Impreza steering rack mod
Discussion
Gathered parts to convert my 1996 chim 500 to power steering, TVR bottle, pump, hoses, and longer steering arm with UJ on each end, also a classic impreza rack and Impreza steering arm with UJs. Removed my standard rack, things noticed so far, impreza rack is longer, so the threads will need to be cut/ died back to get the correct overall length, the impreza Track rod ends seem to have a slightly different taper to that in the hubs, the Impreza mounts are square, so to get the centre of the rack to be in the same position as the original TVR rack, seems I need to fettle the chassis brackets to accomadate the square Impreza rack rubbers, has anyone else done this, or have I missed something?, will also remove pinion cover and rotate for trial fit before fetting chassis rack mounts
Cheers Steve
Cheers Steve
I fitted some 5mm or thereabouts spacer plates under the rack mounting points and used U bolts and poly rubber type mounts.
These picked up the original mounting points without alteration to the original chassis plates.
I had to cut a tiny nick into one of the gusset plates on the offside to clear the rack iirc.
These picked up the original mounting points without alteration to the original chassis plates.
I had to cut a tiny nick into one of the gusset plates on the offside to clear the rack iirc.
Just had another look at TVR rack, I assumed the mounting lugs were on the rack centreline as the chassis has a curved cut out between the bolt holes, but no the mounting is at the edge so just measured both rack diameters/ and square on impreza rack, they are very close, so I now assume that I need to fit a plate between the 2 bolt holes then sandwich the impreza rack Between plate and bracket. Will measure more accurately and see how thick the plate can be, also need spacers if I iuse the Impreza brackets/ rubbers
Would anybody have a pair of the rack to chassis mounting brackets spare? Long term I'd like to make some that fit "properly" and don't need spacers but originals would be good for initial set up.
The pipe connections to the rack, I'd guess the smaller one is pressure and the other return?
Are the threads something "normal" ? BSP, NPT or similar. I'm thinking do it all in flexible to the pump rather than the rigid/flexible pipes Subaru use.
Any idea what kind of pressure there is in the system when running, I'm looking at how to modify the two pipes on the rack when the pinion housing bit is turned

Thanks in advance for any advise or help.
phillpot said:
Would anybody have a pair of the rack to chassis mounting brackets spare? Long term I'd like to make some that fit "properly" and don't need spacers but originals would be good for initial set up.
The pipe connections to the rack, I'd guess the smaller one is pressure and the other return?
Are the threads something "normal" ? BSP, NPT or similar. I'm thinking do it all in flexible to the pump rather than the rigid/flexible pipes Subaru use.
Any idea what kind of pressure there is in the system when running, I'm looking at how to modify the two pipes on the rack when the pinion housing bit is turned
Thanks in advance for any advise or help.
There £58 a set so doubt any will be spareThe pipe connections to the rack, I'd guess the smaller one is pressure and the other return?
Are the threads something "normal" ? BSP, NPT or similar. I'm thinking do it all in flexible to the pump rather than the rigid/flexible pipes Subaru use.
Any idea what kind of pressure there is in the system when running, I'm looking at how to modify the two pipes on the rack when the pinion housing bit is turned

Thanks in advance for any advise or help.
WinstonWolf said:
It's very close to being a bolt on kit now, just the ball joints and splined shaft to find in a catalogue 
Is it better to have the rack refurbished and does it have a different feel once fitted ? Ive heard the TVR rack is quicker .
Do you have a different steering feel ?
SILICONEKID345HP said:
Is it better to have the rack refurbished and does it have a different feel once fitted ? Ive heard the TVR rack is quicker .
Do you have a different steering feel ?
You could have it refurbed, probably around £100+.Do you have a different steering feel ?
I reckon it feels very similar and has the same gearing.
SILICONEKID345HP said:
WinstonWolf said:
It's very close to being a bolt on kit now, just the ball joints and splined shaft to find in a catalogue 
Is it better to have the rack refurbished and does it have a different feel once fitted ? Ive heard the TVR rack is quicker .
Do you have a different steering feel ?
Hi All, current parts SO FAR
2 off plates that fit between rack mounts and chassis mounts 120mm long, 25mm wide, 5mm thick stainless, with 2 off M10 holes 80mm pitch. 4 off M8 bore, OD 20mm, length 25.4mm stainless spacers to fit between impreza brackets and chassis mounts, 4 off M8 hez head bolts 50mm long.
2 off new power steering pipes that are required due to rotating the rack pinion 180 degrees, so 2 off 1/4 OD pipes and 4 off M12 * 1mm pitch male ends. New impreza mount rubbers, note the impreza brackets can be 25mm or 30mm so measure before purchasing new mounting rubbers, will also affect the width of the 120mm long plates, my brackets were 30mm wide. Ford Fiesta 1.4 2008-2013 steering arm uj, this does not need a spline, just 2 flats on 18mm diameter, so will hopefully be an easy job, having my steering pinion machined to suit. Metric die M14 * 1.5mm pitch to die down the steering arms to allow scooby track rods ends to wind in further.
cheers
Steve
2 off plates that fit between rack mounts and chassis mounts 120mm long, 25mm wide, 5mm thick stainless, with 2 off M10 holes 80mm pitch. 4 off M8 bore, OD 20mm, length 25.4mm stainless spacers to fit between impreza brackets and chassis mounts, 4 off M8 hez head bolts 50mm long.
2 off new power steering pipes that are required due to rotating the rack pinion 180 degrees, so 2 off 1/4 OD pipes and 4 off M12 * 1mm pitch male ends. New impreza mount rubbers, note the impreza brackets can be 25mm or 30mm so measure before purchasing new mounting rubbers, will also affect the width of the 120mm long plates, my brackets were 30mm wide. Ford Fiesta 1.4 2008-2013 steering arm uj, this does not need a spline, just 2 flats on 18mm diameter, so will hopefully be an easy job, having my steering pinion machined to suit. Metric die M14 * 1.5mm pitch to die down the steering arms to allow scooby track rods ends to wind in further.
cheers
Steve
you can rebend the hard lines from pinion to rack, but i just had them remade by the local hydraulic chaps.
easiest option on the pinion fluid connectors is to convert to an6 or something with adaptors, then fitting the pipes is a doddle and you can fit the pump wherever suits.
the main reason to modify the pinion is that when a uj is fitted, it fouls the chassis, so the pinionneeds shortening, which then means it also needs to be remachined to take a uj. if you can roll a spline, its not difficult, but it was easier for me to machine a hex than to roll a spline, though I'm sure one could be done
you could of course use a weld on uj to the pinion, but that would be cheating!
if you've already a rover pump, that works fine with the scooby rack.
when you machine flats for the uj, leave them oversize and trial fit often. the pressed ford uj is a bit variable in its dimensions. use an oversize hardeneed bolt to tighten the uj, and make sure that the bolt fits tight against the pinion shaft to prevent it moving 9i think i recall filing a groove in the pinion to ensure it was a really snug fit and a m10 bolt rather than m8)
HTH
easiest option on the pinion fluid connectors is to convert to an6 or something with adaptors, then fitting the pipes is a doddle and you can fit the pump wherever suits.
the main reason to modify the pinion is that when a uj is fitted, it fouls the chassis, so the pinionneeds shortening, which then means it also needs to be remachined to take a uj. if you can roll a spline, its not difficult, but it was easier for me to machine a hex than to roll a spline, though I'm sure one could be done
you could of course use a weld on uj to the pinion, but that would be cheating!
if you've already a rover pump, that works fine with the scooby rack.
when you machine flats for the uj, leave them oversize and trial fit often. the pressed ford uj is a bit variable in its dimensions. use an oversize hardeneed bolt to tighten the uj, and make sure that the bolt fits tight against the pinion shaft to prevent it moving 9i think i recall filing a groove in the pinion to ensure it was a really snug fit and a m10 bolt rather than m8)
HTH
Edited by SteveSPG on Wednesday 21st January 20:26
CHIMV8 said:
You will need the uj from a Ford Ka
This is the fitting i got from Andrew Page suppliers

This is the end thats fits onto the TVR round pinion bar

This is the end that fits onto the Scooby Rack stub pinion

where there are angled flats on the end if the uj, (your pic 2) you may need to grind these a little more to give clearance to the chassis This is the fitting i got from Andrew Page suppliers

This is the end thats fits onto the TVR round pinion bar

This is the end that fits onto the Scooby Rack stub pinion

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