I do not own a Porsche yet, I hope to be in a position to pick up a 996 in the not to distant future.

I have seen many posts about supercharges on the 996 which is why I ask the question here.

From time to time someone will wonder about turbo charging an N/A car. The overall response is, "go buy a 99X Turbo". Yet I see praise filled threads about 996 cars that have been supercharged. A motor doesn't know where boost is being derived only that it is seeing boost.

Why the conflicting view points when adding boost to 911's?

I am not saying that I want to add a turbo, but I am confused as to why the opinions differ so much. I have seen many other brands add turbos to N/A cars with little effect on the cars drivability. In my experience it comes down to careful fuel/air tuning and turbo matching. This is really no different when dealing with FI on any car.


Thanks all!!

 

do a search for supercharge(er) and you will find a mountain of reading here in the 996 forum. There have been several pro/con threads, etc.

 

I had the same thoughts you do, but I am a little more tempted, owning a 2000 C2 Cab.

I think it boils down to how much gain you want, tolerance for failures and $'s to spend.

Some take aways I have read... To boost (Turbo) a NA 996 3.4 or 3.6 to say 1.0 atmos, you will probably shred the motor. The compression ratio is initially too high. Then they say you can gap the heads to lower the ratio to then allow/handle the boost. Then there are the injectors and ecu to contend with. Sounds like most think you would be better off buying a factory equipped capable vs going thru the upgrades. I might even agree with that for ultimate performance.
On Superchargers, the boost comes in at say .5 atmos, then maybe the engine can hang in there. Still got the injectors and ECU, but then there is the parasitic loss on that dude. So if you not using the performance, you simply draining your gas tank.

My take on it is, go for it, I would not hesitate boosting (turbo) but holding back to 5-6 psi or less. Some extra power and easier on the motor. Supercharging does not give me the WOW that comes from turbo(s) whining. Never really push the car hard anyway so it may even last!

IMHO of course - Opinions and bungs / everyone has 'em and they all stink...

RB

 

In the world of Subaru (at least in the States) prior to the WRX pushing more than 6psi was a death sentense. The scooby motor likes a lot of feul and very little boost. The 3.4L running IIRC 11.3 comp would be very sensitive to boost as well, but you should be able to be a better power return per PSI with a turbo over an SC.

I am not sure how modular the Turbo bits are on the 996TT cars or even if you could use some to fasion a DIY turbo on an N/A car but that would be a cost effective way to making nice power.

 

the turbo motor comes built for it from the factory, for the price to supercharge a 996/997 roughly 15-20k to do it "right" your gonna be at about the power levels of a stock turbo.

 

From what I have seen the cost of the SC is 10K, which seemed to cover all of the required items to make 460CHP+


I understand that the factory turbo motor is built for boost, my point is that people on the board seem to jump on people when they ask about turbocharging an NA car while applauding supercharged NA cars. I don't get this... that car doesn't know what is producing the boost.

 

the car doesnt know what is producing boost your are correct, but its really interising how boost psi doesnt equal the same horsepower, a turbo kit at 5 psi might make 350 rwhp and a supercharger kit at 5 psi may make 320 but what matters is the curve, on the street the supercharged kit may be faster. to maintrain drivability on a turbo car you really need 2 small turbos instead of one large one (porsche does it for a reason you konw) so you dont have 930 ish driveability.
Turbos are great but adding them to a car costs alot of money to do it right costs lots and lots of money. YOu have more plumbing, intake and exhust, you have oil lines to run and have to get the oil to and from the turbos, coolant lines, wastegates, over run valves ect ect much more complex then spinging a compressor thats forcing air into the throttle. ANd then after all that work you have to find someone to tune the car on a dyno, i dont know of to mnay people who have that ability to dyno tune a prosche, its much easier to buy the supercharger kit and bolt it on and use the supllied safe tune so you motor doesnt end up molten in the middle.

 

I agree that a turbo is a more complex system, but it is more effecient. I would also think that with all of the turbo parts already around for the Porsche turbo that the costs could be minimized by useing some of them.

Also a properly size single turbo can give you a nice compromise or mid and high end power as well.

Tuning is tuning for the most part... (I realize that is a dangerous statement) air fuel ratios are the biggest concern. Bolting an S/C on without a dynotune is just as foolish as doing so with a turbo. Both are subject to detionation.

One question I would have is, can the 996 Turbo manifolds bolt to the NA heads? If this is the case then you are half way there. I would be that you can get parts off of a wrecked TT for a fairly good price.

I see "turbo kits" for other cars often, some of very high quality. None are near the 10K mark, what should make a Porsche any different?

 

like i said you cant bolt on a s/c and call it a day but the s/c mfg has flash software tuned for their package. Properly sized turbo can help but you still wind up with less driveabilty.

no the turbo manifolds wont bolt on, even if they could the turbos wouldnt fit in the car. the outlets would never line up with any thing, the turbo charge pipe wont fit behind the engine like on a turbo
theres no where to put the intercoolers on a narrow body car and you have to cut the vents on a wide body car to get air flow across them.
the engine mangement is diffrent between a na and a turbo so your up a creek there too.
its not impossible but its not cost effective either.

turbo kits for other cars are out there. but you have to account for the companys r&d and production volume
theres lots of turbo civics so the kits are cheap 2-3 k
theres some turbo vettes but only some some so its 7-15k
a porsche kit would be at least that and i dont know that theres enough market for someone to make one.

You need more then a tuirbo and some piping and tuning and an intercooler, you also need a fuel system, stock pump and injectors arent gonna cut it.
the na motor isnt desgined for boost and probaly wouldnt last long at boost levels over 5 psi

it can be done, but for he money its cheaper to go s/c or sell it and buy a turbo.

 

Only 7 letters.......P-O-R-S-C-H-E

 

Have you shopped for used Porsche motors and or parts? Don't know about the "fairly good price" comment. Guess it depends on your idea of a good price. 10K supercharger kits are the result of two things. 1)Most folks that own a 60-100K Porsche are reticent to slap on a turbo(or supercharger) kit for which they (the Porshe owner) will be the beta tester. 2)All Porsche upgrades are subject to the Porsche Tax. Prices determined by the market and all that. It's a market populated by folks with a bit of disposable income.

A mechanically driven SC is definitely the better aftermarket route (vs. a turbo) as you really don't need watercooling and a control system (wastegate). Don't have to screw with the exhaust either. You don't need to deliver a ton of boost to a high compression motor to get big gains, so no need for exponential gains in air delivery that a turbo delivers vs. a mech. SC.

An engine that was designed for supercharging(meaning forced induction by either a mechanically driven charging device or an exhuast driven compressor) has many features built in that are typically lacking on a NA motor. I don't really know about 996 turbo motors specifically, but things like, piston squiters, pistons, head design, oil and water cooling capacities, crankcase ventilation all come to mind. Not to mention driveline improvements, gearing, brakes to handle the additional weight of all the aforementioned items/systems.

Listen to 99firehawk. He knows what he's talking about.

 

I was just trying to get an understanding as to what limiting factors were in the way of turbo vs SC. From what has been said I would have to agree that the SC is the way to go. I am not really partial to one over the other, I would take it application by application.

I appreciate the back and forth though.

Thanks guys!!