Basal Skull

I've seen the posts on pros and cons of manual steering...
I've also heard previously from one of the local mechanics that in his old 993tt he removed the power assist for both the steering and clutch. I understand that the 'rare' 993 cup / 964 rsa maunual racks can be used for the steering.
Question: how easy is it to do a manual clutch conversion? anyone done it? what's involved?

Texas993

As my car is a converted C4S, I don't have an assisted clutch. When I first bought it, it had the DMF and the clutch felt easy (but not as easy as an assisted TT clutch). When I upgraded to the LWF and RS clutch, the pedal is firm, but not punishing.

That doesn't begin to answer your question. But know that a LWF non-assisted TT is great. The folks at RAC (RUF) have told me several times that they prefer the "feel" of the non-assisted clutch. Works for me...

I am sure that you will figure it out!

Mike J

Good question and be interested to see if an definitive answer can be nailed down.

I bet you will need to replace the master cylinder, put in a standard slave cylinder, cap off the pressure circuits from the power steering pump (or remove the plumbing and cap at the pump), keep the reservoir but use brake fluid instead. You should be able to use the same clutch circuit for the low pressure side till you get to the transmission.

I would go through the parts guides and do the same circuit as the C4S, and compare part numbers to see what is different. You wil have to get the pipe right near the transmission so you can use the standard hose to the slave.

Not sure about the heaviness/lightness of the pedal if you do this. What clutch are you running?

cheers,

Mike

Texas993

Mike, see my post above.

Mike J

I was asking Basal what clutch he is using - it could impact the heaviness - he might be running a heavier pressure plate, etc.

Cheers,

Mike

Texas993

Oh, I see. I don't know much about the differences. Curious to learn.

Essexmetal

I am running a manual slave working the heaviest pressure plate available. This was a forced retrofit as opposed to wanting a manual clutch. While the engine / trans were out of the car someone at the body shop stepped on the clutch pedal and blew open the slave cylinder. Parts were lost. So manual was the easiest fix. The pedal pressure is certainly higher but not objectionable. Much better feel during clutch engagement. Been in a traffic jam, not fun, but great for quick launches when required.

Installation is not an issue. The master cylinder is the same as a non turbo. Standard 993 slave. Sorry I can't remember if I used the turbo's flex line to the slave or if it required a non turbo one. I plugged the booster lines at the slave end as opposed to the distribution block (oil tank side, with power steering lines). Did that in case the manual slave did not work. The return was a simple line plug, pressure line got a cap on to the fitting on the line. When I am in there this winter I will terminate the lines at the distribution block.

I like the idea of manual steering but as I age and the tires get stickier I can be content that the powersteering is there. It offers enough feel for my driving. Removing the two systems would certainly remove a bunch of complexity from the passenger side of the engine. Living through the small fire from the P/S steel line splitting at the attachment tab, as it does on so many turbos, would be one less thing to deal with at the track. For those that have not inspected the hard line from the powersteering pump to the distribution block. There is a welded strain relief tab on the line. The crack starts beside the weld. Leaks at first, splits at the track when running hard, at least it did for me and two other I know in town.
Rick

Mike J

How would you rate this mod for a daily driver? You mentioned that traffic jams are not fun - have you driven an RS clutched non-turbo as a point of comparison?

I currently have a stock clutch but its getting close to end of life - the clutch pedal engagement is very high. I like the power assist but do not like the $$$ the slave seems to cost, but I just replaced it so hopefully it will last a while. I plan to put in a RS Flywheel, GT3 RS disk, and Sachs Motorsports pressure plate - which is heavier than stock but not going overboard. What clutch setup do you have?

Cheers,

Mike

Texas993

Mike, that is the set up that I have. Agree with Essex's assessment. I wish that you could come down and drive mine!

pstoppani

Mike, you can drive mine next time you are in the area. I have the RS clutch and LTW flywheel w/ unassisted clutch and find it a non-issue.

Essexmetal

Mike, I use the car in the summer as a daily driver and not a problem. My comment on the traffic jam was one of the 1/2 hour move 50 feet at a time jobs. Since I won't sit with the clutch in it gets double the strokes and can get tedious. I am embarrassed to say I don't know which clutches I have been running. Called my buddy and he sent me the clutch for the 3.6. It was a RS Pressure Plate and Disc. When it went to the 3.8 he sent "the heaviest clutch that fits that flywheel". His concern the RS unit would not work with the increased power and torque. With that said the manual slave works fine under this clutch set up, a lighter pressure plate should not be objectionable at all.

Mike J

Yeah, sounds like a good way to go, sure simplifies the cars operation.

Cheers,

Mike

Basal Skull

Hi good info.
My car was stranded at the 'ridge' for a week waiting for the new hydraulic line earlier this year after the exact problem Rick posted about above, think I might have posted about it. Frustrating thing was I had replaced it as a preventative not long ago since I know it's a fail item (having seen a friend's split at the track a few years ago and thought I had some weeping from one end).

So was thinking about having to carrying a spare line, but remembered mechanic (John B) saying he had deleted the power steering and clutch in his old car and started to think about 'delete' the power hydraulics. Might be some weight loss too, and as a change in driving experience.

I have a rs lwfw, rs disc, ? stock pp, I'll have to check my records.

Looks like I need a regular 993 slave.
Have sourced a used 964 rsa/993 cup manual rack - they're rare and expensive...

Do you guys think I can do the slave change, cut the hydraulic pump belt/remove the pump - with the trans/engine in the car???

Basal Skull

Can I keep / use our turbo slave and cap off the high pressure side? I know the clutch seemed to work okay, just a little firmer when the accumulator failed (until the pressure built up)...

Mike J

Not sure about that one - I think the accumulator is just a pressure tank that keeps the pressure at the assist when the car is shut off - that way the clutch is nice and light next time you start it (within a few hours or even days if the accumulator is good).

If the power assist slave is leaking or failing, it still assisting so I do not think you can use the slave without the high pressure circuit. You can try it by capping off the pressure side as you said and see what happens. However, I would replace the slave with a stock NA cylinder anyways, its a pretty cheap part from Sunset, it will cleanup the area, and then its failsafe.

You can disconnect the pump and remove it withouth dropping the engine, but you will be swearing a bit if you do not have a lift - its pretty deep up there to access lying on your back - but its doable. I would just cap the plumbing and take off the belt first until you are certain you want to drive the car this way - the steering will be heavy on parking and low speed positioning, but should be nice and light at speed.

Cheers,

Mike