Notices

Stability under hard high speed braking

Thread Tools
 
Search this Thread
 
Old 25 August 2003, 09:36 AM
  #1  
Jake
Scooby Regular
Thread Starter
 
Jake's Avatar
 
Join Date: Aug 1999
Location: North London, Xbox Live Gamer Tag: Jake Shiney
Posts: 1,621
Likes: 0
Received 0 Likes on 0 Posts
Post

I seem to have a serious problem with my MY00 UK, when I brake hard at high speed (100mph) the car just won't stay in a straight line, infact its all over the shop and I sometimes struggle to keep in line with the road. It happened yesterday when I was playing with a ferrari as soon as I have to brake hard round a corner the car is a nightmare and scares the life out of me!!!

I should mention that its running with eibachs & bumpsteer plus 18 inch OZs'and has plenty of HKS parts fmic etc...

Is it time to bin the eibachs and get some coilovers or can I tweak the current setup with arbs and drop links etc?????





[Edited by Jake - 8/25/2003 9:40:04 AM]
Old 25 August 2003, 11:38 AM
  #2  
Mungo
Scooby Regular
 
Mungo's Avatar
 
Join Date: Apr 2000
Location: West Byfleet, Surrey
Posts: 1,653
Likes: 0
Received 0 Likes on 0 Posts
Post

An easy win would be to check the tyre pressures - get an accurate gauge rather than rely on a petrol forecourt one. This could easily be the problem.
Failing that, sounds like you either need to have your geometry set up checked, or you've got some kind of brake balance problem. I assume by "all over the place" you mean the back end isn't staying in line?
Old 25 August 2003, 12:32 PM
  #3  
Jake
Scooby Regular
Thread Starter
 
Jake's Avatar
 
Join Date: Aug 1999
Location: North London, Xbox Live Gamer Tag: Jake Shiney
Posts: 1,621
Likes: 0
Received 0 Likes on 0 Posts
Post

Something like that its difficult to explain as it happens so damn quick, Its just that I have to fight the car to keep it going straight as I hit the brakes hard.

What should the pressures be??

[Edited by Jake - 8/25/2003 12:33:08 PM]
Old 25 August 2003, 12:34 PM
  #4  
nigelward
Scooby Regular
 
nigelward's Avatar
 
Join Date: Oct 2001
Posts: 831
Likes: 0
Received 0 Likes on 0 Posts
Post

Brake before the corner, no amount of geometry work will prevent the car scaring the hell out of you when braking hard while cornering.
Old 25 August 2003, 01:37 PM
  #5  
Mortywrx
Scooby Regular
 
Mortywrx's Avatar
 
Join Date: Jun 2003
Posts: 684
Likes: 0
Received 0 Likes on 0 Posts
Post

press the brakes on a corner and your bound to go sideways!! But braking from 140mph(on private land) I get brake judder but no sideways action it stops in a nice straight line

Look under the car and make sure your rear brakes are not sticking? then start going for better suspension...coilovers, ive got H&R coilovers and think there quite good.

Darren
Old 26 August 2003, 06:41 AM
  #6  
JIM THEO
Scooby Regular
 
JIM THEO's Avatar
 
Join Date: Oct 2001
Posts: 1,833
Likes: 0
Received 0 Likes on 0 Posts
Post

Some tires tend to follow more than others road surface, also camber (more=less stability on braking) and toe has a huge effect on how the car stops!
JIM
Old 26 August 2003, 09:14 AM
  #7  
Jake
Scooby Regular
Thread Starter
 
Jake's Avatar
 
Join Date: Aug 1999
Location: North London, Xbox Live Gamer Tag: Jake Shiney
Posts: 1,621
Likes: 0
Received 0 Likes on 0 Posts
Post

I think its justs tramlining massively under hard braking. Its only started doing it since I fitted 18in wheels?
Old 26 August 2003, 09:23 AM
  #8  
mutant_matt
Scooby Regular
 
mutant_matt's Avatar
 
Join Date: Sep 2000
Location: London
Posts: 7,039
Likes: 0
Received 0 Likes on 0 Posts
Talking

What tyres are on those new 18" wheels? Are the wheels and tyres new?

Matt
Old 26 August 2003, 08:30 PM
  #9  
Jake
Scooby Regular
Thread Starter
 
Jake's Avatar
 
Join Date: Aug 1999
Location: North London, Xbox Live Gamer Tag: Jake Shiney
Posts: 1,621
Likes: 0
Received 0 Likes on 0 Posts
Post

Yes they are new they have covered approx 500 miles, Toyo T1s 215/35/18 on OZ Superleggeras.
Old 27 August 2003, 08:43 AM
  #10  
mutant_matt
Scooby Regular
 
mutant_matt's Avatar
 
Join Date: Sep 2000
Location: London
Posts: 7,039
Likes: 0
Received 0 Likes on 0 Posts
Talking

Bear in mind that Proxies can take a while to start working properly though by 500 miles, you should be nearly be there.
Old 27 August 2003, 10:16 AM
  #11  
vindaloo
Scooby Regular
 
vindaloo's Avatar
 
Join Date: Apr 2003
Location: South Bucks
Posts: 3,213
Likes: 0
Received 0 Likes on 0 Posts
Post

My car tends to do this sort of thing too.
Running 225/35 Bridgestones on 18s.

Pity you get the problem with Toyos as they were going to be one of my fixes. Looks like it'll have to be Goodyears.......

Vindaloo.
Old 27 August 2003, 05:38 PM
  #12  
Mungo
Scooby Regular
 
Mungo's Avatar
 
Join Date: Apr 2000
Location: West Byfleet, Surrey
Posts: 1,653
Likes: 0
Received 0 Likes on 0 Posts
Post

I've got Goodyears (only on 16s) and they've started to tramline now tread is down to 3-4mm.
Old 27 August 2003, 06:11 PM
  #13  
mutant_matt
Scooby Regular
 
mutant_matt's Avatar
 
Join Date: Sep 2000
Location: London
Posts: 7,039
Likes: 0
Received 0 Likes on 0 Posts
Talking

I've got 18" Proxies on my MY02 STi and it doesn't tramline at all - never did and so far, the tyres have about 6000 miles on them......

Matt
Old 27 August 2003, 06:19 PM
  #14  
russell hayward
Scooby Regular
 
russell hayward's Avatar
 
Join Date: Mar 2000
Posts: 1,606
Likes: 0
Received 0 Likes on 0 Posts
Post

when was the last time the geometry was adjusted ?
Old 27 August 2003, 06:46 PM
  #15  
Jake
Scooby Regular
Thread Starter
 
Jake's Avatar
 
Join Date: Aug 1999
Location: North London, Xbox Live Gamer Tag: Jake Shiney
Posts: 1,621
Likes: 0
Received 0 Likes on 0 Posts
Post

Geometry was done about 6 months ago but with 17" wheels though, would this make a difference?
Old 29 August 2003, 08:40 AM
  #16  
mutant_matt
Scooby Regular
 
mutant_matt's Avatar
 
Join Date: Sep 2000
Location: London
Posts: 7,039
Likes: 0
Received 0 Likes on 0 Posts
Talking

I don't *think* changing the wheels should make any difference to the Geom...
Old 02 September 2003, 05:25 PM
  #17  
cliff_vtr
Scooby Regular
 
cliff_vtr's Avatar
 
Join Date: Nov 2002
Posts: 340
Likes: 0
Received 0 Likes on 0 Posts
Post

If the overall rolling radius has changed then the gemotry will be out.

Cliff
Old 05 September 2003, 01:36 PM
  #18  
PhilA
Scooby Regular
 
PhilA's Avatar
 
Join Date: Jan 2003
Location: P1 0790, Durham TTS
Posts: 952
Likes: 0
Received 0 Likes on 0 Posts
Post

The overall rolling radius always changes by some amount when changing wheel sizes. Obviously it's only usually be a few millemeters. Different tyre manufacturers can have quite a few millemeter difference as well. I know this is only a few millemeters but when you are talking about geometry setup a few millemeters can make a massive difference. May be worth getting it checked.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Pro-Line Motorsport
Car Parts For Sale
48
21 July 2017 09:50 PM
Mattybr5@MB Developments
Full Cars Breaking For Spares
28
28 December 2015 11:07 PM
Pro-Line Motorsport
Car Parts For Sale
11
21 November 2015 06:08 PM
shorty87
Other Marques
0
25 September 2015 08:52 PM
JackClark
Computer & Technology Related
1
25 September 2015 06:50 PM



Quick Reply: Stability under hard high speed braking



All times are GMT +1. The time now is 02:13 PM.