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  Topic Review (Newest First)
01-23-2019 04:10 AM
fzust Remember folks, when operating within the cooling limits of the Rad, the thermostat dominates. You might still see a degree or 2 difference, but where you notice the difference is when the Stat is Wide Open and the temp starts creeping above 190-200F. If you are above the heat shedding capacity of the rad a cooler thermostat does nothing(or very little).

I agree with mwhenes about pulling the laminova. Not that there isn't a place for that, but when you want to double or more the whp output and run it on the track(sustained load), adding more heat load to the existing coolant system is counter-productive. Better to run a separate side cooler for the oil.

The reason the F1 is so effective is that it has very tight tube and fin spacing. The tubes are 1/4" on center, I believe. Thus the surface area is very high. Thinner helps because as you increase the surface area you naturally restrict flow of air. Since has far less heat capacity vs water, the temp of the air as it goes through the rad is already quite high as it passes the first 37mm, there is little point to going thicker. It just adds airflow restriction with minimum cooling. The theoretically perfect radiator has the perfect balance between maximum surface area(restriction) and thickness. We've approached this the closest with the F1 rad. It supported our 380WHP Optima car very well. For most users the 42mm all-aluminum rad is a great improvement in performance vs cost.
01-22-2019 06:37 PM
mwehnes FYI - In this thread Glagola1 (post #11) claims a ~10 degree difference between OEM and the F1 Radiator. Take that with a grain of salt, probably not the most scientific study but still good feedback.

Radiator aside there are a number of other changes you can make to increase cooling.
1. Increase system pressure - Change out the pressure cap on your header tank to increase pressure, which raises the boiling point.
2. Use less Antifreeze - Water is much more efficient at heat transfer by itself. Increasing the amount of distilled water in the system will help but needs balanced as the boiling point goes down (without a pressure increase) and your freezing point raises. You can get the same boiling point of 260F but more efficiency with 100% distilled water and water wetter @ 20psi than you can with a 50/50 mix at 12 psi. Clearly there are freezing issues here you'll have to be prepared to handle.
3. Electric Water Pump - you can program most of them to run (and the fans) after engine shutdown to continue coolant flow. Helps between AutoX runs.
4. Convert to Puller fans - As already mentioned.
5. Remove the Laminova - This may be your biggest issue as that thing is just burdening your radiator even more with the additional heat.

For what it's worth as the OP I ended up approaching this the way I kill spiders, overkill. I purchased BWR's 42mm radiator (not the F1) and did #1,2,3,4 above as well My logic was, similar to your issue, the lack of real data to do a comparison and I only wanted to mess this once and move on.
01-22-2019 02:10 PM
JiveTurkey
Quote:
Originally Posted by +TSRAGR View Post
By design, the # of fins and tubes is inversely proportional to the radiator thickness. Unfortunately, you're comparing too many variables between single and double pass radiators to be able to draw firm conclusions about heat transfer based solely on surface area.

If you want maximum radiator heat transfer, you should convert to puller fans and ditch the condenser. The factory setup yields good flow across the condenser (for better AC) at the expense of maximum radiator cooling.
These are all single pass. Based on the data available, the relationship does not appear to be strictly inversely proportional. Should still be able to glean some idea of performance from the surface area info.

In my particular circumstance I am running a Blade 300 tune (260whp), AC and a Laminova system with a 170F thermostat. Would like enough headroom for 350whp.

I know puller fans are bout 20% more efficient than pusher fans but would like to keep the pushers for AC efficiency as the car is 90% street driven. Car needs to be capable of 30 min track sessions (M1 concourse & Waterford Hills) and back to back AutoX runs.

I question whether anything but the Denso unit would be up to the task, but am curious as to where the EP performance radiator and Koyo fall. The hope is the core specs will help shed some light on that.
01-22-2019 01:44 PM
CRG53 I can't help you with any of your questions, but I can give you this info.
Last year I changed my stock radiator to the Pro Alloy one from Boe, I had a very minor leak in the stock one. After the new radiator was installed, I did a bunch of test driving under different conditions and found there was no difference in the performance between the 2 radiators. A month or so later I changed my thermostat from the stock one to a 170 degree aftermarket one. That made a big difference, my water temp dropped on average 15 degrees, whether I was on the street or on track, so my conclusion is that the radiators, stock or aftermarket have plenty of spare capacity, the stock thermostat was what was holding back the rest of the cooling system.
01-22-2019 01:16 PM
+TSRAGR By design, the # of fins and tubes is inversely proportional to the radiator thickness. Unfortunately, you're comparing too many variables between single and double pass radiators to be able to draw firm conclusions about heat transfer based solely on surface area.

If you want maximum radiator heat transfer, you should convert to puller fans and ditch the condenser. The factory setup yields good flow across the condenser (for better AC) at the expense of maximum radiator cooling.
01-22-2019 12:10 PM
JiveTurkey
Quote:
Originally Posted by Mr.C View Post
What kind of performance information do you get from tube spacing or fin density without knowing any other important facts which influence the performance of a radiator and the entire cooling system (pressure drop, heat transfer rates (which highly depend on design characteristics like turbulator design, end tank design,...), etc)?

The outer geometry of a radiator is not really a good indicator of its performance.
Ideally we would have heat transfer rates for each radiator. Unfortunately that information is unavailable to the unwashed masses so the best we can do is gather information on core surface area which in theory should have a fairly high correlation to the heat transfer rates. Perfect? No, but certainly not useless.
01-22-2019 11:39 AM
Mr.C What kind of performance information do you get from tube spacing or fin density without knowing any other important facts which influence the performance of a radiator and the entire cooling system (pressure drop, heat transfer rates (which highly depend on design characteristics like turbulator design, end tank design,...), etc)?

The outer geometry of a radiator is not really a good indicator of its performance.
01-22-2019 09:04 AM
JiveTurkey I have e-mailed EP and Koyo to request the tube spacing and fin density info on their products. Also reached out to a friend who recently installed a Koyo to see if he can check in case I don't hear back from them. Will update if I hear anything.

@turbophil do you have the fin density and tube spacing info available for the ProAlloy you sell? Also is this the same radiator they list on their site HERE? Confused as they call it out as a 43mm core but it is listed as 45mm on your and other sites.

@fzust do you have the tube spacing available for the "ALL ALUMINUM HIGH PERFORMANCE RADIATOR" you offer?
01-22-2019 08:33 AM
JiveTurkey Interesting info about the core density. Populated all the info I could find for single pass radiators out there (minus some offerings from Hanger111, Elise-Spares & Elise-Shop as they appear to be the same as others). Anyone have any further missing info on the fins/inch or tube spacing? Specifically interested in the Koyo HH series and EP radiators. Seems to be very little discussion of these here on the forums.

Denso F1 Core - 27mm thick - single row - 21 fins/inch - 6.4mm tube spacing (Link to BWR - $795)


ProAlloy Core - 45mm thick - twin row - ??? fins/inch - ???mm tube spacing (Link to BOE - $550)


Wizard Core - 57mm thick - twin row - 16 fins/inch - 9.5mm tube spacing (Link to GRP - $480)
Wizard Core - 37mm thick - twin row - 16 fins/inch - 9.5mm tube spacing (Link to GRP - $460)


BWR Core - 42mm thick - single row - 18 fins/inch - ???mm tube spacing (Link to BWR - $450)


EP Upgraded Core - 45mm thick - twin row - ??? fins/inch - ???mm tube spacing (Link to EP - $410) *Says they use F1 Tech?


Koyo HH Core - 48mm thick - single row - ??? fins/inch - ???mm tube spacing (Link to GRP - $400)


ChampRad Core - 40mm thick - twin row - 14-16 fins/inch - 8mm tube spacing (Link to InoKinetic - $375)


EP Normal Core - 42mm thick - single row - ??? fins/inch - ???mm tube spacing (Link to EP - $260)
01-12-2017 07:02 AM
ERDoc74 Thanks David for the pics!
01-11-2017 06:56 PM
oldmansan
Quote:
Originally Posted by darkSol View Post
Ask and you shall receive. Very slick and clean installation. Vented front under tray not pictured.

Crazy laser jammer not included
Thanks for the pics.

San
01-11-2017 05:07 PM
darkSol
Quote:
Originally Posted by ERDoc74 View Post
I unfortunately don't have any pics of their install, but there is a thread somewhere here on LT of a guy who installed it there with lots of pics IIRC.
Ask and you shall receive. Very slick and clean installation. Vented front under tray not pictured.

Crazy laser jammer not included
01-11-2017 04:40 PM
Coyne I'm going to pick up a radiator from Ron Davis. Local. Much cheaper than the ones labeled "Lotus".
01-11-2017 03:20 PM
eldonz I opted for the Pro-Alloy setup that EliseParts sells. It gave me a Water to Air IC and a new radiator. I was able to keep the AC condenser. The W2A IC works great for auto-Xing and I do not have problems on the track of either getting hot or losing HP due to IC temps.

I looked at several options because of the IC temps and this was the best solution I could find and was more cost effective than trying to get a new IC and lots of duct work.

Later,
Eldon
01-11-2017 02:50 PM
ERDoc74
Quote:
Originally Posted by mwehnes View Post
Can someone post pictures how the BOE Front HEX is installed under the crash structure? really curious what this looks like and how the airflow interacts with it.
I unfortunately don't have any pics of their install, but there is a thread somewhere here on LT of a guy who installed it there with lots of pics IIRC.
01-11-2017 05:44 AM
mwehnes Can someone post pictures how the BOE Front HEX is installed under the crash structure? really curious what this looks like and how the airflow interacts with it.
01-11-2017 01:54 AM
fzust
Quote:
Originally Posted by oldmansan View Post
Great information on the BOE frount mount hex and retaining the AC, but does this compromise the amount of horsepower that can be attained with the REV400? What kind of numbers did you attain, if you don't mind divulging?

San
San, on a peak HP doubtful, however for heat soaking on the track it might be a little better up in the airstream. The front mount outperforms the side mount in either location. However a Small price to pay for "cool runnings" for both the driver and engine.
01-11-2017 01:33 AM
ERDoc74
Quote:
Originally Posted by oldmansan View Post
Great information on the BOE frount mount hex and retaining the AC, but does this compromise the amount of horsepower that can be attained with the REV400? What kind of numbers did you attain, if you don't mind divulging?

San
I don't think so.... I ended up with 369 RWHP..
01-11-2017 12:21 AM
oldmansan
Quote:
Originally Posted by ERDoc74 View Post
Just an FYI, the BOE front mount hex (intercooler) can be installed under the crash structure to retain the AC... BOE did this for me and other LT member installed his this way as well I believe. If retaining the AC is important to you (as it was to me).
Great information on the BOE frount mount hex and retaining the AC, but does this compromise the amount of horsepower that can be attained with the REV400? What kind of numbers did you attain, if you don't mind divulging?

San
01-11-2017 12:01 AM
ERDoc74 Just an FYI, the BOE front mount hex (intercooler) can be installed under the crash structure to retain the AC... BOE did this for me and other LT member installed his this way as well I believe. If retaining the AC is important to you (as it was to me).
I have the pro alloy rad and the BOE Rev400 btw. Wish the F1 Rad from BWR was avail when I replaced my rad (because I always want the "best"), but phil did does not seem to think it's necessary in my case (mix of street and frequent track use) I have only done one track day since my build was completed in late fall and had no overheating issues.... Temps were in the 80's IIRC, so we will see if there's issues with overheating with higher ambient temps this upcoming summer.
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