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is it possible to modify a steering rack
daniel mason - 18/7/13 at 09:24 PM

one thing ive noticed on the ADR is the lack of steering angle. 1/2 a turn of the steering wheel is full lock and turning circle horrendous!



as you can see the stops only allow a couple of inches of travel on the rack. is there any way to increase lock? as i dont think it will even get round a tight corner as it is!


mark chandler - 18/7/13 at 09:59 PM

It is possible yes, you need to strip it down and validate that by shortening the ends you still retain bearing surfaces and the toothed rack has enough teeth.

If that's all good chop an inch off each sleeve end and weld up.


daniel mason - 18/7/13 at 10:05 PM

what about the rack mounting clamps?
they are on special brackets welded to chassis but right on the outer edge of the rack body


Simon - 18/7/13 at 10:21 PM

You'll have to weld on new mountings.

I had my old Sierra rack shortened by Gerry Hawkridge for about £150

ATB

Simon


r1_pete - 19/7/13 at 06:50 AM

How about shortening the pivot point on the hub levers? looks do-able on your setup.


Mr Whippy - 19/7/13 at 06:55 AM

I'm going to be brutally honest, if you have to ask don't do it

It's a tricky job and safer if you just got a new rack that gave you enough travel without being altered. Something like a fiat cinquecento rack looks like it would fit there

I think you'll still have to get a new mounting plate burnt out to fit it, looks like aluminium


Mr Whippy - 19/7/13 at 06:57 AM

quote:
Originally posted by r1_pete
How about shortening the pivot point on the hub levers? looks do-able on your setup.


Sure looks like that's possible, interesting hub design

Steering will obviously get heavier though

[Edited on 19/7/13 by Mr Whippy]


MikeRJ - 19/7/13 at 07:23 AM

quote:
Originally posted by Mr Whippy
quote:
Originally posted by r1_pete
How about shortening the pivot point on the hub levers? looks do-able on your setup.


Sure looks like that's possible, interesting hub design

Steering will obviously get heavier though

[Edited on 19/7/13 by Mr Whippy]


And quicker. I suspect it will already be fairly quick.


Not Anumber - 19/7/13 at 08:06 AM

quote:
Originally posted by Simon
You'll have to weld on new mountings.

I had my old Sierra rack shortened by Gerry Hawkridge for about £150

ATB

Simon


How is old Gerry, ive not seen him for years since i built the Hawk AC ACE replica.


britishtrident - 19/7/13 at 11:37 AM

The rack looks do-able at a modest cost but you would need check out the required new mounting points on the chassis are viable.
If the new mounting points aren't suitable it might be possible to make an adaptor plate to fit between the rack and the chassis.


I would advise against shortening the steering arms as it is likely to have nasty implications for the steering geometry .


daniel mason - 19/7/13 at 11:55 AM

i think they were meaning re drill the bracket out and move the the pivot point closer to the wheel. shouldnt affect geometry but will make steering slightly heavier. but would mean the same amount of steering input would increase turn in a small amount. i may take it to procomp to set up and let them take a look! cheers guys


britishtrident - 19/7/13 at 04:36 PM

quote:
Originally posted by daniel mason
i think they were meaning re drill the bracket out and move the the pivot point closer to the wheel. shouldnt affect geometry but will make steering slightly heavier. but would mean the same amount of steering input would increase turn in a small amount. i may take it to procomp to set up and let them take a look! cheers guys


A wee bitty more complex than that it will effect the steering geometery as the fore-aft dosposition of either the rack-ends ends or outer the track rod ends has an effect on the toe accross the axle in turns.

[Edited on 19/7/13 by britishtrident]


Not Anumber - 19/7/13 at 04:57 PM

Whatever you end up doing to the steering rack dont let an amateur drill and tap the end. Having a track end detach is no fun at all.


britishtrident - 20/7/13 at 04:25 PM

I think the OP just intends to shorten the outer tube of the rack.


Uphill Racer - 28/7/13 at 11:19 PM

How tight a corner do you need to navigate, what are you using the car for?
BT is correct in that moving the outer track rod ends can affect Ackermann but done right reducing the length will “speed up” the rack, reducing the outer casing will give more travel but will need more steering input. If you are using the car for a different discipline you may want to alter Ackermann to suit.
Some racks are easier to alter than others, this is a late model Mini rack drastically modified.


Simon - 2/8/13 at 07:45 PM

quote:
Originally posted by Not Anumber
quote:
Originally posted by Simon
You'll have to weld on new mountings.

I had my old Sierra rack shortened by Gerry Hawkridge for about £150

ATB

Simon


How is old Gerry, ive not seen him for years since i built the Hawk AC ACE replica.


No idea, this was about 8 or 9 years ago. I do remember the conversation quite well though - after intros were made, it went along the lines of:

"What are you building?"

"A seven type car from Ron Champio......."

"Ron Champion's a c***"

That's all I remember, and a vague explanation of bump steer

ATB

Simon


rdodger - 2/8/13 at 07:53 PM

quote:
Originally posted by Simon
quote:
Originally posted by Not Anumber
quote:
Originally posted by Simon
You'll have to weld on new mountings.

I had my old Sierra rack shortened by Gerry Hawkridge for about £150

ATB

Simon


How is old Gerry, ive not seen him for years since i built the Hawk AC ACE replica.


No idea, this was about 8 or 9 years ago. I do remember the conversation quite well though - after intros were made, it went along the lines of:

"What are you building?"

"A seven type car from Ron Champio......."

"Ron Champion's a c***"

That's all I remember, and a vague explanation of bump steer

ATB

Simon


Good old Gerry. He isn't known for his tact!