Carl Fausett

Just got off the phone with my friend Dave Lindsey at Lindsey Racing... he developed a very unique extruded aluminum tube last year that houses air down the center and water around the perimeter.

His goal was 944-turbo related.... the 944 Turbo intercooler only flows 250 CFM and he was trying to develop a replacement that would be less restrictive. He did. The "Hard Pipes" as he called them, flow 500 CFM in the 2.75" size. A pair of them in parrallel flows 1000 CFM...

Anyway: I will let Dave Lindsey work out all that 4-popper stuff.

I saw his Hard Pipes and saw a number of 928 applications.

There is about 18" of tubing from the supercharger at the front , along the right cam tower to the rear where it goes into the motor that we could use for cooling - and yet, as we all well know, the under-hood space on a 928 comes at a premium (especially on the 85/86 cars with the "pipe organ" intake).

This tubing comes in 2.75" inner diameter - same size as the Murph 928 kit that we sell. Perfect. We see applications on all Centrifugally Supercharged P928's, 16v and 32v alike.

You can install a single coolant line, or as many as 8 coolant lines at each end to put the cool water in and take the hot water out. Basically you can go as nuts as you want...

Excellent installation diagrams/options are available here:
http://www.lindseyracing.com/Merchan...ry_Code=CONFIG

Lindsey Racing is moving into their new shop in the next coupla weeks - so my development of this for the 928 is paused for now. But, Dave and I will pick it up again in November and be putting together a little kit with pumps and instructions so you can install this to any tube-fed 928.

I hope it will be the intercooler solution the 85/86 guys have been waiting for - but we will make kits for all.

AO

Very cool! (no pun intended) But it looks expen$ive! $$$

Ketchmi

That sure looks like it was derived from the Laminova style cores...

If he has perfected them and made them compliant with the 928's requirements, all the power in the world to him. Good job!

Carl Fausett

A little history - before I developed the plate and tube intercooler that we have now, I went down this very design road that Dave Lindsey did - and developed a intercooler that would fit in that 20" straight run on a 16v SC 928.

It suffered (as most designs of this type do) with surface area within the intercooler - so although it was very fast with little/no pressure drop, the hot air did not spend much contact time with the cool walls while it passed thru. So it did not produce the numbers we wanted, and we went to the traditional plate-type intercooler instead.

The key here is the extruded fins that run within the pipe - that's where we are now picking up the sq inches of contact area that my earlier design lacked.

SharkSkin

Carl, wasn't there another IC option that replaced the stock air box? Whatever happened to that idea?

blau928

This is not the laminova style core.. this is very similar to if not the PWR type core...

The laminova core is very different, and the fin spacing is much finer.. In addition the fins are on the outside of the barrel/tube over which the air flows. The core in this setup has air flow inside the tube with the fins protruding inwards..

Just my $.02

fst951

Hi there Carl.

I don't belive the 250 cfm numbers on the 951 intercooler are accurate as with just touch of modification they can be made to flow much more. I have personally gotten 350cfm with 1.1psi drop at sea level with just changing the intake and outlet angles and that is pretty easy I have worked with many more 951 engines than anyone expect maybe Tom Charlesworth and Jon Milledge. I will be interested in seeing the numbers on these, however. The technology has been around for awhile, but I hope he can make it work.

Thanks,

Garrity

Imo000

Very nice concept. I've been thinking of something like this before. Nice to know it's already availabel.

Carl, I have an idea. Noticed when changing my whife's Ford Contour 24V water pump that the pump is totally seperate from the engine. The design is almost as if Ford forgot to design a water pump when developing the 24V engine and justt grafted one after the R&D was done. This is good cause the pump is totally seperate from the engine block. It's a stand alone unit just like a power steering pump. It's a mechanical pump driven by a small belt. It would be a perfect candidate to graft this to an SC'ed and intercooled 928 to pump the intercooler water.

It's worth at least looking into the possibility of using this in a SC application. This would totally eliminate the need for an electric water pump. Mechanical pumps are always more dependable and being an off the shelf item, the cost is nominal.

This is just an idea.

DFWX

While it would seem to flow more air than the typical air/water intercooler, there seems less contact area with the air - and would seem to cool the air less. What would two of those cost?
Mark
DFWX

TAREK

a silly question. Why don't the fins extend further outside the tube wall? seems that the ability for the coolant to extract heat can be increased by increasing contact area between coolant and heat sink

SharkSkin

It seems to me that given the length of these units, the surface area should be adequate. Especially if you consider that many intercoolers only have the air moving through an inch or two of passageway. It would be interesting to see figures for temp drop end-to-end in a working system. It would seem that the idea is just too different to sell to many folks without hard data.

Carl Fausett

Mark is spot-on with this.

Of course, this is a compromise. (What isn't?) Yes, the amout of sq in available in a straight-tube shell like this is less than a plate-and-tube type heat exchanger, so the thermal efficiency is less. But the pressure drop is also less.

To extract the most heat from the air, you must disturb the air flow and MAKE it move close by your cooling material and stay in contact with that cooling material as long as possible. This of course, slows it down, so you get resistance and pressure drop. So, as a designer, you balaance between pressure-drop and thermal efficiency.

The better the intercooler is at extracting heat, the more pressure drop it will have - as a general rule of thumb.

The 3rd factor is "how much room do you have?".

Where this application is concerned - especially the 86/86 928 with the "pip organ" manifolds - there is not a lot of room for a standard plate and tube intercooler and the straight-tube concept allows us to provide some heat relief in a very small space.

The first bench-test we did of a 8" section of this intercooler showed a 40 to 50% efficiency. That's pretty good for an 8" tube (short). A plate and tube intercooler like those we use in the 16V Stage 2 kits will have 75% or more efficeincy.

I have added a picture of one of our plate-and-tube intercoolers from our 16v Stage 2 kits below so you can see what that looks like.

BTW - It would be better to run two 8" straight coolers in series than one 16" cooler - the reason is then you can re-insert cold water again half way down the run.

JEC_31

Hmmmm.....

Very Interesting....


Hmmmm.....

lorenolson888

Seems pretty cool... uh... neato I mean

Carl can you explain efficiency comaparison to us laypersons...

In terms of inlet and outlet temps.

Sounds like the pressure loss will be minimal...

Thanks,

LO

Herr-Kuhn

Intercoolers are a double edged animal...you balance heat transfer and pressure loss. My preference is air to air with a bar and plate design core. Mine use what is called a bump style turbulator...lots of surface area without huge pressure drops. There is more aluminum in a bar and plate compared to a tube and fin style, therefore it can handle a slug of heat more effectively. It is hard to argue with the simplicity on the air to air, but I agree the air to water does have merit in tight quarters...but contrary to popular belief there is ample room on the 928 for air to air.

I have seen these tube style units out there, but I don't see how there would be much heat transfer effect with them. The air has to be able to snuggle up to the aluminum before it can give up its heat...that is where the turbulator comes into play. Perhaps use these in addition to the intercooler?