964 vs 993, a systems analysis

[jeffreyallen]

Hi Bill,

I have a '92 964 C2 that had original shocks and springs. I wanted to lower the car (and improve handling) so I had my local shop install ROW M030 springs with Bilstein HDs. Was aligned and corner balanced etc. Problem is that I don't think the car is even 1/8 inch lower. Was expecting 3/4 inch to 1 inch based on online posts. Is there any way to adjust the ride height? Can the shocks be installed in a way to compress the springs more, or did I just get the wrong springs for lowering?

Many thanks for any advice you have.

Jeff

[Bill Verburg]

Originally Posted by jeffreyallen

Hi Bill,

I have a '92 964 C2 that had original shocks and springs. I wanted to lower the car (and improve handling) so I had my local shop install ROW M030 springs with Bilstein HDs. Was aligned and corner balanced etc. Problem is that I don't think the car is even 1/8 inch lower. Was expecting 3/4 inch to 1 inch based on online posts. Is there any way to adjust the ride height? Can the shocks be installed in a way to compress the springs more, or did I just get the wrong springs for lowering?

Many thanks for any advice you have.

Jeff

W/ the exception of RS, none of the 964/993 factory suspensions are designed w/ lowering in mind.

here is a front and rear 993 M030 shock spring set.


The front gas a very short set of threads that can be used for corner balancing, the rear uses different thickness shims to adjust height a small amount.

[rbogh901]

Originally Posted by Bill Verburg

Exhaust
964 uses a very inefficient x-over system, the right bank cylinders merge and x-over to the left where they further merge w/ the left bank cylinders

Hi Bill, Do you have any info regarding the 964 Cup car manifolds/exhaust? I was under the impression that did not use a x-over/merge.

[Cupcar]

Mufflers (8 & 9 in diagram) are straight through pipes on 964 Cup

[Bill Verburg]

Originally Posted by rbogh901

Hi Bill, Do you have any info regarding the 964 Cup car manifolds/exhaust? I was under the impression that did not use a x-over/merge.

relative flow
#6 cat 442
#8 muffler 462
#9 muffler 396

weight per Perlet
OEM 964 exhaust
12 lbs left
16 lbs rt.
13 lbs cat
41 lbs total

[gints]

Hi Bill, I have 92 964 c2 cab with stock shocks and lowered springs. I wanted replacing broken front sway bar (20mm) and drop links to 993 sway bar and 993 drop links. Is it possible? What is difference between 964 and 993 sway bars? Many thanks for answer.
Gints

[JohnnyT]

Bill et al,
Great informative thread!

I recall seeing somewhere an electric power steering mod for the 993.
Anyone aware of how to do this?
Electric Pump located in front boot, to supply pressurized fluid to the OEM power steering unit?
Or true electric assist power steering rack?
Anyone have information regarding such an application?

Thaks,
John

[Cupcar]

Originally Posted by JohnnyT

Bill et al,
Great informative thread!

I recall seeing somewhere an electric power steering mod for the 993.
Anyone aware of how to do this?
Electric Pump located in front boot, to supply pressurized fluid to the OEM power steering unit?
Or true electric assist power steering rack?
Anyone have information regarding such an application?

Thaks,
John

I have not done this, but people have used a 997 Cup electric power steering oil pump with the stock rack. This requires wiring and plumbing the pump into the front of the car. This allows removal of the engine driven oil pump and lines going to the back of car.

[Bill Verburg]

Originally Posted by Cupcar

I have not done this, but people have used a 997 Cup electric power steering oil pump with the stock rack. This requires wiring and plumbing the pump into the front of the car. This allows removal of the engine driven oil pump and lines going to the back of car.

As Bob says a 996/997 Cup electric pump, plumbed into the stock rack

It looks like this


As an aside, anyone else notice several missing pages in this thread?

[JohnnyT]

CupCar, Bill,
Thanks for the reference.
Here is another photo of Power Steering Pump!
Looks good!
Looks like Air Jack behind the pump.

[perelet]

Pump itself does not need to be strictly part from 996/997 cup. There are MB, Toyota etc pums that are as good. As far as I understand pump should be from 2005 or earlier car, later cars have CAN bus connector, also some pumps from later cars have variable assist pressure.

Pre CAN bus pumps fall in to 2 cathegories -

1. constant load pump - works all the time at full load.
2. variable load, pump pretty much idles when steering is straight, when steering is turned pump has senses it via liquid pressure switch and ads rpm's.

Type 2 pumps do not create alternator/battery load while steering is straight.

There are good threads in 928 land about conversions.

Oleg

[Bill Verburg]

I'm getting really curious about this
some times I look in this thread and find 9 pages others times only 6

How many pages do you guys get?

[BimmerDob]

Today 9 pages

[Bill Verburg]

Originally Posted by BimmerDob

Today 9 pages

Really strange, this is pg 6 today on my screen

[e3photo]

I'm getting 9 pages.



Emerald

[rbogh901]

Originally Posted by perelet

Pre CAN bus pumps fall in to 2 cathegories -

1. constant load pump - works all the time at full load.
2. variable load, pump pretty much idles when steering is straight, when steering is turned pump has senses it via liquid pressure switch and ads rpm's.

Type 2 pumps do not create alternator/battery load while steering is straight.

There are good threads in 928 land about conversions.

Kewl!





9 pages to here today.

[SouthCoastPhil]

9 pp for me today.

[75Carrera]

Thank you Bill! Just bought another car to play with over the winter in the garage. 95 993 cab. This is a wealth of information about the models and the comparisons are eye opening for sure. When are you gonna write a book? Only a few of you guys left with the history and passion for the air cooled years.
Merry Christmas from me and my faithful '75 ;D
Donny

[jimmyzee]

Bill:
Your knowledge is just outstanding. I am a mechanical engineer and own a 1992 C4 964 cab. I like to get my hands on as much information as possible on these cars. You should put it in order and publish it some day. There are a lot of guys like me who would like to see it. Keep up the good work!

[simonozrs]

Bill
Just want to thank you for the effort you put in to pull this thread together. Its an invaluable resources to those of us with 964 and 993's.
Ive got a 1996 Carrera RS Club Sport stashed away. If theres any way I can help you with photographs or information relevant to the M003 optioned 993 RS cars, it would be a privilege to help.
Regards
Simon