Been thinking about radiators

[Driftin_AW]

I've often thought the MR2 would benefit from having all the airflow through the radiator ducted out the bonnet, in terms of both cooling and aerodynamics. Anyway, I thought I might actually do it now, so here's what I'm planning

1. swapping the radiator for an sw20 turbo one (pretty much identical, but my radiator is a bit bent and I have a spare sw20 one)

2. lying the radiator and the rad for the w/a intercooler horizontal, at the height of the big support beam in the bumper

3. making a shroud coming from the opening in the front bumper, then coming up under the radiators, meaning every tiny bit of air that goes through the bumper goes through the radiators

4. Leaving the stock fans on the sw20 radiator (which will be the upper of the two radiators), make two shrouds, one coming off each fan, then ducted into the frunk.

5. cut two vents into the bonnet, similar to a Ferrari F50, but a little squarer to suit the AW11

6. Cut the little beam that the radiator normally sits on off, becauser mine is stuffed due to the previous owner driving it drunk and smacking into a kerb. Is chopping this likely to cause and hassles structurally? The current one is barely attached on one end so I don't see it being any worse than it is now.

Some pictures:
This is one I did ages ago, when I had my first aw11 and was thinking about how I'd like it to look, took a wire frame drawing and gave it widebody guards, a wicked engine lid (which I actually did a while ago), and the bonnet, which is the important part - this is basically how I envisage doing the bonnet.



and here's a shot of the radiator support beam's damage - it's pushed back about 2 inches and it's only held on by one or two spot welds

[Paul Woods]

never mind the rad install,how cool is the widebody plan! lovin that mate.

As far as the rad goes as you know mr2's have very efficient systems,my v6 on full chat doesnt raise the needle above halfway and the fans cut in and out only slightly more often that they did before....is any alteration necessary do you think?

[podge]

gotta be said that wide body plan is the dogs mate fair play

[Driftin_AW]

did you also notice the lights are wider? The plan was to install some wider, shorter lights, like a couple of those smaller rectangular ones (found on trucks and later 70's Celicas etc) side by side

Anyway, I guess I didn't explain my reasons for wanting to do this. I definitely think the stock cooling system is adequate (to be fair, that radiator is huge!), but I don't like the idea of all the air that comes through the front going under the car, especially on a light fronted beast like the aw11.

Also, engine cooling isn't the only thing going on up the front. Since I have a w/a intercooler, the efficiency of the w/a radiator plays a big part in whether the car will heat soak during long periods of boosting. I'm sure the design outlined above will provide more airflow and hence more cooling for the w/a radiator, and the coolant temp wont be effected (ie overcooled) thanks to the thermostat. Also, with the radiators mounted horizontally, pretty much all heat from the engine radiator will rise upward when stationary, so it shouldn't heat the intercooler radiator as much as it would if they were side by side vertically.

[djdna2000]

I'm deffo going to do this, though I was thinking of keeping the rad in the stock orientation (or at least only angling it slightly). IMHO it will help front-end downforce no end too. My rad is shagged, so I'm going to go on a junkyard mission and find the biggest fecker I can fit in there - I'm going to be using mine as a track weapon and it'll need all the cooling it can get.

[Jiff Lemon]

Ducting out through the bonnet would probably be the single biggest improvement you could do on an a mr2. I don't think increasing size will do anything for efficiency - We're already at an advantage as we've a good few extra litres of water cos of the layout (think it's nearly double that of the same engined FWD model).

[nik]

in all my years of owning mk1s the fans have never come on..and i see the same cooling efficiency with the mk1 rad on the 3sgte..
really must get that PapaL hood vent done again though..:???:

[djdna2000]

I don't think increasing size will do anything for efficiency

eh? It absolutely 100% definitely will make the cooling system more efficient. However by doing some clever ducting you are increasing the efficiency still further (assuming the ducting increases airflow). As you say you could just do that and not go for a bigger rad and still get benefits.

[superchargedsam]

I think that by lifting the rads and making them horizontal you are cancelling out the extra effects of downforce by increasing the centre of gravity at that point therefore increasing more centrifugal loading on these points so the extra downforce you gain in a straighline may be at the risk of decrased grip while cornering due to the effect of moving the rad and all that coolant way above the wheels ! thats only IMHO but I hope you see what I mean ! I think you may be better keeping main rad in stock location and then putting the W2A rad on a bracket near the gearbox and duct air to it there which means reduced runs of piping and you will get some good airflow there if ducting air from under the car as it will flow up through the rad there very quickly indeed to meet the negative pressure above the car at this point ! Scoop on the the front should defo increase downforce on the front as long as your making all the air go through it, and to increase this effect a large and low front dam would help but may also increase total air resistance so its swings and roundabouts !

[Jiff Lemon]

eh? It absolutely 100% definitely will make the cooling system more efficient. However by doing some clever ducting you are increasing the efficiency still further (assuming the ducting increases airflow). As you say you could just do that and not go for a bigger rad and still get benefits.

Nooooo, what I meant was, that as we're already blessed with a hugely effective cooling system, sticking a bigger rad in isn't really going to improve it; If you've got cooling issues at the moment, its more likely to be age of components then design. Ducting the air through the bonnet interests me more from a aerodynamics point of view than a cooling one;