Impressions so far...let's put the btrakes on...

Impressions so far...let's put the btrakes on...

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griff59

Original Poster:

273 posts

69 months

Friday 6th July 2018
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Two weeks ownership of my Griff, all is well, it's strange how driving such an extreme car can become a "normal" experience in such a short time, well almost normal, I'm not quite 100% comfortable in her just yet, and every drive still leaves me physically drained wanting a cold beer and a cold poultice!
What makes a TVR special to me is that I know, no matter how long I have it, it will still continue to have that thrill and sense of mystery that it had before I even drove it.
It's lived up to my expectations completely, but one thing I'm not getting used to is the braking, I'm used to driving a modern ABS equipped car, and I have to keep remembering that I don't have that on the Griff, in fact, it's one of the first modifications I'm going to have done, uprating the braking system. Any help and guidance regrading improving the braking would be extremely welcome.

steve-V8s

2,899 posts

247 months

Friday 6th July 2018
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What is it that you don't like about the standard arrangement ? There was a fashion for fitting bigger discs and “better callipers” but I have never really understood why, unless perhaps you are thrashing round a track and things are getting a bit overheated.

Provided it is all working correctly I have always found the standard arrangement nicely balanced and perfectly adequate. Even with the softest of racing slicks fitted the car still stops nicely.

Fitting new standard discs and some reasonable pads, Ferodo 2500 for example gives plenty of stopping power and reasonable feel. For a better feel on the pedal swapping the flexible hoses at each corner for braided ones gives a noticeable improvement. If it hasn't been done recently you could treat the entire system to a complete fluid change.

900T-R

20,404 posts

256 months

Friday 6th July 2018
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^^^^ I'm with him. Before you go on a wholesale attack on the braking system, I would have the standard brakes checked over - calipers, fluid and see if someone before you didn't put cheapo pads in it that were meant to get 30 year old Escorts and Sierras through their last MOTs. TVR did use a decent Ferodo compound (4003 does faintly ring a bell, the Steve Heath bible knows more) as standard fitment.

griff59

Original Poster:

273 posts

69 months

Friday 6th July 2018
quotequote all
steve-V8s said:
What is it that you don't like about the standard arrangement ? There was a fashion for fitting bigger discs and “better callipers” but I have never really understood why, unless perhaps you are thrashing round a track and things are getting a bit overheated.

Provided it is all working correctly I have always found the standard arrangement nicely balanced and perfectly adequate. Even with the softest of racing slicks fitted the car still stops nicely.

Fitting new standard discs and some reasonable pads, Ferodo 2500 for example gives plenty of stopping power and reasonable feel. For a better feel on the pedal swapping the flexible hoses at each corner for braided ones gives a noticeable improvement. If it hasn't been done recently you could treat the entire system to a complete fluid change.
Thanks, braided hoses have been fitted. But nothing else has been done.
It's when the brakes are cold, the first few miles that stopping power seems inadequate, the more I use them the better they feel. I pulled up at some traffic lights a mile from the house and they barely worked, it was quite disturbing, but a few miles down the road they felt more or less OK, strange?

steve-V8s

2,899 posts

247 months

Friday 6th July 2018
quotequote all
If they don't work from cold it could be you have pads which are really meant for circuit use, a lot of people seem to sell these. They need to be quite hot before giving any bite and shouldn't really be used on the road.

Do they actually not work or do you just have to press harder ? Could be the servo is not as it should be or there is a leak in the vacuum pipe. There is a one way valve in the pipe which is often missed but is worth checking.

Another thought with the symptom you describe is the master cylinder. It has two separate pistons with four outlets (only three of which are used on the Griff ) the idea being if there is a catastrophic failure on one of the circuits the other will still work a bit. The down side to this system is when the seals get past their best fluid can circulate around inside the cylinder rather than getting forced down the pipes, this effect can be intermittent if the sealing edge if the washer has badly degraded.

You could seek out a local friendly MOT man ( you will need to find one at some point anyway) and ask him to pop it on the brake rollers, would be a very quick test and even if it reveals no problem would at least give you some confidence that all is working.

griff59

Original Poster:

273 posts

69 months

Friday 6th July 2018
quotequote all
steve-V8s said:
If they don't work from cold it could be you have pads which are really meant for circuit use, a lot of people seem to sell these. They need to be quite hot before giving any bite and shouldn't really be used on the road.

Do they actually not work or do you just have to press harder ? Could be the servo is not as it should be or there is a leak in the vacuum pipe. There is a one way valve in the pipe which is often missed but is worth checking.

Another thought with the symptom you describe is the master cylinder. It has two separate pistons with four outlets (only three of which are used on the Griff ) the idea being if there is a catastrophic failure on one of the circuits the other will still work a bit. The down side to this system is when the seals get past their best fluid can circulate around inside the cylinder rather than getting forced down the pipes, this effect can be intermittent if the sealing edge if the washer has badly degraded.

You could seek out a local friendly MOT man ( you will need to find one at some point anyway) and ask him to pop it on the brake rollers, would be a very quick test and even if it reveals no problem would at least give you some confidence that all is working.
Thanks, I'll get all that checked out, it's just had an MOT, and the brakes were flagged up, but the dealer rectified the problems and it passed the MOT fine. The car was given a thorough going over by the dealer and whole car was checked before delivery.
As you say, it may have racing pads, I'll get that sorted out straight away.



steve-V8s

2,899 posts

247 months

Friday 6th July 2018
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Do you know what work they did ?

If you already have brand new pads and discs they can feel a bit hopeless until bedded in. You should be able to see if they are new as the will look....new, they stop looking that way quite quickly.

blitzracing

6,387 posts

219 months

Friday 6th July 2018
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Worth a squint at the brake pad colours- if EBC ones have been put in there they are colored for intended use- Red and yellow are track day pads.

cavebloke

640 posts

226 months

Friday 6th July 2018
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I think it's also worth thinking about whether the system has been bled properly when servicing or after fitting the braided hoses.

If the pedal is soft then there is probably air trapped in the top of the master cylinder. The master cylinder is fitted on the back of the pedal box in the Griff and is inclined upwards making it near impossible to bleed completely when the car is level. If you see the section in Steve Heath's book on the Griff/Chimp he talks about lifting the back end of the car in the air to get the master cylinder level and achieve a good bleed. I've also seen people drill additional ports in the wing to gain access to the master cylinder ports (not the reservoir) to aid bleeding. From my own experience of taking the car to TVR specialists - many do a poor job of bleeding the brakes (which should have a very firm pedal and excellent feel when properly sorted).

I would agree with previous comments that the standard brakes are fine when well set up (and with good pads). Remember the car only weighs 1050kg so there's not much weight pushing down on the tyres. Bigger brakes may just lock the wheels up more readily.

Simon

chj

763 posts

212 months

Friday 6th July 2018
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I would get in touch with the dealer and get them to sort it out. Standard brakes are definitely good enough for normal road use in my opinion.

griff59

Original Poster:

273 posts

69 months

Saturday 7th July 2018
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Brakes seem OK this morning, just went to top up at the local BP and all seems fine right from cold, typical!
I'm off to the Lydden Hill Classic today, I'm going as part of the TVRCC, should be lots of fun.

thumbup

ChimpOnGas

9,637 posts

178 months

Saturday 7th July 2018
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The standard brakes are indeed fine, but that most certainly doesn't mean they can't be massively improved on!

Better brakes enhance your confidence in any car and the pleasure it gives, and lets not kid ourselves here.... the brakes that come with even a work-a-day modern car are immeasurably better than what was going on much faster cars in the 1990s. While ABS is unquestionably the most significant development in automotive braking since the disc brake, the truth is unless you're driving everywhere like a complete twaaat ABS activations should be rare. ABS is there to save you, its a predominantly a safety feature not something to be used during normal or even moderately aggressive diving, if you're activating ABS regularly or even using it when pressing on... the simple fact is you need some proper driver training.

So for 99.9% of driving, modern car brakes aren't better because they have ABS, they're better because they are so much more powerful and offer better feel. Car manufacturers spend millions on brake development using teams of super skilled and qualified engineers to achieve their results. For these reasons you can't really compare the brakes on a 2018 car with a twenty year old TVR that borrowed it's brakes from an early 90s Ford.

The OP feels he'd like better brakes, so I'm not sure its all that helpful to respond by telling him he doesn't need them, I too was told I didn't need better brakes on my Chimaera which I chose to ignore because just like the OP, quite simply... er "I wanted better brakes"!.

I bought a set of used ally four piston Brembo GT calipers, while they were in good shape for complete peace of mind I had them reconditioned with new pistons and seals. These excellent calipers where used extensively by a number of car makers during the early 2000's including Ferrari who put them on the 360 and 612 models.

Fortunately the exact same caliper was also used on the E38 BMW 7 series to slow that 1.8 ton 155mph executive express, they made tens of thousands of E38 7 series BMs so it's easy to find these calipers on eBay for very reasonable money. By a happy twist of fate because the Griffith & Chimaera use a ford Sierra front upright you can use some neat laser cut brackets offered by Capri Sport for Sierra Cosworth enthusiasts looking for a cost effective brake upgrade.



https://caprisport.co.uk/p/cosworth-2-wheel-drive-...

The above is a tried and tested upgrade that uses inexpensive and readily available 325mm Mk1 Focus RS discs, quality pads for the Brembo caliper are also readily available from any decent motor factor, just order a set for a 3.0 Litre V8 or the big bad boy 5.0 litre V12 E38 because both models (and the E38 8 series) used this excellent Brembo caliper.

The above is an easy bolt on kit, you do however need 16" front wheels as used by TVR themselves on the last run of Griffs & Chimaera and a set of spacers but I was fortunate here too as the guy I bought my TVR from had fitted a pair of 16" rear Imolas to the front of my Chimaera. Fitting 16" front wheels to replace the standard 15s is a common mod, mostly it's done because it broadens your tyre choice but it also makes space for bigger brakes. If you struggle to find a pair of 16" Imolas or Estorils because they are getting rare and expensive these days you can always use the smaller disc & caliper kit from Capri Sport, and a few Chimaera owners have done just that.

The beauty of this conversion is you're not buying some track day caliper made by a small outfit on a industrial estate, you're buying into all the design and development skills of the largest most respected brake manufacturer in the world. Brembo calipers are OEM quality, they have to go through the most intense and punishing destruction testing you can imagine before the likes of BMW will put them on their cars.

Better still the consumables (discs & pads) are cheap and readily available, I pushed the boat out and bought Brembo pads and Brembo discs to complete the OEM package.

But the best thing about this conversion is you can do the whole thing for £500, compare this with any other brake upgrade offered for our cars and it's getting on for half price for what I would argue is a better result because you get OEM quality brakes with all the intense R&D that comes with it, Brembo vs HighSpec ect scratchchin... No Contest!.

Read how to complete this outstanding and cost effective Brembo/Big Disc brake upgrade on your TVR Chim/Griff here...

https://www.pistonheads.com/gassing/topic.asp?h=0&...

So yes, the standard brakes on our cars are fine, but if you want to take your TVR to the next level of braking my God this Brembo conversion gives fantastic results. You really need to experience the difference to understand the night and day difference between standard Chim/Griff brakes, but I can guarantee you it'll be the stand out best upgrade for £500 you'll make to your TVR, and by a massive margin too.

On the face of it braking sounds like a rather dull element of driving, the reality however couldn't be more different, when you upgrade brakes the pleasure and confidence they give is huge. So despite all the comments from the 'standard brakes are fine' brigade my experience says the OP is very much on the right track when he says he wants better brakes. Finally to put all this into perspective I drove my mate's Chimaera 500 recently which has well maintained standard brakes, yes they were fine, but compared with my Brembo caliper and 325mm disc set up, and because I'm now so used to them, the standard arrangement actually felt broken the first time I touched the brakes!






griff59

Original Poster:

273 posts

69 months

Sunday 8th July 2018
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ChimpOnGas, I'm going to sum up by saying that I'm definitely not happy with the overall braking performance of my car, it may be as intended, and about the same as any other stock Griffith, but it definitely "does not" inspire confidence.
If it is posdible to upgrade, and at the £500-ish you mentioned then that would be money well spent IMO.

ChimpOnGas

9,637 posts

178 months

Tuesday 10th July 2018
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griff59 said:
ChimpOnGas, I'm going to sum up by saying that I'm definitely not happy with the overall braking performance of my car, it may be as intended, and about the same as any other stock Griffith, but it definitely "does not" inspire confidence.
If it is posdible to upgrade, and at the £500-ish you mentioned then that would be money well spent IMO.
Exactly!

Most spend £500-600 to complete this upgrade, I went with quality Brembo discs and pads which meant I hit the £600 mark but you will not get a better brake upgrade for twice the money.

My original Ford mono piston calipers needed an overhaul, sticky pistons are common so this may be why your brakes don't inspire confidence. The thing is by the time you've rebuilt your originals or bought new calipers you're already half way to the cost of the Brembo upgrade which is night and day better.

I went from the original 260mm disc and iron mono piston calipers that were partially seized, to the full house 325mm disc and ally four piston Brembo caliper setup. As you can imagine the difference was an insane, and six months after completing the upgrade driving my mates Chimaera 500 with well maintained standard brakes was a shock, its very easy to get used to better brakes.

To say the standard anchors felt underwhelming on my mate's 500 would be a massive understatement, back in my car 10 minutes later and all that was going through my head was... "my God these Brembo brakes are outstanding"!

I wouldn't listen to the people trying to convince you the standard brakes are fine, they are fine.... but the Brembo upgrade is simply in a different class.

You will not be disappointed!

jimed

1,500 posts

205 months

Tuesday 10th July 2018
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I had thought that the brakes in my Griff were not that wonderful. They did seem to be a bit better after service and braided hoses made a good improvement. I spoke to Heath (X Works very knowledgeable) about this and what options there were. His view was that the standard brakes are ok, some of the other pads need to be warmed up before they work well so for general road use they aren't the best. The improvement after service was probably down to the fact that the brakes get stripped and cleaned with the pads being deglazed, he said that with the age of the car and with the pads almost certainly being the original ones they would have gone hard and become less effective. The recommended solution being to replace the old pads with a good quality standard pad. This has been done with (think) Ferodo pads and they are much improved and now perfectly fine. That might be your problem as the dealer might just have cleaned and reglazed the pads or fitted some cheaper ones.
Jim

Barreti

6,680 posts

236 months

Wednesday 11th July 2018
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Do you have a 4.x or 5.0ltr car.
I thought I'd ask because not everyone knows the 4.x cars have smaller front brakes and its an easy upgrade to fit the 5.0ltr setup.

griff59

Original Poster:

273 posts

69 months

Wednesday 11th July 2018
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Barreti said:
Do you have a 4.x or 5.0ltr car.
I thought I'd ask because not everyone knows the 4.x cars have smaller front brakes and its an easy upgrade to fit the 5.0ltr setup.
Mine is a 500, I had a really nice drive on Sunday, down some lovely country lanes and B Roads. On a long straight section there was a bend coming up and the road narrowed more than I expected after the bend and I had to brake sharply to pass an oncoming car, my car pulled to the left a bit which was concerning, and the braking power was sort of "OK" but not inspiring. It was a good test, and it still leaves me wanting to upgrade the brakes, I'm in no doubt about that, and that Brembo conversion is already on my shopping list.

Edited by griff59 on Wednesday 11th July 17:13

Aussie John

1,014 posts

230 months

Wednesday 11th July 2018
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I guess the big problem will be getting hold of some 16" estorils, not cheap or plentiful.

deeen

6,079 posts

244 months

Wednesday 11th July 2018
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Based on my usual principle of "start with the cheapest fix", when was the last time the brake fluid was changed? Over 2 years and you will feel the difference with new fluid, IMHO.

TV8

3,118 posts

174 months

Wednesday 11th July 2018
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The early Cars had 240mm front discs and unventilated rear discs. I wasn’t happy with them and changed the fronts to new 260 mm discs and new matching callipers. Basically, the front half of the standard set up you have.

Add some Good brake fluid, good quality pads and braided hoses and that set up gave me an excellent pedal feel and no fade even during hard track use.

On the current car, the set up is the same but with bigger and vented rear discs. I haven’t had that much time on track but enough to know they work fine and a lot Better pedal feel than the brakes on my 987 Boxster!