Help Me Design My Cooling System

[Simon-S14]

I've decided to build an overkill cooling system for my competition drift car as I have a pretty good system ATM yet still gets hot after hard laps on hot days.

So what I have planned is to put a large radiator inthe boot with sealed ducting in and out and two large fans pulling air out. I plan on laying the radiator almost flat on floor with a slight upward angle, air will be taken in from each rear 1/4 window which will be replaced with vents and ducted to a single Y joiner when then feeds the sealed duct to radiator.

The radiator I had in mind was an all alloy vx v8 radiator..they are huge along with two zirgo 3600cfm 16 sands behind it. I'll use a header tank in the boot and the engine vary to prevent air pockets.

can anyone see any potential issues?

[GTSBoy]

That will work. Minimum 300mm diam duct from each window. Where is the fuel cell? If underfloor, then you are going to have to make your exit vent in the rear panel between the taillights. There's low pressure behind the car there anyway, but perhaps less so when sideways.

Stand the radiator up as close to vertical as you can. You'll hate yourself trying to duct in and out of it if it is lying down at a low angle.

[Simon-S14]

Using stock S14 tank since its plastic and in an ideal spot as far as weight distribution goes. I've got pics if a design I have seen that looks brilliant

[urtwhistle]

I have seen this done some where before. nearly exactly the same as you have described. I think it was in a Aston martin though. The made the Y piece and tubes from Fiber glass or carbon so that they could get it the way they wanted it.

[Simon-S14]

this was what i was thinking along the lines off... not doing it in carbon tho.. sheet alloy will do fine.

[KiwiRS4T]

There's a big 500 Mercedes V8 racing here with a radiator in the boot - lots of extra piping and things to go wrong! Have you got as decent oil cooler? Maybe get a bigger one?

[Simon-S14]

trust me ive tried a lot of things over the past few years and my current set up is as good as it gets. RB in an s chassis is always difficult to keep cool. it works fine for 90% of the time but low speed, high rpm, hot weather and continuous laps sees the temps sky rocket

[1400r]

seemed to work for kuroi from memory in pics of the front end Ive seen there's like 4 coolers in there though

lots of the jzx100 guys run twin oilcoolers ever thought of that?

Edited November 22, 2012 by 1400r

[Simon-S14]

if**k all room up front for multiple oil coolers and i dont want to mount them between the radiator and inter cooler.. i dont like having them in the front corners of the car also due to impact zone

[sky30]

doesnt the raadiator need to be more up right so the water can flow from top tank to bottom as it cools through the core?

[Simon-S14]

well the water pump creates flow so that part isnt a problem.. but the only issue i have with laying it flat is possibility of air bubbles getting trapped

[Risking]

If your laying it flat you'll need air bleeds on the top of the tanks. Header tank in the boot is not nessiary. It would be far better if you bought a PWR core and built you own end tanks that have a deliberate high point folded into them with a -6an air bleed fitting.

Lotus' have a frontal radiator with bleeds at the highest point. It makes life much easier if you use an evacuation filler when putting the coolant in.

Sucks the system into a vacuum and that same vacuum is used to draw coolant back into the system.

I've seen a couple of failed boot radiators that we've looked at fixing for customers but its usually easier to either redo the whole setup or go back to a proper air dam/frontal radiator setup.

[Simon-S14]

yeah was planning on welding some fittings onto an alloy core. that part is easy.

what have you seen gone wrong or set up wrong that you have had to fix up?

[Risking]

The big things are air bleed points.

Cheap radiators.

The factory water pump won't be up to the job. It will circulate the water too slowly over that distance.

Hot spots in the system where air sits and steams.

The fan setups. The only thing you are doing essentially is removing the intercooler from in front of the radiator and increasing capacity. If you have a good quality cooler now then it probably isn't an air flow restriction.

If possible have you ducting coming from the underside the fans blowing up through the radiator and the shroud venting out from the topside.

Hot air rises so with low road speed your going to have radiating heat going upwards into the ducting channels only to be sucked back down through the hot radiator via the fans.

Yes the hot air should be sucked out but the heat will radiate upwards even when air flow is downwards.

Put an air temp sensor in the coupling you fabricate and monitor the heat inside there to determine if its working. Ideally ambient is best obviously

Your best source of info is actually to look at as many lotus exige setups as possible. They are done perfectly with air feeds from the bottom, coulings venting into negative pressure air flow, air bleeds at all critical points etx

[Simon-S14]

thanks for the feedback mate much appreciated!

yeah i'll be going an EWP set up for this.. i dislike the davis craig fan controllers tho so i may just run it all the time

[discopotato03]

Years ago that fella from Nispro had an I think S14 and he made a way for some of the post rad air to spin off the tips of the mechanical fan and ducted this air out through a hole in the bonnet .

I wouldn't think you're running the RBs std fan but it may be possible to do something with elec fans . I don't think the radiator cares where the hot air goes as long as it can go somewhere so more can be pulled through the core .

A .

[britz1]

Mate i just had a brain fart......

we have been drifting 500hp s1x Rb power cars for years here in WA and we have sorted the cooling problems... you neeeeeeeed to f**k off those thermo fans they just dont work... then use the old nidssan clutch fan and shroud, koyo rad and oil cooler (lots of guys put them in the corners but there gay and hit shit sooo i have a put mine inbetween the rad and FMIC and i cant get my oil temp over 90deg)...

and the biggest thing is fuel... we run e42 (E85 mixed 1/2 with BP98) Jewmix but E85 is even better.

oh and btw we had a guy do the rear radiator setup on a s13... it never worked just overheated constantly... he gave up and did what we where all doin

Edited November 26, 2012 by britz1

[Simon-S14]

I have all that and it still won't work have clutch fan and new blades. quality radiator and everything else you mentioned and it works great but couldn't handle multiple laps of WA heat

[britz1]

I have all that and it still won't work have clutch fan and new blades. quality radiator and everything else you mentioned and it works great but couldn't handle multiple laps of WA heat

hmmm well my car has a cold air unduction pipe and a 12L jun sump maby its the big sump that did the goods... took longer to heat up the oil.... oh and btw i was at adgp in my R33 and it was overheating during prac... but it runs BP98 and adgp was stupid hot this year and prity hard on the cars

[Simon-S14]

Yeah mine had been fine all year for temps never going over 90 deg.. But adgp barbs sent it over the edge lol