Impreza steering rack mod

Impreza steering rack mod

Author
Discussion

ChimpOnGas

8,474 posts

118 months

Tuesday 12th March
quotequote all
phazed said:
I had the standard hydraulic pump .

By doing away with the pump you get rid of the long hydraulic lines and the reservoir situated on the top of the engine. Take it all away, put a small electric pump with built-in reservoir in the corner of the engine bay with shorter hydraulic runs to the rack and you neaten up the engine bay considerably which is very pleasing to me!
Thanks Peter, the reason I ask is I have a little play in the straight ahead position on my original TVR power rack, the thing is while I believe there's some adjustment via shims I fear taking out the free play in the straight ahead will mean I encounter tight spots at the extremes of the rack (full lock both left & right) ?

I'm aware parts are no longer available for the TVR power rack which got me thinking an Impreza rack may be the answer scratchchin, however with my LPG vaporisor where you've mounted your electric PS pump I'm kinda stuck for where to put it. I guess an electric PS pump could go where my carbon canister once lived but on a Mk2 grill putting anything in the void between the rad and the grill means a rad out job if I ever suffer leaks or electrical issues at the pump... which is not ideal in my opinion frown

I do get and respect the neatness and reduction in hose length argument for using an electric pump, but in my case under bonnet real estate is limited so I can't help feeling I'd be better off sticking with the existing mechanical pump unless there's a good reason not to that I've missed?

The way I see it couple of longish lines and a reservoir clamped to the O/S of the plenum is exactly what I have now, and other than replacing TVR's dumb arsh leaking Jubilee clipped 'U' pipe with a proper crimped hose I really haven't had any issues with the 23 year old setup.

In summary and if you dont mind Peter, I have couple of quick questions for you:

Q1: Can you see any reason why the Subaru PS rack wont work on my Chimaera with my existing Land Rover pump?

Q2: Would you agree replacing my original TVR power rack with the an Impreza rack would be the most cost effective solution to the play that's developed in the straight ahead?

Many thanks in advance of any advise and support you can give me with this Peter.

Dave thumbup



phazed

17,353 posts

143 months

Tuesday 12th March
quotequote all
I see your point Dave.

My rack had a little straight ahead play which was irritating!

I sourced all in all 4 other used TVR PS racks and they all had play so a common thing.

The Subaru rack replacement is quite easy, no more than a days work if you have dove one before.

As to cost, I believe I said before that it can be done for about £200.

wuckfitracing

822 posts

82 months

Tuesday 12th March
quotequote all
ChimpOnGas said:
wuckfitracing said:
I did do a full write up with photos when I did mine last year, however my computer decided it was too large a file to send anyone and when I tried compressing it deleted it.
That's super annoying, you must have said a few choice words when the file deleted itself weeping

wuckfitracing said:
I may get round to writing it again as I still have all the photos.
I and many others would be massively grateful if you could write it all up again, unpicking this post isn't particularly easy.

Question: Why are people using an electric power steering pump? I assume because they are converting a manual rack car so a PS pump isn't present scratchchin
Yes I was more than upset at losing hours of typing and arranging photos in order. I also did a parts number list. All gone.
As you assumed I went from manual hairy chested steering to power steering hence no existing pump or pulleys/brackets to run a standard mechanical pump.

Belle427

3,541 posts

172 months

Tuesday 12th March
quotequote all
I reckon by the time im finished i will be in it for around £350 but some extra expense came from having to order new steering rods from Tvr parts to save any hassle of getting the wrong ones.
Thats converting from a manual rack.
Possibly just a ford item but i couldnt be bothered looking!
Im using a Vauxhall electric pump.

Classic Chim

8,788 posts

88 months

Tuesday 12th March
quotequote all
This mod being something that once the TVR racks are capput will be very important to keep cars safe so could really do with a detailed explanation and parts list etc and a hugely valuable one at that.

My PS rack has a little free play, i nipped up the grub screw a 1/4 of a turn which helped but sooner or later it will wear itself out.
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ChimpOnGas

8,474 posts

118 months

Tuesday 12th March
quotequote all
phazed said:
I see your point Dave.

My rack had a little straight ahead play which was irritating!

I sourced all in all 4 other used TVR PS racks and they all had play so a common thing.

The Subaru rack replacement is quite easy, no more than a days work if you have dove one before.

As to cost, I believe I said before that it can be done for about £200.
Many thanks Peter, I'm also finding my play irritating!

£200 seems very good value indeed, I now need to start accumulating the parts.


Classic Chim said:
My PS rack has a little free play, i nipped up the grub screw a 1/4 of a turn which helped but sooner or later it will wear itself out.
That's good to know Alun, I considered doing the same but was warned the rack may go tight at the extremes of lock, I'll try 1/4 of a turn and see how I get on scratchchin


Thanks all thumbup

Dave.

phazed

17,353 posts

143 months

Tuesday 12th March
quotequote all
From memory, my costs were as follows.

An eBay rack, £40
Silicon mounts were given to me but can't be that much. Probably about £20
Metal plates and bolts were from stock. Allow £10
Hoses, approx £120
Ebay Clio pump £25
Fuse holder cables and sundries £25
Ford Ka uj £25
I used a longer splined shaft that I had but it was cheap, Car Builder Solutions iirc, about £20

I transferred the track rods from the TVR PS rack.

So a total of £285 for me or thereabouts.


phazed

17,353 posts

143 months

Tuesday 12th March
quotequote all
BTW, I tried adjusting all the TVR racks and they all stiffened up!

ChimpOnGas

8,474 posts

118 months

Tuesday 12th March
quotequote all
phazed said:
BTW, I tried adjusting all the TVR racks and they all stiffened up!
Yup, that's me fear frown

Classic Chim

8,788 posts

88 months

Tuesday 12th March
quotequote all
I remember now I nipped mine up maybe 1/4 turn while it was off the car and found the steering tight so loosened it off to about 1/6 of a turn and it’s been ok since but frankly it’s never been perfect anyway.

I hurtled round Bedford autrodrome in the Phazed beast once, what a drive that was,, did I notice the steering,,, nope biglaugh
Only when Peter asked me did I even consider it much which sort of shows how similar it is to our racks but without that bit of play.
Excellent replacement for our racks when the time comes.

Belle427

3,541 posts

172 months

Friday 15th March
quotequote all
Can you guys that have done the conversion remember how you centralised the rack for final set up?
Is it just a case of marking the shaft with tippex and finding its central point, then fit the steering and track rods?
I measured disc to chassis with a spirit level before I stripped down so know roughly where the wheels should be just as a guide for re assembly.

phazed

17,353 posts

143 months

Friday 15th March
quotequote all
Remove the rubber boots from the ends of the rack and centre the rack by ensuring each end is even.
With the track rods on adjust the track rod ends so each wheel is approximately parallel with the rear wheels. This can easily be done with a couple of chalk lines or straight edges from the back wheels.
With everything connected you are good to go to your local Kwik Fit and have a cheap laser alignment. From memory, adjust to 10 minutes toe in.
Ensure they centre the steering wheel.

Belle427

3,541 posts

172 months

Friday 15th March
quotequote all
What would you consider to be a safe thread engagement for the track rod ends?
Initial set up shows me I've got about 15 mm engagement on the passenger side which is a bit less than I'd hope for.
Drivers side will need to be threaded some more and shortened.

Sardonicus

15,832 posts

160 months

Friday 15th March
quotequote all
Would not be happy with 15mm frown sorry , thats bare minimum for thread diameter calculation I would want 20mm minimum on a tie rod and even then you would need to keep tabs when toe is adjusted for example plus its a coarse thread also in steering arm terms , just my cents

Belle427

3,541 posts

172 months

Saturday 16th March
quotequote all
My only option really is to centre the rack and then wind it out an extra 5 mm or so on that side so it’s not quite centred in theory.
Can anyone see a problem in this as long as the wheels don’t foul anywhere and have their full travel?

Steve_D

12,142 posts

197 months

Saturday 16th March
quotequote all
Far better to fit a track rod extender on that side which may require the existing rod to be shortened a little.
You can then be happy with plenty of thread engagement.
Can't remember the thread size just now so this may not be the right thread.
https://www.ebay.co.uk/i/290909311531?chn=ps




Steve

Belle427

3,541 posts

172 months

Saturday 16th March
quotequote all
Steve_D said:
Far better to fit a track rod extender on that side which may require the existing rod to be shortened a little.
You can then be happy with plenty of thread engagement.
Can't remember the thread size just now so this may not be the right thread.
https://www.ebay.co.uk/i/290909311531?chn=ps




Steve
Thanks, that looks a good solution.

Xcore

254 posts

29 months

Saturday 16th March
quotequote all
Belle427 said:
My only option really is to centre the rack and then wind it out an extra 5 mm or so on that side so it’s not quite centred in theory.
Can anyone see a problem in this as long as the wheels don’t foul anywhere and have their full travel?
Would you lose 5mm or so of lock on one side? I may be completely wrong however

Belle427

3,541 posts

172 months

Saturday 16th March
quotequote all
Xcore said:
Belle427 said:
My only option really is to centre the rack and then wind it out an extra 5 mm or so on that side so it’s not quite centred in theory.
Can anyone see a problem in this as long as the wheels don’t foul anywhere and have their full travel?
Would you lose 5mm or so of lock on one side? I may be completely wrong however
I think so yes but thought it may not be too critical on full lock.

phazed

17,353 posts

143 months

Saturday 16th March
quotequote all
My tyres rub on full lock so you don’t need the full movement the rack can give you.