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Discussion Starter #1 (Edited by Moderator)
So we've been playing with a new project at BWR. Our Ultimate street car has been upgraded with alot more power with full racegas tune etc. This car is seeing alot of track duty and combined with the front mount intercooler, we've had trouble keeping temps down. Additionally, I wanted to get some weight out of the radiator compared to the big double thick monster in the XP car.

So after talking to several experts in the field, we found a radiator core like none other. It is the Denso F1 core.

It is called the F1 core because F1 cars(as well as NASCAR, INDY etc) use it.

What makes it special? Essentially the tube spacing of the car is very small, only 0.25" center on center vs 0.4" So there are more tubes running across which gives more surface area for the water. Additionally, the fin spacing is very high at 21 Fins per Inch vs 14-18 for other solutions. This gives more surface area for the air to transfer heat.

Here's the last bit that will blow your mind. It is 27mm thick. Yep, not 42, not 45mm, 27mm. That's it.

How can that possibly work? Simple. Specific heat of water is 4.2 times higher than air. That means it takes 4.2 times more energy to heat a qty of water 1 degree than air.

When the cooler outside air hits the radiator, the air heats up 4.2 times the rate the water cools down. Thus the outside face of the radiator does alot of cooling but halfway through the radiator, the air is much hotter but the water only a little cooler. So the back half of the radiator doesn't do much since cooling is also a function of delta between the water and air temps. As the radiator experts told me, the first 1/3 of the radiator does 2/3s of the cooling.

Better to make the radiator thinner, use more tubes and fins to get the flow and surface area for the water and air to exchange heat. This is a more expensive manufacturing process.

We just tested this design on the car this weekend. The car did not get above 190F and recovers much faster. Previously we would see 225F+ Although contrary to conventional wisdom, this radiator will support over 400HP

The last advantage is obviously less weight. Nearly 2.5 lbs lighter! Saves even more in water weight.

The only downside is that it is spendy. As we have learned the hard way, "Buy it Nice or buy it Twice!"

We have a small batch on order. Order while supplies last!

27mm Denso F1 Radiator
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I will totally buy this! Thanks for making it for our cars!
 

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You continue to be a great assets to the community.
 

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Can't wait to get mine and install.

Shameless plug: I've been running this radiator for three years now and it's amazing. No overheating issues ever. It even has an extra 0.3 gallons of coolant capacity.
Thanks for this darkSol - I was a little worried about reliability/durability since this radiator is so thin compared to the others. Sounds like I don't have anything to worry about. Perhaps you have any pics of it as it sits in your car that you can share please?
 

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waiting...I was informed it will be a few weeks.
 

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Installed and things looking good! Sits lower in the front of the Elise, lot more room underneath the front clam and those end tanks, welds and overall build is nice! I found myself staring at it last night. LOL

The temps remained normal and planning to run it this week as it will be some nice 90+ degree days.
 

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Like @goelise who just had his radiator upgraded to the Denso F1, I am currently having my radiator upgraded to this model. I'm looking forward to driving my car after this upgrade, at which point I will surely post my observations.
 

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Entropy240 - when I came to pick up my Elise I took a quick pic of our rides as they parked them next to each other ....



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I asked for my old parts. Pics of the old Factory Radiator, 15k miles on it ...

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Goodbye plastic tanks.

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The new F1 Radiator sits noticeably much lower than the factory radiator. Love seeing the all aluminum rad in there.

Kudos to Jon A. and Lotus of Glenview, IL:
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Been driving around and temps are very stable at operating levels.

To test everything I also turned on the AC to see if temps rise in traffic and did not notice the temps rise like it used to since it was stop-and-go type driving scenario. I heard the fans go on and I do notice I can feel more airflow coming out of the front vents. Just first impressions and all looks good. No coolant leaks and going out some more this whole coming week.

Entropy240 hope your car gets done soon and looking forward to your impressions.
 

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Nice pics @goelise of the cars. They look like two dogs who haven't had dog companionship in a long time. So happy to be together.

I will be sure and post my impressions after I get the car back.
 

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So I picked my car up on Friday after the Denso F1 radiator got installed at Glenview Luxury Imports, and so far the improvement is noticeable. Ambient temperatures were in the low 90's and engine coolant temperatures were consistently running cooler than it used to under similar conditions previously with the OE radiator. Moving even at low speeds the temperatures were 186-188°F. In slow city traffic the coolant temperatures took longer before it would start to rise, the peak temperature I would estimate to be approximately 10°F cooler than with the OE radiator, and once I got moving again the coolant temperatures would start recovering much quicker than it ever did before.

Now this was only one trip thus far after upgrading my radiator, but the improvement is profound. Simply, everything @fzust claims about this product I have observed personally. I can't thank Fred @fzust and the other various vendors we have out there supporting the Lotus community enough. We are all fortunate to have such great after market support!

Also, several people have inquired about shops in the Chicago land area, and I can say that I am thoroughly pleased with the service that Jonathan at Glenview Luxury Imports provided. It is also great to have Lotus factory support where we can get it.

Regards
Terry
 
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