Using Aquamist for brake cooling system!?
 

Hi guys, I just came across this forum, and though I might be able to pick someone's brains regarding a project I'm busy with.

It's got nothing to do with engines I'm afraid!

I'm trying to design a brake cooling system for a stage rally car, using watermist sprayed into an air duct in the front bumper. It's not a new idea, and there are complete systems on the market, but I want to do my own, and do it properly :)

My ECU is already monitoring/logging brake temps, and I have a spare switchable output, so my plan was to use the ECU to switch the water pump on/off when required based on brake temps and road speed.

So my question is really, what other components will I need?

Obviously a pump. Are there options here or are all the pumps the same?
Nozzles - the watermist needs to be as fine as poss. So which nozzles? And will this dictate pump type/pressure?
Will I need solenoid valves in the system or can I just switch the pump on/off? It doesn't really matter if it takes a fraction of a second to build up pressure, but I wouldn't want to be squirting (non atomised) water into the air duct for very long.

Last question, what sort of flow rate do these things get through? I would need to carry maximum enough water for 10minutes of spraying, 15 max (planning to use water bladders strategically placed about the car for weight distrubution)

Many thanks in advance for your help,
Tom

Re: Using Aquamist for brake cooling system!?
 

Most modern kits now use the same Shurflo based pump. It's quite big but pretty reliable and flows well.
Aquamist do a range of nozzles, compact in size and with an excellent mist/spray. Given what you're doing, I'd think a simple off/on would suffice.
Or via a solid state relay you could maybe PWM the pump itself and run nit directly from the ecu for variable flow.

Only testing will tell how much water you need to spray to achieve the cooling you need.

Re: Using Aquamist for brake cooling system!?
 

Thanks for that,

Is there a particular Shurflo pump I need? I can't find one on their website that does more than 50psi?

Re: Using Aquamist for brake cooling system!?
 

Most of the water injection people say they modify them for the purpose. Most are rated at 150-200psi.

Why not contact Aquamist ? it's their forum, they sell them

Re: Using Aquamist for brake cooling system!?
 

Any 12v 100psi pump will work for this application. Can be found from $50 on up. Shurflo 8000 series if I remember right.

Use the Aquamist jetting chart to see what the jets will flow. You will need to get an idea of how much water you need to get adequate cooling and work out capacities from there.

When you turn the pump off, the unit will bleed down and spray for a second or two. While a little more to install, I would highly suggest a solenoid valve to start and stop the flow of water for a clean cutoff and no "pissing" of the jets after the pump is turned off.

For a control strategy I don't think you need anything fancy, maybe two modes, #1 full on, and #2 on/off in 1 second intervals.

Re: Using Aquamist for brake cooling system!?
 

That's very useful, thanks Howerton. Are you able to sell me the jets and soleniods? Cancel that, I just found your website, will drop you an email later.

I was proposing to have mount the pump towards the rear of the car, for weight distribution and packaging as much as anything - whereas the jets will be right at the very front. Am I right in thinking the solenoid should be mounted as close to the jets as possible?. Thanks again for the advice so far guys...

Re: Using Aquamist for brake cooling system!?
 

Where abouts in the UK are you, I have a Shurflo with Aquamist 6mm pipe fittings.

Re: Using Aquamist for brake cooling system!?
 

Yes I would put solenoids as close to the jets as reasonable. With a clean cutoff from a solenoid, it can be a little further away while still achieve a good cutoff.

Its leaving a pump spinning down that makes a long lingering spitting effect. Check valves don't hale that much either.

Let us know if there is anything else we can help with.

Re: Using Aquamist for brake cooling system!?
 

Given the jets will be placed low down, a check valve or solenoid will be essential anyway to prevent fluid simply running out of the plumbing.

Re: Using Aquamist for brake cooling system!?
 

I know this topic is old so the OP is probably no longer on here. I have always suffered brake fade issues on my S2000 with uprated XP10 pads and uprated discs. Anyway i done abit of research and came up with water cooling to the inside vane of the brake discs. Currently i have purchased a 5 litre go kart fuel tank to stick in the boot and a 100psi ebay special diaphragm pump.

I got some jets from aquamist and i have timed the water flow and at full output i use 5litres in 10 minutes. I have also ordered some smaller jets to see the effect on cooling against water consumption.

I have sourced a delay off relay which means that i can have the pump only switch on during brake pedal application and then i can set it to continue to run for say 5-10 seconds after the brake pedal has been lifted. Obviously this will need fine tuning to ensure water consumption isnt excessive and that i still get adequate cooling.

I worked it out that based on the amount of time i spend on the brakes per lap on track and figured 5 liters will last 30 minutes. Which is more than enough for the average track session.

The one issue i have at the moment is that the cheap pump is abit of an unknown and to be fair it produces a very good mist and when i wound the adjustment in abit the pressure increased alot. Im going to fit an inline 150psi pressure gauge so i can actually see whats going on.

I have tested everything off of the car so far and seeing how it goes tomorrow i will plumb it all in along with the brake ducts.

Probably abit OTT for a weekend/trackday car but i love tinkering with things and this seemed like something that would be interesting to test and develop.

I know the jets aren't cheap and probably work out as the most expensive part of the project but it was well worth spending the money on them. Its amazing how much surface area the water covers when it sprays at such high pressure. The water just lingers in the air. I did consider spending more money on the pump but size is abit of an issue and to be honest until i test everything a larger pump might be unnecessary.

Re: Using Aquamist for brake cooling system!?
 

What pump is it ?

Any of the typical ?100 or so water injection pumps would be more than adequate.

Dont forget to include a check valve so water doesnt syphon when not in use, as I presume water tank/pump will be higher than the actual outlet nozzles ?

I've had good luck with Carbon Lorraine pads, never used the Carbotech before though

Pagid always get good reviews too.

Re: Using Aquamist for brake cooling system!?
 

The issue with the S2000 is that you cant fit bigger brakes under the OEM wheels and that the rear discs aren't vented. What tends to happen is that front brakes get heat soaked and then the bias goes more towards the rear and the rears overheat and this happens.

https://fbcdn-sphotos-g-a.akamaihd.n...9a8f28ea48cadd

Im just hoping to get the temperature down by another 150c or so just enough to give the pads and easier life and to prevent the fade i occasionally experience. Hopefully my new ducting and spray will archive this.

Pump wise it was dirt cheap

http://www.ebay.co.uk/itm/2011222180...%3AMEBIDX%3AIT

I know its cheap and reliability will be a unknown factor but it will hardly ever run apart from when i do trackdays maybe 6-7 times a year. I do need to measure the pumps actually output thou. Looking at the flow charts for the jets the 2x 6mm jets would use about 500ml a minute at 100psi. This would suggest the pump is supplying this sort of pressure as i emptied my 5 litres in 10 minutes but i know until i fit a gauge then i don't really know.

The pump might only run for 15 seconds every minute during braking and then switch off.

Can anyone recommend a decent pump? I looked at the AEM meth pump ?130 and high pressure but it has push in 1/4 nylon fittings which arent compatible with my aquamist fittings. Aquamist pump looks good but pricey
Internal bypass pump would be best because i could then fit a solenoid near the jets that would be operate by the relay. Im just abit wary of spending alot of money on something thats not necessary but obviously im open to suggestions.

Oh and check valves are sorted, i read up abit on here before hand and sourced some check valves to work with the 4mm pipe

Re: Using Aquamist for brake cooling system!?
 

That shouldnt happen with good pads. Ive raced with discs glowing bright red and brakes still working and pads not falling apart.

What size wheels are they ? What size discs ?

That pump was cheaper than I was expecting lol. But on paper it sounds good. No reason why it shouldnt work.

Re: Using Aquamist for brake cooling system!?
 

Hi Steve,

That is the first failure i have had with the carbotechs and to be fair to them they were down to about half thickness and had done probably 5-6 trackdays. It had only happened to one pad out of the 4 on the rear. Im hoping that the enhanced cooling will increase pad life abit more and this whole set up is 50% cheaper than the pads are to buy.

Front discs are 300mm x25mm and the rears are 282mm x 12mm solid disc and OEM 17 inch wheels.

Car is probably weighing 1400kg+ with driver and full fuel load so its quite a heavy car to slow down on a trackday. I don't mind adding a few kilos of water . Alot of people moan about the standard brakes and fade. It seems that you can stop the fade with higher rated brake pads but the heat absolutely destroys the brake discs in no time. I'm just hoping to cut the temperatures down and stop the rears from having to deal with the braking when the fronts fade.

Pump is from what i can see is pretty much identical to a lower line shurflo pump. I will stick a pressure gauge on it and video some results, might stick a multimeter inline as well and measure current. I wouldn't want to use it on water injection into the engine but hopefully it will be alright for my application

Oh and unrelated to my diy system my brother runs aquamist water/meth injection on his mini cooper s and has recently removed the supercharger and had a turbo fitted. With aquamist injecting 100% pure meth he has over 350bhp at the wheels. The car is an animal and hes ironing out a few issues before using it on track next year. He has loved the system ever since it allowed him to get 250bhp out of his old supercharger set up.

Re: Using Aquamist for brake cooling system!?
 

Surely you can fit plenty more under there ?

I've 330x32 floating discs under 16" wheels with 4 pots ( not Honda obviously )

Really, fitting uprated pads to standard discs is almost a waste of time, they will not be compatible with each other.
The further apart you go, the worse it will be for the discs.

Even a much higher quality disc/bell arrangement could make a huge difference to braking performance, used in conjunction with the right pads.

Aggressive pads can actually create far more heat in the disc than some milder pads, so actually make the problem worse even if you think it's the right way to go.

There is also the risk that spraying too much water onto a hot disc could also lead to premature failures. It will be trial and error though

For all things braking...speak to Bob at http://www.bgdevelopments.co.uk/contact-us

He will be able to build you something much much better than what you have.

Or a quick google says Wilwood offer stuff already ? Bob is mostly an AP guy, I'm sure the Wilwoods would be cheaper.

http://www.importtuner.com/reviews/p...ig_brake_kits/

Re: Using Aquamist for brake cooling system!?
 

Thanks for the info.

The problem is that the cost of the brake kits is ?1500 plus and then on top of that you need to buy new wheels and possibly spacers and other parts for it to all work together.

OEM wheels don't provide another clearance for aftermarket brake solutions. Even the Spoon calipers don't fit the OEM wheels. Its annoying as you would of thought a car often used on trackdays would have more off the shelf solutions.

Two piece floating discs would be ideal but they only make in the US by a company called racing brake and people have given them mixed reviews so far.

I cant really afford to spend ?2000+ to eliminate the odd bit of brake fade during the few trackdays a year. Don't get me wrong i would love to but i havent got to the point where im going to spend that sort of money
At the moment i have cheap disc and pads for use over the winter and then i'm swapping to directional vaned discs which make quite a difference plus the ducting i'm in the process of fitting should also make a difference.

I will keep upto date with how i get on, the brackets im waiting for to mount the tank in the boot havent showed so wont be happening this weekend, can get the plumbing and wiring done thou.

I was hoping to inject the water into the ducting so that it mists into the air from the brake ducts rather than pours on to the discs and weakens them. Obviously there is a chance that this doesn't work all together but at least it means in the future i have parts to do a water injection installation if i supercharge my s2000

Re: Using Aquamist for brake cooling system!?
 

Exactly what is the makeup of the OEM setup ? Any photos ?

I'd be amazed that you could go larger one way or another, even if it meant fitting adaptors and re-using the standard calipers or another sliding caliper.

It would be very easy to have some discs/bells made up and just stick with your existing calipers and diameter if you really could sort anything else. That would at least allow a proper disc to be used that will take the heat from racing pads, then use suitable pads.
That should only be a few hundred quid

Not sure where your existing pads fall, but some milder ones might actually help the heat situation when used with cheap discs.

As for water...maybe spray near the hub, so water gets expelled outwards through the vanes ?
No idea really where might be best for spraying.

Re: Using Aquamist for brake cooling system!?
 

https://fbcdn-sphotos-e-a.akamaihd.n...ab2e89b95dc4d7

The water spray has been used quite successfully on the Nissan GTR which also suffers brake heat issues.

http://www.willallracing.com.au/gtrbrakes.htm

They all rave about the system but obviously the brakes would be higher quality than

Photo on track

https://scontent-a-lhr.xx.fbcdn.net/...d7&oe=548DEE7B

photo of where the brake duct ends up pointing directly at the vanes

http://i1157.photobucket.com/albums/...psf935217b.jpg

Re: Using Aquamist for brake cooling system!?
 

Looks like there is room to mount the caliper off a bracket off the rear side of the upright ? then offset the disc 15-20mm or so ?

That would then allow a much larger diameter disc with the existing calipers.

Duct looks pretty good, I guess it should be fairly easy to spray water there. Only concern might be if it sprays onto only 1 surface of the disc, it might cool unevenly ?

Although maybe there wont be so much water that it's a risk

Re: Using Aquamist for brake cooling system!?
 

Thanks for the reply steve, your advice is appreciated.

I was hoping that with the directional vane pumping effect of the disc that the mist will be sucked into the vanes and thats distributed internally.

I got round to running the lines and the wiring today, had abit of a mare when the high pressure nylon line kinked passing it through the bulkhead, typical but i had enough left to finish it off.

Just need the brackets to turn up and i will be able to finish it off during the week. Will have to wait ages to test it properly thou as road testing wont be consistent or accurate.

Re: Using Aquamist for brake cooling system!?
 

That pump looks very similar to the flojet pump that Howerton used for the motorcycle injection kit. An Aquatec will be your best bet, and 3/8" female NPT heads are available. I've got one that I bought to replace the head on a Coolingmist kit but sold before I got the head in.

Re: Using Aquamist for brake cooling system!?
 

Well the fittings all showed up today to test what this pump actually puts out.

I was shocked to be honest, i really thought that i might get 50-60 psi of pressure out of the pump before it ran out of puff. I tested the pump the other day connected directly to the car battery with the engine running so the full 14v and wound the pressure adjustment screw in all the way. It made a great mist but i still didnt know the pressure.

Anyway today i tested it on a tiny 1.2ah 12v cell that measures 12.7 volts with no load. Connected everything up and fired it up. The pump straight away went up to 125psi and held there during the duration of the test apart from when the battery start to lose charge. I really was not expecting 125psi and the mist from the pump is smooth no annoying pulses that you get with pressure switches.

?11.50 odd for the pump which i think is good going seeing the results i get. Especially when you think its flowing 500ml+ at 125psi.

Video of the test

https://www.youtube.com/watch?v=WQ8VqX05_uU

Im planning on winding the pressure down abit to lower the current and possibly give the pump abit of extra life. After 10 minutes of constant running it gets reasonably hot but in theory on track it will run for 50-60 seconds per 2:30 lap so it will get some rest time.

Re: Using Aquamist for brake cooling system!?
 

definitely a bargain !

Re: Using Aquamist for brake cooling system!?
 

Have you tested it yet?

I need water spray on both front and rear brake discs on my car,
I have big 365mm in front and 325mm in rear but they still gets to hot on the race track and I have not room for air intake for brakes in my front,
So water is the only solution for me, but I don't know what I should buy.

Re: Using Aquamist for brake cooling system!?
 

What pads/discs are you using ?

It'd be interesting as well to get some IR temp sensors if they work in a suitable range, to actually see what sort of disc temperatures are being seen.

Re: Using Aquamist for brake cooling system!?
 

First I had XP10 in front and XP8 in rear
But when my Carbotech XP10 was worn out I put in PFC 08 in front.
PFC = Performance Friction.

But I have the biggest problem with the rear brakes, I think it's because there is only one piston calipers so then there is very little brake fluid in them so that the brake fluid gets overheated.
I have RBF600 brake fluid and replace it in the rear brakes after every track day and the old brake fluid is almost black every time!

I have Audi RS6 C5 brakes in front and Audi RS4 B7 in rear.

Re: Using Aquamist for brake cooling system!?
 

Here you can see my front discs glow in the dark ;)

http://youtu.be/dh303VbH0ms

Re: Using Aquamist for brake cooling system!?
 

Glowing discs is common and always looks cool, but with the right pads it doesnt mean they stop working.

Is the fluid actually boiling ?

I've had good luck in the past couple of years using Carbon Lorraine pads, they do some pretty extreme stuff.

Or if it is largely a fluid issue, what about one of those devices that allows fluid to circulate within the system which should prevent fluid boiling ?

Sounds like a cool car, love the S8's !

Re: Using Aquamist for brake cooling system!?
 

If I run hard too long time, over 20 minutes on the race track, then will the brake fluid boil and brake pedal goes to the bottom!
But it's always my rear brakes that has the problem, because the brake fluid in my front 8 piston calipers is always clear and fine when I bleed them.

The advantage of water spray is that you get longer life of the brake discs and pads, and you do not have to run multiple cooling lap each time you want to run into the pits.

And even though I run several cool-down laps it crackles and snaps always from the brake discs due to the heat when I stand still in the pits after the run.
So I putts car back and forth so not the brake pads will burn into the disc