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Project Supra gets an ETS intercooler upgrade, which should provide the best of both worlds in flow and cooling efficiency. 

Project Supra MKIV Part 7: Intercooling

More than just “bigger is badder”

by Pablo Mazlumian

We know this project is taking a while—trust us, we want this car finished before any of you do.  But it’s the extra time (and money) and incidentals that sometimes make projects drag out.

That said, as far as we can tell, we’ve got everything needed to proceed, from the fuel system—which we’ll talk about in an upcoming part—to the new engine management system, which will also be unveiled shortly.  In the meantime, it was very important to select a very good intercooler for our application.

Until now, the Supra’s boost was chillin’ through a 3.5-in thick, 28-in long Spearco bar-and-plate core, which worked fine.  The temps would stay between 20-25F over ambient at the back of the intake manifold, even at the daily-driven 650 whp.  Going by our numbers, we were probably fairly close to maxing out what an intercooler could do for us in terms of efficiency—in other words, the charge air probably wasn’t going to get much cooler with any other intercooler.

Still, we wanted to see if we could get the same—or even slightly better—efficiency, but with significantly improved airflow.   Simply going bigger wasn’t the answer, because not only could we introduce more lag, but the efficiency (especially at the rear of the core) and the flow itself could be compromised if we didn’t pick the right design.  And that’s all just in the core—we’re not even talking end tank design yet.  That said, an eBay knock-off from China wasn’t going to cut it today.

Thankfully, we found a firm that builds its intercoolers in-house, taking all of the above into account, and then some!  Enter Extreme Turbo System (ETS), from which we ordered a 4-in intercooler kit.

 


The ETS intercooler core for the Supra measures 24x12x4-in (30x12x4-in including end tanks), and has a flow rating of 1272 CFM with 81% efficiency at 850 horsepower.  This is perfect for our application, and yet it’s the narrowest core ETS offers, which will keep ambient pressure drop to our factory cooling components to a minimum.  The firm also provides optional anodized colors of Black, Gold, Red or Blue.

ETS intercoolers can be found in high-powered Import, domestic and even European cars, and it should be of no surprise that they’re all bar-and-plate design (as opposed to the O.E.-popular and cheaper tube-and-fin units).  But even more than just bar-and-plate designs, ETS spends a lot of R&D maximizing both ambient and charged airflows through the intercooler while not sacrificing the desired heat exchange (because if air goes through the core too quickly—whether it’s the outside ambient air or the inside charged air—it doesn’t get cooled enough). 

According to ETS, it’s all in the fin packs.  Says ETS’ Michael Roark, “The reason our cores work so well is our fins are a ¼-in tall, versus ½-in like a lot of our competitors.  The height of the fins is crucial.  By having a smaller fin pack we get more heat-transfer plates.  On a 12-in core, it’s usually 4-6 more charge rows.  Each charge row has a heat transfer plate on each side, which is where actual heat transfer takes place.”

Roark adds, “So, when we have six extra charge rows, this results in twelve extra heat-transfer plates.  Having these additional plates is especially important in cars that have limited surface area to work with, or a core that is not fully exposed.  It’s how we get better heat transfer than our competitors.”

He continues, “since we have more heat transfer plates, we can loosen up the internal fin pack for more flow (less back pressure), but we still maintain optimal efficiency due to more charge rows (or fins) and more heat-transfer plates.  Both fin packs are offset and staggered, which allows for good air flow, and forces the air to split multiple times (for multiple fin contact), versus straight-through internal fins like eBay cores, which have minimal contact with the outside of the fin, similar to a tunnel.”

“We also changed our fin design from a “/\” to a “TT” design, which gives us great fin-to-heat-transfer-plate contact,” says Roark.  “This results in better heat transfer, which takes place right at the tip of the fin pack.”

 

This is what the staggered and offset fin packs looks like, as described above.  ETS reports this improves airflow and forces air to split multiple times for multiple fin contact, as opposed to air flowing straight through like in a cheap eBay core, which will provide less cooling.

ETS reports that, due to the staggered and offset design, ETS’ external fin pack also provides better airflow to the radiator and other cooling components that sit behind the intercooler, as opposed to when the fins are simply louvered.

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Comments
Supercharged111
Supercharged111link
Monday, February 03, 2014 10:06 AM
That exhaust is a work of art, but please tell me you won't have black brake fluid like that 1100whp Supra! What's your latest estimated completion time frame? I can see why it's taking so long, when every nut and bolt are painstakingly selected to serve their purpose better than their predecessor. It can be difficult to project completion as that's a never ending process.
Motary
Motarylink
Monday, February 03, 2014 11:55 AM
The intake piping looks very good, however why is there a 90 degree silicon bend right where the pressurised air exits the compressor housing as this increases turbo compressor load? Rest of the piping has alloy bends, but that area does not.

Keep up the interesting to read project updates and thank you for posting this.
cbgoding
cbgodinglink
Monday, February 03, 2014 3:46 PM
Looks like you took the wraps off your intake manifold. What's the story there?
warmmilk
warmmilklink
Monday, February 03, 2014 4:17 PM
that Evo turbo kit looks like its for an Evo X (2008+), the intercooler is for a X for sure.
DrunkenMessiah
DrunkenMessiahlink
Monday, February 03, 2014 9:32 PM
I thought I've read rants by Eric Hsu here on the MotoIQ pages that tube-and-fin construction inter-coolers, when built correctly, are much better than bar-and-plate units? He seemed to indicate that construction of high-end tube-and-fin intercoolers is a lost art and that el-cheapo bar-and-plate units pushed them out of the market. Curious.
spdracerut
spdracerutlink
Monday, February 03, 2014 10:29 PM
@drunkenmessiah, define "better" ;) In general, bar and plate is better at cooling the charge air (air compressed by the turbo and going to the engine), whereas tube and fin are less restrictive to the external air going through it therefore allowing more air to the radiator, etc. Drag car or just the occasional pull here and there? Bar and plate all day. Road course car? I'd lean to tube and fin.
Pablo Mazlumian
Pablo Mazlumianlink
Tuesday, February 04, 2014 12:52 AM
hi y'all, thanks for reading!
@supercharged111: brake fluid will be new! Thanks for your comment, and to address both your comment and question: while the project will be ongoing, we should be able to have the car up and running full-tilt by early-to-mid Spring.

@Motary: I had it setup this way with my previous setup and liked it over having a neck welded to the turbo. The bend is very gradual, and the silicone is very thick.

@cbgoding: no change to the intake manifold--the heat shielding is all underneath. It was originally intended to keep unwanted block heat away.

@DrunkenMessiah & spdracerut: Having had the previous bar-and-plate Spearco unit on previously, I had zero issues with radiator cooling (although it's also a large PWR unit). In fact, if it dropped below 40F ambient, I couldn't get my water to get past 130F!
At least for this application, bar-and-plate should be fine in terms of the ambient air flow. Granted, this staggered setup will slow it down even further, but I've got room to spare with coolant temps (and we've even got dual electric fans on now vs one large mechanical fan).
Also, while not fully relevant (the setups were different on the these cars--ie intercoolers weren't blocking radiators, etc), it's interesting to see bar-and-plate designs on two of the most iconic turbo (and high speed!) cars of all time--the Porsche 959 and Ferrari F40, if I'm not mistaken. I assume they had good reason (and hesitate to think it could have been for cost savings!).
SWR
SWRlink
Tuesday, February 04, 2014 6:28 PM
1272 cfm... at what test pressure? CFM without the test pressure tells you nothing... and in 99% of cases, if you test an IC in a flowbench the rated core CFM number is a mile off as the end tanks usually are fitted with piping so small they not only restrict the core a lot, but induce lag instead of removing it.. :)
Dan DeRosia
Dan DeRosialink
Tuesday, February 04, 2014 8:46 PM
Looking at racing photos I have handy, the Nissan ZX-Turbo GTP cars used bar and plate ICs too. The advantages of tube and fin ICs passing air through may be a lot less important on cars where the radiator and IC aren't sharing the same airflow and so you can just worry about heat transfer efficiency. This is in reference to the 959 and F40 by the way - I know the Supra shares flow between the rad and IC.
TnF
TnFlink
Wednesday, February 05, 2014 8:07 AM
You know ETS can fabricate you custom intercoolers? I've designed one while being abroad with just simple measurements and even did a simple cfd. ETS quality is awesome. And actually it's not even expensive for what you get! Car in question is an 200SX S13 with a CA18DET (yeah laugh). Here's some pics i could find: http://imgur.com/a/yz1kK
From then i replaced the stock radiator with a driftworks one. Btw a question you may answer. As you may know the european ca18det's came with a water to oil cooler because of the autobahn (as well as a diff cooler). On long top speed runs above 200km/h even with the new radiator which keeps water temps in check, my oil temps will rise to 120oC even at ambient temp of ~20oC (using castrol edge 10w-60 - hot Mediterranean country). I didn't push it more than this. How long does the oil keep without breaking and loosing pressure? Anyone from experience? CA, RB engines? What's a safe temp?
SWR
SWRlink
Wednesday, February 05, 2014 8:18 AM
TnF, get a Mocal (Laminova) heat exchanger and hook it into your cooling and oil circuits instead of the stock one or better yet, in addition to it. That'll even out your temps nicely, especially if you have some cooling capacity to spare for your engine coolant.. We did so to keep drift cars on slow circuits from boiling the water while the oil was still frigid, and saw nothing but improvement in all aspects. Steady 90-95ºC for both now, compared to 60-65ºC for the oil (too cold, I know) and peaks of 120ºC for the water - marginal boiling - after a hard stint.. Oil temps get to running temp faster too.
TnF
TnFlink
Wednesday, February 05, 2014 8:50 AM
Thanks for the response. And i was going crazy running water over 85oC :p If i had money to spend on it i would add one right away..But when you start it never ends. Add the fact i'm a student studying in UK (and probably staying here since i'm finishing my masters in a couple of months) i don't even know when i'll drive my car again :/ The correct way is to add a sandwich plate with a thermostat. Running oil temps so low it's bad from a performance point of view.
SWR
SWRlink
Wednesday, February 05, 2014 10:42 AM
TnF; running oil temps at 60ºC or lower like we did before the Mocal entered the Supra is not just bad for performance if the engine is not made for it... We killed a Mitsu 6G72 (3000GT) V6 with that. Had high temps - coolant - before, compensated with plenty oil cooling, did not help much, guys ran thick oil too, then we completely reworked the coolant cooling system. Water temps dropped by 40ºC down to 70ºC. Oil temps hit 50ºC or so, I found in the logging later on. They did one hard pull in 4th.. and it ate the bearings for lack of flow. They did not think of going to 10w-30 from 20w-50 when the temps dropped that much.. :/
SM_Clay72
SM_Clay72link
Wednesday, February 05, 2014 11:02 AM
^ Seems weird. Flow rate should not matter that much as long as the pressure is there. Pressure is what keeps the film in the bearings. It's not like oil will not flow to all locations it is pushed to at 50C. Your bearings aren't going to dry out unless the engine has a very poor oiling system. If that were the case, every moron kid would be blowing out bearings everytime they do a cold start and hammer on the car.

I agree low temps are bad, but i would be more concerned with low temps in terms of engine not getting up to temp and clearances being out. Those moron kids are doing damage. Can't deny that.

SWR
SWRlink
Wednesday, February 05, 2014 11:55 AM
SM_Clay72; True, but when the oil is thick enough all you do is punch open the relief valve and the "end user pressure" as measured at the end of the oil path drops as the volume doesn't go where it should because of increased viscosity. Path of least resistance and all that... So you lose oil volume and local pressure. Like at the rod bearings.. Maybe not enough on a stock engine beater, but add to that 750+ AWHP, 2 tons of daily driver and 1.2 miles of straight, empty freeway. Might have been marginal to begin with, but it has run longer stints now, at the same clearances and thinner oil.. :)
Dan DeRosia
Dan DeRosialink
Wednesday, February 05, 2014 9:19 PM
Flow rate actually does matter; oil pulls heat away from the bearings too. It's not like babbit metal takes much to soften.
TnF
TnFlink
Thursday, February 06, 2014 9:23 AM
Yes usually engineers will design engine component tolerances at a specific usually narrow temp range. As mentioned above oil flow rate is as important as pressure, actually localized pressure. Because if the viscosity is too high the pressure from the oil pump to the crank bearings will differ a lot in terms of magnitude. And running too cold therefore it will be to tight for the rpm and load you are running. Then you throw a rod out. Actually i'm probably the last or couple last that haven't blown up the CA18DET engine, which from every story i heard it was due to oil pressure problems usually because of overheating. Not to mention that i never serviced the internals; >135k miles 22 years old. Actually check this video: http://www.youtube.com/watch?v=N1JVRPgk6y0 Don't bang me why this is in a highway. Normal oil temps at the start, 120oC by the end of the run. Not too long. I can't remember if i had the stock radiator at that time but it even with the aftermarket one oil temps don't tame.
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