Problems with the beeza under heavy braking

[Dolly_Gti]

Has anyone else had any problems under heavy heavy braking, this is mainly aimed at trackday people..

recently doing around 80ish, on a fair large duel carraigeway was forced to slow down some what quickly, so i hit the brakes hard.... ive never had the back end of a car step out and go as skitish as mine did, had to counter steer it, and although it wasnt going to spin out or cause a problem, got me thinking is there a way to stop all the weight shift to the front, i.e adjust brake bias or chuck some slabs in the boot to keep some weight over the rear?

P.s dont condone speeding on public highways i just get carried away sometimes

 

[AlpineWhite]

i think i've read before that people space out the rear wheels to make the rear end less twitchy.

 

[Dolly_Gti]

im wandering how much of a difference that would make

 

[AlpineWhite]

i guess it would make more difference in the twisties as opposed to braking in a straight(ish) line.

 

[Dave_R]

I would say get some 15 or 20mm rear spacers on the car. The rear axel is 30mm? (correct me if i'm wrong) shorter than the front, increasing the width of the rear axel will improve stability of the car at the rear and prevent the car “stepping out” under hard braking and fast cornering.

 

[jcs356]

I get this on my car - I put it down to the fact that thanks to the stripped out interior, there is no weight at all in the back of the car. I've got 15mm spacers on mine. I agree, it can be offputting if you hit the brakes hard, you lockup the rears and it starts to squirm.

I got the garage to check that the brake bias adjuster was working ok (it is) - it should vary the rear brake bias based upon load in the rear. Just that with no weight in it, it makes no difference. Might get a manual bias adjuster and set it up so that the rears can never lock (have to remember to adjust it back again MOT time), or put some bags of cement in the boot.

 

[Dolly_Gti]

my mate whos an ex rally driver spoke of a manual adjuster just cant get carried away ie, the back locks up before the front lol, im using my car for the odd track day/sprint so i dont think this is the best choice.. the only thing i can do is stick some spacers on the back and see what happend..

i didnt think they was an auto bias adjuster on these cars, , i assumed it was a set figure ie 65% front 35% (for example)

 

[F2 Stu]

I dont get this as much with the Cordoba than with the Ibiza, but its part rear track and back end is massivly overbraked

looking into fitting bias valves & junking the ABS at some stage

 

[Dolly_Gti]

ill have to fit spacers and see, this is an intresting one this

yeh ABS is for girls.. for people who dont realise when the wheels lock up you aint going to turn.

 

[jcs356]

i didnt think they was an auto bias adjuster on these cars, , i assumed it was a set figure ie 65% front 35% (for example)

There is on the GTi - it is self adjusting box on the rear beam - works by a spring and the compression on the rear beam. Hence it should adjust the rear bias by a small amount depending upon how weighted down the back of the car is. Can get stuck in one position and is quite expensive to replace.

A mate of mine raced minis and his advice was to fit a manual bias valve and set the car up so on full braking you can just hand turn the rear wheels (car jacked up, obviously). That way no chance of a rear lock-up. Won't pass an MOT that way, however.

Someone else said that I could get some rear suspension springs bespoke made for the weight on the back of the car - i.e. something with a bit more give in it to try to keep the car on the tarmac. Probably going to be an expensive option.

 

[Brummy]

my old 1.4 was a LOT more rear -end happy than my Cupra is.. I used to have SOOOO much fun kicking its ar$e out 'a- la' drift mode on islands etc.. scared the bloody life out of Damns (usedto come on here before he got a TT) once , going to a meet up by the airport in Brum

 

[F2 Stu]

Said self adjusting box is otherwise known as a 'load dependant valve'

However these wern't fitted to all models oddly enough, genarally if the car has ABS it does not have one (ABS controls bias) with the exception of the 1.8 16v where it has both ABS and the load valve, on Cordoba's Ive only ever seen the valves on varios

 

[edc]

Someone else said that I could get some rear suspension springs bespoke made for the weight on the back of the car - i.e. something with a bit more give in it to try to keep the car on the tarmac. Probably going to be an expensive option.

Won't be that expensive, relatively speaking. Have a look at Faulkner springs as a guide, varying options for reasonable money.

 

[Hayz]

I wouldn't really call weight shift a problem - You slam your brakes on on a slight bend all the weight moves forward giving you a lighter back end, and maybe making it a bit slippy.

I really don't see how spacing your wheels is going to help!

 

[F2 Stu]

I wouldn't really call weight shift a problem - You slam your brakes on on a slight bend all the weight moves forward giving you a lighter back end, and maybe making it a bit slippy.

I really don't see how spacing your wheels is going to help!

You're right about the weight transfer bit, but increasing the rear track to match the front offers better stability and in turns affects the way the back end snapping out.