m73m95

2.5" piping
4.90625 sq in = 2.453125 x 2
300 cfm = 100 mph
400 cfm = 133 mph
500 cfm = 166 mph
600 cfm = 200 mph
700 cfm = 233 mph
800 cfm = 266 mph
900 cfm = 300 mph

huh huh huh???

KSira

Me too!!

Chris White

Yep, that’s right – how many folks thought that the air was travelling at 200mph through their intercooler pipes?

If you change the intercooler pipe diameter to 2” (stock) the result changes to 313 mph….

Also keep in mind that regardless of the intercooler pipe size the throttle plate is approx. 55mm - so that the air speed by the throttle plate will be 268mph….!

Now think what happens when you up the power by 50%....

pettybird

so does the end tank mod on a stock intercooler actually do anything you'd notice?

m73m95

Ok, so this is where my brain starts to lose steam....


When testing the aerodynamics of a car in a wind tunnel, fluid and air (for testing purposes) have the same properties. I'm sure every one on here has seen the Mythbusters use the fish tank with moving water to test the aerodynamic properties of cars....

So, in my head, a radiator and an intercooler should have the same properties for cooling their respective mediums. The longer and thinner the pipes inside the radiator, the more time the coolant has to lose heat. Also the slower the coolant moves through the radiator, the better, so there is more time for the heat to pass into the fins of the radiator.... So why doesn't the same thing seem to be true for an intercooler?

Usually, they are short in length, with big square tubes for the air to go through. And there aren't very many tubes (comparatively to a radiator). So the air is moving fast, doesn't get spread out, and doesn't stay in the intercooler for very long.

In my brain, the larger and thinner the intercooler, the better it would work... as in the FMIC.... However, I know its not true. I just don't know WHY its not true. The short, boxy, stock intercooler is a better design. I was thinking the Lindsey stage II would be a good idea, but I am now thinking its not the best design either (As already posted in this thread).

For a bone stock engine, the stock unit is the best thing to have.... What about for an engine making 400+ RWHP? The stock unit cannot flow enough to handle that kind of power, yet a FMIC isn't good for the street due to heat soak, and its a "poorer" design.....

Could someone modify the stock intercooler to have more tubes? Can't make it any longer, but someone could add another few rows of tubes, front and back.

User 41221

KSira,

Since you insist on being an annoying pratt and evidently don't think I know what I am talking about, despite not knowing what my qualifications/education actually are; because you evidently believe anything that a vendor posts on their website regarding their products; and because I don't intend on participating in an ongoing pissing match, read the following paper by Albert Raczynski. If that doesn't expain in WAY more detail than I would care to try to duplicate just because you want to turn this into math class, then there is no helping you.

Hopefully others that are reading this will have enough common sense to understand why its a bad idea to undo what Porsche did when they designed and built the stock intercooler. There are plenty of ways to improve the intercooler for a 951 that actually needs it (imo, your average street driven 951 doesn't). Time and technology keep advancing, but you will need to remove the stock intercooler completely and replace it with a different design (ala like what the SFR FMIC is doing, altho thats not intended to be a statement validating the product, I am not familiar enough with it to say).

http://www.dvdtfab.com/intercoolertestlab.pdf

KSira

I have read the paper and there is nothing new. In fact it does not back up your statements about the stock IC at all. It concludes with basic knowledge about fluid dynamics. And no this is not a pissing contest but it now clear that you do not have the knowledge to even understand your own reference to backup your claims. It was never about me now believing you it was about you backing up your statements and the fact that if you really new what you where talking about I wanted to learn. Oh, and if you had the knowledge you could have taken my first grade math and embarrassed me badly.

If you need to personally attack me to compensate for your lack of knowledg, well then go ahead and see how much I care

User 41221

You do that well enough on your own.

anders44

it should be noted that ksira isn't popular because of his boyish good looks, but the brainpower inside his head he also has background in flow and calculations..

KSira

EDIT: Point proven on my part, I will redesign my IC you will not. Case closed on my end

George D

This intercooler was specifically designed for my 3.0 motor. The CFM calculations were done based on our expected hp and needed flow. The intake resides in the driver fender and calculations show a max cfm in the 1100 range. This intercooler is designed to flow as well as the intake.

We'll be moving alot of air.

m73m95

Anyone can correct me if I'm wrong, but here is my thinking with that intercooler...

The tubes are very short. With the air moving so fast in the intake system (as already shown above), the air won't have any time to lose any heat. The tubes in the stock cooler look to be 2, maybe 3 times the length of that one.

V2Rocket

more tubes is better than longer tubes.

m73m95

How and why? Shorter tubes are better for flow, but not for cooling...which is the reason for having the intercooler....

Longer tubes give the air more time to lose heat.

V2Rocket

you are right about short tubes being better for flow. but i believe that the overall frontal area of the IC, given considerations to endtank and internal/external fin design, is the big factor of heat absorption/rejection. so in pure heat terms, either works. but with the money that GeorgeD put into his monster-car, i bet the science was worked out for that spiffy IC.

from my bible (corky bell's supercharged!)

"Unless overwhelming reasons dictate otherwise, the core should always be positioned to present hte greatest possible internal flow area. For example, the intercoolers in Fig 8-28 (two IC's with the same frontal area, one with "vertical" channels like George D and one with "horizontal" like the 951 IC) take up the same space, but the vertical-flow units has more internal flow area (as a result of more channels, and hence, considerably less restriction."

The note on Fig 8-28 says..."The top and bottom cores have the same frontal area, heat transfer area, and efficiency, but the top (vertical) core has much greater internal flow area, due to the larger number of channels - and, therefore, lower pressure loss. Furthermore, long tubes inherently have more drag than short tubes."

The picture below that has two IC's compared, made from the same cores, one being a small IC with tanks welded on and the other being two of the same core welded top-to-bottom so that it is twice as tall yet the same width between endtanks..."This is the proper way to make a bigger intercooler. Always increase the core area by adding a greater number of internal passageways. Do not just make the same number of passages longer."

If you can have two IC's with the same size and heat capacity, the deciding factor should be how well they flow, as that affects how hard the turbo works, lag, etc.

for the record i have not stayed at a holiday inn express in several years.