paul corrigan

drove a uk car with ap 6 pots on the front but standard on the rear and under heavy working the car wanted to swap ends
ive had a look at several upgrades but to balance it out the rear req.upgrade at a cost of 1200 so the the total upgrade will cost about 3000 ouch not nice.
better than repars but high and expensive all the same
my car is running on the standard full setup ,and had a go of this car to see what its like ,the driving experience put me off just upgrade the front and the price put me off the full package
any other options ??
thanks paul

alanjack

[img]images/smilies/mad.gif[/img] I am , I thought the car was better to drive than you make out Paul. You make it out as tough it was terrible.

paul corrigan

it wernt that bad just alittle scarey ,i felt that in some situations it could become dangerous with the back end unpridictable under hard braking.maybe you will get use to it but i want a package for my car that costs less than 3k and when i press the brakes im not in for any unwelcome end swapping
but at the same time they stop it with some force felt like my internals wanted to become externals as they very nearly did ,out of my rear when it started the funny stuff
enjoy them aljack and thanks for the go

alanjack

Hoppy

Paul, what suspension did the car have and what tyres?

I've got APR 6-pots and standard rears (with DS2000 pads) on my UK00 car, plus Prodrive suspension, and absolutely no problems on road or track. I did some tests at Bruntingthorpe and such was my confidence in the brakes that I finished off by tripping the ABS from 100mph with my hands off the wheel The car stopped dead straight

However, I recently had some crap tyres on and under very heavy braking the car squirmed rather more than I liked. And under-steered.

Point is, there's nothing wrong with the brakes and you don't need to upgrade the rears (in fact probably undesirable - could upset brake bias). Something else is amiss. Could be suspension or tyres, but I would guess the geometry is out when fully compressed. I have also had the bump-steer removed.

Richard.

ALi-B

iTrader: (1)

I get the back-end dancing thing with EBC pads and dics up front. My impression was the crappy Avon ZZ1 tyres, as the car understeers like it was on ice on wet slow tight bends or small roundabout (25MPH!!).

paul corrigan

the car is aljacks he is running on uprated springs only and 215/35/18 falkon fk451s i have the same tyers on mine and find them to be a little slippy under power but fine on stopping apart from not quick enough

Tone Loc

iTrader: (1)

I'd say its definately the tyres. Why spend over £1500 on the brakes and settle for cheap tyres? They're you're only contact with the road and as far as im concerned one of the most important parts of my car. Ditch the cheap and nasty tyres (more suited to Novas!!) and you're be able to enjoy the superb brakes you've got.

Btw what springs are you running Alan, did you find much improvement?

Tony.

Mo

Paul,

I'd say that this is just your interpretation. Have you driven any others with big brake kits? they'll probably feel the same to you.

I would very much doubt that the car would swap ends if it's tracked up correctly and all braking is completed in a straight line.

If you braking this heavy to cause so much weight transfer on public roads surely your driving style needs attention.

IMHO 6-pots are overkill unless your on track running coil-overs and slicks, and if this is the case then this 'looseness' of the rear can be used to your advantage.

Pete Croney

Paul

I agree with others here that the problem is almost certainly suspension.

6 pots on 330mm discs can provide so much braking force that the front suspension will be on the bump stops and the rear wheels will have virtually no load on them at all.

A decent suspension set up will hold the car flatter under braking and will allow much more of the braking force to be used.

There is little or no point in having massive brakes if they upset the handling of the car so much that your resultant cornering speed is slower than it was before they were fitted.

Putting more braking on the rear, in this situation, would only make matters worse.

With such serious brakes fitted, your driving style also needs adjusting. You must get your braking done in a straight line, or use less than full braking if braking mid corner.

rjben

posted a question RE this a while back and didn't get many responses. When I was thinking about getting a big break upgrade for my old chimaera I was told by the mechanic, who buy the way builds and races Tuscans, to be sure that I got them set up properly as the bias would be wrong. He said that if I didn’t get them ‘set up’ the backs would lock up as the new bigger fronts would require more bias to break with the same force, hence in normal set up with bigger fronts, the back would get more force and become ‘light’.

Basically I want to upgrade my 2 pot fronts but don’t want to ruin the decent balance that the car has in normal trim.

Any body got any info on this?

Cheers,

Rob

paul corrigan

having done carting for several years and the occasional rally sprint day i hope i can drive to a reasonable standard none of this i dont think ill make it slam on the brakes stuff ,arrrr why has the back end come away??
the braking was done in a straight line just to try there stopping power and on the open road and gave the same results
als car is running on standard scoob shockers and leda springs

alanjack

Paul, They are Eibach Springs NOT leda.
Pete, are you saying that improving the rear by uprating Pads and braided lines will make matter worse
Thanks.


[Edited by alanjack - 4/30/2002 7:19:35 PM]

Mo

Paul,

just trying to give you some constructive opinions I hope you didn't get offended. From your original post it was easy to make these assumptions. Although I would like to add that carting, as I'm sure your well aware, is absolutely nothing like driving a road car and I'd be surprised if the car you used for the sprint days had brakes with the same stopping power as the AP 6-pots.

Alan,

don't worry about improving the rear by uprating pads and braided lines it'll only really firm up your pedal feel. Give Pete a call he can set your mind at rest.

I ran AP 4-pots with standard struts and Eibach springs on both road and track for quite a few months without the car ever getting out of control under braking you've just got to stick to the rules. As Pete says a suspension set-up to match will really release their true potential and to be honest fitting these kind of brakes without the intention of upgrading the suspension is OTT.

Pete Croney

Paul

A kart is probably the ultimate example of how suspension affects braking.

A kart has no suspension, so there is no weight transfer. All of the braking is on the rear, but the lack of forward roll means that the brakes can still be used very effectively. OK, not quite true as the chassis flexes and the CoG is above the point of contact. But the amount of weight transfer is negligable.

Alan, if you are using big brakes on the front, don't put aggresive pads on the back. As Mo says, lines/good fluid will firm up the pedal and this can make a big difference to accurately controlling the brake pressure at the limit of adhesion.

paul corrigan

taken offence !!i am now red faced with rage and if i see you about ill kill you
only messing none taken at all just saying i can drive to a good standard ask alan
thanks for the help guys i was put off a mad upgrade for a while but you have convinced me to go for one dont know which one yet as always with us under payed over worked ******* money will come into it so its time to shop around and get some prices
alan im sorry for getting the spring type wrong hope your feeling better mate and next time you are feeling sick run faster and dont cover the floor to an almost finished job with stella puke
thanks paul