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Re: Understeer on the limit
[Re: ]
#932276
10/11/2009 10:44
10/11/2009 10:44
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suba
Unregistered
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suba
Unregistered
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what is your current suspension / handling setup?
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Re: Understeer on the limit
[Re: ]
#932284
10/11/2009 10:54
10/11/2009 10:54
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MrT
Unregistered
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MrT
Unregistered
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KW V2 and standard roll bars, it's a pretty good setup but with all that weight at the front I think it struggles a bit. I should think that a decent LSD would help a lot as well.
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Re: Understeer on the limit
[Re: ]
#932287
10/11/2009 11:01
10/11/2009 11:01
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suba
Unregistered
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suba
Unregistered
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You'll never change the weight up front - I spent a lot of time and money trying. You can get it better though.
What is the ride height, and alignment settings?
LSD is not needed IMO, but you could certainly do with an uprated rear ARB and increasing both camber and caster. Camber could be done with Camber bolts, but to increase the caster you'll need custom top mounts. Corner weighting will also help.
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Re: Understeer on the limit
[Re: ]
#932290
10/11/2009 11:06
10/11/2009 11:06
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dave_t
Unregistered
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dave_t
Unregistered
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If you:
* uprate the rear ARB (or potentially both the front and rear ARBs) * increase the front camber to -1deg to -1.5deg (with camber bolts) * replace the rear subframe bushes with solid ones * put on front strut braces (upper and lower)
then you'll have a pretty sorted car with understeer minimised pretty well
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Re: Understeer on the limit
[Re: ]
#932312
10/11/2009 11:22
10/11/2009 11:22
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MrT
Unregistered
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MrT
Unregistered
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Cheers guys, that sounds a lot easier as well. The reason I was thinking about increasing the track was because I did this on a BMW 2002 track car I built that I'd put a 535i lump in which was a lot heavier than the original 4 pot. I widened the track by 40mm each side and this absolutely transformed the cars handling, the weight transfer to the out side wheel on hard cornering had been reduced by nearly 100 kilos, althought it was a lot easier to do on a rwd vehicle!
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Re: Understeer on the limit
[Re: ]
#932459
10/11/2009 14:09
10/11/2009 14:09
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Joined: Jan 2006
Posts: 3,034 Sweden
Per
I need some sleep
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I need some sleep
Joined: Jan 2006
Posts: 3,034
Sweden
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If you:
* uprate the rear ARB (or potentially both the front and rear ARBs) * increase the front camber to -1deg to -1.5deg (with camber bolts) * replace the rear subframe bushes with solid ones * put on front strut braces (upper and lower)
then you'll have a pretty sorted car with understeer minimised pretty well That, and lower springs, adjustable shocks and battery at the rear will make your understeer pretty much go away. (People always question me about moving a heavy lump like the battery, but The Fact is I did it and I felt the difference) Dunno about 40mm extra track in the long run, your wheel bearings will suffer. But if you can afford that, sure!
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Re: Understeer on the limit
[Re: Per]
#932506
10/11/2009 16:01
10/11/2009 16:01
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suba
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suba
Unregistered
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Lowering the car does not help much - if at all!
I never tried putting the battery in the boot, so I'm not sure what difference that would make. However taking out the spare wheel does make a difference to the rear 'lift' when on the brakes.
The biggest difference you will notice without spending a lot of money is the tracking - I found half a degree of toe out on the front really helps getting power down out of bends, which in turn helps stop understeer.
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Re: Understeer on the limit
[Re: phil_20VT]
#932702
10/11/2009 22:00
10/11/2009 22:00
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Joined: Jan 2006
Posts: 3,034 Sweden
Per
I need some sleep
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I need some sleep
Joined: Jan 2006
Posts: 3,034
Sweden
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I guess he must be using rain-x with an empty washer bottle and carrying a passenger well here we go again.. old joke matey.. If you're keeping you Coupe strictly std - fair, but this mod is as worthy as any of those more/less silly braces etc. I felt less difference before/after the Sparco strutbrace. Soak it in.. put the battery on the left hand side of the boot:) Yeah was just about to say it.
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Re: Understeer on the limit
[Re: Per]
#932784
11/11/2009 00:50
11/11/2009 00:50
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Redd
Unregistered
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Redd
Unregistered
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You're never really get rid of the understeer. the coupe has tons of mechanical grip though. adjust your lines a bit to take advantage of what the coupe has - boatloads of torque and power - and you should still do good laptimes.
im competitive with similarly powered RWD silvias and 4WD evos cos i know my lines.
redd
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Re: Understeer on the limit
[Re: Per]
#932863
11/11/2009 10:08
11/11/2009 10:08
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Marco20valveT
Unregistered
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Marco20valveT
Unregistered
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I guess he must be using rain-x with an empty washer bottle and carrying a passenger well here we go again.. old joke matey.. If you're keeping you Coupe strictly std - fair, but this mod is as worthy as any of those more/less silly braces etc. I felt less difference before/after the Sparco strutbrace. Soak it in.. put the battery on the left hand side of the boot:) Yeah was just about to say it. sorry if its off topic but can you you do a how to guide on locating the battery to the boot please!
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Re: Understeer on the limit
[Re: ]
#932878
11/11/2009 10:26
11/11/2009 10:26
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MrT
Unregistered
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MrT
Unregistered
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I am just about to do this on mine Marco, not necessarily to move weight around but to make a bit more room under there! I'm also taking the aircon off for the same reason. I've already run the cable through so I'll do a few pictures when I do the rest.
There's been lots of different ideas and comments on this understeer thread, all valid but don't get me wrong the coupe was still very quick, I should have some video to post soon.
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Re: Understeer on the limit
[Re: ]
#932939
11/11/2009 11:30
11/11/2009 11:30
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Joined: Jan 2006
Posts: 3,034 Sweden
Per
I need some sleep
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I need some sleep
Joined: Jan 2006
Posts: 3,034
Sweden
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sorry if its off topic but can you you do a how to guide on locating the battery to the boot please! Yes I suppose I can, did one on the old forum but that's long gone..
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Re: Understeer on the limit
[Re: Per]
#932983
11/11/2009 12:25
11/11/2009 12:25
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Joined: Dec 2005
Posts: 6,567 Northampton England
Sedicivalvole
Club member 2092
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Club member 2092
Forum is my life
Joined: Dec 2005
Posts: 6,567
Northampton England
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it maybe around in the archives?
Vinci Grey LE Alfa 147 GTA 3.2 V6 BMW E92 M3 4.0 V8 Fiat Tipo Sedicivalvole 2.0 16v ABS
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Re: Understeer on the limit
[Re: Sedicivalvole]
#932989
11/11/2009 12:32
11/11/2009 12:32
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Nobby
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Nobby
Unregistered
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Re: Understeer on the limit
[Re: ]
#933109
11/11/2009 16:03
11/11/2009 16:03
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Joined: Jan 2006
Posts: 3,034 Sweden
Per
I need some sleep
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I need some sleep
Joined: Jan 2006
Posts: 3,034
Sweden
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As mentioned in the thread, two updates on my guide: # there are better routes for the pluscable thru the bulkhead, namely behind the left wing. # thicker plus cable # use gelbattery's (I now use twin 18Ah gel's) which will reduce acid stains on the boot paint..
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Re: Understeer on the limit
[Re: Per]
#933123
11/11/2009 17:25
11/11/2009 17:25
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Marco20valveT
Unregistered
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Marco20valveT
Unregistered
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hmm, having a little trouble translating Pers guide in Swedish...
any help?
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Re: Understeer on the limit
[Re: ]
#933129
11/11/2009 17:32
11/11/2009 17:32
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sparco
Unregistered
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sparco
Unregistered
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Understeer - Fronts are probably too stiff and you need more stiffness in the rear. Also with the coupe being a heavy front engined car understeer will always be a problem. I feel you have to drive the car accordingly whih means be a bit more firm with turn in which in turn will get the rear moving and help you at the same time. You can spend fortunes trying to alleviate it when you might only need to alter how you drive it. Remember you are on track which is smooth and grippy tarmac, not the road so don't be shy and get the chassis working for you don't wait until it tells you what it wants to do.
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Re: Understeer on the limit
[Re: ]
#933132
11/11/2009 17:36
11/11/2009 17:36
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Marco20valveT
Unregistered
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Marco20valveT
Unregistered
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and thats exactley what i saw you doing to yours Marco at time attack!
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Re: Understeer on the limit
[Re: ]
#934021
13/11/2009 12:48
13/11/2009 12:48
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MrT
Unregistered
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MrT
Unregistered
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Just got the video through which shows a fair bit of body roll and my nephew who was following me and filming said that the rear end looked very "twitchy" which perhaps confirms that it was the back end that was letting it down.
What rear ARB and solid mounts are recommended?
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Re: Understeer on the limit
[Re: ]
#934023
13/11/2009 12:52
13/11/2009 12:52
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Nobby
Unregistered
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Nobby
Unregistered
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Whiteline or eibach 22/24mm ARBs.
Solid mounts are custom made jobbies only I'm affraid. There was a group buy for them, plus I think that dink can also get hold of some.
Chris
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Re: Understeer on the limit
[Re: ]
#934043
13/11/2009 13:35
13/11/2009 13:35
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MrT
Unregistered
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MrT
Unregistered
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That's great, thanks Chris.
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Re: Understeer on the limit
[Re: ]
#934158
13/11/2009 17:16
13/11/2009 17:16
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dink
Unregistered
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dink
Unregistered
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Whiteline or eibach 22/24mm ARBs.
Solid mounts are custom made jobbies only I'm affraid. There was a group buy for them, plus I think that dink can also get hold of some.
Chris The ones from the GB are based on my design nobby In fact it was me who provided the drawings to MatB way back in 2007 who in turn passed them on to 13ad13oy who launched the GB then again sederich was the first one to have them on the car i guess.
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Re: Understeer on the limit
[Re: ]
#934173
13/11/2009 17:26
13/11/2009 17:26
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dink
Unregistered
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dink
Unregistered
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Further to the understeer problem i like to get the car as neutral as possible towards oversteer.
Here's my recipe:
rear axle (requires the biggest amount of work) : - 22mm anti-roll bar reduces understeer the rear becomes more stable and better fell with the car. One of the best mods i'd say - Stiffer springs will further reduce understeer and also a bit less roll - Solid bushes are recommended if your bushes are worn, new OEM bushes are pretty ok too. .
Front : - Keep the stock roll bar you will get less understeer, only for race cars i'd recommend a bigger font roll bar. - -1 to -1,5 degrees of camber for a road car - like mentioned 0,5mm of toe out seems to work well - Powerflex bushes: ok here's the snag, it will steer a lot better and put the power down with the bushes on but in theory they aid understeer. A necessary evil i'd say.
braking : - Adjust the brake proportioning valve to increase the braking on the rears.
Finally: tracking, tracking, tracking... Good tires...
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Re: Understeer on the limit
[Re: ]
#934201
13/11/2009 18:07
13/11/2009 18:07
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Joined: Dec 2005
Posts: 10,728 N.E Scotland
mattB
Club member 6
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Club member 6
I AM a Coop
Joined: Dec 2005
Posts: 10,728
N.E Scotland
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Whiteline or eibach 22/24mm ARBs.
Solid mounts are custom made jobbies only I'm affraid. There was a group buy for them, plus I think that dink can also get hold of some.
Chris The ones from the GB are based on my design nobby In fact it was me who provided the drawings to MatB way back in 2007 who in turn passed them on to 13ad13oy who launched the GB then again sederich was the first one to have them on the car i guess. Indeed you did. And I'll take the opportunity to say thank you once again.
Death-rattle-tastic
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Re: Understeer on the limit
[Re: mattB]
#934247
13/11/2009 19:26
13/11/2009 19:26
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Joined: Jan 2006
Posts: 3,034 Sweden
Per
I need some sleep
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I need some sleep
Joined: Jan 2006
Posts: 3,034
Sweden
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Don't forget the front lower brace (here's mine: mine 1 and mine 2.) It's not reducing understeer much, BUT with negative camber + toe-out you WILL get much more torquesteer. This reduces torquesteer heavily.
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Re: Understeer on the limit
[Re: Per]
#934269
13/11/2009 20:15
13/11/2009 20:15
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MrT
Unregistered
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MrT
Unregistered
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Thanks for this everyone, very helpfull indeed. Next question is, do I keep it how it is or make it into an all out track car?
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Re: Understeer on the limit
[Re: ]
#934847
15/11/2009 14:42
15/11/2009 14:42
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dave_t
Unregistered
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dave_t
Unregistered
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Great video. It looks like you had a good day. You certainly weren't hanging around
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Re: Understeer on the limit
[Re: ]
#934874
15/11/2009 16:22
15/11/2009 16:22
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anthrax
Unregistered
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anthrax
Unregistered
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^ and at 2.20 nice flame
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Re: Understeer on the limit
[Re: ]
#935655
17/11/2009 00:29
17/11/2009 00:29
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Joined: Jan 2006
Posts: 3,034 Sweden
Per
I need some sleep
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I need some sleep
Joined: Jan 2006
Posts: 3,034
Sweden
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Re: Understeer on the limit
[Re: Per]
#936221
17/11/2009 22:50
17/11/2009 22:50
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MrT
Unregistered
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MrT
Unregistered
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Cheers guys, I must admit I liked the flame bit myself I'm looking forward to getting back on the track with new brakes and those suspension mods you recommended and see how much difference it makes.
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Re: Understeer on the limit
[Re: ]
#937289
19/11/2009 11:29
19/11/2009 11:29
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Joined: Dec 2005
Posts: 1,513 Banbury
stevo
My life on the forum
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My life on the forum
Joined: Dec 2005
Posts: 1,513
Banbury
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I have recently fitted eibach anti roll bars front and rear, team dynamics pro race 1.2 alloys 18". This complements bilstein dampers with eibach springs which I had already and the car is now amazing. I can go into corners and the car feels completely planted with no hint of understeer, I can carry more speed into the corners confidently and power out with geater dynamic stability. I think the anti roll bars are one of the best mods to get. Still have some camber bolts which need to be fitted and waiting on delivery of my lower front strut brace. It's coming along nicely.
Nice video by the way, I was thinking while watching it how beautiful the coupe looks. Also it looks a fair bit faster than the M3.
Last edited by stevo; 19/11/2009 11:31.
362bhp of warble
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Re: Understeer on the limit
[Re: ]
#937641
19/11/2009 21:11
19/11/2009 21:11
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dave_t
Unregistered
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dave_t
Unregistered
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Yes ... that's a great photo And, coincidentally, very similar to my sig photo
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Re: Understeer on the limit
[Re: ]
#937743
19/11/2009 23:18
19/11/2009 23:18
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MrT
Unregistered
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MrT
Unregistered
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That's true, although yours seems to be cornering a lot flatter than mine, back to those anti-roll bars again
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Re: Understeer on the limit
[Re: ]
#938208
20/11/2009 17:09
20/11/2009 17:09
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suba
Unregistered
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suba
Unregistered
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having the car flat through the corners is good in theory, but you do want some roll in a coupe to load up the outside front and scrub off the understeer.
If you look at clio 182's / trophies they handle very well and are on three wheels most of the time as the inside rear lifts loading up the outside front....
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Re: Understeer on the limit
[Re: Per]
#938245
20/11/2009 18:03
20/11/2009 18:03
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suba
Unregistered
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suba
Unregistered
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Lucky you - it's the other way round for most!
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Re: Understeer on the limit
[Re: ]
#938805
21/11/2009 19:16
21/11/2009 19:16
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addict
Unregistered
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addict
Unregistered
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I'd suggest wider track at front will make a big difference. Sure it will put some strain on the bearings etc. but they will have some capacity in-built.
I have 40mm at front with 7 x 17's and the car grips like anything. I keep up with very fast rwd cars out of the corners.
I'll have to make a track day with some of you 20VT guys and see how it compares.
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Re: Understeer on the limit
[Re: ]
#938976
22/11/2009 10:28
22/11/2009 10:28
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MrT
Unregistered
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MrT
Unregistered
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Glad you agree with me addict, that's how I stsrted the thread by saying I wanted to widen the track, but I intended moving the whole hub out rather than use spacers with would keep the steering geometry correct and wouldn't put any additional load on the bearings. The raeson for running as wider track as possible is that it reduces the lateral load transfer which judging by the state of my N/S/F tyre is fairly high!! It's also true what Dave-t, Suba and Per etc say which is by carrying out the mods they have done on their cars I will have a pretty sorted car which will be more than a match for my limited driving ability and at the end of the day for me it's all about having fun It would be good to get a few Coupe's out for a day at Brands though!!
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Re: Understeer on the limit
[Re: ]
#940692
25/11/2009 12:12
25/11/2009 12:12
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suba
Unregistered
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suba
Unregistered
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I'll certainly be up for a day at brands, though wont be in a coupe now......
Last edited by suba; 25/11/2009 12:12.
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Re: Understeer on the limit
[Re: ]
#940789
25/11/2009 14:38
25/11/2009 14:38
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sparco
Unregistered
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sparco
Unregistered
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Good video and the car doesn't look too bad. I really liked Brands and this year was the first for me in a car. Here's a little video for a different perspective from a slightly more modded coupe. http://www.youtube.com/watch?v=CaCoxoS3gDkThe noise is the back unloaded rear locking up.
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Re: Understeer on the limit
[Re: Jimbo]
#940820
25/11/2009 15:53
25/11/2009 15:53
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sparco
Unregistered
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sparco
Unregistered
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They are road legal and i was pushing a little hard. Suba was there on the day so he can vouch for me not holding back.
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Re: Understeer on the limit
[Re: ]
#940823
25/11/2009 16:07
25/11/2009 16:07
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sparco
Unregistered
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sparco
Unregistered
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Jimbo if you watch the final round at Snetterton you can here the difference in gearing with the new gearbox. Still locking the rears up which you can see and hear. Sorry for hijacking this thread but i suppose it's still on a handling theme. http://www.youtube.com/watch?v=x-FFS3SiYLI
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Re: Understeer on the limit
[Re: ]
#940831
25/11/2009 16:33
25/11/2009 16:33
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suba
Unregistered
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suba
Unregistered
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Yep - you could definately tell when you were on a 'hot' lap.....
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Re: Understeer on the limit
[Re: Jimbo]
#941083
25/11/2009 23:35
25/11/2009 23:35
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MrT
Unregistered
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MrT
Unregistered
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Excellent video and nice driving , I'd be interested in seeing the spec on the car. Sounds like we could get a few together at Brands in the new year.
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Re: Understeer on the limit
[Re: Per]
#941131
26/11/2009 08:33
26/11/2009 08:33
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sparco
Unregistered
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sparco
Unregistered
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I spent over 2k fiting a proper race pedal box which gives me complete control over the brakes so basically we haven't finished palying with it. By the final at Snetterton we had dialled out the rear locking up completely. I think we may have mixed up the front and rear master cylinders as they have different internal sizes which meant we were naturally getting more bias to the rear than we thought. It has got the comp brake kit on the rear too along with new seceret Pagid rear race pads.
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Re: Understeer on the limit
[Re: ]
#944745
02/12/2009 22:05
02/12/2009 22:05
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Joined: Jan 2006
Posts: 3,034 Sweden
Per
I need some sleep
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I need some sleep
Joined: Jan 2006
Posts: 3,034
Sweden
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Talking of my oversteer, you can actually see it in this pic of mine. No big problem really, I like it. As said, only problem can be a bit poisonus lift-off oversteer. So an uprated front ARB would be nice.
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