Notices
General Technical
Sponsored by:
Sponsored by: CARiD

Impreza just understeers

Thread Tools
 
Search this Thread
 
Old 12 September 2000 | 09:04 AM
  #1  
jwhitton's Avatar
jwhitton
Thread Starter
Scooby Regular
 
Joined: Sep 2000
Posts: 148
Likes: 0
From: Stratford Upon Avon
Post

Well after a 5 month wait I now have my MY00 4 door turbo. After 1200 miles a service and another 500 miles its ready to go.

Two issues:
1. It understeers worse than my RS Turbo. More power, less power, flicks, back off nothing will stop the thing understeering for a short period. Once the power is reapplied it will just understeer like crazy.
I am disappointed to say the least whats the point of 4WD when it does the same as my FWD RS Turbo. Maybe more fun can be had in the wet but not on a public road!
I would just like the car to be a bit more neutrally balanced instead of all on the front. Is this why the EVO always wins against any Impreza (22B, P1 etc...) in AutoCar. Must check the propshaft has not fallen out and the car is a FWD

2. Where is all the power?
I thought these things were supposed to be fast. Loads of torque in the mid-range but the higher end power again to say the least is disappointing. As per previous threads I will run on SUL and see how the engine loosens up until the next service. Should the exhaust really be that black! My RS is a beautiful shade of light-grey.

There are a number of cures for the above:
1. Trade the UK spec for STi Type R or 22B
2. Trade it for EVO V or VI
3. Drive my 200+ bhp RS Turbo

Yours disappointed

jon
Old 12 September 2000 | 09:47 AM
  #2  
Stupot's Avatar
Stupot
Scooby Regular
 
Joined: Dec 1999
Posts: 422
Likes: 0
Post

Understeer: you are right about this and no mistake. It can be all but eliminated tho by paying a visit to Powerstation and letting them have a bit of a play with your bumpsteer. I also changed my springs for an Eibach setup and that helped no end too. You may find your geometry is miles out as others have found even from new! As for the power, its barely run in man! Let her loosen up a bit more and if your still dissapointed, try a few breathing mods to free up those revs
Stu STI4
Old 12 September 2000 | 07:17 PM
  #3  
sonu's Avatar
sonu
Scooby Regular
 
Joined: Jul 1999
Posts: 727
Likes: 0
From: South London
Thumbs up

That's funny,

I manage to get oversteer if I power thru the corner correctly. I have'nt modded the suspension at all!

Thanks

Sonu
Old 12 September 2000 | 08:29 PM
  #4  
MatthewR's Avatar
MatthewR
Scooby Regular
 
Joined: Nov 1999
Posts: 88
Likes: 0
Post

Hi...

Understeer: As has been mentioned, the Powerstation setup is awesome... You could also be experiencing understeer due to the tyres you have. When I changed from the standard SO1's (jap import) to Toyos, understeer was virtually eliminated. By getting Powerstation to set the car up after this, understeer is no longer a problem and I love the way the car handles.

Power: The small turbo on your MY00 is great in midrange, but runs out of puff at high revs. Couple this with your restrictive exhaust (I am assuming you're running the std item here) and you aren't getting the power you could be. Bear in mind the cars take a while to loosen up anyway.

And yes, Subarus run very rich!

Sorry to hear you're disappointed, but I think you should add an option to your list:

4. Modify your MY00.

You never know, you might end up liking it...


Matthew
Old 12 September 2000 | 10:48 PM
  #5  
RON's Avatar
RON
Scooby Regular
 
Joined: Sep 2000
Posts: 10,011
Likes: 1
From: Deepest Darkest Dorset!!
Post

Hi....
Yes I thought that mine understeered badly, and then I went to Micheldever Tyre Services, and had the geometry done to Prodrive setteing and hey presto! it no longer understeers. And all it cost was £50.
Get it done!
You will not regret it!
Enjoy
Ron
Old 12 September 2000 | 11:01 PM
  #6  
AllanB's Avatar
AllanB
Scooby Regular
 
Joined: Feb 2000
Posts: 2,924
Likes: 0
From: Potters Bar
Post

Give it around 3k and its will start to loosen up noticably and it will get quicker and quicker. I'd strongly advise you to get a Scoobysport back box. It sounds awsome without being too loud and seemed to make a difference to the car.

When I got my car in April the tracking was poorly set up and I got this realigned and this made a big difference.

AllanB
Old 13 September 2000 | 07:56 AM
  #7  
jwhitton's Avatar
jwhitton
Thread Starter
Scooby Regular
 
Joined: Sep 2000
Posts: 148
Likes: 0
From: Stratford Upon Avon
Post

Thanks for the info. I have spoken with Powerstation and yes they can mod the camber and toe on the front and camber on the back for my UK spec MY00. The Jap spec ones castor can also be modded. All for £100+VAT.

Will see how she goes once she is closer to 10k miles. May even add a free flow exhaust and ITG.

I am not going to get rid of the car since I have waited 5 months for it.

jon
Old 14 September 2000 | 09:13 AM
  #8  
jwhitton's Avatar
jwhitton
Thread Starter
Scooby Regular
 
Joined: Sep 2000
Posts: 148
Likes: 0
From: Stratford Upon Avon
Post

What are the usual UK spec wheel alignment settings?

What are the Prodrive ones?
Are the Power Station any different to the Prodrive ones?

I would assume more camber on the front and possible toe mods.

jon
Old 14 September 2000 | 09:22 AM
  #9  
Stupot's Avatar
Stupot
Scooby Regular
 
Joined: Dec 1999
Posts: 422
Likes: 0
Cool

Just do a search on Prodrive settings and Bumpsteer and you will find all the info u need. Either that or give Powerstation a call, they know their banannas them lads
Stu
Old 14 September 2000 | 05:17 PM
  #10  
MarkL's Avatar
MarkL
Scooby Regular
 
Joined: Mar 1999
Posts: 130
Likes: 0
Post

Or click on the "FAQ" link at the top of this page! It contains info on the standard and Prodrive setings at least.

Prodrive settings (1mm total toe front and rear, and 1.3 degrees negative camber on the front), coupled with a set of Bridgestone S02's made a big difference for me.
Old 14 September 2000 | 10:31 PM
  #11  
Greg Jones's Avatar
Greg Jones
Scooby Regular
 
Joined: Feb 2000
Posts: 124
Likes: 0
Post


Yes I'll agree that the old camber set-up does make a great deal of difference. Micheldever obliged and after the tyres 'bedded in' from using a different part of the tyre (mine were out quite some) it eqauls to awsesome power slides.


Greg
Old 15 September 2000 | 10:10 AM
  #12  
Triggaaar's Avatar
Triggaaar
Scooby Regular
 
Joined: Feb 2000
Posts: 661
Likes: 0
Question

Guys,

I've had the powerstation setup (inc bump steer removal) - the handling in general has improved, and the biggest improvement I've noticed is under breaking (WRX).

However, I still get loads of understeer when on the power - it's ridiculous on track. I'm not sure how much of it is down to tyres (like Matthew, I've started on standard SO1's (jap import), and RE010 on track - hopefully a change to Toyos/S02s will improve things).

Is anyone else with the powerstation setup still suffering loads of understeer when on the power?
Old 15 September 2000 | 10:46 AM
  #13  
Trout's Avatar
Trout
Scooby Regular
iTrader: (1)
 
Joined: Jan 1999
Posts: 15,271
Likes: 0
From: UK
Talking

Bump steer removal/shimming the steering rack was the biggest improvement I made in this area...

...also combined with anti-lift kit which will give you some positive (excuse the pun) improvements with castor.

Powerstation geom settings not as aggressive as Prodrive, but they have a different overall objective which includes the bump steer adjustments - so you can't really compare.

On the road the car shows little, well none really, evidence of oversteer. Also helped a bit by 17in wheels and S02s. Not sure about the track - will know in three weeks time
Old 15 September 2000 | 11:55 AM
  #14  
subverbal's Avatar
subverbal
Scooby Regular
 
Joined: Nov 2000
Posts: 193
Likes: 0
Lightbulb

As mentioned before on these pages, applying the brakes slightly when turning in will cure any understeer problems. Usually when entering a corner you're on the brakes anyhow, just ease off a tad later than normal. Personal experience of this on a track produced some seriously outrageous oversteer if taken too far.

Neil.
Old 15 September 2000 | 03:04 PM
  #15  
Colin Berry's Avatar
Colin Berry
Scooby Regular
 
Joined: Aug 2000
Posts: 496
Likes: 0
Post

Can someone advise a 'thickie' here please (me )

Does altering the geometry settings create greater/uneven tyre wear?

Was does the bumpsteer mod do. I heard Anders talking about this on his 22b but I just nodded and smiled!
Old 15 September 2000 | 03:36 PM
  #16  
MorayMackenzie's Avatar
MorayMackenzie
Scooby Senior
 
Joined: Jun 1999
Posts: 3,410
Likes: 0
Cool

Do a search on "bumpsteer"... that should sort you out.

Briefly, bumpsteer is the change in toe related to the travel of the suspension... if a car bump-understeers it will toe out slightly as the front suspension is compressed, so it will appear to understeer. Bumpsteer is engineered in by the manufacturer to help prevent customers who don't know much about car control killing themselves.

Bumpsteer can be removed by altering the relationship between the suspension arms and the steering control rods. Powerstation do this by shimming the rack by the right amount for your car... they need to have it on their digital alignment ramp to find how much adjustment is needed.

My car was used as the guinea pig for the first bump-steer removal experiment, that was ~9+ months ago... I have yet to find a drawback to the change.

Moray

[This message has been edited by MorayMackenzie (edited 15 September 2000).]
Old 17 September 2000 | 05:55 PM
  #17  
jpratchett's Avatar
jpratchett
Scooby Newbie
 
Joined: Aug 2000
Posts: 5
Likes: 0
Post

I am just about to pick up my new scooby from Mill lane Subaru. As I live about 3 miles from Micheldever Tires I would like to get them to set up the geometry.

Ron..

I believe you got your's set up to Prodrive spec, could you let me know the settings you had everthing set yo so that I can get them same.

While I'm at it any advise on running in?

Thanks

Jon
Old 17 September 2000 | 06:38 PM
  #18  
GavinP's Avatar
GavinP
Scooby Regular
 
Joined: Jun 1999
Posts: 1,430
Likes: 0
Post

Jon,

It's also worth playing with the tyre pressures - quite a few people run with the rear tyres 2 psi less than the fronts.

Thanks

Gavin
Old 17 September 2000 | 09:15 PM
  #19  
RON's Avatar
RON
Scooby Regular
 
Joined: Sep 2000
Posts: 10,011
Likes: 1
From: Deepest Darkest Dorset!!
Post

jpratchett
Check your mail
Ron
Old 22 September 2000 | 10:59 AM
  #20  
AndyG's Avatar
AndyG
Scooby Regular
 
Joined: Oct 1998
Posts: 70
Likes: 0
Post

This rear-pressures-lower-than-front business - surely this is going to produce understeer? (Assuming we're talking vaguely sensible pressures.) On the basis that lower-pressure-equals-more-grip?

I run slightly higher pressure in the rears (33,35); still get understeer though (slightly more oversteery since I put the nearly bald front tyres on the rear!).

It seems to me the Impreza (like nearly all 4wd cars?) is never going to do anything other than basically understeer. Easy to provoke oversteer through lifting off of course, but that's just cheating ;-)

Having said that, it looks like the Scoob isn't as "bad" as the Audi RS4, at least going on the basis of Tiff's report on TG last night.

Andy

[This message has been edited by AndyG (edited 22 September 2000).]
Old 22 September 2000 | 03:36 PM
  #21  
crusher's Avatar
crusher
Scooby Regular
 
Joined: Jan 2000
Posts: 460
Likes: 0
Post

Apart from Powerstation,is there anywhere in Wales/West Midlands to get the suspension geom mods done that anyone would like to recommend....
Old 25 September 2000 | 02:03 PM
  #22  
Ragos Elias's Avatar
Ragos Elias
Scooby Regular
 
Joined: Nov 1998
Posts: 208
Likes: 0
Post

Hi all.
My 98MY euro spec GT was fine with a light Prodrive suggestion settings.(0,75 neg.Camper and 1 mm total front and rear toe. S02 was my tyres.
After the ALK and rear adj.sway bar fitted I tryed the same settings but now the car has a very heavy st.wheel, loads of understeer and I dont know what to do. The new P Zeros I have now seem to add a lot to the understeer.
Any Ideas what to go for neutralise the car again?
Elias
Old 26 September 2000 | 12:17 AM
  #23  
jwhitton's Avatar
jwhitton
Thread Starter
Scooby Regular
 
Joined: Sep 2000
Posts: 148
Likes: 0
From: Stratford Upon Avon
Post

Had the PowerStation setup done yesterday and the car's handling has been transformed!

Started with not alot of front camber and large amounts of bump steer (46 minutes) as measured.

Came out with 1degree 19 minutes of negative camber on the front and all wheels set dead ahead. Bumpsteer reduced to 6 minutes as measured with the same amount of front suspension travel.

The bumpsteer mod is to add exact spacers between the cross member and steering rack to lower the rack.

The car turns in better and tramlines less also.

Recommend it to anyone, at 100+VAT:
Old 29 September 2000 | 07:16 PM
  #24  
CharliePsycho's Avatar
CharliePsycho
Scooby Regular
 
Joined: Sep 2000
Posts: 210
Likes: 0
Thumbs up

Had horrible understeer on my P1, went on a track day though and played with the tyre pressures/right foot... Solved everything

Seriously though, a lot of it is driving style and learning to deal with the foibles. (might still look into th ALK tho )
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Jonny mac
ScoobyNet General
10
09 October 2015 12:25 PM
shorty87
Subaru Parts
1
07 October 2015 11:52 AM
buckerz69
Wanted
2
03 October 2015 09:54 PM
jaygsi
Subaru Parts
0
01 October 2015 12:59 AM
madmover
Member's Gallery
4
28 September 2015 10:46 AM



Quick Reply: Impreza just understeers



All times are GMT +1. The time now is 06:20 PM.