James-man

Why are you arguing with me Ryan? Chill (and yes you can can use a air-air or a water intercooler and don't have to wear metal clothes to do so).

You state good facts and I am not disputing any of them. I never said air to air is more efficient. My agreement with Jim was the slam dunk preference of water intercoolers for drag racing. The several gallons of water offers a lot of cooling capacity making for a better heat sink before the car gets up to high enough speeds for air flow to do anything. Yes, I also agree with you that water will always be higher in temperature than ambient air temps once the system is operating.

Here is where you may think I am crazy. At 100+ mph, I don't believe that speed of transfer of heat between air and water makes much of a difference to an intercooler system. Still, I am not saying air-air is better at high speeds. And still maintain that air air is not more efficient so don't try to put those words into my mouth.

As far a applications go, I remain indifferent in my choices between the two systems in a 928.

I can critique Enzo's freezer analogy as well - there is very little airflow in a freezer. Clearly a water intercooler is superior for 1/4 mile burnouts.

shaaark89

good points, z
one thing i have wondered about though is how warm the intercooler water gets after driving the car for a period of time (normal driving.) since the water is still circulating through the system it will be subject to the underhood heat and even with the 2 heat exchangers i would be surprised if it didn't heat up a fair amount. would be a good experiment to try.
the big advantage of air to air as i see it is that you have an unlimited supply of cooling substance (atmosphere) which theoretically at least should keep the charge air as close to ambient as possible.

hopwood

400rwhp, 440rwhp, 500rwhp ... jesus what do you guys do in your sharks, 997 Turbo hunting? :-) What about us poor sods stuck with 240hp at the crank? This thread is making me feel like my shark is slow!

Joel
79 928 5spd
87 S4 5spd

AO

Remember that ambient temperature on the road or track is often times significantly higher than the "outside" temperature. SO on a sunny day you may have an outside temperature of 80* and the road/track temp could be as much as 100*+.

With and air-air IC setup, you would immediately be at 100*+ IC temp. With the air-water IC setup you'd be running at the 80* IC temp until the water reached the 100*+ which would take some time. (Any good thermal dynamics engineer can probably figure out how long it will take to warm up.)

And of course the air-water should never deliver warmer temps higher than the air-air IC setup as long as your heat exchangers are properly sized.

backnblack

Z and James these are great things to think about this is why I love this forum, this is where great idea's come from.

Hey Joel after getting a ride in Andrew's car I realized anything without a SC is slow so read and learn because once you have been in one you'll just have to have one.

It's all I can think about
Matt

Carl Fausett

I agree with this:

The Murph kit has the benefit of having the most installs on the S4 model, and more years in the field. The installation is very do-able by a regular guy in a regular weekend. Many satisfied customers on S4's and GT's.

killav

So if an individual wanted to buy a "Stage III" kit, who do you buy this from? Tim or Carl. I have looked at each site, and the Stage III kit is not listed on either.

Carl Fausett

I can see some are confused by our supercharger kit offerings.
Perhaps I can help.

We manufacture and sell our own SC kits for the 16v 928 and the Ferrari Modial, 308 and 328.
We also are the Dealer for Murph kits for the 87-95 32v 928. I have been selling and supporting Tim's kits for about 3 years, and carry spares (belts, mostly) for his customers.

There is a small overlap at this time - Tim has a kit for the 85/86 32v 928 and I am just coming out with one for the same car. There is a thread about our new kit now on the Rennlist.

The Stage 3 kit from Murph is an improvement over the Stage 2 kit, and may in time supplant it completely. His Stage 3 kit has produced over 500 RWHP reliably and safely. I think the world of it. It is priced about $1k higher than the Stage 2 kit. I am taking orders for it now, and Tim is shipping them - but I do not have it listed on my website yet as I have insisted on a dyno chart to accompany the web page listing and Tim does not quite have one yet to give me.

killav

Carl,

Thank you. PM sent.

Leon Speed

Carl, are there plans to change the Vortech to a Raptor on the kits for the 87+ since you went with that on the 85/86 kit?

hacker-pschorr

The 87+ kits are produced by Tim Murphy and sold through 928 Motorsports.

Tim will not be switching to the Raptor or any other brand supercharger any time soon.

Carl Fausett

I do not think Tim has any plans on migrating to a different blower than Vortech at this time.
There would be little to gain, the Vortech units are pretty good and he is having good success with them.

We (928 Motorsports) are developing SC kits for the other late-model 32v cars and we will be using the Raptor supercharger in our 928 32v kits for 87-95.

Right now, I'm just putting the finishing touches on the 85-86 32v kit.

Leon Speed

Ok, thanks for the info!

RyanPerrella

Sorry, why would you want the Raptor anyway? Whats better about it?

I know Carl your the distributor for it, so you obviously want to integrate it into your kit so you sell more units. But Ive never heard of Raptor before whereas Vortech has been around forever.

Whats better about the "raptor" surely can't be the name. Sorry that name has as much to do with a SC, as does the Bismark to the 928.

largecar379

OK, Ryan.......

I give up.

intercoolers (water to air) are better.


This next reference will send you over the deep end----


It has been pointed out by your favorite "poster", the market for turbo's, SC's, strokers, (whatever's) is probably less than 200 guys worldwide. He may be correct, so what's the big deal of one's better than another.....?


There are many alternatives to upping the power output of a 928 in general, in the end it's just a matter of money and preference?