2 Speed fan mod from Mod-Wise, settings ?

[tvr4ever]

Just received my 2 speed fan mod from Mod-wise, xcellent piece of kit. There are two dials to select the on temperatures for 50% speed and 100% speed. I'm planning to go up the Stelvia pas so the engine will run pretty hot. Is there anyone who has this mod installed, and how are your settings.

Cheers Fred

[burriana500]

Getting mine back in an hour or so from Christopher Neil's where they have been kind enough to fit the 2-stage kit whilst it was in for something else.

Will let you know how it is when I've had chance to test it - I asked them to initially set the half speed to come on at about 84, and the full to come on at standard factory setting, which is about 92 I think.

Lots of people on here have it fitted and I haven't heard any bad reports - like you though, I could do with some guidance as to best settings as it's trip to Spain is looming fast!

Al.

[GreenV8S]

It depends which hose you have the sensors in. If you have them in the bottom hose (I recommend this) then slow speed 60 deg full speed 70 deg will be about right. If you have them in the top hose (boo hiss) then add 20-25 degrees to this.

[victormeldrew]

Steve

Why the preference for bottom hose? (Apologies if we've been here before.)

I'd have thought the top hose (ie engine outlet/rad inlet) would be the best spot as the coolant here will be more indicative of engine temp, which is what you are trying to cool after all.

[GreenV8S]

Top hose tells you how hot the engine is, which varies slowly by a small amount as the engine heats up when there is not enough cooling air. Bottom hose tells you how successfully the rad is cooling the water, this changes quickly over a wide temperature range when there is not enough air flow, which is exactly when you want the fans to come on.

[RichB]

Pete - out of interest, have you got one of David's early jobs or the later unit with adjustable settings etc.? I have an early prototype with one temp. sensor and I have it placed (with zippy ties) sort of hanging over the exahaust manifolds, in that way it senses the general under bonnet temps and when they reach 80 deg it switches on half speed. I tried it on the lower hose but it seemed to be on all the time? Rich...

[tvr4ever]

In the instruction leaflet they advise to tie the thermostat sensors to the outlet radiator hose, the one on the drivers side. Because mine is a lefthanddrive it figures that i should use the other side.

The full speed cut in cant't be adjusted to high up, if you adjust the temperature to high the original fan cut in point will be used, neat.

This one also has the fans stay on till all the heat has gone after switching the ignition off mod.

Phew, what a sentance..

And last but not least, it takes the starter motor feed for extra power.

I only have to find a way and place to install the control box, it does not have brackets or any mounting holes in it.

Fred

[burriana500]

Fred - one of the guys at Back Home said he placed his on the top cross member where the Vin No is stamped - used some silcon to set it in place then also secured it with ties.

[david beer]

As`Peter said, they will be much quicker to recognise you are slowing if on the outlet of the rad. Settings vary as different water stats will be fitted! You cant over cool or leave too late, so you can play with them. As for mounting the box, on a Griff they can normally be "popped" on the air filter box, not all though! Rich, its about time you had an upgrade ?

[Toffer]

GreenV8S said:

Top hose tells you how hot the engine is, which varies slowly by a small amount as the engine heats up when there is not enough cooling air. Bottom hose tells you how successfully the rad is cooling the water, this changes quickly over a wide temperature range when there is not enough air flow, which is exactly when you want the fans to come on.

Absolutely...you get a cooling system hysterisis.

Better to know how well the radiator is coping than how hot the engine has become (spot the tense?)

[simpo one]

What's the difference between hysteresis and feedback loop? (this is not s joke!)

[Toffer]

OK, a fedback loop is dependant on a sensor in the system (whatever system) detecting a change and automatically compensating for the change and thereby restoring equilibrium to the system.

Hysteris is the effect of the sensor not detecting a change in the system quickly enough to avoid "overshoot" or hysterisis.

In the case of a cooling system, if the sensor is detecting the over temperature and then compensating for it by increasing cooling (say by turning on fans) then it may be too late to prevent a temporary over temperature?

Detecting the cooled water should enable a degree of "anticipation" of a change to the system so minimising any hysterisis...got it?

Kindest regards to "Simpo One" from "Toffer", we haven't had that beer yet...IOU1.

[victormeldrew]

Not entirely. Surely the first place the increase in temp would be seen is the top hose. Slight increases in engine temp might be caught by the rad cooling enough, but the engine temp is increasing.

Oh I see - why is the engine temp increasing? - because the rad isn't catching airflow. Hence as soon as the rad fails to cool the coolant enough on come the fans. Dunno why I couldn't see that before!

[burriana500]

well, I got mine back yesterday and although I have still to play around with the settings, on the drive home on a hot afternoon, with rush hour traffic the temperature stayed at a steady 85 in traffic, raising to just short of 90 before dropping back... once on the open roads it was running at about 82.

Previously it would run at 90 and rise to 100 in traffic. Oh, and the automatic fan run on works a treat.

The heat sensors however have been attached to the rubber top hose as opposed to the metal. I'm going to email David at Modwise and see if this makes much difference.

So far so good

[GreenV8S]

If you've attached to the outside of a rubber hose I would expect it to be slower to detect changes, and to read low unless you also lagged the outside of the whole thing. I would recommend clamping firmly to metal pipe and then lagging.

[apcouldwell]

Origionaly had mine in bottom hose with a 82 degree thermostat and had to set unit at 85 and 90. By the time the fans came on half speed the coolent temp was quickly rising to 90 and the fans then running full speed.
Now have the sensor in the bottom hose (cable tied to the metal pipe with the foil insulation wrapped around it). Half speed is set at 80 degrees and full speed at just below 90 with the otter switch as back up. I also now have a 74 degree stat fitted. Next step is to try some water wetter.
Anybody know where I can get some water wetter. I know Leven sell it as part of their cooling kit and I think Demon Tweeks also sell it. I've tried my local Halfords but they've never heard of it.
My rad really needs a re-core but don't have the money at the moment and the 2 stage kit really helps keep the temperature down. Also the single fan fuse hasn't blown since fitting the mod.

Alan