Under bonnet temperatures
Discussion
Everything is working properly on my car, cooling system, fans, switches, the lot. The car does not overheat and can sit in traffic as long as necessary without any ill effects mechanically.
However - the heat transfer into the cabin on a really hot day is starting to wear a little thin. I am also not too happy about cooking everything under the bonnet to death which can only lead to other problems.
Has anyone done anything to reduce under bonnet temperatures that has made a significant difference. Like I said the engine is not overheating so I am not talking about fan mods, I am looking for other ideas/suggestions.
Anyone else done anything about this?
However - the heat transfer into the cabin on a really hot day is starting to wear a little thin. I am also not too happy about cooking everything under the bonnet to death which can only lead to other problems.
Has anyone done anything to reduce under bonnet temperatures that has made a significant difference. Like I said the engine is not overheating so I am not talking about fan mods, I am looking for other ideas/suggestions.
Anyone else done anything about this?
Ribol said:
Everything is working properly on my car, cooling system, fans, switches, the lot. The car does not overheat and can sit in traffic as long as necessary without any ill effects mechanically.
However - the heat transfer into the cabin on a really hot day is starting to wear a little thin. I am also not too happy about cooking everything under the bonnet to death which can only lead to other problems.
Has anyone done anything to reduce under bonnet temperatures that has made a significant difference. Like I said the engine is not overheating so I am not talking about fan mods, I am looking for other ideas/suggestions.
Anyone else done anything about this?
Part of my exhaust system has been heat wrapped, also I've had the Leven cooling kit fitted. Not sure how much real difference it makes. These cars do run very hot and there isn't that much you can do about that! However - the heat transfer into the cabin on a really hot day is starting to wear a little thin. I am also not too happy about cooking everything under the bonnet to death which can only lead to other problems.
Has anyone done anything to reduce under bonnet temperatures that has made a significant difference. Like I said the engine is not overheating so I am not talking about fan mods, I am looking for other ideas/suggestions.
Anyone else done anything about this?
The only thing I can say about cabin temps is to shut off the heater valve under the passenger side of the dash. This prevents hot water flowing into the heater matrix so it blows cool air even when stationary (well it does on mine anyway). It also seems to make the engine run a couple of degrees cooler when moving.
I have fitted a Levin Aluminium radiator,the old Tvr radiator looked ok but if you poked your finger into it the core disintergrated into powder ! my manifolds and Y piece are decatted and have been ceramic coated.off the top of my head the car used to run at about 80/85degrees,winter/summer but now runs at 65/70 degrees winter/summer with a noticable drop in cabin temperature.i even use the heater some times !
dhf said:
I have fitted a Levin Aluminium radiator,the old Tvr radiator looked ok but if you poked your finger into it the core disintergrated into powder ! my manifolds and Y piece are decatted and have been ceramic coated.off the top of my head the car used to run at about 80/85degrees,winter/summer but now runs at 65/70 degrees winter/summer with a noticable drop in cabin temperature.i even use the heater some times !
Decatting will obviously remove a constant heat source but I would like to leave that as a final option as I really like the way the car sounds as it is.My rad has been recorred with a "better" core and works fine so I can't see scrapping it for the ally one making too much difference.
The ceramic coating route sounds interesting though, are there any claims made on this as far as containing heat goes or is it purely cosmetic?
Having to use the heater would be a dream
Do make sure the heater valve is set to fully cold in the passenger footwell and if air entering the car is not totally cold close the round louvre vents in both driver and passenger sides.
The Chimeara bonnet is very good at removing heat from the manifolds through its gills, the only problem is that it rather inconsiderately dumps most of it through your open windows.
A partial remedy for this I have found accidently, when I superchaged mine, part of the kit from SC Power was an exhaust manifold heat shield for the passenger side. This seems to have the effect of reducing the heat that comes through the nearside gill and therefore less comes in that side of the car.
Its not very scientific I know but it has made a difference and I'm thinking about getting one for the other side.
Andy
The Chimeara bonnet is very good at removing heat from the manifolds through its gills, the only problem is that it rather inconsiderately dumps most of it through your open windows.
A partial remedy for this I have found accidently, when I superchaged mine, part of the kit from SC Power was an exhaust manifold heat shield for the passenger side. This seems to have the effect of reducing the heat that comes through the nearside gill and therefore less comes in that side of the car.
Its not very scientific I know but it has made a difference and I'm thinking about getting one for the other side.
Andy
Speak to Michael at Peninslar TVR but as far as i remember the ceramic coating not only improves gas flow but significantly reduces engine bay temperatures prolonging the life of the components.again if i remember correctly even removing the pre cats reduces engine bay temperatures and doesn't dramatically change the engine sound.
dhf said:
Speak to Michael at Peninslar TVR but as far as i remember the ceramic coating not only improves gas flow but significantly reduces engine bay temperatures prolonging the life of the components.again if i remember correctly even removing the pre cats reduces engine bay temperatures and doesn't dramatically change the engine sound.
Yes i would second that,removing Precats removes underbonnet temps noticably,the manifolds do ring(tinnie sounding) ever so slightly after removal but thats not an issue. Go for the wrap or the ceramic coating on as much of the exhaust as you can it knocks about 20° off the engine bay temp ( measured at the alternator with a temp sticker)
The ceramic coating is the better option but 250 quid I think? as opposed to 20 quid for the wrap.
Only thing to consider is that the manifolds must be stainless to survive being wrapped.
Make sure the engine stat is an original TVR big opening type and the 82 or 78°C as well.
Make sure the under car spoiler is still there as this forces more air through the rad and through the engine bay
Matt
The ceramic coating is the better option but 250 quid I think? as opposed to 20 quid for the wrap.
Only thing to consider is that the manifolds must be stainless to survive being wrapped.
Make sure the engine stat is an original TVR big opening type and the 82 or 78°C as well.
Make sure the under car spoiler is still there as this forces more air through the rad and through the engine bay
Matt
The Fan override mod may help by turning the fans on even if the engine temp doesnt require them. More air flow in engine bay.
I have the over ride fitted as well as the Leven mod. i.e.lower Otter temp and lower Stat opening.
If its hot the surely the roof is off the best cabin cooler.
Trev
I have the over ride fitted as well as the Leven mod. i.e.lower Otter temp and lower Stat opening.
If its hot the surely the roof is off the best cabin cooler.
Trev
Having boned up on the ceramic manifold coating a bit it certainly seems worth considering.
Has anyone done this without any other mods, was the underbonnet heat reduction worthwhile?
Were the parts sold already done outright/exchange basis or were your own parts coated?
Any ideas on timescales/price etc?
Has anyone done this without any other mods, was the underbonnet heat reduction worthwhile?
Were the parts sold already done outright/exchange basis or were your own parts coated?
Any ideas on timescales/price etc?
Ribol
If you're undecided between the wrap and the ceramic coating then I'd go for the wrap. I have experience of both and my belief (without resorting to experimentation) is that the latter does a better job.
You can get enough wrap for your manifolds for about £30 from Ebay and with a bit of fannying about have the job done in half a day. See what you think. The downside is that it becomes a bit fragile over time and can get damaged during maintenence etc. Some say that it will rot your system as moisture is absorbed and held within the fibres; I've not experienced that and my car is kept out of doors under a cover. Do make sure you use a ss lockwire (or ss ties) to hold it in place though or any electrolyis goin' on will leave you with discoloured ring marks around the tubework (I've wrapped both OE systems and aftermarket SS).
The ceramic coating is expensive, you have to remove the system, get it someplace, wait, then re-install it (with new gaskets). It does look good though and if you have access to blasting equipment and have a large enough oven that does 500 Deg. C then you can also do the manifolds yourself for about £30 (or at least the outer surfaces).
What you can't do however, is wrap a system that has been ceramic coated. I know, I tried it to my cost, the coating will crumble away. Can't think of a reason and no-one else has been able to offer one. I took the precaution of asking the opinion of those that I thought would have the answers before I tried it too, but there you go.
Bruce
If you're undecided between the wrap and the ceramic coating then I'd go for the wrap. I have experience of both and my belief (without resorting to experimentation) is that the latter does a better job.
You can get enough wrap for your manifolds for about £30 from Ebay and with a bit of fannying about have the job done in half a day. See what you think. The downside is that it becomes a bit fragile over time and can get damaged during maintenence etc. Some say that it will rot your system as moisture is absorbed and held within the fibres; I've not experienced that and my car is kept out of doors under a cover. Do make sure you use a ss lockwire (or ss ties) to hold it in place though or any electrolyis goin' on will leave you with discoloured ring marks around the tubework (I've wrapped both OE systems and aftermarket SS).
The ceramic coating is expensive, you have to remove the system, get it someplace, wait, then re-install it (with new gaskets). It does look good though and if you have access to blasting equipment and have a large enough oven that does 500 Deg. C then you can also do the manifolds yourself for about £30 (or at least the outer surfaces).
What you can't do however, is wrap a system that has been ceramic coated. I know, I tried it to my cost, the coating will crumble away. Can't think of a reason and no-one else has been able to offer one. I took the precaution of asking the opinion of those that I thought would have the answers before I tried it too, but there you go.
Bruce
I went the DIY ceramic painting route since the cost of a professional baked ceramic coating was prohibitive. The paint itself was quite expensive (£100 or so from memory) and I had the manifold professionally blasted and then painted it myself. The paint is supposed to be good for about 1000C but is starting to look a little distressed around the exhaust ports so I guess they're getting close to the limit. Wrapping would make things hotter and perhaps push the temperatures beyond what the paint will tolerate?
The Fan Override switch is the cheapest and quickest, though probably not quit as effective as wrapping (but don’t know cause I haven’t done it).
The switch has kept my Griff happy for many years, I have recently had coil problem’s and by leaving the fans on constantly has cooled it enough to keep it well under control. I would have thought with the vents you have this would make the fans even more effective, though you would need a properly working cooling system and the correct stat fitted else you could over cool the engine, just keep an eye on the gauge.
Cheers,
Simon.
The switch has kept my Griff happy for many years, I have recently had coil problem’s and by leaving the fans on constantly has cooled it enough to keep it well under control. I would have thought with the vents you have this would make the fans even more effective, though you would need a properly working cooling system and the correct stat fitted else you could over cool the engine, just keep an eye on the gauge.
Cheers,
Simon.
IMHO It's better to fit the Modwise 2 stage fan cooling kit rather than use an override switch. You can then forget about watching the temp gauge once it setup,,,, but old habbits do die hard don't they!!
I replaced my override switch with this kit and it works great. I tidied it up a bit by painting it glosss black and attaching the heat shrink stuff immediately below the control box. I also made some neat brackets, so its held in place with the fan shroud bolts. No need for drilling holes anywhere after that. You will know what I mean when you see it and fit it. I also and added a switch on the control box so that I can choose how the fans run on after ignition is turned off. I can now set it so the fan runs on or not after ignition and in one or two stages. Helps cool the car quicker when its parked up.
If you do decide to fit the modwise kit.........Do not remove the override switch wiring. This can be simply be used to add two LED's in the cockpit so that you can see when the fans on at half or full speed. This aids initial setup and is also piece of mind because the fans come on so smoothly when its done in two stages that its hard to tell when they are now,, except when at full speed of course.
DB I need the heat shrink you promised please. Mark, Austria!!
I replaced my override switch with this kit and it works great. I tidied it up a bit by painting it glosss black and attaching the heat shrink stuff immediately below the control box. I also made some neat brackets, so its held in place with the fan shroud bolts. No need for drilling holes anywhere after that. You will know what I mean when you see it and fit it. I also and added a switch on the control box so that I can choose how the fans run on after ignition is turned off. I can now set it so the fan runs on or not after ignition and in one or two stages. Helps cool the car quicker when its parked up.
If you do decide to fit the modwise kit.........Do not remove the override switch wiring. This can be simply be used to add two LED's in the cockpit so that you can see when the fans on at half or full speed. This aids initial setup and is also piece of mind because the fans come on so smoothly when its done in two stages that its hard to tell when they are now,, except when at full speed of course.
DB I need the heat shrink you promised please. Mark, Austria!!
Edited by m4rk on Wednesday 30th July 20:16
Not sure that my solution solves the cabin temperature issue but it improves the under bonnet temp. I devised a circuit which keeps the fans to about one third of their speed once the fans have been on once, so instead of dropping back to completely off they keep pumping cooler air under the bonnet.
If anyone wants a copy of my hand drawn circuit I will gladly send it if you contact me direct.
Mike
If anyone wants a copy of my hand drawn circuit I will gladly send it if you contact me direct.
Mike
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