Power or no power is the question
Discussion
phazed said:
My old chim didn't have PS then I fitted a PS rack and kit, what a difference.
I would NEVER buy one without, especially with more modern grippier rubber.
^^^^THIS^^^^I would NEVER buy one without, especially with more modern grippier rubber.
TVRJAS said:
I've had two TVR's without,and the one I have now has it.
If I was in the market for another TVR I would by pass the adds that didn't have it. It's all down to your own personal preference but not having it on the V8s didn't stop me enjoying the car.
Crossing over to the latest Chimaera that has it I much prefer the driving benefit of it for those moments and times when in close tight spaces. You can call me a wimp if you like words don't bother me
^^^^AND THIS^^^^If I was in the market for another TVR I would by pass the adds that didn't have it. It's all down to your own personal preference but not having it on the V8s didn't stop me enjoying the car.
Crossing over to the latest Chimaera that has it I much prefer the driving benefit of it for those moments and times when in close tight spaces. You can call me a wimp if you like words don't bother me
I would also add this.....
In there great debate between the power and unassisted racks people always seem to focus on the low speed and parking advantage of a Chimaera fitted with power steering, this in my opinion is the lesser of the two clear advantages power steering gives the car.
What is often ignored or more likely not understood is the unassisted rack is a lazy 2.5 turns lock to lock, wheres the power rack is a much sharper 2.2 turns lock to lock.
This seemingly small difference in gearing actually makes a big difference at the wheel!
Any minor dulling of steering feel that may or may not be a consequence of going hydraulic power steering (debatable in itself) is completely negated by the vastly improved feel you get from the sharper 2.2 turns lock to lock rack.
The only reason TVR chose 2.5 turns lock to lock for the unassisted rack is because the car would be undrivable if it was any higher geared, 2.5 turns lock to lock most certainly isn't the optimum gearing for feel & steering response on such a car.
Move to a power rack and the mechanical hydraulic advantage immediately gave TVR the opportunity to choose the optimum geared steering for the car.
In summary the unassisted 2.5 turns lock to lock gearing is a compromise forced on the car because the steering would simply be too heavy if they geared at at the optimum 2.2 turns lock to lock.
2.2 turns lock to lock is actually a very fast rack for a road car, the surprising thing is that TVR managed to use this gearing without the steering feeling twitchy on the road at all, this was quite a trick to pull off and credit to TVR for achieving it especially when you look at the limitations imposed by the adapted Sierra McPherson strut front uprights.
To my mind the 2.2 turns lock to lock suits the character of the car perfectly, it really does give delicious feel and controllability absent in the slow whited manual rack.
Saying that the best steering feel I've ever experienced on a road car was on a Ferrari 458 Italia which is just 2 turns lock to lock, the steering on the 458 is nothing short of amazing on the track but somehow Ferrari managed to make it totally controllable on the road too.
Ferrari could never offer such wonderfully sharp, direct & communicative 2 turns lock to lock steering rack without the help of power steering, and even though electric power steering was available at the time the 458 was developed Ferrari chose an old school hydraulic system because quite simply it still gives unrivaled levels of feel.
So before you choose your Chimaera rack on the basis of low speed & parking effort, consider the benefits of feel & controllability the faster 2.2 turns lock to lock power rack gives.
The power rack really is the best of both worlds and having driven the manual rack car even if I never drove the car in town I would still not lose my wonderfully communicative 2.2 turns lock to lock power steering.
Extract from SteveSPG who supplied my kit of parts for the conversion.
As a very rough cost
Scooby Rack 50
Vectra Pump 50
Uj 20
Shaft 30
Hose 30
Elec parts 30
New tie rods and ends 50
New tie rod boots 20
Rack hard lines 30
Hydraulic fittings for rack and pump 3 off at 10 each Rack Mounts 20
BEWARE buying S/H TVR PS racks as most are knackered.
I bought one with pump and hoses for £650.00 from a well known PHer
but it had play and I gave it away!
As a very rough cost
Scooby Rack 50
Vectra Pump 50
Uj 20
Shaft 30
Hose 30
Elec parts 30
New tie rods and ends 50
New tie rod boots 20
Rack hard lines 30
Hydraulic fittings for rack and pump 3 off at 10 each Rack Mounts 20
BEWARE buying S/H TVR PS racks as most are knackered.
I bought one with pump and hoses for £650.00 from a well known PHer
but it had play and I gave it away!bababoom said:
Is SteveSPG his user name? I did a search but nothing came up with that name.
Doh!http://www.pistonheads.com/gassing/profile.asp?mem...
TV8 said:
..... but it is too light at speed compared with the non powered in my opinion.
I agree with that though overall I prefer it because it makes low speed and parking so much easier.Is there anyway that the output pressure of the Land Rover sourced pump could be reduced to 'stiffen up' the feel a little? There must be some form of by-pass valve in the pump to give a constant pressure regardless of engine revs. Surely all you would need is a valve that blows off sooner?
ChimpOnGas said:
What is often ignored or more likely not understood is the unassisted rack is a lazy 2.5 turns lock to lock, wheres the power rack is a much sharper 2.2 turns lock to lock.
This seemingly small difference in gearing actually makes a big difference at the wheel!
...
2.2 turns lock to lock is actually a very fast rack for a road car, the surprising thing is that TVR managed to use this gearing without the steering feeling twitchy on the road at all, this was quite a trick to pull off and credit to TVR for achieving it especially when you look at the limitations imposed by the adapted Sierra McPherson strut front uprights.
To my mind the 2.2 turns lock to lock suits the character of the car perfectly, it really does give delicious feel and controllability absent in the slow witted manual rack.
^^^ hits the nail on the head for me.This seemingly small difference in gearing actually makes a big difference at the wheel!
...
2.2 turns lock to lock is actually a very fast rack for a road car, the surprising thing is that TVR managed to use this gearing without the steering feeling twitchy on the road at all, this was quite a trick to pull off and credit to TVR for achieving it especially when you look at the limitations imposed by the adapted Sierra McPherson strut front uprights.
To my mind the 2.2 turns lock to lock suits the character of the car perfectly, it really does give delicious feel and controllability absent in the slow witted manual rack.
The speed of the rack is probably the most outstanding factor for me in terms of the handling and nimbleness of the car, and still delights me after 3 years of ownership...
phazed said:
Extract from SteveSPG who supplied my kit of parts for the conversion.
As a very rough cost
Scooby Rack 50
Vectra Pump 50
Uj 20
Shaft 30
Hose 30
Elec parts 30
New tie rods and ends 50
New tie rod boots 20
Rack hard lines 30
Hydraulic fittings for rack and pump 3 off at 10 each Rack Mounts 20
BEWARE buying S/H TVR PS racks as most are knackered.
I bought one with pump and hoses for £650.00 from a well known PHer but it had play and I gave it away!
Is there a thread or web page link to show this conversion by any chance? And a list of the actual part numbers?As a very rough cost
Scooby Rack 50
Vectra Pump 50
Uj 20
Shaft 30
Hose 30
Elec parts 30
New tie rods and ends 50
New tie rod boots 20
Rack hard lines 30
Hydraulic fittings for rack and pump 3 off at 10 each Rack Mounts 20
BEWARE buying S/H TVR PS racks as most are knackered.
I bought one with pump and hoses for £650.00 from a well known PHer
but it had play and I gave it away!Thanks
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