wellcraft290

Ilko ok because people post turbo is hotter it must be true? I mean it is the internet and I am a Nigerian multi millionaire. The truth is most turbos are for track usage and s/c have been used for drag racing. so yes a turbo will be hotter because of prolonged usage. Now turbos are taking over the drag strip as well.

If a diesel engine which makes more power the cooler there are run on turbos instead of s/c if there cooler? Also with higher boost s/c intercoolers are recommended as well. I honestly feel there are really similar and not one or the other is better or worse just different.

ilko

I took an issue with your statement about heat, not which is better.

wellcraft290

still you said s/c don't cause as much pressure. I want to know how you figure that when they both push air in under boost or forsced induction. Force being the key word.

I really have no idea why one would have hotter air then the other if they both push air. I could be wrong but noone has any proof just ideas.

raspberryroadster

they are both excellent systems, but of course create heat (ie engine stress/wear).....and incidentally lotus may dispute your view that sc's are only for the strip - the fact is that most drivers at the strip ran/run sc's because they deliver power instantly - no lag time, only lately have new turbo designs allowed for faster power delivery.

sc's do deliver colder (and therefore denser air) vs a turbo which delivers hot air and therefore has to deliver more..). when i upgraded my factory sc'd cobra - was debating between upgraded sc or going to turbo i researched the net then talked to as many owners that had gone sc or turbo (install costs for a turbo were about 200% higher-2 days or a little more - vs 1 for a sc and generally pro tune is more of an issue)....so
read all you can....begin my doing simple search on net "turbocharger vs supercharger"......then start pm's with the guys that have done it.
after all reading likely you will reach conclusion (that most do):

-for mild to mid boost installs an SC is lighter, cheaper to install & maintain and runs cooler - delivers power earlier and in a more linear fashion (providing there is room in engine compartment), they do not reduce back pressure in the exhaust system-which in some cases reduces torque
-turbo's are smaller installations more efficient especially at high levels of boost and more adaptable to special installations (eg there are installations developed for the trunk of a car). they take up less space. they are the installation needed to add extreme power. new twin turbo/sgl designs are increasingly efficient and have eliminated spool up time

but installed at same level of boost = basically equivalent power added

i agree with you - in all cases of forced induction intercooler provides added measure of comfort

the na 964 is not the best candidate cause of high compression....so factoring the all in cost of the install and the fact it may NOT be a value enhancement - why not just buy a turbo?? (generally always cheaper/safer to buy power on the hoof)

raspberryroadster

???? you really are stubborn on this one - both systems operate on the same premise - they take exceptional quantities of air & compress it - force it into the engine
the act of compressing air creates heat. a supercharger's source of air is cold dense air directly from (cold air) intake. a turbo's source is exceedingly hot exhaust gas (and mixed with air from cai).
therefore most supercharger designs (roots type may be the exception) in the act of compressing air create less heat (particularly the twin screw/modified twin screw designs).

wellcraft290

Ok turbos run hotter but rasberry in our cars are cheaper by quite a bit too even installed. That I know.

raspberryroadster

thks for that....guess costs may be higher - not a lot of demand likely for a sc'd porsche 964-so surely expensive install....
..for me will stay na - installing forced induction on an engine with 11:1 compression ratio - does scare me a touch.
actually after coming out of big power - am enjoying this car for how it is. if my wife & my investment portfolio continues to climb out out of the grave we would love 2nd car to be 993 turbo...or her wish lotus (sc'd) exige.

wellcraft290

I agree think I am going to leave mine stock and just buy a 996TT or 997TT. prices have really dropped on all of the newer porsches and for a daily driver would be more practical then spending 10k or so on the 964

BobH20man

Neil,

TPC installed its SC w/ intercooler on my 1991 C4 in 2006 at it shop in Maryland. Since then I've put over 25,000 miles on the motor. I have tracked it many days since and it runs great with no problems or "flat spots." There is adequate room under the OEM decklid for both the SC and intercooler so you do not need a wing (although I put one on). I returned my car to TPC in 2008 to convert it to a C2 with a 6-speed gearbox and turbo brakes, and at the same time got the unichip installed. Whenever I call or email Tom at TPC with other questions he usually gets back to me same day, so they are very responsive. Good luck with your decision. Bob

wellcraft290

bob why did you go s/c over turbo? Glad your happy with the car. I have heard nothing but positive things about TPC. Do you still have your heat?

BlueHeeler

They do not act on the same premise. A turbo works by utilizing wasted energy of exhaust velocity to create boost. SC works on a mechanical drive.

The turbo will be hotter. A SC will be less efficient because power is sapped from the crank especially at high rmps. Trade off.

IMHO wellcraft has the right idea, 996tt or 997tt is the simple way forward rather than trying to re engineer a 20 year old design to accept boost.

wellcraft290

plus i found a few 996tt for like 30k-36k

BobH20man

Wellcraft290--yes, I had heat until recently when took out along with the AC. I went with SC over the turbo for cost reasons at the time.

rotorheadcase

Thanks so much for posting Bob, i'm pleased that your install has worked out so well. I am still trying to find someone here in Australia comfortable with tuning the kit but it's not proving to be easy. I will call TPC and see if they can answer some of my questions and suggest a way forward for me.

Thanks again,

Neil

Christer

Personally I wouldn't do an SC install. Most applications tend to give a "muscle car" power delivery which is just blasphemy in a Porsche

I would just buy a Turbo if you want to turbocharge your n/a 964.

I agree though that naturally aspirated tuning is expensive in comparison.