AlexM

Hi,

I have a MY98 UK, which has AP 4-pot calipers and 304mm front disks under standard MY98 16" rims.

When I brake firmly from high speeds, the front suspension compresses to the extent that the rear of the car feels light and unstable, which isn't nice!.

I think the problem here is excessive weight transfer to the front, and also some possible aerodynamic issue as a consequence of the diving.

I have been thinking of some suspension or brake system changes to try to fix this - I'd appreciate some feedback from anyone who has experienced this problem (hello Stef ). I'm not really interested in a track orientated setup, rather the best solution for a road car.

My options are as follows (in no particular order):

1) Fit Prodrive suspension package - What does this package comprise and what are the spring rates like compared to standard?. How does the car ride compared to standard suspension?

2) Fit another aftermarket suspension kit (Leda, AVO, other).

3) Fit Eibach springs or similar

4) Upgrade the current solid rear disks to >MY99 ventilated disks with better pads to move the brake bias slightly to the rear.

I'd appreciate some feedback.

Cheers,

Alex


[This message has been edited by AlexM (edited 04 March 2001).]

Rich_R

Alex

I've got the same AP kit and I get some dive but the car feels very very stable on both road and track. I can stamp on the brakes at whatever speed without any problems at all at the back

I've also got Eibach springs (still on standard shocks) and the bump steer mod which I reckon help.

Rich
ps the car is a MY00

[This message has been edited by Rich_R (edited 04 March 2001).]

Andy W

Adding the Prodrive suspension geometry settings to the std suspension may reduce some of the feeling of lightness. Try it. It only cost me £25 to get mine set the last time. I have a feeling though that you may feel more comfortable with uprated springs.
Andy

AlexM

Oops... I forgot to mention that I have had the bump steer mod done, but this feeling of lnstability was there before I had this done (and afterwards) even with the STI 4-pots. I don't feel that it has really helped (much better in other respects though).

The car is now running zero toe as the bump steer has been dialed out - could the front suspension be going to toe out as the bushes compress?.

I suspect that weight transfer is to blame though.

Rich-R I'm sure that your Eibachs made a considerable difference - tell me more.

Cheers,

Alex



[This message has been edited by AlexM (edited 04 March 2001).]

IWatkins

Alex,

Word is that the Anti-Lift kit is just as good as an Anti-Dive kit. Do not have any experience of it myself, so cannot comment. But may be worth following up.

Cheers

Ian

Gary Foster

I have the ALK (+ bump steer, eibachs on standard shocks).

I don't have AP 4 Pots, but my MY98 does have STI Fronts, and as of last week also has the vented MY99 rear + calliper.

I get an unstableness at the rear as well, but only on track, esp if bumpy (I don't brake to the point of locking up at high speed on the road). I still get loads of dive.

Unfortunately I don't know if the ALK (extra 1 deg of castor I think) has helped as I didn't take the car on track before hand.

Sorry, not much use.

Gary

Danny Fisher

Alex, I have some uprated suspension, AP 4 pots, ALK and solid drop links on my car. Ant when on the track I have also compained of the rear of the car being lite/unstable.....

I am thinking of doing something with the rear brakes to try and compensate.

Dan

Fizz

iTrader: (1)

I have the following suggestions -

a) carry a bag of sand in the boot.
b) tow a caravan
c) perhaps a mail to stef as he has AP's and after seeing how he tries to dig his way to oz with his front bumper I suggest you talks to him!

LOL - I suggest c)

Rich_R

Alex here's the full list:

Bump steer mod
ALK
uprated sway bar links
thicker rear anti roll bar
Eibach springs
PE Brake support bracket
AP 4 pots (AP japan pads front, pagid rear)
Vented rear disks (MY00)
braided hoses, dot 5.1 fluid etc.
17" wheels (SO2 PP 215/40)

The Eibachs definitely reduced dive on my MY00 OE 4 pots - got the AP's later.

Straight line braking is perfect and turning in still on the brakes will pivot the car nicely in a very controllable way.

If you are in the area - you are welcome to try my setup before parting with cash. I might be at the Quays meet next sunday (not 100% sure yet)

Danny - u going?

Rich.

Stef

Hi Peeps.
The Eibachs will help, but if you've seen the 'Steffi Stuka' picci, I had them on my car then so they don't do a great deal.
Upgrading the rears to increase rear bias will help, as the car would then 'sink' as oppose to 'dive'.
I have recently fitted an ALK, but have not used it properly yet. My current AP discs have a fault in them meaning I can't brake very hard at the mo'. I will obviously let everyone know how it affects my braking when I've given it a proper work-out. It is supposed to be very effective though.
I guess the best way to stop dive is to fit much stiffer springs (Leda, etc), but then there's always a compromise somewhere.
I actually like the rear of the car feeling so light as it enables you to set it up better (in theory! ).
I'll let you know how I get on with the ALK.

Stef.

AlexM

Hi Stef,

I think stiffer springs + a possible rear brake upgrade is the way to go, but I'd be interested to get some feedback on the ALK once you've tried it.

I think that there is only so far that you can go with geometry changes when you're doing >1g stops!.

Anyone have any comments regarding the Prodrive, Leda, AVO, or other suspension kits?.

Finally, how much would I be looking at to upgrade to MY99 ventilated rear disks or RA-type 2-pot rear calipers?. Would I need an adjustable brake bias controller to stop it from trying to lock up at the rear?

Cheers,

Alex

Gary Foster

Scoobysport did me the MY99 Callipers for £100 (second hand) + the disks / pads of course. Very reasonable I thought.

Danny Fisher

Rich, I should be at the Quays meet on Sunday, Just to annoy Ronnie and Alex the Muppets!

I have something that may be of interest to you. Will speak to you if I make it, if not I shall mail you!

Dan