Any downfalls of one sided front mount intercoolers?

[Skip01]

Just like the title says are there any downfalls of say this http://cgi.ebay.com/ebaymotors/FMIC...emQQcategoryZ33742QQihZ009QQitemZ190077531932
intercooler vs say this one http://cgi.ebay.com/ebaymotors/JDM-...tegoryZ33742QQihZ020QQitemZ300045714782QQrdZ1 ?
Thanks ahead of time!

PS. i have searched and have found very little respnose to this question.

 

[adiffrentcity]

regarding deletrius' pic, look very closely at DSMunknowns first option. It looks like there is a partition plate to separate flow that was welded from the inside before the tanks were mounted to the core. Anyone else see that ridge in the in/out tank? It's kind of a bad pic Im looking on ebay now for a better one.

 

[adiffrentcity]

Well here's a pic that shows what I think might be a plate to split flow, see the line?
http://s1.promotionsupplies.com/ebay/etdmotors/images/ic/au-ic0014-2.jpg
Even better if you could fit it
http://s1.promotionsupplies.com/ebay/etdmotors/images/ic/au-ic0010-25-1.jpg

 

[adiffrentcity]

Has anyone tried one of these "one-sided" intercoolers? What about pressure drop and other specs from the manufacturers?

 

[kenamond]

maybe so but the pressure drop in most side to side FMICs is quite low, and lower temps>higher pressure.

But if you are boosting 2psi higher, the air is hotter. I'm not sure which wins, but if the top-bottom intercooler is almost as efficient at cooling and has much less pressure loss, it might win by keeping the turbo outlet temps down more than the temp difference from it's slightly less efficient cooling properties.

If you get a lame endtank design in a top/bottom FMIC that doesn't have internal guides to force the air to distribute itself evenly all along the core to its far end, they can act like a core that is half as wide. That makes me wonder about calcifer's statement about having the inlet/outlet on the same end of the core. If they're on opposite sides, the air is probably going to spread out more on its own without as much of a need for the internal endtank guides. Where's my Maximum Boost book?...

Another issue with all of these intercoolers is the flat front edge. They don't make airplanes or race cars with square fronts on them for a reason. You end up flowing less outside air through the core because of it...where's that book...

 

[DSMunknown]

But if you are boosting 2psi higher, the air is hotter. I'm not sure which wins, but if the top-bottom intercooler is almost as efficient at cooling and has much less pressure loss, it might win by keeping the turbo outlet temps down more than the temp difference from it's slightly less efficient cooling properties.

It depends on a number of things - how well/poorly the designs of both competing intercoolers are, how well the intercoolers are matched to the turbo, etc.

If you get a lame endtank design in a top/bottom FMIC that doesn't have internal guides to force the air to distribute itself evenly all along the core to its far end, they can act like a core that is half as wide. That makes me wonder about calcifer's statement about having the inlet/outlet on the same end of the core. If they're on opposite sides, the air is probably going to spread out more on its own without as much of a need for the internal endtank guides. Where's my Maximum Boost book?...

I completely agree. Flow dividers are extremely important (I believe that can be said for most, if not all, intercooler designs). I wonder if there is a mathematical formula or scientific calculation that can be made to address the optimal design/placement of flow dividers for a specific application...

However, I think flow dividers are beneficial for all FMICs. SMICs might be a different story, or it might be the case that flow dividers on larger SMICs are even more beneficial than on a FMIC.

Another issue with all of these intercoolers is the flat front edge. They don't make airplanes or race cars with square fronts on them for a reason. You end up flowing less outside air through the core because of it...where's that book...

Just need some clarification here - Are you refering to the "rectangular-ness" of some end tank designs seen on many FMICs? If so, then I also concur. It seems to me that for the same/similar reasons aftermarket intercooler piping doesn't take hard 90 degree turns like seen in the photo below, this would also be a foolish design for end tanks.

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[Low Impedance]

a curved 90 bend reduces pressure enough (~1psi loss) [which is another reason why i HATE the 'long pipe route' FMIC kits.] That rectangle thing should be left for things like railings on buildings. I wouldnt even want to know what kinad of backpressure that thing would make. You'd get a nice tumbling in that sharp corner that would make a "ball" which would block a damn good portion of the air coming through.

 

[Dorifto]

http://i64.photobucket.com/albums/h167/daviticus/DSM/My GSX/100_0221.jpg

This Saab FMIC is divided in half, as mentioned earlier in this thread. Outflows the stock SMIC by a longshot, even a lot of smaller FMICs available both on eBay and junkyards.

I'll admit, it's small and probably not worth the cost, but in my case it was free, and FERNCO couplings are easy enough to find here for cheap.

 

[PieEyedPiper]

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Hah, thats is an exact representation of the elbow for my greddy "style" hard IC piping. Time to hit up napa for a 90* coupler!!

 

[kenamond]

Just need some clarification here - Are you refering to the "rectangular-ness" of some end tank designs seen on many FMICs? If so, then I also concur. It seems to me that for the same/similar reasons aftermarket intercooler piping doesn't take hard 90 degree turns like seen in the photo below, this would also be a foolish design for end tanks.

What I mean is that the outside air which is trying to squeeze between the bars runs into a flat wall. The edges of the bars are flat. This causes flow problems that effectively diminish the rate of outside air cross flow through the core. If you look at the stock SMIC, the bars are rounded on the edges. Corky Bell (found my book) refers to these as extruded-tube cores.

Another thing to consider with the top/bottom core is that the air moves slower through the core. Even though the air has a shorter distance in which it can transfer heat, it is moving slower, so it's in the core longer. I suspect that a top/bottom IC with a good endtank design would be better if you can fit it in there.

For what it's worth, Maximum Boost, Chapter 5: "Rule: The single most important aspect of intercooler design is low internal pressure loss." I have to argue with this a bit, because no intercooler has less pressure loss than any intercooler, and that's not a better solution. Anyway, I think his point is that pressure loss is very important.

 

[kenamond]

Here is the core design with better flow below (from HKS IC site):

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Notice the rounded front edges.

 

[DSMunknown]

Mack-



Does Mr. Bell discuss end tank pipe diameters in relation to IC pipe diameters? That is to say, what is the relationship between the end tank pipe diameters and the IC pipe diameters? A side issue - is there an equation/formula to apply this to when considering end tank design in relation to IC design?

How am I thinking about this? Well, hopefully this summer I can have custom end tanks replace the Supra SMIC end tanks that I currently have to deal with. As I'm sure you are well aware, both end tank pipes are roughly 2.5" in diameter. However, the IC piping is somewhere around 2.25". So what kind of theoretical advantages (if any) could come of making the end tank inlet/outlet smaller to accommodate the smaller IC piping?

My own initial reaction would be to claim that the end tank outlet would be causing more restriction to the flow of the compressed air because the piping decreases as it goes through the 2.5-to-2.25 inch exhaust adapter.

However, I am not completely sure of the effect the other exhaust adapter (between the LICP and end tank inlet) has on the flow of compressed air. That is, I'm not sure if the adapter would have the same/similar effect (I assume it wouldn't). Presumably, this adapter would have a different effect on the flow of compressed air, because it is opening up into a larger reservoir of containment (namely, the end tank).

 

[kenamond]

Mack-



Does Mr. Bell discuss end tank pipe diameters in relation to IC pipe diameters? That is to say, what is the relationship between the end tank pipe diameters and the IC pipe diameters? A side issue - is there an equation/formula to apply this to when considering end tank design in relation to IC design?

Unfortunately, I'm at work, and my book is at home. I'll try to take a look sometime, but work is hectic, and I'll be gone next week. Also, the one textbook I sold back to the college bookstore for beer money in college that I regret not having today is my "Mass and Heat Transfer" book which describes flow in pipes, etc.

A smaller pipe diameter will have increased pressure loss per unit length than a larger pipe. Yes there is a formula, but it's in that book I sold for beer money. I'd have to look around online.

Also, the "quality" of the transition from larger to smaller diameter also has an effect, as the inertia of the air next to the wall of the larger pipe carries it off of the wall of the smaller pipe kinda like a bike hitting a jump (called separation) if the transition is too abrupt. The airflow ends up funneling itself into a smaller opening than the smaller pipe for a bit before it re-expands to the diameter of the smaller pipe farther downstream. That smaller "funnelled" region acts like a smaller diameter pipe and gives a bit more pressure loss in that region. Also, if the air is moving fast enough and has the right "Reynolds number" (characterizes the density and viscosity of a fluid in one number) the separated air may not "unseparate", but I'm not sure how much of a problem this is.

The trick is to use a more gradual transition without corners, but the details of this will depend on that Reynolds number again. If the Reynolds number is low, flow will be laminar and smooth and non-stirred up, but if it's high, it will be turbulent. The behavior will depend greatly on whether the airflow is turbulent or laminar (two different sets of equations, as I recall). Considering that the compressor probably stirs the crap out of the aircharge, it may be turbulent entering the intercooler. I'd imagine the exit flow from the IC would be more likely to be laminar.

As for the increase in diameter going into the IC, that should be smooth as well, or the air will separate like riding a bike quickly off a short wall onto the street.

That's probably all too textbooky, though. I think the best you can do if you're keeping your IC piping is to gradual transition, but it may still not be a big deal. You could have the endtank pipes tapered from 2.5 to 2.25, but that'd trash being able to go to 2.5" IC pipes later. Also, there's not much room to work with on the outlet of the Supra SMIC, but you might be able to shorten the UICP and add a 2.5-to-2.25 recuder/coupler which is internally tapered. Might be too tight, though.

So I doubt I answered your question...

If I get a chance, I'll let you know what Corky has to say about it.