cis 3.0sc 204 row
 

hello

if i dont want to take cis away. How far it can handle power
250hp? 300hp? more or less?
In that 911 performance book it says in one sentense that cis can hold 400hp But is there many different models of cis?

Replacing the CIS alone won't increase your HP by much if any.

You'll need to perform internal modifications (head work, pistons and cylinders, cams), exhaust and your choice of "other" induction.

400HP?...you better have some boost with either CIS or EFI.

cis
 

Thanks fast reply!

Ok i try to say this other way.
I want stay whit cis! But i wonder how mutch i can ad more pewer my motor that cis stil can hanldle that.?
I have eaton m90 super charger whits i maybe but in it!
Also i had ordered 964 cams from camgrinder.
Can some body tell when cis is too small to deliver fuel.?

cis
 

Thanks fast reply!

Ok i try to say this other way.
I want stay whit cis! But i wonder how mutch i can ad more pewer my motor that cis stil can hanldle that.?
I have eaton m90 super charger whits i maybe but in it!
Also i had ordered 964 cams from camgrinder.
Can some body tell when cis is too small to deliver fuel.?

SC CIS is smaller than 930 CIS.

930 CIS can maybe deliver 400hp, but that's max number well past it's envelope. 350hp is probably top limit as far as 930 CIS goes.

Itäs hard to speculate about SC CIS, but my guesstimate would be something like 270-280hp tops. Also, supercharger isn't as efficient as turbocharger and you would need low compression pistons.

Building a supercharged SC engine with high compression pistons and low capacity SC CIS is going to be...errr...unrewarding expirience to say the least.

You can always run an extra (7th) fuel injector in the intake that is powered by a pressure switch. A few of us use an extra 911 sc cold start valve for fuel enrichment on our 911 sc turbo engined cars.

His 204hp 3.0 ROW car has 9.8:1 C/R pistons. They aren't "boost friendly".

Depends on how much boost you throw at it. If you keep it below 8lbs and have fuel enrichment and timing retard he will be fine. Anything over that will need to be intercooled and or water injected.
It sounds like he is only looking to obtain 300hp which wouldnt take that much boost 6 to 7lbs is all he may need the CIS can handle that without enrichment 9.8:1 compression would be fine.

cis
 

Greit

Thanks those repleys:)

Yes your are right about that , at i'm looking only 280hp max
Just because i have notiset that i have cr 9,8:1 pistons.
But i wondering if i can lowering that c/r if i put extra copper ring under cylinders. And i also use only low boost max 0,5 bar. And also i deffenetly use inter cooler.
Only thing is, will my cis be ok. for those hp's.