Honda Engineer States Adding a Bigger IC Won't Combat Overheating

[ACUITY]

So this raises a few questions for me. Is this worth doing if not tracking the car but would still like to maintain cooling?
Are there are any other mods that are suggested to be supplemented with these rad hoses?
What's the install like? Is it pretty straight forward like swapping these hoses, or being that they are reverse flow is there more involved??

If you have never overheated your FK8, are staying in the same climate for the duration of owning the FK8, and don't plan to push your car any harder than you have already, I would not say you need to worry about hoses that will cool your car better. If you expect to start tracking more than you have or may be moving to a warmer climate, then you might consider some cooling mods. We are a business, so of course we make and sell products, but as a team of engineers that take their work and motorsports seriously, we don't particularly care for making parts that aren't needed and we definitely don't try to sell customers something their specific application does not call for.

If your OEM hoses start to go at some point, then you might consider silicone over stock EPDM rubber. Silicone will outlast the OEM EPDM, so by using it, you may avoid ever swapping the rad hoses again. As for installation, it is no more or less involved than installing OEM hoses. If you'd like to see exactly what's involved in the install process, checkout the install guide we made for these as acuityinstruments.com/install . That guide even covers how to pressure bleed and funnel bleed the system so you have options.

~Russ

Sponsored

 

[.grimace]

If you don't track your car why do you need to buy track parts that stop overheating... makes no sense.

Wish I hadn't just done my 2020 radiator install I'd of totally got these. No interest to rip that all apart again ooof

 

[fiend busa]

LOL, this is a common response from people without a background in heat transfer. We come from a level of motorsports where an F1 or LMP team will literally pay 10's of thousands of dollars to drop coolant temps a few degrees F. That's an extreme case, but the point is rejecting heat without adding a ton of weight or drag to a car is very involved. These add no appreciable weight, no appreciable drag, and can get 4.5F more cooling out of a system that's already been optimized as much as possible. That's a big deal. Make no mistake, these hoses are meant for the track, where the FK8 struggles on hot days. Last year, I can't tell you how many FK8's we saw overheat at time attack, road race, and hpde events. It was insane. For the guys that have overheated at the track already, have tried other cooling mods, and still aren't getting temps where they need it, 4.5F (2.5C) can be a lifesaver. If you are pushing your car in hot temps and/or with an upgraded IC, you are going to have to deal with overheating and will eventually need silicone hoses. Our philosophy is that you are going to have to get silicone hoses if you are pushing your car, would you prefer silicone hoses that do nothing more than handle increased temps or would you rather some that help make your car better? It's a small gain, but it's coming from hoses and when you're fighting overheating, every little bit of thermal performance helps.

~Russ

Sorry - I wasn't trying to come off bashing the product, it's just what I read when I opened the product page lol

I mean im still going to buy it once I get my bolt ons done since it's not that expensive.

 

[ayau]

Great stuff @ACUITY. Thanks for the great work!

Just to make sure I understand how these radiator hoses work....

The Acuity hoses reverses the flow of the water in the radiator, correct? In factory form, hot water falls down and gets cooled. With the Acuity rad hoses, the hot was flows to the top and gets cooled?

Any negative effects by reversing the flow of the water?

Does removing the AC condenser do much to improve water temps?

Any opportunities to improve the factory ducting to the radiator?

 

[ACUITY]

Sorry - I wasn't trying to come off bashing the product, it's just what I read when I opened the product page lol

I mean im still going to buy it once I get my bolt ons done since it's not that expensive.

It's ok! We were prepared for there to be skeptics. Hell, if you told me that flipping hoses would reduce temps, normally response would be something like "yeah, i doubt it." haha. Myself and my co-founder both spent years spending 100% of our engineering time designing high-performance automotive cooling packs and heat exchangers for race teams, so we knew going into this project that there were potentially gains to be had but that there would be plenty of skeptics, and rightfully so. We actually had these hoses in testing for about a year and a half just to make sure our theory held water (no punn intended). Now, they're standard on HPD's TC turnkey race cars and a number of other Honda-sponsored race teams are running them as well.

~Russ

 

[ACUITY]

Great stuff @ACUITY. Thanks for the great work!

Just to make sure I understand how these radiator hoses work....

The Acuity hoses reverses the flow of the water in the radiator, correct? In factory form, hot water falls down and gets cooled. With the Acuity rad hoses, the hot was flows to the top and gets cooled?

Any negative effects by reversing the flow of the water?

Does removing the AC condenser do much to improve water temps?

Any opportunities to improve the factory ducting to the radiator?

You're understanding correctly. "Falling" is not a good word to describe the downward flow of the OEM configuration though. Remember that a cooling circuit is a closed-loop, so gravity effects of the water flowing "up" are negated because it flows down again later in the loop. The best analogy of this is how you can put a hose in a bucket, make it go up quite far, but as long as the outlet of that hose is marginally below the bucket's water height, the water can flow freely after siphoning. The only (theoretical )additional pressure loss is from the water having to go through slightly more hose, but it is so minor that the additional pressure drop is not measurable.

Regarding the condenser removal, yes that can help a ton too, but remember air needs to flow into the engine bay AND out. That said, I would opt for a vented hood before I opted for condenser removal. With the AC off (it normally is at track days), the condenser just adds pressure drop to the cooling pack(which reduces airflow), but it doesn't contribute heat.

Unfortunately, ducting to the radiator wouldn't do a ton (although blocking off small areas around it where air can escape may help very slightly), and there's no room behind the rad for a proper duct, so venting the hood is about as good as you can do in that regard.

~Russ

 

[Lust]

Was the temp difference measured when the car was idle?

 

[ACUITY]

Was the temp difference measured when the car was idle?

No, you'd never see the gain during idle. Our data was recorded during on-track sessions.

 

[Lust]

No, you'd never see the gain during idle. Our data was recorded during on-track sessions.

That's what I figured. Just asked because that's what another member was suggesting in our group. Thanks.

 

[ACUITY]

That's what I figured. Just asked because that's what another member was suggesting in our group. Thanks.

All good! We braced for questions regarding these (hence why we made that tech video), but honestly we've been a bit surprised at how much chatter there's been around it. It's good though because serious gearheads really need to understand cooling systems more deeply to get their cars performing optimally. So one important thing to understand about cooling upgrades is they generally only shine when they are pushed to their limits. When ambient air temps are very low or there's very little load on the heat exchangers (so when boost is low for intercoolers or when engine load is low for radiators), it's very hard to see the difference between an average component and a high-performance component. It isn't until you start to find the limits of the system that you start to appreciate and quantify the gains the mods add. That's to say, if you live in a climate that is cold all year, you really have nothing to gain from cooling mods. It's really a case by case basis depending largely on how you drive your car and in what climate.

 

[TypeRNY]

If you have never overheated your FK8, are staying in the same climate for the duration of owning the FK8, and don't plan to push your car any harder than you have already, I would not say you need to worry about hoses that will cool your car better. If you expect to start tracking more than you have or may be moving to a warmer climate, then you might consider some cooling mods. We are a business, so of course we make and sell products, but as a team of engineers that take their work and motorsports seriously, we don't particularly care for making parts that aren't needed and we definitely don't try to sell customers something their specific application does not call for.

If your OEM hoses start to go at some point, then you might consider silicone over stock EPDM rubber. Silicone will outlast the OEM EPDM, so by using it, you may avoid ever swapping the rad hoses again. As for installation, it is no more or less involved than installing OEM hoses. If you'd like to see exactly what's involved in the install process, checkout the install guide we made for these as acuityinstruments.com/install . That guide even covers how to pressure bleed and funnel bleed the system so you have options.

~Russ

you guys are dope. Thank you.

 

[ayau]

This is a pretty genius way to solve a problem without having to shell out a lot of money.

Not sure if Honda considered this trick but I’d imagine that a tech servicing a car with reversed flow would be quite confused lol. I’m guessing that’s a big reason Honda wouldn’t do something like this from the factory since that would deviate too much from the “standard” way of thinking.

It’s also good to know that the HPD TC car runs this setup. Just adds more credibility to your team’s work!

 

[ApexEight]

I, for one, am very happy Acuity developed and released this product. Every little bit helps. Now if we could just get a low temp thermostat cheaper than the Spoon unit... (I know they won't help a cooling system that's already capped out, but it'd be nice if there were a cheap addition, like a high pressure radiator cap, to top off a cooling package).

If you're tracking your CTR on hot days, I recommend the following:

Step 0, if needed) Heat on full blast
Step 1) eBay grille or equivalent
Step 2) 2020 radiator
Step 3) Acuity reverse flow radiator hoses
Step 4) Oil cooler
Step 5) Properly vented hood or hood vents (I like Race Louvers, look them up)
Step 5.5, optional) High pressure radiator cap and/or Spoon low temp thermostat (if you want to throw one in there while you have everything apart, they're like $130 though, so I totally understand passing)

Additional steps would look something like getting the big/hot OE catalytic converter/downpipe away from the radiator/out of the engine bay and replacing it with a heat coated/wrapped high-flow or catless downpipe, heat coating/wrapping the section of the OE front pipe that passes under the oil pan/doing the same with an aftermarket front pipe, and lastly heat wrapping a bunch of other shit, but I would try the first 5/5.5 steps first. Higher flowing exhaust = more power = more heat.

All that paired with a quality synthetic motor oil and OE Honda coolant (not sure I'd want to mess with water wetter), and you put yourself in a good position to keep your oil and water temps in check. I would also recommend getting an oil pressure and temperature gauge(s) so you have actual data, and also further monitor water temps even if it's just through OBD2 (via Torque app). Might as well monitor fuel level there too while you're at it to avoid low fuel limp mode. Even though it's just an estimate, the stock fuel gauge also isn't that accurate/doesn't update very quickly sometimes, so the more data the better.

If you don't track your car, you don't need this stuff. Get a big, dense intercooler if you want.

Disclaimer: I don't own an FK8 (currently in an FA5 and saving for an FK8), but I've developed this opinion based on a shit ton of reading and talking with people that are much smarter and more experienced than me. ?

 

[02SilverSiHB]

Isn't that a/c cooler sitting in front of the radiator...so that is two things blocking the radiator lol.

 

[ACUITY]

Isn't that a/c cooler sitting in front of the radiator...so that is two things blocking the radiator lol.

Yup, if you checkout our tech video we have on our youtube channel, we mention that and explain why the ac condenser is a touch different from the IC in terms of its impact.

Sponsored