powerflex bushes, worth the money?
Discussion
Depends on what you want the car to do. For cruising to the pub on a sunny Sunday and the odd tour the standard bushes are fine, arguably they are probably the better option. If however you want to sharpen up the handling with a view to going round corners quicker then Poly bushes and correct alignment are a significant improvement. After fitting proper dampers this remains the best mod and gained more time in competition driving than anything else I have done to the Griff
As with most things it is a compromise. The tighter you make the handling the further it moves away from a comfortable cruiser.
Can’t understand whey they would last less time than the rubber ones.
As with most things it is a compromise. The tighter you make the handling the further it moves away from a comfortable cruiser.
Can’t understand whey they would last less time than the rubber ones.
Clivef
I thought I gave you very sensible and concise advice. You won't get any bullshit from me - a spade's a spade.
The polybushes now come with heat shields for the ones next to the exhaust manifolds.
I don't find them any harsher than the originals either.
OscarT
PS Why don't you develope a rear diffuser?
I thought I gave you very sensible and concise advice. You won't get any bullshit from me - a spade's a spade.
The polybushes now come with heat shields for the ones next to the exhaust manifolds.
I don't find them any harsher than the originals either.
OscarT
PS Why don't you develope a rear diffuser?
Oscar - the rear diffuser is on the drawing board. There is already one available, so it may not go much further.
Clive - I remember you commenting about the ride in my Griff. I wasn't hanging around if I remember correctly
So yes, polybushes are well worth it. They're also easier to change when the time comes!
Clive - I remember you commenting about the ride in my Griff. I wasn't hanging around if I remember correctly
So yes, polybushes are well worth it. They're also easier to change when the time comes!IMO there's no difference in the location of the wishbones one std or poly bushes (if you go for hard poly) .. have you seen how litle rubber there is in a tvr bush? it's virtually rock solid 
However the std bush is a typical bonded rubber arrangement and desn't take shearing forces well before ripping itself apart .. the poly bushes with their rotating glacier bearing sleves are a much beter long-term bet.
Diffusers : are pretty much a waste of time on the rear of a TVR .. they aren't flat botomed cars so there's significant aero lift under the body anyway i would imagine .. we have the std T350 rear difuser thingie on the rear of our race T350 and it didnt fall off at the last race despite it only having 4 of its 10 retaining bolts in place .. not much downforce being generated there then!
However the std bush is a typical bonded rubber arrangement and desn't take shearing forces well before ripping itself apart .. the poly bushes with their rotating glacier bearing sleves are a much beter long-term bet.Diffusers : are pretty much a waste of time on the rear of a TVR .. they aren't flat botomed cars so there's significant aero lift under the body anyway i would imagine .. we have the std T350 rear difuser thingie on the rear of our race T350 and it didnt fall off at the last race despite it only having 4 of its 10 retaining bolts in place .. not much downforce being generated there then!
The underside of a Griffith could be smoothed out by lightweight undertrays and the exhaust at the rear forms a natural venturi so a simple diffuser placed between the tailpipes could create significant down force at speed IMO. It could also be more than adequately secured by four bolts - why use more than you need?
OscarT
OscarT
Edited by OscarT on Monday 29th October 09:19
OscarT said:
The underside of a Griffith could be smoothed out by lightweight undertrays and the exhaust at the rear forms a natural venturi so a simple diffuser placed between the tailpipes could create significant down force at speed IMO. It could also be more than adequately secured by four bolts - why use more than you need?
OscarT
There are two basic approaches to underbody aerodynamics. The original approach, which is utterly safe and reliable, is to block the front off with an air dam to reduce the air flow under the car and hence reduce pressure, lift and drag. The alternative approach, which is a gamble, is to streamline the underside of the car and profile it carefully so you get a venturi effect. For this to work you need lots of air going through it which means taking the air dam off the front, and you also need to get the shape exactly right (bear in mind air comes in from the sides as well as the front; this is hard to get right). To get substantial benefits you need to put the exit of the venturi in a low pressure zone such as the underside of a wing. The bad news is that this can easily go wrong, and even if you get everything right it's horribly sensitive to ride height and rake and may stop working for the silliest of reasons mid-bend. It's a gamble. If you're tackling this as a DIY job without any formal aerodynamic training then your chances of getting it working are slim. In any case, without a wing to give you the low pressure exit the gains will be minimal. As a separate problem, if you remove the exhaust and transmission from the air flow under the car you will greatly exacerbate the transmission cooling problems.OscarT
trackcar said:
the std bush is a typical bonded rubber arrangement and doesn't take shearing forces well before ripping itself apart .. the poly bushes with their rotating glacier bearing sleves are a much beter long-term bet.
Hi CliveThe man talks sense. Mine were how shall we say ... fecked.
Resulting problem is that the wishbones can actually move about 10mm front to rear which can make for an interesting handling motor, with variable geometry at every roundabout
These were sold to me as a "fit and forget" product. I'll believe it when I see it, but as Joolz says, the glacial bearings must go a long way to helping the longevity of the bushes over standard.
Good thing is any resultant failings should not be as bad as the origonals as they take up the slack between the wishbone and the mounting flange (fancy being allowed the word flange on a public forum, before the watershed)
I say go for it if you like precise handling (needless to say I do)
These, decent shocks, increased negative camber and 888's and you'll have a remarkably improved ride over standard.
2nd best mod after increasing your driving ability (goes for us all)
Then worry about spending $$$$$ on more power if 3G cornering doesn't float your boat sufficiently, or shiny bits to give you something to do instead of driving it
Cheers
Moose
Hi Andy 
will be investing in these over the winter, hopefully Joo has `em in stock, had the shocks replaced last spring, so a set of these will finish it off nicely.
Rear difuser, I don`t think its necessary, the car looks great as it is, and would take a shed load of dosh to make, and develop, and to my mind would need testing in a wind tunnel to prove that it does work, surely a rear spoiler thingy on the boot lid would give more downforce if it was needed?
will be investing in these over the winter, hopefully Joo has `em in stock, had the shocks replaced last spring, so a set of these will finish it off nicely.Rear difuser, I don`t think its necessary, the car looks great as it is, and would take a shed load of dosh to make, and develop, and to my mind would need testing in a wind tunnel to prove that it does work, surely a rear spoiler thingy on the boot lid would give more downforce if it was needed?
Are we talking about the powerflex ones with the glacier bearing in them?
If so , I have had them on for a few years.
As stated they are easy to fit once the standard ones are out.
In fact mine are about to be checked when I strip the chassis.
Think I fitted about the second set to a griff.
If so , I have had them on for a few years.
As stated they are easy to fit once the standard ones are out.
In fact mine are about to be checked when I strip the chassis.
Think I fitted about the second set to a griff.
Clivef
Wash your mouth out - a spoiler on the bootlid would be totally naff.
A discrete carbon fibre (or you can have one in SS if you insist) diffuser would do the job better and look like it belonged - get down on your knees behind your Griffith and look at the nicely concave underside between the exhaust pipes - that's where to fit it.
It doesn't have to be huge - just properly designed - I agree a wind tunnel would be necessary though - a nearby friendly University Aeronautical Department should have one.
If some of you 'professional' guys don't do it soon I'll just have to do it myself.
OscarT
Wash your mouth out - a spoiler on the bootlid would be totally naff.
A discrete carbon fibre (or you can have one in SS if you insist) diffuser would do the job better and look like it belonged - get down on your knees behind your Griffith and look at the nicely concave underside between the exhaust pipes - that's where to fit it.
It doesn't have to be huge - just properly designed - I agree a wind tunnel would be necessary though - a nearby friendly University Aeronautical Department should have one.
If some of you 'professional' guys don't do it soon I'll just have to do it myself.
OscarT
OscarT said:
A discrete carbon fibre (or you can have one in SS if you insist) diffuser would do the job better
Which job? If you're only after something cosmetic or just want to add some ballast to the back end that's easy enough to do, but if you intend it to anything useful to the aerodynamics I think you'll find that's quite a hard trick to pull off.its already been done, see here, and its been tested in various CAD programs including wind simulators and road/race cars.
http://www.tvrmonster.co.uk/newsaero.html
also my boot spoilers works as can be seen here via the cement dust trail.
I think it looks OK?
http://www.tvrmonster.co.uk/newsaero.html
also my boot spoilers works as can be seen here via the cement dust trail.
I think it looks OK?
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