How to improve engine cooling on an Evora S

[Arregueti]

I was in the Italian Dolomites (until Covid-19 kicked me out, but that is another story) at the peak of the heat wave in July. My car was experiencing almost constantly a slight overheat due to high temperatures and low speed through towns, heavy traffic, etc. Nothing serious as the fans kicked in as necessary, but at some point it went into limp mode when I tried to restart after spending a couple of hours in the sun. At Gavia, of all places… The codes showed an issue with the throttle actuator and it was solved by simply disconnecting the battery, with the help of other members of the group. For the rest of the trip it ran perfectly but I could feel the engine noise changed at times and the fuel/air mix seemed to have been changed. At points, mostly at low speeds in second gear, it seemed to be running like a car on carburetors when the mixing was not ideal. It struggled a bit before catching up normally. Back at home I washed the car and I could see rests of fuel leaving the rear bumper and diffuser…there was even a petrol-color taint in the water… I guess the mix was very rich in an effort to protect the engine, but I am no expert.

This rose the question as to how to improve the engine cooling and what are the best mods in this regard. What would you advise? New manifold and cats (the car is ten years old now, would this be advisable anyway)? Would one of the fancy carbon boot lids currently on offer help? Bigger/better radiator? Any other ideas?

Apologies for the long post, but I thought some background might help.

 

Many thanks in advance for your suggestions.

[hamza]

I think the price is enough to justify the carbon louvred tailgate. Do it!

My 2010 NA has the additional fan fitted for the Middle East market to help with cooling the engine. The previous owner @series_one had it fitted with an override switch and said to always use it when it’s hot and moving slowly.

[series_one]

Airflow around the enginebay keeps all the components healthier. Particularly the wiring and fuel system. 
 

As summer temps increase or the Evora stays stationary the heat bakes everything in a way the set up was not designed for - front rad and fan blowing onto the engine. Hence the middle east market cars getting the ecu controlled fan in the right hand vent. And in the later cars the vented lid instead of glass.  Ideal in my mind would be clear polycarb with louvres.

I am absolutely certain my cars / now Hamza’s engine ancilaries are in better condition because of the fan. 
 

At this price is a no brainer. Lovely and highly beneficial part.

[tim_marra]

Is anyone running their car without the inner engine cover? I have thought of leaving it off, but have yet to do so...

[Bruss]

Just on track, Tim.

[Bravo73]

6 hours ago, tim_marra said:

Is anyone running their car without the inner engine cover? I have thought of leaving it off, but have yet to do so...

Yes. 

I’ve been using cf versions of the Exige covers for years:

[Arregueti]

Probably difficult to judge, but have you perceived an improvement @Bravo73? It would be nice to find a simple and easy way to improve things. 

[Doug Ashley]

On 17/08/2022 at 13:48, series_one said:

At this price is a no brainer. Lovely and highly beneficial part.

I think given we are probably now a 'hot territory' in the UK, I'll look into fitting this.

If you don't mind expanding on the process a bit more, presumably all that's needed are parts 11-17 on the page below?

https://www.bellandcolvill.co.uk/deroure?qs=1&preview=1&make=1&model=20&groupid=12727

Can this plug into something already in the engine bay, to be controlled by the ECU, or did you set up a new wiring circuit specifically for this?

TIA, Doug

 

[21gg]

I know a few have fitted the 400 endertray or the boe fab undertray which have a full width intake to get more air through the engine bay.

[windymiller]

what about ceramic coating the manifolds ?? seen claims of 30% reduction in engine bay temp and doesnt seem that costly ?

[series_one]

Yes that fan and the adaptor plate. Lotus Motorsport installed it for me. If one was to do it now I would get RRR to install. Gregor knows the Evora electrics / ecu better than most as he worked on it at Lotus. A simple on off and timer on shut down would work just the same as mine did via the ecu. The ecu stays active for 3mins or a bit more after the alarm comes on and mine was set up to run on shut down with the switch on for that period, in addition to me running the fan when stationary or creeping in heavy summer traffic. 
 

I also had completely ceramic coated tubular system to reduce the engine bay heat. It all worked very well imo. 
 

the only thing I woukd do is use CamCoating instead of Zircotec. Z marks and chips off. Camcoating (Ive put on the 340R system) does the same job and doesnt mark or chip off. And they are cheaper than Z so win win. 

[Bruss]

Couple of pics of the underside.

 

 

It was a while ago and I can't remember who I got the bobbin/cotton reels from but it was from ebay.

 

[series_one]

Ooh cap head instead of head bolts. 0.3% aero improvement but mechanics are hating you. 
 

actually droping the floor to give the cooling slot kills the aero anyway. 
 

but its good cololing opp unless you drive through a flood at some point lol

[Bruss]

 

🤣

[series_one]

😂😂

 

 

well I may have driven the Evora through a flood and realised after that it was not a good idea for someone with clean and proper OCD!!!

 

 

[Arregueti]

On 17/08/2022 at 14:48, series_one said:

Airflow around the enginebay keeps all the components healthier. Particularly the wiring and fuel system. 
 

As summer temps increase or the Evora stays stationary the heat bakes everything in a way the set up was not designed for - front rad and fan blowing onto the engine. Hence the middle east market cars getting the ecu controlled fan in the right hand vent. And in the later cars the vented lid instead of glass.  Ideal in my mind would be clear polycarb with louvres.

I am absolutely certain my cars / now Hamza’s engine ancilaries are in better condition because of the fan. 
 

At this price is a no brainer. Lovely and highly beneficial part.

 

On 19/08/2022 at 12:09, series_one said:

Yes that fan and the adaptor plate. Lotus Motorsport installed it for me. If one was to do it now I would get RRR to install. Gregor knows the Evora electrics / ecu better than most as he worked on it at Lotus. A simple on off and timer on shut down would work just the same as mine did via the ecu. The ecu stays active for 3mins or a bit more after the alarm comes on and mine was set up to run on shut down with the switch on for that period, in addition to me running the fan when stationary or creeping in heavy summer traffic. 
 

I also had completely ceramic coated tubular system to reduce the engine bay heat. It all worked very well imo. 
 

the only thing I woukd do is use CamCoating instead of Zircotec. Z marks and chips off. Camcoating (Ive put on the 340R system) does the same job and doesnt mark or chip off. And they are cheaper than Z so win win. 

Thank you for your posts @series_one

I have been discussing alternatives with my contact at Komo-tec based on your input and he suggested to go for their improved radiator rather than the Middle-east fan. He implied that adapting the ECU would be complicated and/or not adequate for all time driving (ie. driving when it is not hot, as the car could be below operating temperature...) and/or that fitting the switch would be costly, as they have not done it before. He therefore suggested that starting with the improved radiator would be more cost-effective and better for my intended use. Do you have any memories of how complicated this was in your old car? I guess not that easy if you suggest a specific gentleman to do the setup...

I will in any case be swapping to a CF tailgate (bootlid?) so maybe that and the improved radiator should help improve things to start with.

Incidentally, and having looked at my undertray, I saw a big mark of dirt (most likely fuel) on the right side... I hope it is just an isolated incident and not a leak in the fuel system or some damage related to continued overheating. I may be getting paranoiac but will rather sort this properly.

 

 

[cor]

On 17/08/2022 at 21:21, Bravo73 said:

Yes. 

I’ve been using cf versions of the Exige covers for years:

Hello, Jonny,

what air filter housing is this?

thanks Cor

[steamdriven]

16 hours ago, Arregueti said:

 

Thank you for your posts @series_one

I have been discussing alternatives with my contact at Komo-tec based on your input and he suggested to go for their improved radiator rather than the Middle-east fan. He implied that adapting the ECU would be complicated and/or not adequate for all time driving (ie. driving when it is not hot, as the car could be below operating temperature...) and/or that fitting the switch would be costly, as they have not done it before. He therefore suggested that starting with the improved radiator would be more cost-effective and better for my intended use. Do you have any memories of how complicated this was in your old car? I guess not that easy if you suggest a specific gentleman to do the setup...

I will in any case be swapping to a CF tailgate (bootlid?) so maybe that and the improved radiator should help improve things to start with.

Incidentally, and having looked at my undertray, I saw a big mark of dirt (most likely fuel) on the right side... I hope it is just an isolated incident and not a leak in the fuel system or some damage related to continued overheating. I may be getting paranoiac but will rather sort this properly.

 

 

Ref your 'big mark of dirt on the undertray'  -  is that possibly transmission oil spill from the vertical gear shift linkage on the gearbox ?   I ask because I found that during high temperature running of my Series 1 Evora there is a small leak of transmission oil which collects and drips onto the undertray. The source of the leak is possibly the oil seal in the gear shift linkage or from the plastic oil breather at the same location.  I first noticed slight transmission oil smell after a hot day on the track which is caused by a burn-off of the small amount of oil that leaks and collects on the top of the gear box housing. Take a look to see you can see small collection of oil or residue in that area.

[Arregueti]

Thanks for that.
 

It is located at the “end” of the engine bay, next to the rear diffuser. It seems far from the gearbox and it looks “lighter” than oil, so I am inclined to think it is fuel, but I will have a better look.

[phil flash]

Getting back to the original post - "there was even a petrol-color taint in the water…"  makes no sense to me. Petrol goes into the combustion chamber, coolant is in a water-jacket around the cylinders and through the castings of the head. There should be no contact between petrol and coolant - unless there is a crack in the block or head, or the head-gasket has failed. In most cases you'll also see coolant in the oil if that happens.

[Arregueti]

Hi Phil,

Apologies if my wording was misleading. I found that taint of fuel in the water pouring down from the car when I washed the rear bumper. I didn´t say it was mixed with coolant.  I was thinking that it must have been un-burnt "excess" fuel, probably as a result of the mix being much richer in fuel. That is my theory, at least.