Geoffrey

Here is the Racecar Project thread on the various hydraulic boosters when I went through this a few years ago.

Hydraulic Boosters

NP993

Hi Geoffrey -- thanks for all the useful info, much appreciated. Sorry to ask another question -- was there a specific Mini Cooper pump that was the best, or any of them work? And what is "pre CAN" in reference to the Mercedes pump? Many thanks.

KaiB

I don't know much here..but do "know" that the CAN is the data line (bus) through which, well, data transmission occurs.

I think our cars are pre-can and use a different protocol (or hardware, or ports, or bus). I remain amazed at all of this electronic stuff.

My expertise revolves back to stuffing sheet metal screws into linkages to open secondaries up early.

Bright, aren't I?

sml

i had to max out the caster otherwise my tyres hit the guard/fender on the front edge.

evoderby

Alternative: try 30 minutes of go-karting once in a while......afterwards your Porsche will positively feel power assisted for 2-3 weeks to last;-)

SuperUser

Now I am confused, I thought max caster would push the wheel closer to the front edge.

Geoffrey

New electric power steering pumps are controlled in speed by information on the CAN bus provided by engine parameters, vehicle speed, and steering angle. These pumps don't simply turn on, they vary the amount of power. Now, these pumps would be perfect in a race application because they would be off on the straight, and on when needed in the corners, providing for a reduced electrical load on the alternator, thereby freeing up engine HP to propell the car forward. With a CANanalyzer I could figure out what information was being sent and duplicate it with MoTeC.

For most applications though, you'll want a simple pump that is on when the engine is running and potentially a switch on the dash to manually turn the pump on so you can push the car around and steer it easily when the engine is off. I do this on the race cars with a SPDT switch.

I don't know what version of the mini was used, but given the timeframe, I would guess it was the original one.

s4magman

Just purchased a 997 RSR PS pump for my C2 and should have it in a week or so - impulse buy I guess as this article inspired me. Now I just have to figure out how to install it...but it sounds like it will be a fun experience.

Bill Verburg

Talk to Dan J.

s4magman

Thanks Bill - good call and he's local for me.

GrantG

You might prefer the manual steering feel with lightweight front fenders, hood, and bumper. My 73 911 has the lightest manual steering I've ever felt (feels lighter than most power steering systems), but has incredible feel and feedback. All carbon fibre body panels...

Geoffrey

My 3.8RSR at 2225 full of fuel has a manual rack, and is Ok. I have driven various 993RSRs with the power steering and prefer them to mine, but mine is so light it isn't a problem. It does however, have all the 993GT2 front suspension components.

Steve Weiner-Rennsport Systems

Hi Grant,

There are major differences in suspension and steering geometry between 911 and 964/993 cars which make PS much more desirable, especially for track use.

GrantG

Thanks, Steve! Never drove my 993 with the PS out

ghhally

Geoffrey, would you also recommend the electric PS pump as permanent
replacement for the engine driven pump for a street/track car?
I assume they are robust and reliable.

Thx