Suspension/brakes - opinions pls

Suspension/brakes - opinions pls

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Discussion

Leadfoot

Original Poster:

1,901 posts

282 months

Friday 22nd February 2002
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I'm going to have to rebush the Griffith ('96) soon & have decided to go for a complete suspension refurb & brake upgrade.
I've looked at what the specialists are offering & would appreciate opinions from any esteemed members who've had the same done to their velocipede.
>Bushes, stay with standard or upgrade to poly? Will it ruin the ride?
>Dampers - was thinking of Nitron, but have been told today that they lower the car by 1", this is a big no-no for me as it gently grounds out at the top of my drive now. I've also had the later spec standard Bilstein dampers recommended to me by 2 well known dealers (one no longer a TVR franchise) in Surrey - Steve H, I believe you've had both an early and late Griff, any substance to this?
>Brakes, probably going for a 4 pot conversion if funds allow. But AP or Wilwood - is the cost difference justified by extra quality/performance? Or should I look into bigger discs with spacers for the standard calipers?
Questions questions I know - sorry, but it's gonna cost me a large stack of drinking vouchers for this little lot so I don't want to make a mistake.
TIA Ian.

GreenV8S

30,214 posts

285 months

Friday 22nd February 2002
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quote:
Bushes, stay with standard or upgrade to poly? Will it ruin the ride?


Wishbone bushes don't actually make a huge difference to the ride, the dampers (and their bushes) make a bigger difference. Damper rates need to be matched to the spring rate, so the spring rates are actually one of the biggest factors in ride quality. The next factor is quality of dampers, and getting the dampers set to the right rate (basically as soft as possible while retaining body control).

quote:
Dampers - was thinking of Nitron, but have been told today that they lower the car by 1", this is a big no-no for me


Don't quite follow this - Nitrons are ride height adjustable of course just like most of the aftermarket dampers, they also come in any dimensions you want. It may be the person who told you this meant they recommended slightly stiffer springs which would allow you to run the car lower - I don't know. For example I specified shorter front dampers because the uprated front springs on my V8S are so stiff and I run it so low, they would rattle on full droop otherwise. There are various ways round this but shorter dampers suited me. If you want ride comfort and handling, the more you spend on dampers the better a compromise you will get. The Nitrons I have cost a lot lot more than cheaper dampers, but the internal valving is quite different (hence the extra cost) and they have much better characteristics. No way I would be able to get away with such high rates and no bushes with cheaper dampers. BTW Nitron also do low-bleed rear dampers specifically to address the rear end lift problem that Chimaeras and Griffiths have under heavy braking. Guy at Nitron is the best person to talk to about this, trust me he knows what he is talking about.

quote:
Brakes, probably going for a 4 pot conversion if funds allow. But AP or Wilwood - is the cost difference justified by extra quality/performance? Or should I look into bigger discs with spacers for the standard calipers?


No point spending money just for the sake of it. What are you trying to achieve i.e. what problems are you trying to solve? Do you actually need to touch the bakes at all or would the money be better spent elsewhere? If you're overheating the brakes and just need a little more heat dissipation for fast road/mild track use, you could consider a 285mm big brake upgrade for the fronts at a few hundred quid. Combined with the right choice of pads I found this made a big difference to the life of the brakes, and also corrected the excessive rear brake bias that the V8S had as standard. If you are a real track day animal with a 5 liter or highly tuned car you might need to go further and be looking at a 300mm monster brake upgrade with new calipers. But this is going to get expensive (1-2000), and as I said there's no point spending money on bigger brakes than you need. Unless you have unlimited budget you need to spend the money addressing the problems. For example getting top quality mildly uprated suspension components and then getting Moore Racing or the like to do a full suspension geometry and cornerweight set up would likely transform the handling.

Hope this helps,
Peter Humphries (and a green V8S)

MikeyT

16,574 posts

272 months

Friday 22nd February 2002
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For 1.10am Peter, that's a pretty damn good answer (as usual)

paceracing

729 posts

267 months

Friday 22nd February 2002
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Don't forget the master cylinder. Bigger calipers ie large 4 pots require more fluid, so with the standard cylinder it is possible to run out of pedal! You may be O.K. but it's something to consider.

Jas.

Leadfoot

Original Poster:

1,901 posts

282 months

Friday 22nd February 2002
quotequote all
Thanks Peter. It was the Surrey ex main dealer who told me that Nitrons would lower the car. Guess I need to talk to Nitron directly.
My brake probs are the usual I suspect; High wear rates on track days (set of pads per day), fade on the fronts (lost them completely on an airfield day once) & just wanting a bit more braking power.
Ian

ross

219 posts

285 months

Friday 22nd February 2002
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nitrons seem to have a great reputation both here and on the caterham pages, tvr centre did an ohlins kit for the griff, (review on ph somewhere) which did lower the ride height, but was excellent when i tried it. some of the cheaper damper names seem to have quality issues according to some of the caterham guys, and are also very heavy and increase unsprung weight quite alot.

on the braking front, i've got racing fluid and braided hoses on the cerbera with standard discs/pads, and the brakes feel significantly better.

DIGGA

40,354 posts

284 months

Friday 22nd February 2002
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Ian

I had problems on track days with my '98 Griff brakes boiling. It's the very last thing you want to have happen to you on the track!

However, that was mainly at Snetterton - a very high speed circuit - and I seem to have cured this with standard size, drilled and grooved disks (F & R) and some decent pads. A lot of people swear by the EBC 'Greenstuff' pads.

350matt

3,740 posts

280 months

Friday 22nd February 2002
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If you go to Super=Pro they can do replacment bushes in varying shore /stiffness grades even to match the original rubber if you want. A stiffer bush tends to locate wishbone arms a bit better but will transmit more vibration and noise although on most tvrs the tiny bit of rubber sandwiched around the steel sleeve probably doesn't do a lot in any case, so you might as well replace with Poly.

davidy

4,459 posts

285 months

Friday 22nd February 2002
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On the subject of track day brakes

The hard braking effort on circuit days often glazes the pads, this can lead to fade, this can be cured by roughing up the pads at the lunch interval or by fitting cross-drilled or grooved discs which will chew up the pads.

Boiling the fluid is serious as once boiled the fluid tends not to work effeciently ever again. I have boiled Silicon DOT5 fluids in the past and now use an AP racing fluid on any car I submit to circuit work but even this was going soft after 10 hard laps of Oulton Park in an Impreza Turbo. I strongly suggest that all people who do regular track work upgrade their brake fluid, not only might it save them from a horrendous accident but it prolongs the amount of track time. A win-win situation. (Note Race Fluids often tend to be more hydroscopic so need chaning more frequently than standard Road fluids)

Another situation which feels like fade, is that sometimes the pads get knocked back into the calipers (especially the kerb hoppers/grass cutters/etc) (This can also occur if there is a very slight amount of play in the front wheel bearings. If this happens when you hit the middle pedal nothing appears to happen much, but if you release the pedal then depress again, hey presto all your brakes are there. This can be overcome by allowing a bit more braking area and pumping the pedal once (or using your left foot on the brakes gently just before you get to the braking area, then depressing fully with your right foot). If you think you have fade try this out as again it may extend playtime!!!

Its sods law that as the day progresses and you get more confident that the equipment starts to give up. If you look after the car in the morning and concentrate on trying to be smooth, during the afternoon your'll be flying

GreenV8S

30,214 posts

285 months

Friday 22nd February 2002
quotequote all
Anyone tried a car with a brake fluid recirculating system installed? I figure the main heating problem is likely to be in the calipers and cycling fluid round could make a huge difference. But they don't seem to be at all popular, so I wonder whether they actually do work?

Cheers,
Peter Humphries (and a green V8S)

HarryW

15,151 posts

270 months

Friday 22nd February 2002
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quote:

Anyone tried a car with a brake fluid recirculating system installed? I figure the main heating problem is likely to be in the calipers and cycling fluid round could make a huge difference. But they don't seem to be at all popular, so I wonder whether they actually do work?

Cheers,
Peter Humphries (and a green V8S)



Hows that work then Peter

Leadfoot

Original Poster:

1,901 posts

282 months

Saturday 23rd February 2002
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ta muchly. food 4 thought.

Leadfoot

Original Poster:

1,901 posts

282 months

Saturday 23rd February 2002
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Drove a '98 Griff today that had done the same mileage as mine. Looks like the advice about the latter spec dampers is true, the car was much more stable & didn't crash over bumps as mine does. The slightly floaty feel over a series of bumps was absent as well.
Can't have just been down to my knackered bushes either, they'd gone on the newer Griff as well!

GIMPTON

213 posts

271 months

Sunday 24th February 2002
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Just looking to upgrade to a Griff 500 (from V8S) and this is the first upgrade i an going to get done

Therefore i am also looking for some advice, i will have around £2-2.5k(but happy to spend less if poss and upgrade the brakes) to spend on this so is it best to go for the Ohlins kit, or look at Nitrons and a roll bar/cage with alignement done. Has anyone had a good rollbar/cage fitted and is the extra stiffness worth the outlay.

Any info on this topic would be gratfully recieved

Cheers

Rob

Graham

16,368 posts

285 months

Sunday 24th February 2002
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I've upgraded my chim to Nitrons, willwood superlight 4 pots and 285? on the front stanard calipers rear with grovved and drilled disks and ebc green stuff, braided hoses . Together with new standard bushes. car setup and corner weighted by moore racing. The car is totaly different much more stable and alot more controlable under braking. the rear end lift is almost eliminated.

the car handles so much better than standard it almost got me into trouble when i borrowed a standard car and tried to do the same things..

My car is alot lower but this is purley setup and im sure it could be setup higher if you wanted.


the brakes just fit on the frount, i've lost a few balance weights so am putting a set of 17 inch wheels on as well ( if they ever turn up thanx raceline)

zertec

499 posts

284 months

Monday 25th February 2002
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www.pistonheads.com/tvr/index.asp?storyId=2792

Scroll down the article and read the section on Suspension and Brakes


shpub

8,507 posts

273 months

Monday 25th February 2002
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quote:
Steve H, I believe you've had both an early and late Griff, any substance to this?


Yes my 98 Griff is streets ahead of my old 95 one in terms of suspension.
Can it be improved yes but remember that suspension changes are always a compromise. There is no such thing as a perfect suspension.

Steve

DIGGA

40,354 posts

284 months

Monday 25th February 2002
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quote:
Has anyone had a good rollbar/cage fitted and is the extra stiffness worth the outlay.



Rob

Had a 'factory' rear roll cage fitted to my Griff shortly after I got it and, although still on a steep learning curve with regard to track use, found it made a noticeable, positive difference the car.

I'd definitely recommend this, if not just from safety, for the inreased rigidity and feel of the chassis.

>> Edited by DIGGA on Monday 25th February 17:16

Graham B

1,359 posts

284 months

Monday 25th February 2002
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quote:

Mines a 94 griff with only 18k on the clock. I bought it last May with 11k on it, and the first thing I did was replace the shocks and springs with the latest spec Bilsteins.



Quinny, how much were the latest spec Bilsteins? I'm going to look at getting mine done this summer.

Cheers,

Graham

>> Edited by Graham B on Monday 25th February 17:38

mav

63 posts

268 months

Monday 25th February 2002
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YOU ALL SEEM TO BE MISSING THE MOST VALUBLE ADVICE !
Nobody seems to have mentioned the man who designed the chassis and who has the best advice about dampers, brakes, pads, master cylinders, upgrades, roll cages, etc, etc, ........who?
Neil Anderson @ the factory !..you tell him your budget and he will tell you how to get max performance for your dosh.
I spoke to him at Silverstone last year, and it was the best Grand I ever spent!!!