Ritter v4.0

In the context of a 3.8 conversion, are these cams a better (or just different) choice than the OEM RS cams?

They are made from solid billet and not welded regrind- are the RS made the same way?

Also the RS cams will not work with a/c is that correct?

TIA

springer3

I feel a slippery slope starting.

Ritter v4.0

Freefall.

N51

RS cams are the same as C2/C4. A/C and cams are not related.
With regard to JW's cams, talk to him. A premier tuner.

N51

Further clarification,

The RS/RSA cams have no drive for the powersteering.

Ritter v4.0

Thanks for clarifying. I thought I'd read here that RS cams though essentially the same as stock C2 cams, did not permit a/c. Must have been very late one night.

Geoffrey

The 964RS cam profile is exactly the same as a street C2/4 (non RSA) camshaft with the exception of missing the drive on the passenger side to drive the power steering pump.

The stock pistons do not have very large valve reliefs in them so it limits the cam profile and lobe centerline than can be run in the car.

Ritter v4.0

If you run RS cams then you might as well convert to manual steering rack and remove the pump as there's nothing to drive it yes?

Put another way; if you want to keep power steering then put back in OEM C2 cams.

Is that what you run and recommend Geoffrey- RS cams?

Geoffrey

No, the RS camshafts provide no performance benefit over stock camshafts. There is a new 9M USA version camshaft that I'm using in in the two engines we are converting to MoTeC. They were built using head flow data from my flow bench.

N51

Nice echo.

David,
https://rennlist.com/forums/993-forum/426393-long-wait-ahead-of-me.html

It is to your advantage to talk to Rob and wait on his conversion.
Protomotive is biased toward the Mahle pistons/cylinders.

Steve Weiner-Rennsport Systems

A clarification should be made,.....C2/C4 and US RSA cams have the same valve timing: Euro RS ones are different with more duration & lift.

Just to offer another observation based on experience,....we've seen 10-12 HP increases with Euro RS cams and the larger 993 RS intake valves with a good number of both 3.6 & 3.8 engines,...

Naturally, software must be adjusted/optimized for these changes.

N51

"Naturally, software must be adjusted/optimized for these changes." And that is where Porsche(mostly) optimized the 13hp advantage of the 964RS over the common ROW 964. The cams are the same. Adrian can strike me wrong if so. I'm willing to listen.

38D

Steve - that's not correct for the 964 (993, yes). The 964 RS/Cup cams are exactly the same save for the power steering pump drive on the one side. I've got a 964 cup sitting in the garage and Geoffrey has seen more cup engines than you can shake a stick at.

Bill Verburg

Some of you guys are talking 964RS and others 994RS
964RS use the same cams as all other 964(except the p/s drive)

993RS uses a little more aggressive profile than a 993

I've seen very satisfactory results from the 964 ss profile

993 Super Sport(mechanical)
lift .490I/.456E
Advertized duration 260/248
duration at .050" 240/230

993RS(hyd)
lift .490I/.446E
Advertized duration
duration at 1mm 243/232

Webcam 20/21
lift .485I/.452E
Advertized duration 258/246
duration at .050" 238/226

DC cams
Super C2 248/236 duration @ 1mm
.475"/.455" valve lift
Sport 964 254/236 duration @ 1mm
.490"/.455" valve lift
284/274 254/244 duration @ 1mm
.490"/.460" valve lift

It would be interesting to see how 9Ms cams compare to some of these

Ritter v4.0

No doubt it would be valuable to wait and talk with Rob after his is complete but I've already pestered enough folks on this, including many of the guys here (Steve, Geoffry, Bill etc) who have been very generous with their time and advice. I also have a timetable with PCA events scheduled for June if possible.

We've decided to go with Integral cams and because they are custom fab'd, the question is which profile to go with RS, Euro RS, 993RS, SS- or just custom make them for the application.