Thermochill = OOS

[Turtle 1]

Cathar I know you have a bike racing background . Mine is in auto racing . I spent 4 months in hospital with the hurtin .

I have a question for ya . I really like the PA 160's . Pound for pound I consider them the world champs.

In racing cars we use resticters in 700hp+ engines to cool them without the resticters they over heat.
I have found On a single 160 that a lot of flow threw them isn't as good as a metered flow it seems that about 3.2 gpm is the most efficient for single application . But if you use 2 or more in series than higher flow is required.

So I have 2 questions do you restict the flow on your racing bike.

Have you tried 160's in series and what were your results.

By the way a read the [H] forums thread on tube sizing . I am vary sorry TN gave you such a hard time . I like TN have always believed in small tube sizes. The differances between us tho is I understand flow much better than TN . TN has in the past made some good points and I agreed depending on the blocks used. Some of the German blocks back than did infact work very well with small tubes.

I have also always from day one promoted the ideal of using flow control rather than a single loop if more than 1 block is used. I believe if your going to cool with liquid cool everthing and this is were I have run into problems. Biggest problem is the pumps . Getting a pump that flows 8-10gpm thats also quiet is hard and does not dump to much heat in the system. As you well know. With your background I know that you understand the problems I have gone threw trying to get the perfect combinations required to accomplish my goals. I had to build a box to mount the dual pump system in and suspended them and use sound absorbing material inside the box. with air ducting for a little flow over the motors.

With your experiance could you tell me what pumps you would use to achieve 8-10gpm flow that are 12v or 24v . You already know the 3 pumps I am working with a little insight from you would be vary helpful.

[Cathar]

I'd call myself a track-day junkie, rather than an actual bike racer. I get around a track certainly fast-enough to go racing if I wanted to, but racing is an expensive "hobby", as I'm sure you're aware. Even half the guys who fill the grid at the national superbike level here in Australia are basically paying their own way. It is suggested that this is what makes Australians so successful at bike racing in the international scene, because we're all so hungry, and many riders are having to compete with inferior machinery in order to prove themselves against the big boys. I digress though.

So yeah, while my bike is little more than a race-bike with lights, it's still stock in terms of the radiator, and I've never had a problem with it overheating. The engine is probably at around 160-165hp at the crank though (1000cc engine), whereas the really tweaked 1000cc race bikes are up around 210hp at the crank, and the international superbikes up around 220hp at the crank.

I've often heard/read about the restrictors thing in high-powered engines, and to be honest I couldn't answer as to why that would be the case. It might even be a function of the water pump? If the pump impeller is spinning too quickly, cavitation may be occurring when there's inadequate back-pressure, resulting in a reduced flow-rate, and adding in some restriction may be the solution to this.

I'd seriously like to stick a flow-rate sensor onto some of these car-engines where it is reported that unrestricted flows leads to overheating. I personally think that something else is occurring, and as above, I think it'd be related to how the pump is behaving.


Back to the world of PC radiators, and the PA160.1.

When you report 3.2gpm, how are you metering the flow? You are aware that pump heat dump is a significant factor at higher flow rates. Up to a certain point extra flow through a radiator does nothing to increase performance, and indeed performance will even plateau. At even higher flow rates the pump will dump even more heat into the system (even if using a restrictor this happens), and this eventually overcomes the tiny performance improvement you got from those higher flow rates. It's not that the radiators start performing worse, it's cos the pump is dumping more heat with the higher flow rate than the benefit you get from the higher flow rate.

When you say you can achieve higher flow rates with multiple radiators, that actually backs up my assumption above. With more radiators, they can deal with the extra pump heat better, and so you can reach even higher flow rates before pump heat starts to overcome the benefits again. Throw on a third or fourth radiator, and the limit will be even higher again.

Reference this thread for a detailed discussion on this effect.

Don't worry about TN. I can handle myself just fine. I think she, and others, get a little overly defensive about their choice and accuse me of criticising their choice when really I've done no such thing. I support their choice if it suits their needs, but I sit in the scientific middle of the whole debate and approach it with a fairly impassionate eye towards what are the real impacts of what's going on, and leave everyone else to squabble over what's important to them. Some just make the mistake of thinking that I have a "side", when really I don't. I've been attacked by both high-flow and low-flow afficiandos in the past, because they don't realise that I really don't have a side, and so both camps like to paint me as suits their prejudice.

As for 12v or 24v pumps in the 8-10gpm mark, your choices are very limited. Best to first identify how much back-pressure we're expecting to operate against at that level, and then we can construct a solution for the problem. It is unlikely that there's a single pump that will do what you want, but a pair of pumps, such as 2 x Iwaki RD30's in parallel would get you pretty close. I'm not really aware of any stronger DC pumps than the RD30's that are easily available to the general consumer.

[ranker]

Reference this thread for a detailed discussion on this effect.

Don't worry about TN. I can handle myself just fine.

Good thing you don't have to worry about the likes of her here anymore. I'm surprised you manage to keep your composure as well as you do with the inane crap/invective thrown your way. It's not good enough that you settled the peace between the tubing size, but they feel as if you didn't go far enough, hoping for a proclamation from you of "Low flow is the only way to go!"

As for 12v or 24v pumps in the 8-10gpm mark, your choices are very limited. Best to first identify how much back-pressure we're expecting to operate against at that level, and then we can construct a solution for the problem. It is unlikely that there's a single pump that will do what you want, but a pair of pumps, such as 2 x Iwaki RD30's in parallel would get you pretty close. I'm not really aware of any stronger DC pumps than the RD30's that are easily available to the general consumer.

Why two RD-30's in parallel rather than series? I always figured series was the way to go.

[Cathar]

Why two RD-30's in parallel rather than series? I always figured series was the way to go.

A single RD-30 @ 24v can only deliver ~5.3gpm peak. He wants 8-10gpm.

If he ran two in parallel at ~26v, he'd likely achieve his goal. It does depend on the flow resistance though.

[ranker]

A single RD-30 @ 24v can only deliver ~5.3gpm peak. He wants 8-10gpm.

If he ran two in parallel at ~26v, he'd likely achieve his goal. It does depend on the flow resistance though.

Wouldn't running two of them at 26v negate any sort of gains with the flow rate?

I was under the impression from your tests that anything past 18V would be more harm then good.

[Cathar]

Wouldn't running two of them at 26v negate any sort of gains with the flow rate?

I was under the impression from your tests that anything past 18V would be more harm then good.

I don't know what our good friend Turtle1 has up his sleeve. He just asked me "What could I use to do this?", and I answered.

What he seems to be attempting is well beyond the norm of regular PC water-cooling systems, so I'm not making any assumptions at all as to what's going to work out best for him.

Given enough radiator capacity, the heat dump penalty of 2 x RD30's @ 26v can be overcome, but we're likely talking about needing 8 x PA160.1 to do that, or maybe 4 x PA120.3's, to achieve a balance point. Maybe that's what he's got? Who knows?

All I know is that from what little he described of his system so far, that it's not your usual PC water-cooling setup by a long shot, and a lot of what hes delving into doesn't apply to the standard PC water-cooler. While it's not a different set of rules, the limits are different.