Power Steering on a TVR V8S
Discussion
I've managed to get hold of a Chimeara power steering rack to see if it would fit on a V8S.
It does fit.
BUT now I have examined it in detail there are some slight geometry differences.
The main 'core' of the rack (the bit that moves) is slightly shorter (15-20mm approx) each side than the manual rack I've taken off my car.
Here's some pics to try and help clarify this.
On this picture the right hand black line is drawn approximately on the centre line of the inner ball joint of the top (Manual) steering rack.
At the bottom you can see on the power steering rack that the inner balljoint is slightly further inboard.
Here's a zoomed out shot - the camera makes it look out of line but it is in line.
The question is how much of an issue will this be?
Will I get major bump steer and other big issues or just some slight issues?
In every other respect the rack will fit.
All advice appreciated.
Chris
It does fit.
BUT now I have examined it in detail there are some slight geometry differences.
The main 'core' of the rack (the bit that moves) is slightly shorter (15-20mm approx) each side than the manual rack I've taken off my car.
Here's some pics to try and help clarify this.
On this picture the right hand black line is drawn approximately on the centre line of the inner ball joint of the top (Manual) steering rack.
At the bottom you can see on the power steering rack that the inner balljoint is slightly further inboard.
Here's a zoomed out shot - the camera makes it look out of line but it is in line.
The question is how much of an issue will this be?
Will I get major bump steer and other big issues or just some slight issues?
In every other respect the rack will fit.
All advice appreciated.
Chris
Chris...I've been looking at PAS conversions as well, but probably out of my price/determination range...found this on the net though and thought it might help..
Cheers
Anthony
http://kazbarngp4developments.co.uk/default.aspx
Cheers
Anthony
http://kazbarngp4developments.co.uk/default.aspx
Tant said:
Chris...I've been looking at PAS conversions as well, but probably out of my price/determination range...found this on the net though and thought it might help..
Cheers
Anthony
http://kazbarngp4developments.co.uk/default.aspx
WICKED!Cheers
Anthony
http://kazbarngp4developments.co.uk/default.aspx
I've emailed them, thanks for that.
Chris
Response from http://kazbarngp4developments.co.uk
Hi Chris
Thanks for your mail. The situation your in has cropped up before. You will require a longer rackbar to get the tie rod fixings extended at the distance you require. This for a one off, is going to get quite expensive. Just as an example, we had to cut 8 custom rackbars for a WRC team, the actual tooling cost for this ,was a cost to me of over £2500 just for the tooling, the there is the actual product cost itself. And for one offs, the investment usually prevents the project going any further.
I think the best solution for you in this instance is to keep your manual rack but integrate it with an electric column. We have fitted this system to many Escorts in UK rallying and it works very well. You have a speed sensor so you can adjust the weight of the steering to suit the different conditions and tracks etc..
For a fully working electric system, you will be looking at around the £800 mark.
I would like to help, and if you wanted to go down the route of a custom PAS unit, then of course we can do this for you. But i thought it best to let you know on the front end that this is quite an investment.
Kind regards
Barney
Hi Chris
Thanks for your mail. The situation your in has cropped up before. You will require a longer rackbar to get the tie rod fixings extended at the distance you require. This for a one off, is going to get quite expensive. Just as an example, we had to cut 8 custom rackbars for a WRC team, the actual tooling cost for this ,was a cost to me of over £2500 just for the tooling, the there is the actual product cost itself. And for one offs, the investment usually prevents the project going any further.
I think the best solution for you in this instance is to keep your manual rack but integrate it with an electric column. We have fitted this system to many Escorts in UK rallying and it works very well. You have a speed sensor so you can adjust the weight of the steering to suit the different conditions and tracks etc..
For a fully working electric system, you will be looking at around the £800 mark.
I would like to help, and if you wanted to go down the route of a custom PAS unit, then of course we can do this for you. But i thought it best to let you know on the front end that this is quite an investment.
Kind regards
Barney
350Matt said:
At 800 quid I'd be tempted to try the power rack you already have, as if you do get bump steer issues you can change the height of the rack to reduce the effect.
Is the rack the same overall length from ball joint to balljoint?
Google bump steer there's a few guides out there
Matt
Thanks Matt - £800 is a fair bit but the chim / griff racks are so rare now that they fetch big money on ebay - last time I saw one it went for £550, which would help very nicely towards an electric solution.Is the rack the same overall length from ball joint to balljoint?
Google bump steer there's a few guides out there
Matt
I fitted a Corsa electric system to my Tasmin. Total cost of parts £200 inc manual speed adjuster.
I fitted this myself. Ideally your need a welder to make some custom brackets for fixing.
Car's not finished yet, so not tested, but people have got this system working on some of the Tuscan car's, and as said the same system is used in a lot of rally cars.
I fitted this myself. Ideally your need a welder to make some custom brackets for fixing.
Car's not finished yet, so not tested, but people have got this system working on some of the Tuscan car's, and as said the same system is used in a lot of rally cars.
Hi,
Bump steer is primarily effected by the angle of the track rod to the horizontal when viewed from the front, so moving the balljoint in 15 to 20 mm will make negligible difference to this angle, and hence negligible difference to the bump steer. The change in track rod length will change the bumpsteer a bit at the extremes of travel (may be better, may be worse!) but again for the amount of change in balljoint position you are talking about the effect is unlikely to be noticable.
What is much more significant is whether the PAS rack has the same stroke as the manual one, otherwise your turning circle will be considerably different.
Also, you should note that a PAS rack is considerably more compliant along the rack axis than a manual rack. This will have a much greater effect upon the cars steering feel than the position of the ball joint laterally.
Similarly, have you compared the gear ratios of the two racks (mm of rack stroke / turn of the pinion shaft)?
Electric PAS systems have issues with feedback (or lack of it) due to poor reverse efficiency of the motor drive, most vehicle manufacturers have struggle to get these to work well, so I would be cautious about fitting an after market item.
Steve
Bump steer is primarily effected by the angle of the track rod to the horizontal when viewed from the front, so moving the balljoint in 15 to 20 mm will make negligible difference to this angle, and hence negligible difference to the bump steer. The change in track rod length will change the bumpsteer a bit at the extremes of travel (may be better, may be worse!) but again for the amount of change in balljoint position you are talking about the effect is unlikely to be noticable.
What is much more significant is whether the PAS rack has the same stroke as the manual one, otherwise your turning circle will be considerably different.
Also, you should note that a PAS rack is considerably more compliant along the rack axis than a manual rack. This will have a much greater effect upon the cars steering feel than the position of the ball joint laterally.
Similarly, have you compared the gear ratios of the two racks (mm of rack stroke / turn of the pinion shaft)?
Electric PAS systems have issues with feedback (or lack of it) due to poor reverse efficiency of the motor drive, most vehicle manufacturers have struggle to get these to work well, so I would be cautious about fitting an after market item.
Steve
Well I have decided I've got the elusive rack, I only need to source hoses, pump etc to try it - I've come this far it would be rude not to.
Plus if it does have some horrible unworkable issues I'll have a complete power steering kit for a Chim / Griff pre serp to sell, I'll probably be able to retire on the proceeds
Plus if it does have some horrible unworkable issues I'll have a complete power steering kit for a Chim / Griff pre serp to sell, I'll probably be able to retire on the proceeds
Hi,
Just a cautionary note - the rack you saw on ebay might have been the one which I bought which is still lying on the rack as I type. I was on the understanding that it was working when it came off the car but just thought I'd get it checked before fitting it... BONG!
Although off a late car the rack had had serious problems and been bodged on more than one occasion - result, several new parts will need to be specially machined at a cost of £350 probably more now.
Sales@autopost.demon.co.uk is retailing PAS pumps at £500 so like you I've got the point of just giving up and abandoning the idea. Maybe the electric option adjusted for assistance only while parking might be best.
Good luck and let us know how you get on and views on whichever route you decide to go.
Just a cautionary note - the rack you saw on ebay might have been the one which I bought which is still lying on the rack as I type. I was on the understanding that it was working when it came off the car but just thought I'd get it checked before fitting it... BONG!
Although off a late car the rack had had serious problems and been bodged on more than one occasion - result, several new parts will need to be specially machined at a cost of £350 probably more now.
Sales@autopost.demon.co.uk is retailing PAS pumps at £500 so like you I've got the point of just giving up and abandoning the idea. Maybe the electric option adjusted for assistance only while parking might be best.
Good luck and let us know how you get on and views on whichever route you decide to go.
Not quite sure what you mean about the rack but I bought it of a guy in Birmingham it came from his Chimeara which he was breaking due to a blown engine (criminal I know).
Its going to be a range rover pump for me - £40 from the breakers otherwise it just isn't financially viable. The hoses will cost a few quid aswell.
Chris
Its going to be a range rover pump for me - £40 from the breakers otherwise it just isn't financially viable. The hoses will cost a few quid aswell.
Chris
Barkychoc said:
Response from http://kazbarngp4developments.co.uk
...
I think the best solution for you in this instance is to keep your manual rack but integrate it with an electric column. We have fitted this system to many Escorts in UK rallying and it works very well. You have a speed sensor so you can adjust the weight of the steering to suit the different conditions and tracks etc..
For a fully working electric system, you will be looking at around the £800 mark.
I would like to help, and if you wanted to go down the route of a custom PAS unit, then of course we can do this for you. But i thought it best to let you know on the front end that this is quite an investment.
The electric one from Racing Green is over £1500 fully fitted, so maybe 800 is not so bad. Suppose it depends quite a bit on who's doing all the work to get the dash out and in, installing bracing and mounts, etc....
I think the best solution for you in this instance is to keep your manual rack but integrate it with an electric column. We have fitted this system to many Escorts in UK rallying and it works very well. You have a speed sensor so you can adjust the weight of the steering to suit the different conditions and tracks etc..
For a fully working electric system, you will be looking at around the £800 mark.
I would like to help, and if you wanted to go down the route of a custom PAS unit, then of course we can do this for you. But i thought it best to let you know on the front end that this is quite an investment.
depends on you current set-up,
But it took about 3 days to get the Electric PAS installed in the Tasmin. and that was without fitting the ignition key / stearing lock. so you may want to check on this, as most people use them in race / Rally cars, where this is not a problem.
Parts will range from £200-£400 (inc. manual adjuster) S/H or £1500 new.
I may be able to get you the parts for £200 if your interested in trying a self install.
But it took about 3 days to get the Electric PAS installed in the Tasmin. and that was without fitting the ignition key / stearing lock. so you may want to check on this, as most people use them in race / Rally cars, where this is not a problem.
Parts will range from £200-£400 (inc. manual adjuster) S/H or £1500 new.
I may be able to get you the parts for £200 if your interested in trying a self install.
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