944CS

i think everyone's notion that the stock MAF's door is restrictive could be wrong.....the engine pulls a vacuum on the intake stroke of the piston, and couldn't this open up the door as opposed to air pushing open the door?

Porsche-O-Phile

It doesn't really matter, the cross-section of the intake flow is smallest there and it's not laminar to boot. If you look at how the air feeds in from the stock air box, it's got all the aerodynamic qualities of a hardcover book - it's a flat plate with the "barn door" in the middle that (yes) can open but still induces a lot of turbulence into the flow stream. I'm betting that changing to a MAF sensor plus good quality porting & polishing of the heads would easily net 20-30 hp.

idontknow

"What do you think, mild port and polish, 3 angle valve job, titanium valve retainers, cam, and some race springs???"

Great Idea. Still got money? Ti valves on stock springs. The less mass you have to move in the valve train, the more available to move the car. Plus less stress on the timing belt!

The reason for stock springs: When you have heavy duty springs, the engine has to push against the added resistance. This also increases cam/lifter wear. I've also heard of lifters collapsing with the heavy springs. With a light weight valve, you don't need nearly as much spring force to bring it back up.

Sam Lin

By 10hp I meant basically the max with all bolt-ons and the head/cam. There's not much left in the engine unless you do major surgery. Except for head work, I've got basically every bolt-on on my NA, it's dogggg slow. Don't waste money on it.

Sam

Porsche-O-Phile

I disagree. The n/a cars can be made pretty quick if you know what you're doing and are willing to put some money into 'em. Danno recently talked about a big-bore, shaved head, port, polish, and MAF job as ways to net a LOT of power from an n/a car - perhaps as much as 60-70 h.p. or possibly even more. That puts your available power output in the same league as an early 951 out of the same 2.5L block with NO forced induction!

As far as f.i. - what "bolt ons" are you talking about? There are some that would most certainly make a difference - supercharger / turbo kits being one rather obvious example. As far as your implication that every n/a car should just be left to rot, I'd also remind you that they're typically lighter (when stock) and can be built just as well, if not better than a factory turbo. It's just a question of time and money. I will agree that a 951 is a better platform from which to start for a street / track car, easier to mod and easier to get higher h.p. per dollar than an n/a, but it MOST CERTAINLY CAN also be done with an n/a - look around this board for examples of what some people have done with them (968 engine conversions, forced induction, etc.)!

Even stock, the n/a cars are by no means "dog slow". If yours is, then either you don't know how to drive it or it's badly maintained. They're certainly not as fast as the turbo cars, but I would hardly dismiss them in the disrespectful way you are. It is what it is, it's still a Porsche, and it's built to run triple-digit speeds all day long even without a turbo. If you want a faster acceleration type drag car, get a Corvette.

david fracolli

Fast 924 I have a bored throttle body that I don't need anymore. If interested send me an e-mail at dfracolli944@cs.com I will give you all the details.