Build me a nice 3.2 Turbo engine

Any suggestions on different types of combinations to run 1.0 bar of boost out a 3.2 turbocharge engine,not swaping engines or any other adventures. I am all ears....

Regards Juan

Juan,

My suggestion: Get JE 8:1 pistons, a pre-fabricated intercooler designed to work with your manifold, a Blitz DSBC boost controller and a Motronic controller such as the PMS system for Porsche Motronic ECUs at this link: http://www.efisystems.com/pms.htm
This system was used in the Turbo Performance Center 964 turbo conversion.

I have no experience nor do I know anyone who has done this but it should make for one very powerful engine. You have the same crank and rods as a 3.3 turbo with much better heads, cams and manifold plus the motronic ecu. If you have money to burn, then you can add raceware bolts and studs for peace of mind and do the Carillo rods thing too but at 1 bar boost it may just be overkill. Or, you could go the Haltech route, with flame ringed head seals, 98mm p&c's and ....oops, you've just spent $15k

If you were to reach 1.0 bar of boost via supercharging instead of turbocharging, you would probably net more horsepower, save more money, and loose the turbo lag! Just my $.02

-EJ

freefly,

I've got to disagree with you on your point. Please see following the following points that I copied from the Turbofast website comparing the two:

The differences between turbos and superchargers are subtle but important. Both provide additional air into the engine for more power. The most essential difference is the method of driving the turbo or supercharger. Turbochargers are driven by exhaust energy which is usually otherwise wasted out of your tailpipe into the atmosphere. Superchargers are driven by a belt which draws power from your engine's crankshaft. The advantages of turbocharging over supercharging include:

1. More power produced per pound of boost (intake pressure), since the turbo does not rob engine power from the crankshaft like a supercharger.

2. Variable power levels: a turbocharged engine can be set up to provide different power (boost) levels at the push of a button, while a supercharged engine requires changing pulleys and belts to change power levels. This turbocharger versatility can be quite handy in many instances.

3. No maintenance, adjustment or replacement of drive belts and pulleys is required for turbochargers, an aspect which frustrates some supercharger owners.

4. Turbos offer much higher overall power potential, with the ability to be modified easily for higher power levels in the future. Superchargers are more expensive to upgrade for more power, if upgrades exist at all.

5. A supercharger's drive belt will stress the crankshaft and adjacent main bearing due to the additional strain of driving the supercharger, while turbochargers are widely regarded as being quite easy on engines. It is not unusual to see stock type engine components surviving at power levels of two to three times their stock output when turbocharging is employed!

6. The turbosystem will usually be easier to install, especially on four cylinder engines

All of these turbo plus points are well taken, but there is one glairing problem.
The 911 is an air cooled engine. Turbos use heat to function. Heat is the single biggest killer of the air cooled engine. Superchargers generate some heat, but nothing like the turbos.
As for increasing the power of a supercharger, you just change the pulley. It's that simple.
I like both types of systems, but asolutely do not believe that a turbo system is easier to set up than a supercharger. Turbo systems are very complicated.
Supercharging technology has made great strides in the past decade. The auto industry has responded by offering supercharged engines in place of those formerly turbocharged. Very much worth looking into.

OK, I have to chime in on this one too I will freely admit that turbos are more efficient and will make more power.....at higher rpms. However, sc's are more efficient and make more power....at lower rpms and (in total) through the whole rpm range. I will back this statement up with pointing out that you always see turbos on most racing applications. Racing, which is almost always using higher rpms, lends itself to the use of turbos. One of the exceptions to this is drag racing where sc's are still the mainstay. The difference? hmmmm....I would say that drag racing uses the whole rpm range which lends itself to sc's. How does all of this pertain to the never resolved debate of turbo vs sc? I submit, that for street applications the use of the motor will certainly be through the whole rpm range and predominately low to medium. How often and for how long do you scream your Pcar at 7000? In addition to all of this, I also believe the drivability of a sc is superior than a turbo for the street, a la no lag. I would also say that turbos do indeed generate more heat, are harder to set up correctly, add more weight to the overall engine, etc.

Sorry to dribble on so much, I just love this subject so much!

------------------
Mark
www.mark.hargett.com
mark@hargett.com

930Fan,

I also agree with all your points, but one in particular shows where a Turbo can end up being a real double-edged sword.

4. Turbos offer much higher overall power potential, with the ability to be modified easily for higher power levels in the future. Superchargers are more expensive to upgrade for more power, if upgrades exist at all.

Now this obviously isn't a 'problem', per se, but we all know that power and Porsches are an addictive combination, and the way a turbo allows so many ways to up the ante is a little like sending a teenager out on his very first date, but then also slipping him a few thousand bucks and the keys to the local brothel at the same time...

That with enough money and a turbo you can push a 911 into the stratosphere of horsepower means that guys with enough money will do just that, and blow up their engines in the process. It's like a moth and a flame.

To guys who want to do street racing (and I guess Juan does some variation of this), then horsepower is what it's all about, and a turbo makes perfect sense. Superchargers are popular with drag racers, but the 911 engine really isn't. Turbos provide the highest horsepower ceiling for these cars.

I think the advantages of supercharging for 911s come out more when the horsepower and performance goals are less ambitious. With the newer supercharging kits, you have a very modest weight gain, a power increase across just about the whole power band, and nothing that reduces the car's effectiveness in normal street driving, at an autocross, or on a very tight track.

Both setups, obviously, have their value. You've just got to decide what your goals are for your particular car.

------------------
Jack Olsen
1973 911 T (3.6) sunroof coupe
jackolsen@mediaone.net

[This message has been edited by JackOlsen (edited 02-16-2001).]

Turbo vs SC - the topic that refuses to die! Firstly, let me address some of Rarly's points. Yes, turbos use heat to function. However, if properly designed and installed with a correctly sized intercooler for the boost level of the system, this should not be a problem. In fact, if the turbine section and the exhaust leading to and away from the turbine are thermal wrapped then they will retain the heat needed for efficient operation as well as shielding it away from the heat sensitive portions of the motor. Proper intercooling will solve the issue of the intake air being heated by the compression.

As for installation issues, I quote from Natchamp's (fabulous!) web page where he says "Mounting the supercharger, intercooler, throttle body and all the plumbing that goes with it is very tricky and time consuming." A variety of companies out there already make the headers and exhaust systems, intercoolers, oil supply lines and other bits to make turbo installation on any 911 at least as painless as any SC install. Natchamp, can you clarify whether the shortening of the manifold was something necessary for your system only or does the S.o.K system require it as well. I know that the TPC SC system comes with a new (nasty looking) manifold.

As for the issue of lag, for sure the turbo cannot be as lag free as a roots type SC but it can come very close. Check out the Jan. '01 issue of 911&Porsche World. There is a 930 with standard pistons with a Garrett ceramic ball-bearing turbo that produces 510 lb/ft of torque at 3200-6000rpm @ 1bar. These new generation turbos are so efficient that they produce measurable boost at idle and bear in mind that with higher compression/smaller turbo set up the power band will come down further still. It is this type of turbo that is used by the fwd rice brigade to run 9 second 150mph quarter mile with 1.6 litres.

I think Jack hit the nail on the head when he said "I think the advantages of supercharging for 911s come out more when the horsepower and performance goals are less ambitious....Both setups, obviously, have their value. You've just got to decide what your goals are for your particular car"

Btw, Natchamp, I think your project looks absolutely fabulous. Please let us know how you get on with the Haltech system and any tips you may have for anyone else following in your path.

Thanks for the compliments 930Fan. Do you have a project car? If so, do you have a website?

I shortened the intake manifold for clearance reasons. I like the design of the 3.2 na manifold better than the turbo one and I agree that TPC casting is pretty ugly. Actually, if you check out their website and look at some of the pictures closely you will see gobs and gobs of ugly aluminum welding. Anyway, to use the 3.2 manifold and have everything fit I had to take 1" out of the runners. I think I have done a lot of things on my project that are not really "necessary" but I just wanted to do everything as "right" as possible. Heck, I won't be doing this again soon! I think my next project will be a sand rail. A friend of mine does it for a living. I recently road in one that has a racing Nissan GTP motor in it running 30lbs of boost via a Motec M8 and it puts out @900-1000 hp. I can tell you with no uncertainty that is wayyyyyy too much power in a 1000 lb vehicle. The acceleration is shear frightening!

I also agree with you on the efficiency of the newer generation turbos, they are really something.

My Halteck E6K just arrived and I will start installing it this weekend. It's pretty straight forward, the tricky part is having no distributor, being crank fired and being twin plugged. I will be using 6 wasted spark coils and 2 triple pack igniters fired via 3 ignition channels from the E6K.


------------------
Mark
www.mark.hargett.com
mark@hargett.com

Hey Juan, If you want to invest in something wise, get a Halteck E6K or something like it. With proper engine management, you can run 1 bar with stock compression, just look at the S4, same compression as our cars. If you can control all the engine parametres, install larger injectors (40-55 lbs/hr), and intercool it, you can have all the power you want (almost, anyway).

Mike
86 Carrera t