Yea there site is not user friendly. http://eurotoysltd.com/catalog/product_info.php?cPath=49_62_30_506&products_id=38

 

Here's an extract from a Nov. 2009 posting by forum member bankerkys, who was selling a brand new Eurotoys low-temp thermostat. He quoted Eurotoys claim as follows:

Jaguar Low-Temp Thermostat - Jaguar Performance Parts. Get a little more performance out of your Jaguar XJR, XKR, S-Type R Supercharged 4.0/4.2L with this lower temperature thermostat. Eurotoys Ltd. was 1st to test and offer this performance lower temperature Thermostat for your Jaguar. This High-Flow Thermostat has a 13.2 degree lower opening temp than your factory Jaguar Thermostat. Having consistent control of engine temperature allows an engine to operate at its peak horsepower - no matter what the driving conditions. The factory Jaguar thermostat simply opens to late, which is bad for performance.
This Eurotoys Low Temp Thermostat improves performance in two ways: first by inducing less heat into the intake air and second by reducing the engine's tendency to detonate. .

However, the low-temp thermostat is no longer listed on the website, so...

 

qikcat - Yayy - thanks. The site's crazy, not even their own search found it.

Dunno whether I believe them and the "undetectable by the Dealer" could be interesting to get a tech like Brutal to test!

I wonder if it's their tune or the other ones that get mentioned from time to time. It's like there's only one that everyone resells and is just a frozen tune instead of the interactive kind done on the actual car on a dyno. Slightly odd that it's not TCM as well.

 

I would bet a steak dinner its not done in house. I spoke with mike about it and although i didn't ask him who did other then changes for octane (91 or 93) it is pretty well just flash what he has. I would pay good money to find someone that could break the code. My piggy back will only remove timming/fuel so that's a no go to.

 

Cooler 'motor' is pretty nebulous.

Cooler fuel? Good
Cooler intake air? Good
Cooler coolant? Bad- see reason up above. The way an engine makes power is by causing the air in the combustion chamber to expand as much as possible. The greater the temperature delta between pre and post combustion the better so cold air and cold fuel helps. P*ss*ng away some of that valuable energy simply to re-heat the combustion chamber on every power stroke is a complete waste.

As mentioned before the actual reduction of air intake temp is minimal. It takes a 10*F reduction in air inlet temp to gain 1% in power. A 13.2*F reduction in coolant temp might render a 2-3*F reduction in inlet air temp. Net gain might be 1-2HP. Wow.

S-type Rs are not known to suffer from detonation, so that's a non-starter right there.

 

I have a fair grip on how engines make power, it was what I got paid to do for quite a while. Cooler is cooler and coolant works into that and affects the others as well. Cylinder pressures developed just fine cool, there is a reason we heat the drag cars up 30min before a run and then pull them around, well there are a few reasons, one of which is to keep heat out of the motor, block. Your losing a little efficiency in one area to pick up a lot in another area, that's tuning.

 

Drag racers have the problem of having an intake system that becomes heat soaked while sitting at idle and have very little airflow to dissipate it. This means the engine will gulp hot air at the worst possible moment when the power is required.

If we're going to quote 'what the racers do' as substantiation- the NASCAR guys run coolant in the 210*F and up range. I've heard of a few teams that have gone to 235-240*F for qualifying. The reasons they do this is as per explanation above .

What works on the dyno and in 1/4 mile racing to avoid a hot intake doesn't match the long distance conditions of NASCAR and road racing. Street driving where the engine is operated at constant temps for extended periods is more similar to road racing.

Like you, I was paid to deal with this stuff- in my case in engineering at an OEM for over 30 years. We did everything we could to run the engines as hot as possible without melting. Sometimes we overdid it.

 

Actually we run methanol and our intake temperatures stay very cool, to the point the intake sweats in hot weather.

NASCAR guys run high temperatures in qualifying due to blocking the air passages off in the name of aerodynamics, same as guys at the Texas mile tapping up there grills. Heat is the byproduct not the intention. They do it in qualifications because the car woud never last a whole race that way. I worked with Roush when they had the IndyCar motor program, and worked with J3 racing a petit lamans gt3 class team,nce is admittedly not my thing but I do have some experience in it. I only did it about 20 years though and most of my experience was in running them in the real world and developing the motor programs. My data comes from that because its the data that's available, I don't monitor 60 channels on my street car daily and have a million dollar budget to develop it. I did have that on the others.

As you said earlier in your own post the cooler stat will make x amount of power. As I said, running it cooler makes more power rather directly or indirectly. If I were to put in a higher temp stat (which I have never heard of any performance company offering on any platform) would it make more power or less in your experience? Hotter dose giveer fuel economy and emissions in oem settings from what I understand.

I have melted a few motors myself. When your pushing the limits as you said it happens. We spent months locked in a dyno cell at Roush motorsports in Detroit during the winter developing the ecotech program for GM. We would run them for passes, tear it down, try this and that, push head gaskets out with 60+ psi of boost you name it. Making pass after pass on the superflow engine dynos with a 1600+ hp 4cylinder you tear up some stuff :-) Nice thing was in the field when you would get a cracked cylinder wall or head gasket going and I suggested just drop the coolant and run it. I could say with confidence it will make a pass, will drop a few tenths but it will go a burnout and 1320 ' we tried it :-)