930 cam upgrade - SC or 964?
#16
Race Director
Join Date: Oct 2004
Location: KC ex pat marooned in NY
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They don't really add any power, just shift the power band. If you want to increase power a cam, you'll need, a longer duration and higher lift, ie a custom grind. This will also require stiffer valve springs, triple cut valve job and custom notched pistons, etc. I wouldn't shave the heads, this is a flathead ford technique to increase compression.
#17
Thinking of upgrading mine ( '91 964 Turbo) to SC cams along with opening up the intake ports & manifold to 35 mm which should give me good 360-380 HP without sacrificing any torque
Any comments?
Thanks
Any comments?
Thanks
#22
I've had Group B, 964, and SC on mine over the years. Though lately it's a 3.8EFI so that may change some things.
Group B just plain sucked and I removed them as fast as when they went in. I think they were designed for a car that really revs and the power would come on like a sledge hammer just before you need to shift. Maybe that worked at Le Mans. But it sucks in most other situations.
I then replaced them with 964 and that was very nice.
I have since been using SC and I think that is the best. They provide lots of low end torque and I let the K29 turbo look after the higher end power.
SC is how I would go. But 964 is fairly similar.
Group B just plain sucked and I removed them as fast as when they went in. I think they were designed for a car that really revs and the power would come on like a sledge hammer just before you need to shift. Maybe that worked at Le Mans. But it sucks in most other situations.
I then replaced them with 964 and that was very nice.
I have since been using SC and I think that is the best. They provide lots of low end torque and I let the K29 turbo look after the higher end power.
SC is how I would go. But 964 is fairly similar.
#23
Rennlist Member
I had Group B in my car and I was pushing 375whp.
My mods were.
4 speed short geared tranny
K7200
Ghl exhaust
Borla muffler
Euro fuel head with bigger fuel lines
RUF intercooler
Andial fuel enrichment
.9 bar
She ran like a bat out of hell!
Currently in an efi conversion state/motor rebuild to 3.4L twin plugged.
My mods were.
4 speed short geared tranny
K7200
Ghl exhaust
Borla muffler
Euro fuel head with bigger fuel lines
RUF intercooler
Andial fuel enrichment
.9 bar
She ran like a bat out of hell!
Currently in an efi conversion state/motor rebuild to 3.4L twin plugged.
#24
Pro
On my DD '79 turbo, I run stock cams @ advanced cam timing, and Aasco valve springs, just over 1.2 bar , some short tube T304 headers and the car is a handful.
Marty
#28
Burning Brakes
Join Date: Apr 2006
Location: Central Washington State
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here is my car with the group B cams and the mods I listed above minus the current Ruf muffler(in the video it has a Borla).
Porsche 930 Turbo(1986) Sound / European Auto Works, West New York, NJ - YouTube
Porsche 930 Turbo(1986) Sound / European Auto Works, West New York, NJ - YouTube
I wonder....and this is slightly off-topic....if there is a way to determine what grind a person has in their car without removing the cams entirely; i.e., is there some way to measure the lift and duration, etc. whilst still in the car? I have no idea if mine are stock 930 cams or not, but she sure seems to scream right along at the mid to high rpms (probably due to the 7006 turbo, which I installed years ago just because I found a K27 to replace the 3LDZ).
#30
Instructor
The SC330 sport is a great compromise if you’re still on the fence between the SC and 964 as it sits in the middle. I've been happily running them for many years now. Plenty good for track work and playing with GT3’s…