I agree its not an easy topic obviously, we would be rich if we could design without specific knowledge/bucket loads of money.

But here is another thought that one should take into consideration:
There are some extreem hot parts under the bonnet, take the exhaust manifolds/cats.in case on picture #1, if due to the shape (as Tijoe mentioned) you could get (some) air out, is that also what you really want? You could draw much more heated air upwards to the intake components as a result.
As example, when you have driven, stop, open the hood and check the engine components, you can touch almost all parts with your hands, as its not hot enough, Now try to do that if you car had sit for 15 minutes or os and then open the hood.

As #1 is from your car right? You could do the tests as in the link for the ricer (was not intended to mark you as a ricer! I just quickly had to look for another link that gave some explanation) with the strings to see how the air flows, and also do under hood temp measurements but that is more trickier to ensure similar conditions, but then at least you know if it could work for you or not.

 

Gentleman,

Now that we have tried to determine what works and what doesn't, I would like to say, I like the Rear opening on Deuce's Hood (Bonnet), as I think it's cool! But....I 'm not real happy with NASA opening....I've always thought that they look out of place on the Hood (Bonnet) of an automobile; as they take away from the Beauty lines of the Body lines. Sorry, Deuce! I really do like the way the Rear Opening looks...which of course has noting to do with aerodynamics....It's just Cool looking! There again, I don't think I would ever do that as it looks pretty darn good the way it came from the Factory.....Jaguar designed the (2) Vents on the Hood to relieve Air pressure and heat coming from the Radiator and Intercoolers and I think they look great! They also work, as mine continue to lose their shine because of the heat.....Let's face it, Guys! There's not to much that can be done to improve the looks of our XKR's.....

Billy Clyde in Houston,

 

the flows depend a lot on the inclination of the bonnet and the windshield. Excessive inclinations (like Mitsubishi Lancer Evo X) probably increase the pressure a lot more than our cars ..

in the first picture is my hood. but inside (in the lower part of the opening) has a straight part that covers part of the suction pipe. It was not simply cut and raised, but has two parts that are overlapped for a length of 10 cm.

I would then invite you to look at the hood of the new Camaro. has the same system.

I remember that I have the Garmin connected to the ODBII socket to see if the temperatures are lowered .... needless to say that I have had improvements.

Happy weekend to everyone

 

 

Am more then happy to learn, and have searched for Camaros hoods but they are all closed at the end, can you show a picture where its open, ie more like yours?

I do see hoods where they use the same principles as in the Ferrari once (just as example as there are so many that use that principle), so more an opening in the front part where there is under pressure.

@bcprice36
There are good improvements to be made actually, the 2005 front XKR bumper has really improved airflow capacities, tents a little bit more towards a splitter so it create a slight bigger pressure area upfront, a little more under pressure below. Next a larger capacity intercooler radiator (not a same size and thicker version as some so-called tuners sell, but a truly larger surface area one) and some small adaptions around that will help tremendously in supporting cooling capacity. Or a supercharger that generates less heat in the 1st place, as its the source 1st you need to attack.

 

Yes Sir! I understand that...Even at that, the larger Intercooler, although not large enough, does a pretty good job with what we've got to work with.....As you have said, there's not much can be done to increase H/P with the system we have....What can be done? I just about done it all.....now, for the last year, I've spent just about as much on it trying to get it running right that I could have paid you for a Twin-Screw set-up......and here I am still searching for the problem....

I think I have finally gotten a device that will read Fuel Trims...If so I will send you some by P/M....

Billy Clyde

 

 

my ceramic coated exhaust manifolds:

https://www.jaguarforums.com/forum/x...8/#post1966268

 

I am a little late to this game, but I just had to register to answer a couple tech questions that went unaddressed.

Faster moving water always cools more than slower moving water. The more flow, the more cooling. The heat transfer takes place when the water molecules contact the internal surface area of the intercooler/heat exchange. The more molecules you can throw at that surface area, the more heat can be removed. You wouldn't put a fire out with the trickle from a garden hose compared to a fire hose. Extracting the heat from the water is the same process with the energy (heat) flowing in the opposite direct. The ruling factor is water volme and ΔT.

This is the best route if you're looking to remove more heat from the factory intercoolers without actually changing core sizes. More water flow, more water volume, more heat transfer. Two circuits increases flow over just adding a higher flow pump, albeit at the increase of surface resistance from the extra hose, but that's marginal. The factory hose size has a fixed volume flow even with a pump with head pressure high enough to overcome surface resistance and fitting restrictions.

The intercooler water channels is a dual pass design, similar to most automotive radiators. The end tank with two inlets is divided internally while the opposite side end tank is open. This allows the water to flow down the core and back up the other side.


A DEAD EASY way to increase core efficiency in this set up is to convert the water passages to single flow by teeing together the inlets and drilling a new outlet in the rear end tanks . This will reduce the pressure drop across the intercooler caused by internal resistance by 3/4. fluid speed across the core will drop slightly (at the same head pressure), but the decrease in resistance will increase volume flow as the pump will not have as much resistance to work against..