The 24 Hours of Lemons Forums → Lemons Tech → Heater core, leaking, delete or replace?
I haven’t had a chance to take the cover off yet, so hoping it’s just a fitting. But if our heater core is toast do you think it makes a difference in cooling to have that extra space that the water runs through or OK to just delete it?
Cooling isn’t the reason to have a heater core, having a working hot defrost for rainy races is. Our first few builds we took all that stuff out. That was a mistake. Now we leave it all in, to the point that I had to junkyard source some of it for our new Civic), and in the rainy races we have run in the cars since it has proven to be a smart decision. It’s great to be able to see in the rain, and be a little warmer in the spring and fall races when it is cold (and raining/snowing/hailing/sleeting).
I think it depends on the car/engine. My Volvo 4 cylinder turbo has no heater core and does not have cooling problems. Some of the cars I raced before my Volvo needed all the cooling they could get to keep from overheating.
The thing to consider if you're relying on the heater core to keep the engine cool is the weather you're racing in. If you're racing somewhere hot, then blasting the heat to cool the engine will literally bake your driver. We did this to a driver in NJ one year in the daytona before I got that cooling system sorted, and our cool shirt system was acting up that race. Almost killed him, I'm not joking. He had bad heat stroke, forgot how the track went, somehow got off, parked the car in some random paddock space, and started wandering the pits blindly until we could find him and get him cooled down and hydrated. It was scary as hell and I will never again rely on a heater core for engine cooling.
But I do agree the heater core for rainy races is awesome. Driver can get warm, windshield gets help, win win.
The thing to consider if you're relying on the heater core to keep the engine cool is the weather you're racing in. If you're racing somewhere hot, then blasting the heat to cool the engine will literally bake your driver. We did this to a driver in NJ one year in the daytona before I got that cooling system sorted, and our cool shirt system was acting up that race. Almost killed him, I'm not joking. He had bad heat stroke, forgot how the track went, somehow got off, parked the car in some random paddock space, and started wandering the pits blindly until we could find him and get him cooled down and hydrated. It was scary as hell and I will never again rely on a heater core for engine cooling.
But I do agree the heater core for rainy races is awesome. Driver can get warm, windshield gets help, win win.
^This, +1
Neither of the two Miatas I've run have had heater cores and neither have had issues with water temps.
Now building an E46 and keeping the heater core. Not for cooling but for defrosting.
We never run a heater core. If we need the clear the windshield, we install the universal heater grids on the windshield and run it that way.
We never run a heater core. If we need the clear the windshield, we install the universal heater grids on the windshield and run it that way.
What product do you use for that?
chaase wrote:We never run a heater core. If we need the clear the windshield, we install the universal heater grids on the windshield and run it that way.
What product do you use for that?
I forgot where we got ours but check out this site.
https://frostfighter.com/catalog.htm
EDIT: This is the kit we use
https://www.bimmerworld.com/Safety-Race … r-Kit.html
Hey thanks everyone, really appreciate the responses. Since we don't have a dash any longer and no defroster, it would seem best to remove the heater core so we're not heating the cab during our races. We've not had a problem with cooling yet, so hopefully ok with core removed. We'll have to get a grid system or something for potential rainy events - I saw the bimmerworld one on facebook today actually.
Hey thanks everyone, really appreciate the responses. Since we don't have a dash any longer and no defroster, it would seem best to remove the heater core so we're not heating the cab during our races. We've not had a problem with cooling yet, so hopefully ok with core removed. We'll have to get a grid system or something for potential rainy events - I saw the bimmerworld one on facebook today actually.
That may have been my post because I get questions on it. One of the biggest contributors to fogging is windows. From our observations, the cars with the rear window or lexan all around have worse problems.
I'm also a huge proponent of the electric defog kits. We have one and it's amazing. That plus a functioning HVAC blower means zero fogging ever.
Some cars can get away with just chemical treatments on the glass, or chemical plus blower, but the Saab cannot, it fogs like mad with just those. Comes down to a combination of factors like how much natural air movement you get from your open windows, how much water your car holds onto inside, how much you're heating the floor with exhaust (which tries to evaporate the water, which then condenses on glass), and some other factors. Some cars have little to no fogging issues, some are trying to kill you through blindness. Electric defog works on just about all cars though. I love it.
Ours is the same as the bimmer world link, but we got it somewhere else.
That_Noise_Is_Normal wrote:Hey thanks everyone, really appreciate the responses. Since we don't have a dash any longer and no defroster, it would seem best to remove the heater core so we're not heating the cab during our races. We've not had a problem with cooling yet, so hopefully ok with core removed. We'll have to get a grid system or something for potential rainy events - I saw the bimmerworld one on facebook today actually.
That may have been my post because I get questions on it. One of the biggest contributors to fogging is windows. From our observations, the cars with the rear window or lexan all around have worse problems.
Ok, stupid question time then, do we even need one? All of our glass except the windshield has been removed. Can it still fog? I cheated off my twin brother’s homework in science class, and he only got C’s.
chaase wrote:That_Noise_Is_Normal wrote:Hey thanks everyone, really appreciate the responses. Since we don't have a dash any longer and no defroster, it would seem best to remove the heater core so we're not heating the cab during our races. We've not had a problem with cooling yet, so hopefully ok with core removed. We'll have to get a grid system or something for potential rainy events - I saw the bimmerworld one on facebook today actually.
That may have been my post because I get questions on it. One of the biggest contributors to fogging is windows. From our observations, the cars with the rear window or lexan all around have worse problems.
Ok, stupid question time then, do we even need one? All of our glass except the windshield has been removed. Can it still fog? I cheated off my twin brother’s homework in science class, and he only got C’s.
I don't know if you need ti for fogging because it may depend on the car. Do you race where you can get snow/frost. It is helpful in those places because the defroster will melt/clean the windshield very quickly. In the south, it just may not be necessary.
Ok, stupid question time then, do we even need one? All of our glass except the windshield has been removed. Can it still fog? I cheated off my twin brother’s homework in science class, and he only got C’s.
The answer is yes, it can still fog. It's best to just assume that your windshield CAN fog and plan on how you'll deal with it at a rainy race. nothing worse than realizing 2 laps into a stint that you cannot see at all and becoming a danger on track. I can't believe that it's acceptable for the solution to be a rag on a stick that the driver scrubs around while trying to drive. Better to plan ahead and get something to blow air across the inside of the windshield, or add the electric defog kit, or something.
The glass will fog when you get humid air warmer than the glass. Humidity condenses on the cooler glass. Since your floor pan is normally heated from your exhaust that creates a warm humid environment. Sometimes removing all the other glass makes airflow pull that warmer air out, sometimes it does not, all depends on the airflow of your particular car.
That_Noise_Is_Normal wrote:Ok, stupid question time then, do we even need one? All of our glass except the windshield has been removed. Can it still fog? I cheated off my twin brother’s homework in science class, and he only got C’s.
The answer is yes, it can still fog. It's best to just assume that your windshield CAN fog and plan on how you'll deal with it at a rainy race. nothing worse than realizing 2 laps into a stint that you cannot see at all and becoming a danger on track. I can't believe that it's acceptable for the solution to be a rag on a stick that the driver scrubs around while trying to drive. Better to plan ahead and get something to blow air across the inside of the windshield, or add the electric defog kit, or something.
The glass will fog when you get humid air warmer than the glass. Humidity condenses on the cooler glass. Since your floor pan is normally heated from your exhaust that creates a warm humid environment. Sometimes removing all the other glass makes airflow pull that warmer air out, sometimes it does not, all depends on the airflow of your particular car.
To comment further, it isn't going to hurt to have it and not need it....
Cooling isn’t the reason to have a heater core, having a working hot defrost for rainy races is. Our first few builds we took all that stuff out. That was a mistake. Now we leave it all in, to the point that I had to junkyard source some of it for our new Civic), and in the rainy races we have run in the cars since it has proven to be a smart decision. It’s great to be able to see in the rain, and be a little warmer in the spring and fall races when it is cold (and raining/snowing/hailing/sleeting).
^^^ This times 1000.
Sonic wrote:Cooling isn’t the reason to have a heater core, having a working hot defrost for rainy races is. Our first few builds we took all that stuff out. That was a mistake. Now we leave it all in, to the point that I had to junkyard source some of it for our new Civic), and in the rainy races we have run in the cars since it has proven to be a smart decision. It’s great to be able to see in the rain, and be a little warmer in the spring and fall races when it is cold (and raining/snowing/hailing/sleeting).
^^^ This times 1000.
Fully agree and suggest that the temp controls be left functional as well. We have our controls set to full fan and full heat. The only thing the driver can do is turn it on or off. We melted a thin layer of rubber off the windshield wipers onto the windshield at Road Atlanta in December. Might have needed a bit less heat. But we never had a hint of fogging...
I guess it depends on the car and climate ... a topless miata in CA, we've never had a need for defrost or heat. Ours is bypassed and out of the car.. less failure points, slightly less radiant heat in the cabin, a lot more room for working and other bits without all the HVAC stuff, win-win without... at least in our case. Never had a situation where we wanted more heat in the cabin or a defroster... but had dozens of situations where all that extra space came in handy.
Also our transmission tunnel gets hot, like can fry an egg on it hot so our cabin stays hot and dry ... should probably look into that.
That_Noise_Is_Normal wrote:chaase wrote:That may have been my post because I get questions on it. One of the biggest contributors to fogging is windows. From our observations, the cars with the rear window or lexan all around have worse problems.
Ok, stupid question time then, do we even need one? All of our glass except the windshield has been removed. Can it still fog? I cheated off my twin brother’s homework in science class, and he only got C’s.
I don't know if you need ti for fogging because it may depend on the car. Do you race where you can get snow/frost. It is helpful in those places because the defroster will melt/clean the windshield very quickly. In the south, it just may not be necessary.
Surely it can't snow in Michigan in October....right? May need to re-think this.
I removed the entire heater/defroster assembly from my race car (a '67 SAAB 96) because it took up a surprising amount of room under the hood that I thought I'd need for a project that ended up not happening. It's still nice to have the extra space and the very much improved access to the rear of the engine and the transmission but from time to time the absence of a defroster is problematic in that I also use the car as a daily driver here in warm, arid Seattle. It's not enough of an issue that I'm willing to go to the trouble of reinstalling everything but I'd probably leave it all in place if I were to build another 96. Or a 95.
rainx anti fog each morning you might get fog. This isnt a hard problem to solve. We have no heater core and if we remember the anti fog we have no fog issues.
That_Noise_Is_Normal wrote:Hey thanks everyone, really appreciate the responses. Since we don't have a dash any longer and no defroster, it would seem best to remove the heater core so we're not heating the cab during our races. We've not had a problem with cooling yet, so hopefully ok with core removed. We'll have to get a grid system or something for potential rainy events - I saw the bimmerworld one on facebook today actually.
That may have been my post because I get questions on it. One of the biggest contributors to fogging is windows. From our observations, the cars with the rear window or lexan all around have worse problems.
Because having one of your drivers blinded by a foggy windshield slam into a barrel right in front of the penalty box is not good......
Because having one of your drivers blinded by a foggy windshield slam into a barrel right in front of the penalty box is not good......
Disagree.
The driver chose to move the car when they couldn't see beyond the inside of the foggy windshield.
That's why they slammed into the barrel.
Foggy windshields are not good.
Making reckless choices like ^ that is bad.
Thankfully it wasn't worse.
"Simplify, then add lightness" -Colin Chapman.
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