Sorry for the intrusion, but I too am performing the identical modification...this is exactly the question I too was going to post. Thank you all ahead of time. I'm enjoying reading everyone's feedback, its very helpful. Oh, I too could not easily and still can not see the differences between U.S.A. and Euro high compression C/P's. I posted a topic on this a few weeks ago.

Best Regards,

Alex

These cams rock. If you use them, you need to make sure your idle mixture and idle speed settings are correct, your idle control valve is healthy, and use a custom chip with the appropriate mods to catch the idle or possibly face a fall off as Tyson says. Otherwise very smooth, responsive, no loss of driveability or low end, with an impressive top end.

Steve
that sounds great. Do you know the cam specifications for the 993SS profile? Also, I dont suppose you know the standard 3.2 cam spec for a comparison. In you opinion is it better to buy original 993SS cams (assuming they would fit a 3.2) or to buy a billet and have it reground?

Cheers
Pete

It's probably be less expensive if you have your cams reground. Check with Webcam as I believe this is one of their cams and they would have all the specs.

Is the 993SS cam the same as 3.8 super cup?

Noah, I think if your map sensor is between your throttle body and the plenum (not in a place where one cylinder is going to affect the local pressure a whole bunch) you should be OK. I agree that all other major components are similar. I would talk to camgrinder, he has specs for a bunch of this information, and probably knows the details.

since you already have 964 cams, though, I don't think there would be a big power increase if the 993SS is the same as a 3.8 super cup. the specs aren't all that different. The lifts are bigger but the durations are pretty similar.

I believe the 993SS cam is very similar to the 3.8 Supercup cam.


Noah, yes you can run even the Mod-S cam in your car with that induction. (It won't clear those hunch-back CIS pistons though, so stick with the 993SS) But you should put a restrictor inline to the map sensor. A 1.25 carb jet works well for this.


BTW, this is Tyson at Jeremy's computer.

I'm sorry to hijack, too, but when looking at camgrinder's chart, it seems that SC cams can be reground to 993SS cams. Is this true? Will 993 cams work in a 3.0 with CIS? Just wondering...SmileWavy

I believe he's labeled it "Super-S"

btw, that website is his business.

Tyson, are people really running a Mod S with a 3.2 intake for example? I would have thought the lobe centerlines/duration would make for rotten low-end response, lots of waves bouncing around in the shared manifold.

The carrera manifold has very large common chambers which should do a good job at keeping pressure waves and inversions from one cylinder from interfering with the others.

My DC40 is like the Mod-S cam. I like to move the lobe centers when used in larger displacement engines. 102 is good for a 2.2 or 2.4 litre and 108 or wider for 3.0 and larger.
I made a few 108 and 112 lobe center versions of the Mod-S when I was at Elgins. If the person was to recommend the Mod-S cam I would ask about the lobe centers.
The Super-S cam is a custom job I did for someone who wanted the S type powerband with a new style higher lift profile.
I have not tried to grind an SC cam with the Super Cup profile. It may work. I have put it on 964 cams easily by using the 964 lobe center of 113.

John,

Why would you open up the lobe centers on larger engines? Is this using the assumption that the factory fuel injection is being retained?

Matt,
Wider lobe centers are mandatory with factory fuel injection.
I think if you search this board you will find my reasons for opening up the lobe centers on larger engines. If not I can give you some details.
Porsche has also done this, 906= 95 degree lobe centers, 3.0 RSR= 101 lobe centers and the 3.8 RSR has 109 lobe centers.
Of course there are many variables in this comparison.

John, do you have customers runing 108 or 112 mod-S cams with plenum manifolds (single throttle body) and good all-around response?

Thanks in advance!

edit to clarify: obviously you wouldn't just slap these into a stock SC engine, but if other compnents were matched...

I'm ignoring the effects of the CIS flapper, if any. I'm thinking of an engine like a carrera 3.2 manifold or one like noah's, cis->efi

Andy,
With a programable EFI system the Mod-S 112 (DC40-112) cams will work. It will need increased a compression to ratio. (10.5-1+)

My normal choice would be the EVO cam. But if the customer needs more top end power (7500 rpms or so) and was capable of tuning the system, I would choose this profile.

wow, neat. Thanks for the info, John.

Well, there's no way you could get a decent idle with no stalling with a flapper airflow meter, or even a mass-airflow sensor.

But Noah is using a speed-density system with a MAP sensor. It may work with the Mod-S cam, if he uses a restrictor inline to the MAP sensor.


We used Mod-S cams in a 3.2 with the flapper box for a race-only car, and actually got it to idle decently, and have good throttle-response and driveability, but it would fall off idle and stall every time you blipped the throttle. We simply raised the idle to 1400 rpm with Steve Wong doing the chip re-programming for us.

I believe tyson is just talking about a fitting with a smaller hole in it in the hose from your intake manifold to your MAP sensor. Plain old restrictor. I'm not sure what's available but you could just adapt down to a smaller barb fitting if you had to, it would accomplish the same thing. or you could just put some epoxy in a barb fitting and drill a small hole through it.

That's very interesting, Tyson. I was thinking in terms of a speed-density system but I should have said that. on this 3.2 with the flapper box do you remember the lobe centers? I think standard is 102 but I guess john has done the same profile in 108 and 112 as he said above. It would be very cool to experiment with, say, noah's car :D

It might be best to take John's recommendation, though. Probably depends what Noah wants.

I would interested in who has done a speed-density system on a 3.2. Does anyone make a kit? If so who does the software?

I'd convert the whole thing over to megasquirt, if it were me. Tune to your heart's content!

more info in this thread, which addresses a 6 throttle body setup, but the basic megasquirt would work equally well with a stock style manifold:

http://forums.pelicanparts.com/showthread.php?s=&threadid=205837&highlight=megasq uirt

I think it was a 110 or 112 lobe center. Standard early S is 97.




Noah, the restrictor is simply a carburetor jet that you stuff into the vacuum hose going to the MAP sensor. I remember using a 1.25.