Same Side inlet/outlet FMIC question

[sims76]

Here's my 18" x 6" x 3.5" Spearco. Works great at 15psi in 95 degree ambient or less weather with my setup. I have not run it at higher boost or at a higher temperature than that.

 

The way I plumbed it, the hot air goes in the top of the IC and comes out the bottom. I hacked a lot of the radiator support, but a more patient person could probably get away with cutting less.

 

I paid $450 a few years ago on ebay. I think this was part of a Mustang or Grand National kit.

 

I know you're a decent fabricator, check out the spearco core page:

http://www.turboneticsinc.com/ic_cores.htm

 

[Nigel]

Somewhere on-line, I've seen some data that showed that vertical core intercoolers (more short tubes rather than fewer long tubes) with inlet and outlets on the same side were not really superior to any other design. From what I recall, most of the flow is only through something like the 20% of the core that is furthest from the inlet. And apparently, air is actually sucked out of the core closest to the inlet because of the velocity of air moving over it. Idealy, more short tubes are better than fewer long tubes for reasons stated previously, but unless you have a lot of flexibility in your mounting and plumbing options to take proper advantage of that, I wonder if it's really going to make that much of a difference?

 

Nigel

'73 240ZT

[Scottie-GNZ]

Lets go back and look at the design Mike has pictured. The intake charge enters the I/C and is pointed directly towards the other end. The shape of the tank helps the charge maintain velocity and forces the charge downward. Also keep in mind that the entire I/C is pressurized.

[Nigel]

I'm just passing on information I read, based on some actual tests, so I'm not pretending to be any kind of authority on this. I'm just sharing what I read. In fact, I think I actually followed a link posted from a topic on this forum.

 

Lets go back and look at the design Mike has pictured. The intake charge enters the I/C and is pointed directly towards the other end.

 

I think that was the point. I suspect that air has some velocity and momentum, so it's going to want to keep traveling towards the end of the core. And like when you blow across the top of a straw, the air is going to be drawn out of the core closest to the inlet, when the velocity is highest.

 

Anyway, if I can find the link I'll post it, but I don't really have any more to add then that.

 

Nigel

[Brad-ManQ45]

Here's a link to read, I posted this and tried to get some gurus to evaluate the info buyt didn't have any luck...

 

http://www.are.com.au/feat/techtalk/intecoolersMR.php

 

Basically, the first 25% of the intercooler gets the flow due to siphoning action.

 

The fact that the air has to make two 90 degree bends also increases pressure drop.

[Sparky]

I really dig the black text and black background...the essence of good website design.

 

sheesh.

[Guest 280ZForce]

Here's a link to read' date=' I posted this and tried to get some gurus to evaluate the info buyt didn't have any luck...

 

http://www.are.com.au/feat/techtalk/intecoolersMR.php

 

Basically, the first 25% of the intercooler gets the flow due to siphoning action.

 

The fact that the air has to make two 90 degree bends also increases pressure drop.

how do we know what kind of core they were using...vertical vs horizontal? bar/plate? tube/finned?

 

yes, maybe it makes (2) 90* bends at the IC w/ top/bottom end tanks, but most side to side IC setups have many more 90* bends than that because of the piping setup needed on most cars to make those work.

 

As he says, it all depends on your setup and the way your intake plenum faces and where it sits in the engine bay and the amount of piping needed and everything else that will factor along w/ it.

 

Our L series motors happen to have the intake and exhaust on the same side, so it seems more logical and simple to plumb in through 1 side. Less piping, less travel for air flow, faster/more efficient response?, faster/more efficient air flow?

 

who knows I guess until you test out multiple ways on the exact same engine setup and the exact same car. Because we all know every motor (whether it be the same series) all run differently.

[JustinOlson]

You can get custom intercoolers with very nice bar plate garrett cores through from precision to whatever dimensions you'd like:

 

http://www.precisionturbo.net/intercoolers-custom.php

 

Heres a nice example of a big vertical flow intercooler they built for this ls1.

 

[JustinOlson]

Vertical flows are more efficient with everything else being equal. The reason for this is due to the number of passages the charge air has to go through. A vertical flow will have twice as many passages as a horizontal flow core(when comparing a 24"X12" core).

 

Due to the inherent greater cross sectional area, while retaining equal volume, the velocity of air through a vertical flow intercooler is half that of a horizontal flow. The air spends the same amount of time in the intercooler, although it only travels half the distance. Half the distance traveled through a restriction = less pressure drop and more power. Also since the air charge spends the same time traveling have the distance, its going half the velocity. This lower velocity helps reduce pressure drop.

 

Derivation for Flow in a Pipe:

 

 

 

A = Cross-sectional Area of Pipe (SI: m2)

v = Velocity of the fluid in the pipe (SI: m/s)

 

Thats the thing, the motor is ingesting a set amount of air regardless of intercooler design. It is only flowing that set amount. With equal volume cores, it takes the the same amount of time for set amount of air to pass through the core.

 

Regards,

Justin

[(goldfish)]

 

...The air spends the same amount of time in the intercooler' date=' although it only travels half the distance. Half the distance traveled through a restriction = less pressure drop and more power. ....

Regards,.

Justin[/quote']

 

 

Corky Bell seems to agree with that part. He also sates that it is advisable to diverters in the hot side end tank to help even out the air flow all the way to the end in same side apps. like this.

[johnc]

I don't know why there's so much confusion regarding air flow through an intercooler.

 

1. Air is a fluid just like water.

2. Fluids will always flow from high to low pressure taking the path of least resistance.

3. The primary factors regarding the rate of heat exchange are surface area and time.

 

Given these three "truths" how efficient do you think an intercooler is when both the inlet and outlet are on the same side?

[johnc]

I just got off the phone with Jeff at Rotary Power and, based on his testing with pressure and IR sensors, the XSPOWER design as pictured does get a good, even flow through the core. I stand corrected.

 

Also, here's some of the original research on pressure drop through an intercooler:

 

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930085468_1993085468.pdf

[Brad-ManQ45]

THe first time I went to that page it had black letters, the next white.

 

Of interest was the information concerning tuble length vs compressor size - small turbos putting out high boost need longer tubes, big turbos need shorter turbes.

 

For an all-out drag car with a huge turbo, the vertifcal orientation and short tubes makes a lot of sense, for those who have street cars with smaller turbos, the longer tube designs with smaller turbos makes sense.

 

Tradeoffs, tradeoffs.

 

I agree that keeping the volume down in the piping is critical for good response. If you only have a 60mm TB, I see no reason to have 3" piping. If the outlet on the turbo is only 2.5", then no need for 3" either.

 

The one area I found a bit lacking on that page did concern the plumbing issue of pipe sizing - both before and after the IC.....