Convert PAS to Non-Pas - What's needed?
Convert PAS to Non-Pas - What's needed?
Author
Discussion

CrunkleFloop

Original Poster:

780 posts

262 months

Wednesday 13th July 2022
quotequote all
Hi all!

I finally feel I'm a proper PH member as I've acquired my first TVR.

The power steering is very noisy and I would like to replace it with a Non-PAS system as I'm a stickler for weight saving and minimalism.

Is anything needed other than removing the PAS gubbins, getting a shorter Serp belt, sourcing a Non-PAS rack and bolting that in?

Also, am I correct in thinking that both types of steering racks are TVR bespoke items and that there's no off the shelf alternative?

Thanks in advance.

SlimJim16v

6,937 posts

160 months

Wednesday 13th July 2022
quotequote all
CrunkleFloop said:
Hi all!
Is anything needed other than removing the PAS gubbins, getting a shorter Serp belt, sourcing a Non-PAS rack and bolting that in?
That's usually how it works. I've read that you can also strip PAS off the rack, grease all moving parts and you now have a manual rack.

Adrian@

4,420 posts

299 months

Wednesday 13th July 2022
quotequote all
The intermediate shaft and I believe UJ's (or one UJ) is different. A@

phillpot

17,392 posts

200 months

Wednesday 13th July 2022
quotequote all


If fitting a manual rack you will also need a longer splined steering shaft

CrunkleFloop

Original Poster:

780 posts

262 months

Thursday 14th July 2022
quotequote all
Thanks for the help chaps.

Belle427

10,793 posts

250 months

Thursday 14th July 2022
quotequote all
Sourcing a non pas rack may be your issue, some have them left over from a conversion but most are at a breakers and priced accordingly.
Maybe someone who wants pas can offer up a swap over.

Harry Flatters

180 posts

275 months

Thursday 14th July 2022
quotequote all
Alternatively, you could keep PAS but go electric.

I have the Impreza MkI rack in mine, powered by an electric pump out of an Astra. Not the most sophisticated system (not speed sensitive), but works well and would be cheaper than trying to 'un-PAS' yours.

CrunkleFloop

Original Poster:

780 posts

262 months

Thursday 14th July 2022
quotequote all
Harry Flatters said:
Alternatively, you could keep PAS but go electric.

I have the Impreza MkI rack in mine, powered by an electric pump out of an Astra. Not the most sophisticated system (not speed sensitive), but works well and would be cheaper than trying to 'un-PAS' yours.
That's certainly something I could consider. What was involved in the conversion?


Belle427

10,793 posts

250 months

Friday 15th July 2022
quotequote all
CrunkleFloop said:
Harry Flatters said:
Alternatively, you could keep PAS but go electric.

I have the Impreza MkI rack in mine, powered by an electric pump out of an Astra. Not the most sophisticated system (not speed sensitive), but works well and would be cheaper than trying to 'un-PAS' yours.
That's certainly something I could consider. What was involved in the conversion?
There is a very long thread on here documenting it, it’s a pita to be honest and you need a small amount of engineering skill to do it and a lot of patience.
Having done it once I wouldn’t do it again, I’d stick to non pas.


Harry Flatters

180 posts

275 months

Friday 15th July 2022
quotequote all
Belle427 said:
There is a very long thread on here documenting it, it’s a pita to be honest and you need a small amount of engineering skill to do it and a lot of patience.
Having done it once I wouldn’t do it again, I’d stick to non pas.
I assume this is the thread here

I'm afraid that I cannot attest to the level of arse pain involved in the conversion as mine was done by the previous owner. All I can say is that it's not a bad solution to the problem.

One tip though - I've not read all 43 pages to see if this is recognised, but the electric PAS pump can draw quite high loads (70-80 amps, intermittently) and I managed to 'fry' my 100amp rated alternator. Generally, this should be sufficient to power all the systems including the PAS, but if the alternator is not up to spec and combined with high under-bonnet temps on a very hot day which brings the fans in more often, then like mine, you might find it expiring. I have now installed a 120amp unit and, touch wood, all seems OK.

CrunkleFloop

Original Poster:

780 posts

262 months

Friday 15th July 2022
quotequote all
I started to read the 43 page thread and ended up more confused as the suggested parts seemed to keep changing.

I think I'll go down the original plan of Non-PAS as I need to beef up my upper body and like the simplicity.

Panamax

6,686 posts

51 months

Friday 15th July 2022
quotequote all
CrunkleFloop said:
I think I'll go down the original plan of Non-PAS as I need to beef up my upper body and like the simplicity.
SC Power show Caster spacers on their web site to reduce steering loads for those without power steering or changing wheel sizes.
www.sc-power.co.uk

CrunkleFloop

Original Poster:

780 posts

262 months

Friday 15th July 2022
quotequote all
Panamax said:
SC Power show Caster spacers on their web site to reduce steering loads for those without power steering or changing wheel sizes.
www.sc-power.co.uk
Thanks, even better!

I'm pretty convinced now that Non-PAS is what I need. Just need to find someone willing to swap!

CrunkleFloop

Original Poster:

780 posts

262 months

Friday 15th July 2022
quotequote all
Alternatively there's the option of de-powering my existing rack by stripping it down and removing the seals, packing it with grease etc as the MX5 boys do.

That would leave me with a quicker rack than the TVR manual rack and I could retain all my current shafts and U/Js etc.

sixor8

7,072 posts

285 months

Friday 15th July 2022
quotequote all
The castor spacers are stated as unavailable (scroll to the bottom):

http://www.sc-power.co.uk/pages/sc-power-wishbones...

Should be reasonably easy to duplicate maybe?

NicBowman

785 posts

255 months

Friday 15th July 2022
quotequote all
Seriously, fix the power steering and keep it. I have owned a Griff without, plus several others. But, when driving ps vs non ps back to back it’s a no brainer. My current Griff has ps, Ps cars are nicer to drive. Plus, they sell better on the second hand market.

There talk of ps not being so 'direct' at speed, but I don’t see it.

The weight saving will be minimal. Don’t do it!

My thoughts.

Nic

wuckfitracing

990 posts

160 months

Saturday 16th July 2022
quotequote all
Have you tried driving a non Pas Chim ?

andrew_r

234 posts

122 months

Saturday 16th July 2022
quotequote all
Each to their own.

I test drove quite a few Chimaeras, both with and without PS. I preferred non-PS. The PS steering felt too light and didn’t have much feel. Non-PS is heavier at parking speed, but after 5mph it’s perfect for me, both for road and track.

I have 8 inch wide wheels on the front with 225 tyres, and the Non-PS is fine, but it’s all down to personal taste. Others may prefer a slightly quicker and lighter feeling rack.

Andrew.

Classic Chim

12,424 posts

166 months

Saturday 16th July 2022
quotequote all
Many owners seem to dial out the natural body rake with different tyre/ wheel / suspension settings which does make steering seem more vague on some PS models.
It’s best to leave that rake well alone if you want the steering to be as precise as it actually is.
I drive many cars and PS is always more manageable at speed and always preferred if the car gets out of shape ( easier to hold onto).
Tyre pressures just 2psi to high can effect steering quite drastically. Try running about on 30 psi all round and the car will feel like your on a skid pan. thumbup

phazed

22,288 posts

221 months

Saturday 16th July 2022
quotequote all
^^^^^^^

I would never, ever consider a car without power steering. I have had both and the car with power steering is so much better to drive.

You have it fitted, just get it fixed or replace the hydraulic pump with an electric pump.

With regards to the alternator blowing or under bonnet heat, I used mine for dozens of Track Days and never had a problem.

I also converted my first non-PAS car to the Subaru rack
as well as my last car, converting from TVR power steering to the Subaru rack.

Again, don’t do it! It is so ungainly at low speed and as said above, corrections at speed are almost impossible if you lose the back end is the steering is far too heavy for instant correction.