MK5 Golf GTI
All Things Mk5 => Mk5 General Area => Topic started by: SteveS on March 14, 2013, 09:20:27 pm
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Track Width..
To measure am i right in thinking its from outside of each tire and front\rear should both be the same or front wider?
Wider front = less under steer more over steer
Wider rear = more under steer less over steer
Tire Pressure.
Should the front be lower or higher than rear?
Other suggestions welcome..
I have swaybars soft front\harder rear
SuperPro front bushes
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youve put the same thing for the wider front / wider rear.
To be honest my car has decent tyres and eibach springs and i havent felt 1 bit of understeer compared to most cars, it grips nice with a bit of lift off oversteer, what other handling mods do you have?
Edit: just read your sig
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It is probably also down to my driving. But I'm just trying to rule out and think of everything
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Slow in fast out
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have you got the same tyres all around? ive always had odd ones in the past but on my new car there all the same and its fully predictable round every corner, i damaged my rear left the other week and had to quickly get a new budget fitted and it seems to have made it a little bit more unpredictable when turning right, it really oversteers
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You are always going to get understeer in a front wheel drive car when you reach the limit of grip. To reduce it as much as you can you want the best tyres you can afford a decent Geo set up. If you want need to reduce it further then you want to try and get more grip on the front. wider tyres and lower tyre pressures on the front will help. Also adjustable top mounts for some camber.
As i mentioned though you cant get rid of it totally unless you have it set up silly so the back end keeps snapping out. You should however be able to get it so you would be doing silly fast speeds on a bend ( on track ) were you feel you dont have any understeer. :driver:
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Thanks topcat. By wider tires can i use spacers or are you suggesting the actual tire itself?
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Well in theory a spacer gives it a wider track but in reality it wont have any effect at all. It has to be physical grip. by lowering the tyre pressure you are widening the contact patch a smidge which equals more grip again, in theory.
If your car has a half decent set up you shouldn't really experience understeer on the roads unless you go around roundabouts to fast or drive at silly speeds. I would just get your geo done professionally and get some really good tyres, this should see you get rid of understeer on the road. :happy2:
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Whats your suggestion of really good tires?
I will need some soon.
I really do suffer from under steer. The rear track seems wider on look than the front (hence question) and i have put in 2.6 bar all round.
Is it not worth using a tire wider than 225 either?
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Define your understeer, if you can?
Entering a corner, not wanting to turn in?
Through the corner?
Exiting the corner adding power?
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Though and exiting i would say
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As you apply power, do you tend to steer more into the corner to counter the front washing wide?
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probably sometimes.. i guess naturally i would have
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As you do that, you reduce the contact patch, reducing grip.. and because you have an LSD, it power-understeers washing the front wide.
38PSI is too high. Try 34F 36R.
Geo maybe wants looking at, is it 'stock'?
What tyres do you have? a 225 is pretty small for all that power, they need to be grippy.
I think this is a combination of your style and possibly one or more of the above. I can't really tell you how to drive, but try this:
Enter a corner so that you turn in as you brake/lift, getting the weight to transfer to the front and increase grip. As you aim for the apex, gently start to trail the gas, you'll feel the diff hook up and pull you tighter to the line. Use this trailing power to drive you through the bend, only adding more gas as you wind the lock off and exit.
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Thanks a lot.
Lower front psi always make the tires look flat, but ill give it a shot.
Geo is stock i guess, only the superpro bushes in there..
Front Goodyear assy 1
rear Michelin ps2
I had the same issue with the Michelin's all round though
I assume i have to replace the wheels to increase the tire width :\ costly!
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That's cold though, don't forget the pressure increases as you drive.
Hmm, rear geo may have too much camber/toe-in still. Look into it.
Tyre aren't ditchfinders at least. That's your last point of call anyway.
Don't worry about the back end moving around, so long as you keep the gas trailing, it'll follow what you're doing - don't panic and lift/brake mid bend. Smooth is fast - It'll come to you :happy2:
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Ill need to replace tires soon - what?
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As you do that, you reduce the contact patch, reducing grip.. and because you have an LSD, it power-understeers washing the front wide.
38PSI is too high. Try 34F 36R.
Geo maybe wants looking at, is it 'stock'?
What tyres do you have? a 225 is pretty small for all that power, they need to be grippy.
I think this is a combination of your style and possibly one or more of the above. I can't really tell you how to drive, but try this:
Enter a corner so that you turn in as you brake/lift, getting the weight to transfer to the front and increase grip. As you aim for the apex, gently start to trail the gas, you'll feel the diff hook up and pull you tighter to the line. Use this trailing power to drive you through the bend, only adding more gas as you wind the lock off and exit.
This exactly.
On exiting a corner and giving it full throttle (i.e. stamping on it, not feeding it in) it does wash out and understeer a bit... something which i thought the LSD would resolve.
I drove this car a few days ago and its fantastic. The power delivery it brutal, and the VWR brakes are very good and have a good feel.
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Tyres?
Conti 5/Pilot Supersport/GY Assym 2 - or something fruitier, if the insurance allows, such as an R1R or AD048. Have you got room to sneak in a 235??
Rich, before 1 inside wheel span and it just made a noise and went nowhere. Now both spin and the car wants to go straight on.
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PSS dont come in y92? and insurance wont allow 88 im guessing
GY Assym 2 seem to come up better than the conti 5.
The others i think are too summer, with the amount of wet we have.. no gos for normal use.
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GYs are great. They'll do you fine.
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Tyres
Superpro arm kit or anti lift bushes and adjustable ball joints
Anti roll bars
Diff
Adjustable top mounts
Suspension
Engine mount - helps it feel more planted
All will help to a certain degree some more than others
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Dude, i have most of that.. well all, apart from suspension other than vwr springs
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hi,
so am i right in saying you have uprated springs, uprated anti-roll bars and stock dampers?
it would be good to get your damping uprated to live happily with your uprated springs and bars.
and have you got goodyear eagle f1 asy1 front and michelin rear?
it would be good to get the asy2 all round. loved this line from that 2012 18inch performance tyre test regarding the asy2..."Outstanding in the dry, pulling the highest lateral G and shortest dry braking"
and linear throttle mapping would help too.
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Track Width..
To measure am i right in thinking its from outside of each tire and front\rear should both be the same or front wider?
Wider front = less under steer more over steer
Wider rear = more under steer less over steer
Tire Pressure.
Should the front be lower or higher than rear?
Other suggestions welcome..
I have swaybars soft front\harder rear
SuperPro front bushes
Be careful with most simple rules you may find on the internet. :wink:
Slow in fast out
Don't agree. While this may avoid understeer at corner entry it will make you slower than the competition.
Talk to pro racing drivers - fast in, fast out is what you want.
Agree with all what Rich, Tony and Top Cat said.
To get rid of most of the factory understeer:
- get the best tyres you can afford (Michelin PSS for a daily, contrary to popular believe LI '88' WILL be sufficient and street legal)
- get equal camber on both axles (if you don't want camber plates, get TT arms, SuperPro ball joints or reduce rear camber)
- reduce suspension flexing (stiffer LCA bushings, TT or 034 strut mounts)
- reduce body roll (try bot roll bars at stiff)
- try to find the optimum tyre pressure on front and increase pressure on rear
- get a LSD (which vastly imroves traction on corner exit and also reduces understeer on exit)
- reduce toe on rear (or set toe out if you're quite brave)
- set brake assist to lowest setting to make improved brake modulation possible
- on bad surfaces some reduction in unsprung weight may also help (Allegeritas, S3 hubs and arms)
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Id wager that your GEO is out combined with a bit of power understeer from being too heavy on the loud pedal exiting the corners.
You'll be amazed at what difference the alignment makes to the cars handling. Just make sure you use a competent alignment and chassis specialist and not some kwik sh!t fitter. A good alignment setup will set you back about £80-130 depending on how far out it is and what needs adjusting. I cant find my old alignment sheets from centergravity or wheelsinmotion which is a shame as it was a fantastic setup, but others like vRSAlex will be able to give you a set of figures for the fitters to set your car up.
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No problem at all. :wink:
Tell us the the basic hardware you (will) have on the car and we/I will give you some corresponding geo values.