TDR i/c allows way more air to the radiator
 

I changed my i/c from the AVO to the TDR. I measured airflow by taping a sheet of paper above the mouth hanging down, weighted down with 8 quarters. Then turned the fans on. I took a video before and after. Result: waaaay more airflow with the TDR. I expected a difference but not this much. The reason is that the TDR has much more opening area than the AVO i/c. Which is the whole reason I changed over. I anticipate much better cooling. Will measure temps later. See pics below.

Left is AVO, right is TDR.
Top is paper test, bottom is i/c frontal pic.

http://pages.sbcglobal.net/jcuadra/t...r%20breeze.jpg

is that the fans just pulling the air through?

Yes just the fans. It means there's far less flow resistance to air.

that is some major flow diferential oe fans right?

Looks like if you had overheating issues, it'll help quite a bit. At the same time, it'll lower the effectiveness of the intercooled air.

How will it lower the IC effectiveness? unless the internal passages are crimped down or something, it seems to me the heat sink quality is better and more evenly distributed, to make the radiator happy.

Jason- what are you referring too? the position of the TDR (isn't that the tilt for over the rad pipes)? or the actual intercooler construction?

Its basically a comparison between bar/plate and tube/fin. Bar/plate cools better, but is more disruptive to flow through it (to radiator and somewhat to motor), while tube/fin flows better (both ways) and doesn't cool quite as well. Typically tube/fin is also quite a bit lighter than bar/plate.

It's all a matter of picking your poison ;)

are you sure that airs going to the IC?

if I know jason, he's got every gap around the perimeter of all the cores plugged with some big mattress foam. that air should be going through the cores.

and he's NOT running an aftermarket radiator ;)

y8s knows me well.

I have a CSF all Al "racing" radiator, 1" core, but very very high fin density.
With the AVO cooler, I could barely track the car in 95*F weather;

The 2 ic's weigh about the same, surprisingly. (light, much much lighter than the old FM i/c's) I expected the TDR to be lighter.

User datapoints and claims on the TDR i/c is that it has about the same outlet temperature and slightly better pressure loss performance as the AVO. We'll see.

The car feels noticeably faster at the topend, but it may be because of the cool weather today. I will wait for warmer weather to make a datalog.

I'm starting to take wagers on how much torque the TDR makes. I say a bit better spool, and more topend.

Is the AVO bar and plate? Then the flow argument would be contrary to standard thinking- wouldn't it? Curious as to what makes the TDR such an improvement over the AVO - core design?

Don't know, maybe it's just the piping. Yes the AVO is bar/plate. If the temp and/or pressure loss is worse in the TDR then that's the tradeoff.

If it's better, well, the details of a given design matter more than a general "bar/plate vs. tube/fin".

Interested only because I'm considering trading out my short coldside IC pipe for an oil cooler position. That would mean running that cold pipe around the heat exchanger assembly.

Results:

- spoolup, no change
- topend, slight discernible advantage to AVO (~2%, could be meas error, AEMlog acceleration function)
- temp rise during a 2nd gear run: 4°C vs. 6°C, advantage AVO i/c, BUT the temps drop back down more quickly with the TDR. The AVO appears to have more thermal mass but heatsoak, the TDR airflow cools it down quick. Peak temps on the track, unknown.

I have yet to measure pressure loss.

Pressure loss:
TDR is better by 0 to 0.5 psi
2.5 psi pressure loss at 10 psi of manifold pressure, est 240 whp

Oh, and it looks like coolant temps are significantly cooler. On a certain mountain run, temps remained barely above my t-stat cracking temperature, while with the AVO ic it would go about 5°C hotter.

Nice work! Always nice to see actual numbers (even if ecu estimates) vs. "it felt faster."

On a completely different note, did ya get the coils I sent yet?

jason- how is it positioned relative to the AVO? fore/aft? up/down?

was the avo bar and plate?

:inout:

thanks timmy.

so basically the generalizations about how bar and plate vs tube and fin compare is supported.

a thick-wall square-cornered extrusion behaves like a big heatsink and a smooth tube lets air flow around it better.

I remember when "bar-n-plate" was cool

Starion baby!

It's not just that the tubes are smoother, the opening area of the tdr is much greater. Look at the closeups.

The AVO is a very good i/c; just needs a BEGI scoop. 8-p

"opening area" - as in the area between the tubes- right? The area where the air passes through looks to be twice the thickness of the tube on the TDR, whereas it's the same thickness on the bar and plate. (I think that's your point) Same number of tubes on both ICs?

I wished I liked the wizdom front end, because it looks like it would dramatically increase the front end air flow - the scooper just looks too "form follows function". It would be nice to resolve it in a spoiler.
http://www.wickedbodies.net/90-98-Mi...izdom%20fb.jpg

Exactly. However that would suggest a higher pressure loss for the intake airflow. Given that it's not the case, plus the poorer intake air heat shedding, it's possible the TDR has fewer internal turbulators for the intake airflow.

hmmm that wizdom front end isn't that bad on a white miata

Wished I could log the boost levels and air temps pre and post IC with my ecu.

I like the wizdom the best of the "typical" miata aftermarket fronts, just like the OE nose with the OE spoiler better.

It leans into the mouth at the top. The AVO was vertical.
I noticed that with the TDR, there was a much bigger gap for air to go above the i/c into the radiator. The gap is between the i/c and the bumper horizontal steel box section. In the AVO the gap could barely pass a finger.

Today in 85°F weather, 80 mph on the freeway for 20 mins, the a/c, coolant, and oil temps were noticeably cooler. Coolant was ~ 85°C, oil was 87°C max. Small oil cooler in foglight hole. Normally things would be at least 5°C hotter. I'm pleased.

Similar to the barNplate vs. tubeNfin argument - is the spacing between heat exchangers. I followed the the thinking that they should all be sandwiched together (I'm assuming your AVO was this way) so that the oncoming wouldn't create a path around the IC. Of course given you're results, it doesn't seem to matter since the coolant temp has improved and your air temps are too.

I guess you'd really need to put the AVO cooler back in their at the same position/angle to make this a legitimate comparison. ;)

So it was a bit hot today and I took the car to my 2 steep cooling system torture test hills. Talked my way out of a 62 in a 40 ticket on the way there. ;) Road was really wide and really deserted with 6 stinkin' lanes. Rich people complaining...

Result: the coolant is at LEAST 5°C cooler than before in similar conditions. That would mean my car can do track days in at least 10°F hotter weather than before.

Wonder if the gap between the two is also cutting back on any IC heat soak from the rad...

So today it was 98°F out, and I took the car to my torture test hill again.
Result: coolant 107°C, oil 108°C at the top of the hill.
During freeway cruise, coolant was barely 94°C and oil barely 100°C.

With my old i/c, I would get about 114°C coolant and ~115°C oil at the top of the hill under these conditions, and maybe 103°C coolant and 110°C oil during cruise.

A/C was also very comfy on '3', and I'm an a/c fiend.

Peak intake air temps were 55°C; at the bottom of the hill it was 45°C. The highest rise was 6°C, from 8 seconds of partial boost.

So now we need to find an equivalent of this core on ebay. :)

Frank

BTW I recently ran across an old article in SCC (A Silvia IIRC) where they mentioned getting a tube/fin core with a large frontal opening area, like the TDR, specifically to improve cooling.

frank - this ebay tubeNfin unit is practically a direct swap with the barNplate ebay cooler I now have (and fits w/o a/c mods).

If it were me building my setup from new, I'd go with the tubeNfin just in case- given the nature of cooling issues on a turbo Miata. Odds are, if it's reducing coolant temps tthen it's probably also improving the exhausting of hot air under the hood with greater flow through the radiator.

As it stands now, I can only create a rise in coolant temp when I come to stop after running hard (but the fan brings that down). But I'm sure that'd be different with a stock sized radiator.

Makes you wonder if a barNplate could be helped by putting a "wedge" on the front side of each tube. :dunno:
http://i158.photobucket.com/albums/t...r/bNpICmod.jpg

I've got an older FM2 setup now but dang it must weigh 60 lbs and it has the all over the place piping. I do have a PWR rad and SPALs that came with the car and I installed, but the weight savings alone would be worth it for $140.

I always knew there was a reason the Suby STI came with a very light and smallish tube and fin and people seem to make great power with 'em tuned. Heat soak is only a problem at high boost, short bursts without speed limit cruisng to cool 'em back down.

Frank

There is one company that uses cores that have rounded edges instead of square ones thought they are still bar&plate design allowing more laminar airflow.
Now just to find the link. Heck maybe it's BEGI.

The Silvia article in SCC I mentioned earlier talks about exactly that - some Japanese tuning company, may have been HKS.

I find it interesting you bumped this thread, I was just reading through this thread last night. I have just purchased a new tube & fin intercooler to replace my current B&P....

the ducting included in the kit is the magic.

IIRC, it was Dave Coleman's project S13, and the FMIC in question was an Apex'i unit, such as - INTERCLER KIT-ECLPS 95-99 532KM02 by APEXi

They call it "Delta Fin"

There are now eBay/china copies of that design. At least they look like it on the outside. Wonder how it measures up compared to the tube/fin...:dunno:

hey that's what I bought, i thought it was just tube and fin...

Intercooler 27 x 7 x 2.5 delta fin Miata RX-7 RX-8 GTI:eBay Motors (item 200360402212 end time Jul-08-09 11:44:43 PDT)

I'll examine it next week when it shows up.

To bad the TDR IC cost like 8 times more then the average setup.
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are begi intercoolers bar & plate? I've never looked into it.

Hmmm....this looks much more "tube and fin" vs. the Apex'i unit, I wonder how it'll perform?

yes.

Any closeups of that Apexi ic's tubes?

They call it delta fin in the auction, when I purchased it and saw the picture i didn't think anything else but tube&fin. I'll kinda be pissed if I get a true delta fin, because I want tube and fin.

It's a delta tube and fin, very light, very cool. each set of runners point inward so the airflow can easily make it's way into the channel.

http://www.boostedmiata.com/intercoo...%20(Large).JPG

http://www.boostedmiata.com/intercoo...%20(Large).JPG

This makes it more clear:
http://www.boostedmiata.com/intercoo...%20(Large).JPG

needs more pc pro.

Nice!

If I were to nitpick, they shoulda done something similar for the charge air entries.