometry
17'' P1 wheels and Kumho tyres.
A lot done, but what a fab cornering car!
911
The wat I finally killed understeer and got the chassis to be 'right' was to follow Whitelines spec, and a bit further.
WL anti roll bars @ 22mm Fr and Rr (rear on mid setting)
AVO coil overs with 300 lb fr and 250 rr + 30 mm lower
MRT top mounts
Camber bolts
WL rear ower track bars
Full Powerflex bushes
Whiteline Radical set-up geometry
17'' P1 wheels and Kumho tyres.
A lot done, but what a fab cornering car!
911
#10
Scooby Regular
Join Date: Apr 2003
Location: South Bucks
Posts: 3,213
Likes: 0
Received 0 Likes
on
0 Posts
What wheels and what tyres are you running? Are the tyres the same front/rear?
Whilst bumpsteer might be useful, I think that anyone whose driven an Impreza for more than a couple of hours will probably drive around the roll understeer problem. Though it's a pain or worse if you suddenly have to wind off lock.
J.
Whilst bumpsteer might be useful, I think that anyone whose driven an Impreza for more than a couple of hours will probably drive around the roll understeer problem. Though it's a pain or worse if you suddenly have to wind off lock.
J.
#12
Scooby Regular
Join Date: Jun 2003
Location: Founder of surreyscoobies.co.uk
Posts: 2,889
Likes: 0
Received 0 Likes
on
0 Posts
I have std anti roll bars front and rear, eibach springs, std dampers and geometry setup by power engineering, no understeer but not very good tyre wear, i think the geometry is the deciding factor, if its the prodrive settings then it will be "nice and safe" and not much tyre wear
andy
andy
#13
Scooby Regular
Missed the "Prodrive geometry by scoobyclinic" part of the first post.
Personally, I didn't like these settings. Preferred much more camber.
The ARB's do make a big difference to handling, but not on their own. You don't have to fit these to complete irradicate understeer, but cornering speed and grip through is so much better with them IMHO.
Stefan
Personally, I didn't like these settings. Preferred much more camber.
The ARB's do make a big difference to handling, but not on their own. You don't have to fit these to complete irradicate understeer, but cornering speed and grip through is so much better with them IMHO.
Stefan
Last edited by ozzy; 04 October 2004 at 03:10 PM.
#14
I know I'm going to get shot for this, but can I put crappy flexible droplinks on the front to see if this helps the situation?. Its a WRX with the alloy bottom arms so I'm not sure if you can do this.
Interesting points about the geometry. May give it a chance with the above and then see about getting a better setup.
Thanks again people, very helpful.
Interesting points about the geometry. May give it a chance with the above and then see about getting a better setup.
Thanks again people, very helpful.
#15
Scooby Regular
Not sure the droplinks would make that much of a difference. You'd be better sticking the OE ARB on the front to see what it feels like.
Your rear ARB isn't adjustable is it?
Stefan
Your rear ARB isn't adjustable is it?
Stefan
#18
Scooby Regular
Join Date: Apr 2002
Location: Gosport, Hampshire
Posts: 498
Likes: 0
Received 0 Likes
on
0 Posts
I have a very similar setup on my car but without the front anti roll bar! Slight understeer in the wet but nothing to worry about. I would be tempted to try the standard front antiroll bar to see if that makes a difference!
If you have an adjustable rear ARB stiffen it and see if that helps.
If you have an adjustable rear ARB stiffen it and see if that helps.
#20
Scooby Regular
It's worth looking at your geometry settings again. I prefer zero toe-in front and loads of camber
I still get power-on understeer, but only 4 wheel drifts on bends if I push too hard. Can introduce some nice oversteer if I'm very aggressive with the steering.
Stefan
I still get power-on understeer, but only 4 wheel drifts on bends if I push too hard. Can introduce some nice oversteer if I'm very aggressive with the steering.
Stefan
#22
Ive just fitted a Whiteline 2mm adj rear anti roll bar and rear Whiteline drop links to our MY93 Type RA. Ive got a front bar on order but after reading this thread Ill see what its like as it is. The front drop links wouldnt fit, the bottom hole was too small. Are the Type RA drop links different from other Imprezas?
#23
Originally Posted by bren
Ive just fitted a Whiteline 2mm adj rear anti roll bar and rear Whiteline drop links to our MY93 Type RA. Ive got a front bar on order but after reading this thread Ill see what its like as it is. The front drop links wouldnt fit, the bottom hole was too small. Are the Type RA drop links different from other Imprezas?
Thread
Thread Starter
Forum
Replies
Last Post
Scott@ScoobySpares
Full Cars Breaking For Spares
61
11 January 2021 03:08 PM
Mattybr5@MB Developments
Full Cars Breaking For Spares
38
17 July 2016 10:43 PM
ATWRX
Full Cars Breaking For Spares
88
01 February 2016 07:28 PM
MH-Racing
Subaru Parts
18
18 October 2015 04:49 PM