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-   -   Impreza just understeers (https://www.scoobynet.com/general-technical-10/26256-impreza-just-understeers.html)

jwhitton 12 September 2000 09:04 AM

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

Stupot 12 September 2000 09:47 AM

Understeer: you are right about this and no mistake. It can be all but eliminated tho http://bbs.scoobynet.co.uk/smile.gif 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 http://bbs.scoobynet.co.uk/smile.gif
Stu STI4

sonu 12 September 2000 07:17 PM

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

MatthewR 12 September 2000 08:29 PM

Hi...

Understeer: As has been mentioned, the Powerstation setup is awesome... http://bbs.scoobynet.co.uk/biggrin.gif 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... http://bbs.scoobynet.co.uk/smile.gif


Matthew

RON 12 September 2000 10:48 PM

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

AllanB 12 September 2000 11:01 PM

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

jwhitton 13 September 2000 07:56 AM

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

jwhitton 14 September 2000 09:13 AM

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

Stupot 14 September 2000 09:22 AM

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 http://bbs.scoobynet.co.uk/smile.gif
Stu

MarkL 14 September 2000 05:17 PM

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.

Greg Jones 14 September 2000 10:31 PM

http://bbs.scoobynet.co.uk/smile.gif
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

Triggaaar 15 September 2000 10:10 AM

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?

Trout 15 September 2000 10:46 AM

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 http://bbs.scoobynet.co.uk/biggrin.gif

subverbal 15 September 2000 11:55 AM

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.

Colin Berry 15 September 2000 03:04 PM

Can someone advise a 'thickie' here please (me http://bbs.scoobynet.co.uk/smile.gif )

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!

MorayMackenzie 15 September 2000 03:36 PM

Do a search on "bumpsteer"... that should sort you out. http://bbs.scoobynet.co.uk/smile.gif

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. http://bbs.scoobynet.co.uk/rolleyes.gif

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. http://bbs.scoobynet.co.uk/smile.gif

Moray

[This message has been edited by MorayMackenzie (edited 15 September 2000).]

jpratchett 17 September 2000 05:55 PM

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

GavinP 17 September 2000 06:38 PM

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

RON 17 September 2000 09:15 PM

jpratchett
Check your mail
Ron

AndyG 22 September 2000 10:59 AM

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).]

crusher 22 September 2000 03:36 PM

Apart from Powerstation,is there anywhere in Wales/West Midlands to get the suspension geom mods done that anyone would like to recommend....

Ragos Elias 25 September 2000 02:03 PM

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

jwhitton 26 September 2000 12:17 AM

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:

CharliePsycho 29 September 2000 07:16 PM

Had horrible understeer on my P1, went on a track day though and played with the tyre pressures/right foot... Solved everything http://bbs.scoobynet.co.uk/biggrin.gif

Seriously though, a lot of it is driving style and learning to deal with the foibles. (might still look into th ALK tho http://bbs.scoobynet.co.uk/wink.gif )


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