Finally get to drive MY V8S - brakes suck.
Discussion
Hi all,
Have got to drive my new toy at last.....Kevin has stopped removing bits of trim, changing otter switches etc long enough for me to go for a spin.
Don't get me wrong, I had a blast
, but the brakes feel a bit spongy. We've decided that the disks and pads need changing all round anyway and we will upgrade to braided hoses. The question is do we stick with standard spec or do we go for bigger disks/grooved etc. I've no intention of tracking the S but would like more powerful and progressive anchors;Any thoughts?
Emma
>>> Edited by Flygirl on Thursday 17th July 21:03
Have got to drive my new toy at last.....Kevin has stopped removing bits of trim, changing otter switches etc long enough for me to go for a spin.
Don't get me wrong, I had a blast
, but the brakes feel a bit spongy. We've decided that the disks and pads need changing all round anyway and we will upgrade to braided hoses. The question is do we stick with standard spec or do we go for bigger disks/grooved etc. I've no intention of tracking the S but would like more powerful and progressive anchors;Any thoughts? Emma
>>> Edited by Flygirl on Thursday 17th July 21:03
Hi flygirl
wellcome to the madhouse
Which V* did you get as i've looked at quite a few recently as i've only just picked mine up (sat)was it the one in Fernhurst?
As regards the brakes heres a snippet from Ride drive director Julian Smith
-----------------------------------------------------
"The amount of time and distance it takes your car to stop from any given speed is all down to the friction properties of the road surface upon which you are driving. Let me give you an example. You are driving a TVR along a motorway at 70 MPH in lane one and you have a Morris Minor 1000 next to you in lane two travelling at the same speed. Both drivers stamp on their respective brake pedals at the same time and both lock their front wheels into a skid, again at the same time and point along the road. Both cars WILL skid to a stop in the same amount of distance. That is fact!
So if we go back to our friend in his Golf, all he has achieved by shelling out all his cash on the new brake parts is reduce the amount of pressure he has to apply to the pedal to produce a high braking effect at the wheels."
THE CAR WILL NOT STOP ANY MORE QUICKLY THAN IT DID WITH THE STANDARD COMPONENTS FITTED!
------------------------------------------------------
An intresting read and apparently the course is even better, booking mine once "woolley steering is tightened up a bit
wellcome to the madhouse Which V* did you get as i've looked at quite a few recently as i've only just picked mine up (sat)was it the one in Fernhurst?
As regards the brakes heres a snippet from Ride drive director Julian Smith
-----------------------------------------------------
"The amount of time and distance it takes your car to stop from any given speed is all down to the friction properties of the road surface upon which you are driving. Let me give you an example. You are driving a TVR along a motorway at 70 MPH in lane one and you have a Morris Minor 1000 next to you in lane two travelling at the same speed. Both drivers stamp on their respective brake pedals at the same time and both lock their front wheels into a skid, again at the same time and point along the road. Both cars WILL skid to a stop in the same amount of distance. That is fact!
So if we go back to our friend in his Golf, all he has achieved by shelling out all his cash on the new brake parts is reduce the amount of pressure he has to apply to the pedal to produce a high braking effect at the wheels."
THE CAR WILL NOT STOP ANY MORE QUICKLY THAN IT DID WITH THE STANDARD COMPONENTS FITTED!
------------------------------------------------------
An intresting read and apparently the course is even better, booking mine once "woolley steering is tightened up a bit
Hi Pies,
Not the S at Fernhurst although I did test drive it twice (they managed to F**k us off suficiently to loose a sale!!). Finally picked my beast up from Exeter 10 days ago, having scoured the country. (Also test drove your car at Adrian Blythes....lovely car!).
Thanks for info re. brakes, just after a better feel/feedback. We've been considering slightly larger grooved disks, with Mintex pads. Hopefully Peter Humpheries, whose 'been there, done that', on S brakes, can offer some more advice?!
Hope you're enjoying your toy Pies.....
Emma
Will Post pictures once I've figured out how to!!!!
>> Edited by Flygirl on Thursday 17th July 21:35
Not the S at Fernhurst although I did test drive it twice (they managed to F**k us off suficiently to loose a sale!!). Finally picked my beast up from Exeter 10 days ago, having scoured the country. (Also test drove your car at Adrian Blythes....lovely car!).
Thanks for info re. brakes, just after a better feel/feedback. We've been considering slightly larger grooved disks, with Mintex pads. Hopefully Peter Humpheries, whose 'been there, done that', on S brakes, can offer some more advice?!
Hope you're enjoying your toy Pies.....
Emma
Will Post pictures once I've figured out how to!!!!
>> Edited by Flygirl on Thursday 17th July 21:35
Generally a car skidding will take longer to stop than a car that is just nearly skidding. The coefficient of friction between a skidding tyre and the road surface is lower than the coefficient of friction between pads and disk. So ideally to stop in the shortest possible distance you need to get the car almost to the point of skidding.
That is the point of cadence braking, or indeed ABS - so that the car DOESN'T skid. Would every car maker be fitting ABS if it made braking worse?
The tendency to skid is obviously dependent on the tyre width etc. A TVR with wide fat grippy tyres has more grip than a morris minor with wee skinny tyres - therefore it can exert more grip before it skids, therefore it will stop in a shorter distance.
comparison of skidding distance is therefore bollux
That is the point of cadence braking, or indeed ABS - so that the car DOESN'T skid. Would every car maker be fitting ABS if it made braking worse?
The tendency to skid is obviously dependent on the tyre width etc. A TVR with wide fat grippy tyres has more grip than a morris minor with wee skinny tyres - therefore it can exert more grip before it skids, therefore it will stop in a shorter distance.
comparison of skidding distance is therefore bollux
Pies said:
You are driving a TVR along a motorway at 70 MPH in lane one and you have a Morris Minor 1000 next to you in lane two travelling at the same speed. Both drivers stamp on their respective brake pedals at the same time and both lock their front wheels into a skid, again at the same time and point along the road. Both cars WILL skid to a stop in the same amount of distance. That is fact!
Surely the wider rubber of the TVR will mean a larger footprint on the tarmac which should result in greater friction therefore a shorter stopping distance.
However, I'm probably missing some fundamental law of physics and just talking out of my arse (why break the habit of a lifetime?).
Edited because I forgot to say congrats on the new toy Emma!
>> Edited by RichardR on Thursday 17th July 21:42
Ah the old Brake sucking S thing going on hey?
find yourself an old sierra XR4i in a scrapyard (not easy these days) and rob the front discs off it .. they're Griff 500 diameter, 4 stud fixing rather than the converted 5 stud granada efforts TVR sue as std, plus you get the granada sized caliper that doesn't need a spacer between it and the hub for it all to fit together. i have this set-up on my V8S and it's a cheap and cheerful way of getting more front end stopping. If you go for chimaera wheels with 16s on the back you nca have the vented rear brake option too
find yourself an old sierra XR4i in a scrapyard (not easy these days) and rob the front discs off it .. they're Griff 500 diameter, 4 stud fixing rather than the converted 5 stud granada efforts TVR sue as std, plus you get the granada sized caliper that doesn't need a spacer between it and the hub for it all to fit together. i have this set-up on my V8S and it's a cheap and cheerful way of getting more front end stopping. If you go for chimaera wheels with 16s on the back you nca have the vented rear brake option too
With all due respect to Julian, I think either he's been misquoted or he's deliberately oversimplifying the situation for some reason. In the real world, bigger brakes require lower pad contact pressure so the friction coefficient is more consistent, bigger/more pistons distribute the forces more evenly over the surface of the pad so you less distortion of the backplate and fewer hotspots and less gas generation, and bigger brakes run cooler and cool down quicker between applications. The result is it is easier to hold the brakes at the limit of grip without locking up, and you can do this time after time without cooking the brakes. Cooked brakes feel horrible as the fluid goes spongey, the pads lose their mechanical strength and wear unevenly, and the discs can easily be warped leading to brake judder and brakes that lock up prematurely. This is damage which will be with you long after the brakes have cooled down, and will only be cured when you replaced the knackered components. The Moggie versus TVR comparision is also a gross simplification which may hold true in an O level physics class but not in the real world where the TVR will stop quicker than the Moggie even on locked wheels. It has better weight distribution (50/50), lower center of gravity, better suspension (tyre loadings more consistent), wider tyres and lower contact pressure (higher coefficient of friction). As well as softer tyres especially if the Moggie is still on cross-plies! Put it another way, my V8S will pull up to 1 G on locked wheels and 1.15 G if I keep them rolling - and this is on ordinary road tyres. It is a bit optimistic to hope that a Moggie would achieve this.
Where Julian is absolutely right, and this may have been the point he was trying to make, is that changing the geometry/leverage of the brakes to reduce the force on the pedal makes the brakes more sensitive but doesn't stop you any sooner, and in fact makes it harder to hold the brakes on the limit without locking up. It is easy to get used to very light brake pedals on modern saloon cars and think that a brake upgrade that makes your TVR feel like that must be a good thing. Actually, it isn't.
Where Julian is absolutely right, and this may have been the point he was trying to make, is that changing the geometry/leverage of the brakes to reduce the force on the pedal makes the brakes more sensitive but doesn't stop you any sooner, and in fact makes it harder to hold the brakes on the limit without locking up. It is easy to get used to very light brake pedals on modern saloon cars and think that a brake upgrade that makes your TVR feel like that must be a good thing. Actually, it isn't.
Certainly not miss quoted you can read the full text here "ride drive site"
www.ridedrive.co.uk/tipoffs/braking.htm
www.ridedrive.co.uk/tipoffs/braking.htm
Jeez don't you people have a home to go to! Back to the original question, I'd flush the fluid out, fit known good quality fast road pads (Tarox XF, DS2000 etc) all round and bed them in according to the manufacturers instructions, before resorting to steel braided hoses and so on. Drilled discs are the work of the devil, and grooved discs are all very well if you're suffering from overheating or using race pads but really not necessary on the road.
Second the get the fluid changed and new decent fast road pads fitted, standard set up isn't all bad for road use. If you can lock them up then what more do you want, except to do it more often in short succession ala track driving.
Whilst on the subject of brakes has anyone any experience of this Co. www.hispecmotorsport.co.uk/index.htm as they seem quite reasonable and have every shape,size, colour and smell available and if not they'll make it.
Just pondering at the moment.
Harry
Whilst on the subject of brakes has anyone any experience of this Co. www.hispecmotorsport.co.uk/index.htm as they seem quite reasonable and have every shape,size, colour and smell available and if not they'll make it.
Just pondering at the moment.
Harry
HarryW said:
Whilst on the subject of brakes has anyone any experience of hispecmotorsport as they seem quite reasonable and have every shape,size, colour and smell available and if not they'll make it.
Just pondering at the moment.
Harry
Yes, quote a bit of experience over the last eighteen months. Quite outstanding service, truly remarkable and clearly beyond improvement. My new brakes are on order from BG Developments.
GreenV8S said:
Whilst on the subject of brakes has anyone any experience of hispecmotorsport as they seem quite reasonable and have every shape,size, colour and smell available and if not they'll make it.
Just pondering at the moment.
Harry
Yes, quote a bit of experience over the last eighteen months. Quite outstanding service, truly remarkable and clearly beyond improvement. My new brakes are on order from BG Developments.
subtlety has never been one of my stronger points, I take it the fact that BG are getting your custom thats a non recommend then. Harry
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