Difference between Type 85 and Type 89 steering set-up

[Error404]

I'm on a quest to improve the steering feel on my coupe and one if the things i have never been able to get my head around is the difference in steering feel people always mention between the urq and the B3 / B4 coupe quattro

both cars have essentailly the exact same set-up - hydraulic pump, apparently interchangeable bulkhead mounted rack and pinion steering gear (IIRC Marc Swanson fitted a Type85 rack on his V8 CQ?) the subframe, wishbones and uprights are interchangeable too.
The Type85 cars are lighter, but not by a huge margin over the front wheels. they also have a stiffer chassis, although I suspect almost all of this is due to less weight and the rear bulkhead (not being a hatchback).

I have never driven a urq - what do they feel like compared to a B3/B4 car in terms of steering weight and feel?

My thoughts turned to the pump and the rack. I was chatting to my future brother in law who runs a company who build rail plant which uses a lot of hydraulic gear and he suggested we investigate and compare the PAS pumps and the rotary pump in the rack, whch is part of the rack pinion on our cars (the mechanism that guides fluid to the L & R sides of the rack).

We thought that by reducing the assistance of the system, it might also permit better feedback aswell with less of a "damping" effect caused by the over assisted set-up. what are peoples thoughts on this aspect?
There must be a flow control valve in the pump that moderates fluid flow at engine speed rises, this could perhaps be modified to reduce overall fluid flow, or the rpessure relief valve could be modified to reduce fluid pressurep perhaps.

If the Type85 and Type89 the pumps generate similar fluid pressures, then the majority of difference between the steering gear on both set-ups must surely be down to the rotary pump?

[s2driveruk]

have only driven a 2.2 5pot coupe and the steering feel was fantastic. The UR was always praised for its steering and feel and every modern audi since has been berated by the fact that they feel numb and as a result the driver was detached from the car. I'm sure there is mileage in investigating that part and i am sure a stiffer chassis plays a big part too as all information being transmitted back to the driver is sharp and fast, whereas in the jelly mould coupe, i'm sure it gets 'lost' en route.

Will be watching with interest as my pas pump has seen better days

[Error404]

hehe, well i've pretty much done as much as i can to my chassis apart from a cage, and that ain't gonna happen lol.

Weird thing is that both set-ups are soooo similar, but the differences in result are massive!

[Acidburn]

I'd let you know but my cars not on the road atm as you know.

My cq was definately a lot better / lot chuckable and one thing I think to think about is the amount of weight over the front will play a part as the 10v's are lighter at the front than the 20vs etc once you add on the panel weights.

I will see what happens as the urq is getting full s2 running gear (really hope I don't mess up the car by doing this ) but apparantly its just as good but better as the car has a wider track - could this be the difference?

[Error404]

well i've already widened my front track by 30mm which didn't do much to the steering weight or feel TBH, made the car look cool though Can't believe the urq is any ligher over the front axle than my CQ20v though

Anyone got the castor specs on the Type85 and Type89 coupes?

[Flat on my back]

well i've already widened my front track by 30mm which didn't do much to the steering weight or feel TBH, made the car look cool though Can't believe the urq is any ligher over the front axle than my CQ20v though

Anyone got the castor specs on the Type85 and Type89 coupes?

Hmmmmmmmmmmm...my front track has gone up 30mm too, but only fwd, feels better to me? The rear end has stiffer springs too...really needs to get bums in seats for a proper comparison.

[GT500]

Alex,
I like your idea. However i think you are chasing something that just isn't there.

UR steering feel is just as rubbish as type 89.
You need to drive a 911/elise/Noble and you realise what steering feel is. No amount of fannying will get over the mcpherson strut design. I don't think the rack on the bulkhead up high helps either.

Audi never have built a car with steering feel, although not had a go in an R8 yet...

[Error404]

Hi Rob Thanks for the comments

I you're definately right its never going to be great, but I think I would even settle for less assistance and at least a nice weight to the steering - i think its complete the lack of "feel" combined with the stupid one finger steering weight that I find unacceptable

I did wonder when journo's commented how much the ur was to the S2 part of what you were getting was just their nostalgic memories of a first drive in a ur back in the early 80's

[Rusty]

Stock S2 suspension and drive is really soft and wobbly and heavy, compared to the lighter, more focussed car it was never ggoing to stand up.

[Mikes2]

the only major differences are lack of steering damper on the quattro and the wheel / tyre setup.

The t85 chassis are not as strong as the t89. most quattros have rust patches next to the sunroof - this is caused by shell stretch / flex

[quattrostyle]

never heard of that really, did have 2 90 quattro's with sunroof and without problems in that area and seen other also without problems.

[Error404]

Sounds like theres no much else I can do - I binned my steering damper a while ago as it was fecked and I've widened my track by 30mm as mentioned above and running 225mm front rubber, so nothing much more I can do in that respect. Hoping the solid tie rod bushes make a good improvement (not had my alignment done yet ) otherwise increased castor and spherical bearing top-mounts are the only other areas to potentially improve the feedback - as Rob says fighting a losing battle!

Still, I'd feel a lot happier with less steering assistance so this is definately something i'm going to try and achieve by modifying the PAS pump

[AndyP]

What difference did removing the damper make?

[Error404]

Nothing on mine as it was only half full of oil and rattling when I got it off!

But Stiglet also removed his on his CQ and IIRC said it increased the feedback through the wheel a little bit but also the car snatches a bit more at bumps etc as you'd expect.