Rogue_Ant

It absolutely will - and also provide more engine safety.

odurandina

for what it's worth, when you watch corleone's video, you get that impression that if he were not to lean on it so hard, the engine would always be in the green zone.

Rogue_Ant

???

odurandina

corleones turbo setup.... on the 944 turbo forum. running max boost, the video shows about 0-90 mph in just a few seconds. the engine is so perfectly tuned...

Rogue_Ant

Just don't know what it has to do with this thread...

odurandina

turbos and superchargers are both superchargers.


regardless whether or not that air being is powered by a turbine which is driven by the engine's own exhaust gases or simply a mechanical drive, the concern with either member of the family of superchargers is that they make a lot of heat.........


now i'm pretty stupid about this stuff. REAL STUPID. but, from what little i know of the entire subject, it seems the benefits of cooling the superheated air is fairly substantial. and there are far more examples of turbocharged 944s running very near the limit of what is possible, than there are 968s running any kind of supercharger whatsoever.... so i was just making stupid talk, about another member of the family of superchargers.... and my speaking out of turn will end here.

edz968s

But this kit with it`s low boost and efficient ceramic impeller, has been designed to be able to run without an `aftercooler` from the start of the design by Carl. So the kit is a personal choice of if you want to, or have to fit one, in Tim`s case as a race car application, then he would benefit, in my case as a road car with the occasional track day, then it should`nt need one.

Lemming

I know very little about forced induction, but I have read Corky Bell's book "Supercharged" while staying at a Holiday Inn Express Running 5 lbs of boost should increase charge temps by around 60-70oC. The use of an intercooler (efficiency dependent) should bring that number down to around 7o above ambient. With a fan blowing over my intercooler, the piping going into the SC warms up quickly (not overly hot but of course I'm in the driveway, not flogging it around the track). The piping exiting the IC feels to be around ambient, so the IC is definitely cooling the charge air. The cooler air allows for the production of much great HP. Of course, if my IC and piping are crappy, then there will be a decrease in pressure and loss of HP. For my application I'll be happy if I break even, but think that I may come out ahead on HP relative to what Carl has posted (relative difference between NA and FI). However, as Chris said, the main reason for my IC setup is safety as the car will be raced hard in the heat and humidity of the South East. I've been on track at over 100oF air temperature for 3 hr endurance races, that's a pretty brutal environment for an engine (not to mention driver)!

I agree that for a daily driver, once and awhile track rat, there is no need to add an IC to Carl's kit.

Carl Fausett

The temperature delta (gain) on a turbo kits' intercooler compared to an intercooler on a centrifugal supercharger is like apples and oranges. The turbo kit absolutely MUST be intercooled. Positive discplacement superchargers must be intercooled too as their adiabatic efficiency is from 50 to 65%

Centrifugal superchargers come in at about 65% to 75% adiabatic efficiency, and this one approaches 85%

I absolutely agree that the racing application will benefit from an intercooler. It will add engine safety and HP.
Most street installations do not need intercooling with a good centrifugal blower as they just cannot spend enough time at WOT between traffic lights

Keep in mind that our goal here with supercharging is to increase Mass Air Flow. Many think that the goal is boost - and it is not.

As you know, air heats up as you compress it (why your shop air compressor gets hot to the touch). And as you know, hot air expands and is less dense than cool air. So, in an un-intercooled application, we have exchanged air pressure for air temperature - now we have pressurized air going into the motor, but it is hot and less dense. The exchange is not 1:1 so we still gain handsomely from the exercise.

But, if we can cool the air.... then we have pressurized, cool, dense air, and have really effected the air MASS.

And that is the brass ring in boosted systems.

Lemming

Carl,

If you had to guess, how much more HP will be added to your kit by intercooling?

Carl Fausett

Because the adiabatic efficiency is already so high to begin with, the gain will not be as dramatic as a hot air system before and after intercooling.

If I had to guess, I would say maybe 10 to 15 HP on the dyno, and 15 to 20 HP on the race track.

I separate those because the dyno represents a 6-second "pull" on an otherwise (relatively) cool engine. There is not time for the systems to get heat soaked.

On the race track, we will see the intake manifold, the block, oil, everything get heat soaked and the intercooled air will have a higher delta as a result, and therefor show a greater gain.

Of course, these comments are independent of the intercooler and plumbing. It is possible to add so many bends and restrictions in an intercooler system that the net is zero. Using mandrel bent tubing, wide radius turns, a quality intercooler from a quality manufacturer - all these things help to keep the pressure losses as low as possible.

A few Rules of thumb: two 90 degree bends in the tubing equal 1 psi pressure drop. An increase (or decrease) in the pressure in the plenum of 1 psi (temperature constant) is about 20 HP. Now you know why great pains are made to make the runs as straight as possible. Its hard, but worth it. Here is one I just finished.

This system in this picture looses 6 psi in the system. We have 17 psi going into the intercooler, 12 psi coming out, and 11 psi in the plenum (meaning the tubing and throttle body from the intercooler to the plenum has a 1 psi pressure drop)

Carl Fausett

Another rule of thumb:

Do not forget about the cold air intake to the supercharger. Here is a simple way to measure the loss through your cold air supply system.

When you are on the dyno, after you are tuned you should know what HP and manifold pressure you arrived at.

Then remove the air filter assembly and do another pull.

You should show a gain of 1 psi with the air filters off, and the corresponding increase in HP. I do NOT recommend racing without air filters ! No way!

But, I am saying if your air filter assebly/cold air supply is costing you more than 1 psi, something is wrong and it needs to be redesigned.

Again, all these items have been sorted out for you in our kit. These comments are for the racers that are taking our kit and building upon it further.

odb812

Very insightful post. Thanks Carl.

Lemming

I'm assuming that you did this with your kit and the air filter provided is adequate?

Also, with the kits you have, where did you measure the "boost", just after the SC or in the manifold?

Carl Fausett

Yes, we always test our air filter assembly. Thats the filter media and all tubing end elbows up to the supercharger inlet. We had a 1 psi drop, and that is normal for filter media alone.

All boost pressures I report are in the plenum. I do not report boost pressures at the supercharger outlet.