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Reducing under steer.

I decided that it is time to get opinions concerning methods of reducing under steer on our FWD Alfas.
Primarily for track days’ but it will obviously make the car safer for normal circumstances as well.

Apart from the obvious harder coils better shocks and stiffer rear antiroll bar suggestions please.
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Change your driving style!

Get in the right gear and balance the car on the throttle.
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Thanks for that but I am sure we can reduce it slightly by altering Camber and or Toe as well.
For instance a friend is running a combined 2mm front toe in while I am running 0 toe and my car seem to under steer les than his.
I would like to hear from people who have played around with suspension setup so that we can share experience and who knows maybe we all can learn something from it.

The norm with front wheel drive cars is that they are set up to under steer instead of over steer since that is easier to compensate for by a inexperienced driver.

GTV V6 Turbo, Q2, Eibach, Koni, and lots more
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Those thick Eibach ARB's definitely help.

I had a mount come loose on the front one and it wasn't as tight as It should have been, I got understeer.

Now its all tight again I hardly get understeer at all even being rediculous.
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Thanks for the info.
Are you running a stiffer anti role bar upfront than at the rear?
Rule of thumb with front wheel drive is that the rears should be stiffer to reduce under steer. (156 if I remember correctly have a thicker front bar while the GTV 3.0 run more or les the same thickness front and rear)
I changed my 3.2 GTV’s thin front bar to a 156 2.5 unit and I do think it is better than what it was but then I am running Eibach and conies at the rear set at their hardest and the front Konis at the softest setting which helped since it under steered more when it was set at its hardest.
With the GTV turbo I also have Eibach all round but only Koni’s at the rear also set at their hardest with the 156 front suspension and she also seams fine but then again the Q2 probably helps.
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Sorry turbonutters, i couldn't resist.

Quick fix is drop psi by 1 or 2 or/and change tyres.
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Yep front and rear, Maybe eibach do use a stiffer bar for the rears, although they look the same to me.

I would have thought that if the rear was any thicker the back end would start coming out. Mine has a lighter front though as its not a v6.

I've learnt that you need a bit of flex in the suspension to keep all wheels on the ground, which is why I removed my lower strut braces lol
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Now that’s better
The problem is that you start scrubbing the sidewall when you deflate but yes both of us run high pressure for the track so letting it down n bit will definitely help with traction. He is already running slicks while I went out with old Pirelli P7000 from my previous 159 1.9 JTS that have les thread than his semis. I must say the Pirelli’s really impressed me once they got up to temp but the first two laps they were all over the place.
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I would say you need to stiffen the suspension and chassis significantly for track use. When I've had my car on the track the suspension felt quite soft with a lot of roll and that was with Eibach ARB's, Sport spring and Bilstein dampers. Although a nice setup for the road it felt way too soft on the track.

I recently was working on the car and disconnected the front drop links as I was trying to locate an annoying noise from the suspension, therefore the car was running with the front ARB disconnected. This made for quite entertaining handling, a lot of understeer which rapidly turned into a lot of oversteer So getting the balance right between soft front and stiff rear needs to be done with some care and I think getting the whole chassis stiffer with a bit stiffer rear would be the way to start.

156 2.5 V6 24v, Cosmos Blue Metallic, Tan Leather, 17” GTA's, 225/45 Michelin PS2's, Full Zender body kit, GTA Headlights, Eibach springs, Koni FSD's, Eibach Anti-roll bars, Ferrari 360 Brembo calipers, DS2500 pads, Squadra ECU, 45mm Intake Runners, Carbon Intake, Dan & Wizard exhaust

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Quote:
Originally Posted by Laptop_Matt View Post
Yep front and rear, Maybe eibach do use a stiffer bar for the rears, although they look the same to me.

I would have thought that if the rear was any thicker the back end would start coming out. Mine has a lighter front though as its not a v6.

I've learnt that you need a bit of flex in the suspension to keep all wheels on the ground, which is why I removed my lower strut braces lol
Was the OE front and rear the same thickness?

Some people even suggest deleting the front antiroll bar on certain cars but I will rather go thicker or double up the rear antiroll bar.

Yes a stiffer rear setup will loosen up the rear-end but if we can keep it balance like with your matched front and rear antiroll bars it should keep the car balanced and just reduce the total role.
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Pascs The GTV's are already a bit stiffer so with the Eibach Koni combination they do not feel soft on the track.
But the Blue GTV with the 156 front suspension and only Eibach coils upfront I definitely felt that the front is softer than my GTV 3.2’s but it seemed to work well with the rear suspension keeping it balanced.
So I also think a bit stiffer at the back is the way to go.
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Generic set-up for most FWD cars would be to run more front camber (if possible on the GTV) - up to 2 degrees, front toe-out at 10' - 20' and more front bump damping (improves turn -in). Also play with tyre pressures - increase/decrease one end at a time and remember that as the tyres get warm the grip levels change. There is a lot more that can be done - I never stop developing my competition car, but that is a cheap start.
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Also what about ride heights? I'm sure I remember that a lower front, higher rear gives reduced understeer
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In general yes, as it moves the roll centres - but needs new springs or coil-overs - hence expense
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also (as you taught me George) a good starting point is knowing your existing geometry settings for a base line, then looking at which part of the corner your getting the understeer - entry, mid, or exit and is this on or off the power?
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Quote:
Originally Posted by turbonutters View Post
I decided that it is time to get opinions concerning methods of reducing under steer on our FWD Alfas.
Primarily for track days’ but it will obviously make the car safer for normal circumstances as well.

Apart from the obvious harder coils better shocks and stiffer rear antiroll bar suggestions please.
I have both lower ultra racing braces installed it made a hell of a difference on my Sportwagon - it's got the Eibch pro Kit and Koni FSD's fitted too, but considering cornering speeds (still stock antiroll bars) the braces realy made a hell of a difference - the whole chassis feels much more planted to the ground.

front one helps traction a lot
Alfa Romeo 156 Front Lower Bar / Front Member Brace UR-LA4-293

the rear one made a notecible difference in turn in
Alfa Romeo 156 Rear Lower Bar / Rear Member Brace UR-RL4-935

Basicly the softer the rear end (alsow counts for cassis flex) - the more understeer you get.
If your wheelbase at rear is wider than front - the more lazy your steering will get
if you got more traction at the rear than on front - your car won't like sharp bends and fast turns eigher


EDIT: just noticed you got the GTV

in that case...
http://www.ultraracing.com.my/Bars.asp?ID=3828

regards

Selling a Brembo Upgrade for 156's, Project Mu Pads (New) and fitting brake lines (new).

link to the thread

Last edited by Black-Sheep; 20-07-11 at 20:43.
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Chmm, interesting, I always consider lower bars as waste of money on 156
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Problem with the 156 it's still a tad to twisty between front an rear axis... but it's definately way better than before!
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We noticed on a late model 156 SW that Alfa actually added a brace running from the front sup frame all the way back to the rear suspension so I suppose Alfa attempted to reduce the SW body flex.
The GTV’s rigid construction basically eliminates body flex so at least we got something back for the weight penalty we have to live with.

On my toy Blue GTV turbo I will be adding upper and lower front suspension braces shortly especially necessary since she should produce more than 300kw once sorted.

George so you definitely found that toe out assist with under steer doesn’t it hamper the turn in a bit.
What is your feeling on rear toe out since that should assist with toe in if I understand correctly?
I did change the GTV front suspension to a 156 setup so adjusting camber is difficult but I am running almost 1degree – camber up front I will have to reconfirm the tow.
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Quote:
Originally Posted by Black-Sheep View Post
If your wheelbase at rear is wider than front - the more lazy your steering will get
Now this is interesting
The front track of the 156 is a bit wider than the GTV’s so with my current setup of 156 front and GTV rear the difference between front and rear is substantially larger than with the oe GTV setup.
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In general yes, as it moves the roll centres - but needs new springs or coil-overs - hence expense
On the GTV it is easy to ad spacers between the body and sub frame to lift the rear but will it have the same effect as using longer coils at the back and shorter up front?
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Quote:
Originally Posted by Black-Sheep View Post
the rear one made a notecible difference in turn in
Alfa Romeo 156 Rear Lower Bar / Rear Member Brace UR-RL4-935

Basicly the softer the rear end (alsow counts for cassis flex) - the more understeer you get.
If your wheelbase at rear is wider than front - the more lazy your steering will get
if you got more traction at the rear than on front - your car won't like sharp bends and fast turns eigher
The rear one looks good, might try that in the future,

I'd never stick a front one on again unless I was using it for the track only.

Locking the 2 lower wishbones together made my car unbearably stiff - to the point where the steering wheel was vibrating when idling. The slight flex between wishbones reduces engine vibration.

I also had a problem of the wishbone mount threads being physically ripped out as it was under so much strain.

It was more fun on the bends but too much to live with and so it came off.
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Fortunately with my toy GTV that will not be a problem since all the soundproofing are already ripped out and I can see the road and exhaust when I open the boot (still have to fabricate a flat floor for it) so on this car it sounds perfect.
All honesty I did not think that tying the two lower control arms would stiffen it up that much. Definitely ignorance on my part.
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Originally Posted by turbonutters View Post
We noticed on a late model 156 SW that Alfa actually added a brace running from the front sup frame all the way back to the rear suspension so I suppose Alfa attempted to reduce the SW body flex.
you think that brace would be retrofitable?
can you tell a tad more on it?
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Originally Posted by turbonutters View Post
Now this is interesting
The front track of the 156 is a bit wider than the GTV’s so with my current setup of 156 front and GTV rear the difference between front and rear is substantially larger than with the oe GTV setup.
So the front is wieder than rear on your car now?
I found this helps turn in quite a lot - doesn't work on your car?
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