Fangoria

iTrader: (1)

Went out for a blast last night in the sti5 and on bends now I cant control it - it doesnt understeer at all - probably the opposite - on bends and undulating roads its all over the place

Was very close to writing it off the car was all over the road - left/right/left/right.....squirming all over the place and not at huge speeds - and no water on the road

Basic set up:

Antilift Kit
Bump Steer mod
Front and rear MRT roll bars - rear set to hardest setting
Front and rear sti strut braces (front one replaced for a proper - i.e. non carbon fibre brace)
Rear drop links
Set up at 1.5 negative all round - cant remember toe in - all done at Powerstation
Tyres are FK451's
18 Inch alloys 215/35 at 34 front 31-32 Rear pressures

2 Points to note

1. I have a lot of stereo gear in the Boot and also a full tank of water
2. The CV joints at the front are worn and need replacing

The car currently feels very uneasy on the road - its fine in a straight line - but when you add in bends its not comfortable at all

The only real changes to the car in the last 6 months have been - change of Tyres from Toyos and secondly wearing out CV Joints on the front driveshafts

Can someone tell me:

1. Do knackered CV Joints on the front really impact on handling to a huge extent to make the car go all over the place on the road

2. How does all the weight in the boot effect the handling with my current set up

3. What would be the effect of adjusting the tyre pressures front and rear

Are there any experts that could test drive my car and tell me whats wrong with the handling on it?

Rgds

Steve

vindaloo

Waiver: Not an expert....

1) Knackered CVs won't affect the handling unless they're actually broken and not working at all (unlikely as they'd probably break into bits first).

2) Weight in the boot will make it more likely to continue oversteering. Also changes the spring/damper effectiveness (i.e. more wallowey, softer, crappier). There's probably a technical term for this such as 'effective rate' or 'bump/rebound period' but I don't know it.

3) I take it you mean by increasing the rear PSI.


I'd first check the rear tyre pressures and the tyres for signs of 'odd' wear. Check the rear suspension bushes at the same time. Consider running less rear bar. Check the rear shocks. With the stiffer rear bar and the weight in the boot, consider uprating the rear shocks.

Someone sensible may be along in a minute....

Vindaloo.

Jerry B

Surely the most obvious thing to do would be to empty out the boot and drive it unloaded before trying anything else. Then you've got a reference point. You've got all that weight right at the back with rear pressures probably too low for the load I'd think it would be a little 'lively' at the rear before adding in any wear factors etc.

Fangoria

iTrader: (1)

Thanks - fairly obvious I guess

I'll get the CV joints replaced to completely take them out of the equation

Then I'll take out the subs and see what difference it makes

Must say that I've only noticed this since changing the tyres - more likely to be something at the rear thats broken - I'll check under the car tomorrow morning..

vindaloo

Let us know what you discover. I'm interested as mine is running on 18s with an S02/S03 mixture - NVH hardcore

I don't suppose you've got an adjustable centre diff too, have you?

Regards,

Vindaloo.

BART!

Strange....how was it with the TOYO's in the first place as they aren't very predictive and just lack grip. So either the FK's are even worse or just too good....and so changed the handling from initial understeer (caused by lack of grip from the Toyo'S) to oversteer as could be expected with current set-up.

2. Loosen the rear ARB a bit, as the stiffest setting isn't really safe for daily traffic .... (need some space to take a step sideways now and then) Personally I'm not a Fan of stiffer ARB's in combination with standard suspension....

3. I don't think your front CV's /UJ's are gone at all ! They tend to last very long even if there's seems to be a lot of play on them. As long as they don4t produce heavy clonking sounds mid corner, they are alright.

[Edited by BART! - 11/23/2003 9:32:13 AM]

[Edited by BART! - 11/23/2003 9:34:41 AM]

Fangoria

iTrader: (1)

They produce a fair bit of clonking round corners!!

Right - removed rear subs and handling is better - plus I've increases tyre pressures a bit at the rear

The FK451's are not very good in the wet but better than Toyo's in the dry - the Toyos as was said are awful in the dry.... better than Falkens in the wet though...

I will reduce the rear ARB setting to central and maybe remove subs for good........ will change cv joints and see whats what and get another check on geometry - I'm on hols for a while though............

Thanks