Mod Wise Two Stage Cooling Kit. Siting the Control Box.
Discussion
Have just bought one of these kits for my 1999 4ltr. Will be fitting the Relay Module to the fan casing, but am in a bit of a quandary as to the best place to fit the Control Box. The instructions say "away from manifold heat and water ingress".
Would greatly appreciate any info from those who already have a kit fitted. Regards.
Would greatly appreciate any info from those who already have a kit fitted. Regards.
The otter switch is an off/on switch
These run the fans at half speed when the temp hits one setting and full speed when it hits another
There is also an option to have the fans run on once the engine is switched off which helps shift the heat out of the engine bay while the car cools down.
These run the fans at half speed when the temp hits one setting and full speed when it hits another
There is also an option to have the fans run on once the engine is switched off which helps shift the heat out of the engine bay while the car cools down.
Barreti said:
The otter switch is an off/on switch
These run the fans at half speed when the temp hits one setting and full speed when it hits another
There is also an option to have the fans run on once the engine is switched off which helps shift the heat out of the engine bay while the car cools down.
What are the advantages of that ?These run the fans at half speed when the temp hits one setting and full speed when it hits another
There is also an option to have the fans run on once the engine is switched off which helps shift the heat out of the engine bay while the car cools down.
Advantages of the two-speed kit:
- You can select one temperature at which the fans come on at half speed, thus providing earlier cooling before things get REALLY hot under the bonnet. The otter switch can't do that.
- You can select the higher temperature at which the fans come on at full speed. The otter switch can't do that.
- The system works in parallel with the existing otter switch, thus if your otter switch fails the system switches the fans on and off anyway - and indeed even if the system fails the otter switch will still work.
- The fact that the fans come on at half speed earlier will prevent the temperature under the bonnet getting as high as it normally would, helping to prolong the life of rubber hoses, the coil, ignition amp, etc etc etc.
Or this one:
https://www.spiyda.com/magento/index.php/dual-fan-...
It can do everything the ModWise kit does in a smaller package than can be mounted anywhere including hidden under the dash, it also allows the fans to run after the ignition is turned off like every modern car has been configured for the last 20 years.
All for £34.00, bargain!
https://www.spiyda.com/magento/index.php/dual-fan-...
It can do everything the ModWise kit does in a smaller package than can be mounted anywhere including hidden under the dash, it also allows the fans to run after the ignition is turned off like every modern car has been configured for the last 20 years.
All for £34.00, bargain!
Thanks for the prompt responses guys. 
Reasons for buying the kit has been already well explained earlier in this thread. I have never been a fan (oops!) of the on/off/full load/no load nature of the original setup. The two speed kit in my mind provides a more progressive control over engine bay temperature and engine cooling, as well as the otter switch still sat there if all else fails.
Front top chassis cross bar seems to be a favoured option and that's where I'll put mine.
Reasons for buying the kit has been already well explained earlier in this thread. I have never been a fan (oops!) of the on/off/full load/no load nature of the original setup. The two speed kit in my mind provides a more progressive control over engine bay temperature and engine cooling, as well as the otter switch still sat there if all else fails.
Front top chassis cross bar seems to be a favoured option and that's where I'll put mine.
ChimpOnGas said:
Or this one:
https://www.spiyda.com/magento/index.php/dual-fan-...
It can do everything the ModWise kit does in a smaller package than can be mounted anywhere including hidden under the dash, it also allows the fans to run after the ignition is turned off like every modern car has been configured for the last 20 years.
All for £34.00, bargain!
That kit doesn't seem to do the half speed feature. Pretty good other than that though, might try it in the 3000M, it'll be the most complex thing on it https://www.spiyda.com/magento/index.php/dual-fan-...
It can do everything the ModWise kit does in a smaller package than can be mounted anywhere including hidden under the dash, it also allows the fans to run after the ignition is turned off like every modern car has been configured for the last 20 years.
All for £34.00, bargain!
You open a whole can of worms going home made electronics. I bought a similar unit of ebay, and TBH it simply not robust enough for use in an engine bay as it had no voltage regulation, or noise suppression and was not encapsulated to keep out any damp. - Fan motors can generate significant spikes on a 12 volt rail as the switch. After my recent experiences of "fried chips", I would not ever consider a unit like this without running a bi metal otter switch in parallel as fall back. Electronics on the bench is one thing, but a car engine bay at high temp with a glitchy 12v supply is another. In order to get the two speed bit to work, you need at least two additional relays to switch the fans first in series, then parallel.
ChimpOnGas said:
Or this one:
https://www.spiyda.com/magento/index.php/dual-fan-...
It can do everything the ModWise kit does in a smaller package than can be mounted anywhere including hidden under the dash, it also allows the fans to run after the ignition is turned off like every modern car has been configured for the last 20 years.
All for £34.00, bargain!
Modwise kit is complete, that needs temperature sensors.https://www.spiyda.com/magento/index.php/dual-fan-...
It can do everything the ModWise kit does in a smaller package than can be mounted anywhere including hidden under the dash, it also allows the fans to run after the ignition is turned off like every modern car has been configured for the last 20 years.
All for £34.00, bargain!
Had the Modwise one for 7 years following the failure of an otter switch and subsequent boil over.
Works flawlessly, highly recommend it.
My control box is also on the chassis crossmember
SILICONEKID345HP said:
All i know is I have done trackdays ,sat in traffic and gave the car some stick and its never over heated .
... yet.SILICONEKID345HP said:
If the otter fails i have a simple bypass switch .
... which is great, IF you notice the problem soon enough. Otherwise, you're f
ked.SILICONEKID345HP said:
All i know is I have done trackdays ,sat in traffic and gave the car some stick and its never over heated .
If the otter fails i have a simple bypass switch . I`m not sure if all this half speed stuff is needed .
Overall I'm inclined to agree with Daz here If the otter fails i have a simple bypass switch . I`m not sure if all this half speed stuff is needed .
Contrary to common folk law the cooling system on these cars is actually more than adequate assuming its well maintained & working correctly.
However, with the standard system you tend to run the car close to the safe maximum temp then use both fans to bring things down again. My tests have shown if you run one fan slight early, 90% of the time you can actually keep temperatures at safe levels without the need to run the second one.
The objective of both set ups is to keep the engine temperature bang on 90 degrees at all times, ignore what the TVR gauge is saying. If you adopt the staged fan system the idea is you're starting to control things early not just letting the temps surge upwards then aggressively dragging them down again with both fans.
Theoretically the staged fan set up is a safer and more controlled way to control engine temps
I've actually run a number of setups, originally firing both fans from the otter switch in the standard way when I was on the 14CUX system, then both fans controlled by the Canems ECU.
I'm now trying a staged set up, running one fan early switched by the Canems ECU and the second one triggered by the otter switch which also brings in a small Davies Craig electric booster water pump.
With the engine running & the temps climbing above 90 degrees the little booster pump just assists the mechanical pump rather than replacing it, but the pump & the second fan are both wired in such a way as to continue run when the ignition is switched off.
Like I say 90% of the time the single fan fired by the ECU does the job of holding the coolant at the perfect 90-92 degrees, with the second fan & electric booster pump only really needed after extended idling time in hot weather.
As soon as the second fan & pump chime in you can see the coolant temps fall away rapidly, if you turn the ignition off while this is happening they still run so you have both air flow through the rad & water flow through the engine even though its not turning.
The ECU software tells me the coolant temp is quickly dragged down to a safe 80 degrees before the second fan & water pump are switched off. This eliminates the heat surge I've observed when you switch the engine off, I've seen temps surge up to 98 degrees plus with the traditional no fans & no water flow on switch off set up.
With this set up I run an 88 degree Range Rover thermostat which I found holds temps much more consistently at the target 90 degrees than the old 82 degree one TVR specified. TBH the electric water pump started out as a way of driving coolant through the vaporiser as the car warms up, this is to speed up the point I can switch to LPG on cold mornings.
The idea then came to me I could also use the pump to help control engine temps at the upper end and assist in eliminating heat soak when you switch the engine off, so far it's working really well on all counts
ChimpOnGas said:
Overall I'm inclined to agree with Daz here
Contrary to common folk law the cooling system on these cars is actually more than adequate assuming its well maintained & working correctly.
However, with the standard system you tend to run the car close to the safe maximum temp then use both fans to bring things down again. My tests have shown if you run one fan slight early, 90% of the time you can actually keep temperatures at safe levels without the need to run the second one.
The objective of both set ups is to keep the engine temperature bang on 90 degrees at all times, ignore what the TVR gauge is saying. If you adopt the staged fan system the idea is you're starting to control things early not just letting the temps surge upwards then aggressively dragging them down again with both fans.
Theoretically the staged fan set up is a safer and more controlled way to control engine temps
I've actually run a number of setups, originally firing both fans from the otter switch in the standard way when I was on the 14CUX system, then both fans controlled by the Canems ECU.
I'm now trying a staged set up, running one fan early switched by the Canems ECU and the second one triggered by the otter switch which also brings in a small Davies Craig electric booster water pump.
With the engine running & the temps climbing above 90 degrees the little booster pump just assists the mechanical pump rather than replacing it, but the pump & the second fan are both wired in such a way as to continue run when the ignition is switched off.
Like I say 90% of the time the single fan fired by the ECU does the job of holding the coolant at the perfect 90-92 degrees, with the second fan & electric booster pump only really needed after extended idling time in hot weather.
As soon as the second fan & pump chime in you can see the coolant temps fall away rapidly, if you turn the ignition off while this is happening they still run so you have both air flow through the rad & water flow through the engine even though its not turning.
The ECU software tells me the coolant temp is quickly dragged down to a safe 80 degrees before the second fan & water pump are switched off. This eliminates the heat surge I've observed when you switch the engine off, I've seen temps surge up to 98 degrees plus with the traditional no fans & no water flow on switch off set up.
With this set up I run an 88 degree Range Rover thermostat which I found holds temps much more consistently at the target 90 degrees than the old 82 degree one TVR specified. TBH the electric water pump started out as a way of driving coolant through the vaporiser as the car warms up, this is to speed up the point I can switch to LPG on cold mornings.
The idea then came to me I could also use the pump to help control engine temps at the upper end and assist in eliminating heat soak when you switch the engine off, so far it's working really well on all counts
Reminds me of a modern low water content boiler with a timed or temperature pump over run which allows the boiler to dissipate excess heat.Contrary to common folk law the cooling system on these cars is actually more than adequate assuming its well maintained & working correctly.
However, with the standard system you tend to run the car close to the safe maximum temp then use both fans to bring things down again. My tests have shown if you run one fan slight early, 90% of the time you can actually keep temperatures at safe levels without the need to run the second one.
The objective of both set ups is to keep the engine temperature bang on 90 degrees at all times, ignore what the TVR gauge is saying. If you adopt the staged fan system the idea is you're starting to control things early not just letting the temps surge upwards then aggressively dragging them down again with both fans.
Theoretically the staged fan set up is a safer and more controlled way to control engine temps
I've actually run a number of setups, originally firing both fans from the otter switch in the standard way when I was on the 14CUX system, then both fans controlled by the Canems ECU.
I'm now trying a staged set up, running one fan early switched by the Canems ECU and the second one triggered by the otter switch which also brings in a small Davies Craig electric booster water pump.
With the engine running & the temps climbing above 90 degrees the little booster pump just assists the mechanical pump rather than replacing it, but the pump & the second fan are both wired in such a way as to continue run when the ignition is switched off.
Like I say 90% of the time the single fan fired by the ECU does the job of holding the coolant at the perfect 90-92 degrees, with the second fan & electric booster pump only really needed after extended idling time in hot weather.
As soon as the second fan & pump chime in you can see the coolant temps fall away rapidly, if you turn the ignition off while this is happening they still run so you have both air flow through the rad & water flow through the engine even though its not turning.
The ECU software tells me the coolant temp is quickly dragged down to a safe 80 degrees before the second fan & water pump are switched off. This eliminates the heat surge I've observed when you switch the engine off, I've seen temps surge up to 98 degrees plus with the traditional no fans & no water flow on switch off set up.
With this set up I run an 88 degree Range Rover thermostat which I found holds temps much more consistently at the target 90 degrees than the old 82 degree one TVR specified. TBH the electric water pump started out as a way of driving coolant through the vaporiser as the car warms up, this is to speed up the point I can switch to LPG on cold mornings.
The idea then came to me I could also use the pump to help control engine temps at the upper end and assist in eliminating heat soak when you switch the engine off, so far it's working really well on all counts
Two pumps running in line is a no no in the plumbing world .
Edited by SILICONEKID345HP on Monday 6th April 23:15
Heat surge on engine switch off is offten overlooked, people tend to solely focus on controlling coolant temps while the engine is running but what they fail to realise is the hottest the engine coolant gets is actually immediately after the engine is switched off.
When you switch your engine off the car is always stationery so if the fans aren't configured to run there's zero airflow through the rad, all cars for the last 20 years or more are wired so the fans continue to run after switch off for this very reason. Only TVR in their wisdom decided the fans should go completely dead when you turn the ignition off.
With the engine switched off the mechanical water pump is not turning too and with no fans running heat surges up rapidly for those critical few minutes after you've killed the engine. There still remains a circulation of sorts by virtue of thermosyphon but with no fans running things can get very hot indeed at the heads.
I wouldn't be at all surprised if this is when a lot of head gasket failures occur, my system of one fan running and assisted coolant circulation by electric water pump after switch off resolves this heat surge problem.
Its just an added line of defence against leaving hot spots in the water ways around the heads after a hot switch off. Many modern cars are running electric water pumps these days and like all manufacturers run electric fans after switch off they also run the pump after switch off too.
My observations of how the coolant temperature behaves shows airflow and coolant circulation after switch off completely eliminates the potential dangers of heat surge.
If you think the pump is a step too far for you I would still recommend wiring your fans so the stay on after switch of, there's very good reason why all car manufacturers do it this way.
When you switch your engine off the car is always stationery so if the fans aren't configured to run there's zero airflow through the rad, all cars for the last 20 years or more are wired so the fans continue to run after switch off for this very reason. Only TVR in their wisdom decided the fans should go completely dead when you turn the ignition off.
With the engine switched off the mechanical water pump is not turning too and with no fans running heat surges up rapidly for those critical few minutes after you've killed the engine. There still remains a circulation of sorts by virtue of thermosyphon but with no fans running things can get very hot indeed at the heads.
I wouldn't be at all surprised if this is when a lot of head gasket failures occur, my system of one fan running and assisted coolant circulation by electric water pump after switch off resolves this heat surge problem.
Its just an added line of defence against leaving hot spots in the water ways around the heads after a hot switch off. Many modern cars are running electric water pumps these days and like all manufacturers run electric fans after switch off they also run the pump after switch off too.
My observations of how the coolant temperature behaves shows airflow and coolant circulation after switch off completely eliminates the potential dangers of heat surge.
If you think the pump is a step too far for you I would still recommend wiring your fans so the stay on after switch of, there's very good reason why all car manufacturers do it this way.
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