vader

I can't believe how sealed up the underhood area is...short of chopping up the hood pad and plastic...has anyone come up with a clean way to eliminate underhood heat. Trying to blow it all out the underside is futile and a bad design. This car is still warm in the MORNING !!!

Grumpy666

Based on past discussions, it appears the various engine panels are designed to first direct the airflow across the heat exchangers before it is channeled to flow across the exaust manifolds while the car is in motion. If you remove or modify any of them, you'll probably disrrupt the in-motion cooling efficiency, which is on the edge of being adequate. Victor (vrus) was researching this at one time. You might want to shoot him A PM if he doesn't chime in here.

vader

Maybe a nice L88 hood scoop !

PTE

try this ? take care ___PTE___

Rafal

Great mod, I did mine with a hack saw...

chem0

my god you really did!! more pics!!

vrus

I did some checking under the car but decided to leave the bottom panels alone.. They cover and protect the alternator (which is very close to the ground) and other parts of the car. If those panels are removed the components that are low mounted will be exposed to the elements..

Saying all that.. The engine temp was lower with the rearward tray removed. It allowed alot of heat to escape while the car was stationary. Didnt notice any adverse affects of highspeed stability. If it wasnt for the rain and elements I would have left the tray off.

I never had a chance to figure out if cutting out holes/perforations in the panel helped. That might be something to try.. Leave the panel in place but cutout openings in areas where there are no engine components exposed.

vrus

Rafal,

Ok.. Out with it.. spill... How did you do this? Can I ship you my car and have you do it to mine?

I really wanted this done to my hood but I havent found anyone who is brave enough to do it to my car yet.

Details please.

Rafal

Seeing as this seems to be the going rate among "my fellow E55 tuners" :
$5000 each, minimum group buy 15. Advice only, $4500 each

vrus

Uggh.. And the details on how it was done?

OzE55

Surely you faked this.
It doesn't look quite like it follows the contour of the bonnet/hood properly.....so my bet is a fake............please.

vader

Real or not it looks good ! I'm sure you west coasters can find an old school hot rod shop that has a louvering press !! I am pretty sure rule of thumb used to be 100 bucks a louver !!! AMG should have done this !

jangy

LOL!!! Dude, you kill me!!

PTE

About $1700.00 . includes Paint. If you would like closeups . I'll post more pic's. There is srceen in the louvers to keep the sticks & stones out. No water issues to date. Rflow has seen them in person ___PTE___

vader

Cloeseups please ! Which way do you have the louvers pointing ? To pull air in or let air out ?

Grumpy666

When the car is in motion, that section of the hood is a low-pressure area (if you look at the front of the car in profile, it resembles an airfoil - flat on the bottom, gently curved on top). Plus, the uderhood area is in high pressure from the ramming effect of the air through the frontal openings. There won't be any appreciable air entering the louvers. But they will be effective vents, both in motion and standing still. I would have the openings facing rearward, which should help the airflow over the hood in venting the air above the engine. Whether this helps with cooling while you're driving is questionable, but it will help when you're stationary (that hot air rises convection thing).

One other consideration is you'll have to remove the hood insulation around the louvers location. This will expose that section of paint to higher temperatures. It might not be a problem, but it's something to think about.

vader

At speed I would think there is sufficient incoming air thru the grill/front opening to push quite a bit of air thru those louvers no ?

jangy

Is that all the hood insulation is for? It seems like that alone would help to trap hot air under there??

I'd be too scared to cut metal like that, but I'd love the look and the added cooling.

Grumpy666

Yes, and coupled with the low pressure above the hood, flow is further increased. But, how much of the air flowing out the louvers comes from the air flowing into the top of the engine bay? So, are you actually removing heat from the engine, or are you providing a flow path for the incoming air? Probably the only way to find out is to place thermocouples at the front of the engine bay and at bottom of the louvers and see if there's any difference.

Sounds like a good project for you, Bob.

Or, if you don't want to do it, we can always put it on Victor's To-Do list.

jangy

How about adding some turbulence under there, convection oven style!

vader

Yeah I'm thinking Victor needs something to do...besides..I can't find my can opener. I would never have the stones to cut into that pretty hood anyway !! Wish there was a simpler way...MB had their mind set on sealing it off under there pretty good.

GTA23109a

There's a software program that allows one to "map" the pressure over the front of a vehicle (or anything else) at varying speeds. A bunch of diesel guys went through this excersize about a year ago and were able to narrow down the EXACT area of the hood that needed to be louvered in order to have the lowest pressure outside and draw out as much underhood heat as possible. Some other guys backed this up by taping pressure sensors onto the hood in various places and driving around. There's some name for the device they used but I can't remember it. It sounded expensive.

Grumpy666

Agree - that slacker needs to pick up the pace a little.

C'mon, Bob, don't be such a Girly-Man. Grow some stones. Measure twice - cut once.

I think MB realized the limitations of the cooling system and configured the engine bay to direct as much airflow across the exhaust manifolds as possible. They are the major source of heat under the hood.

Grumpy666

Pressure readings usually require a transducer and a digital readout to convert the voltage inputs to a meaningful pressure number. Is this what you mean?

vader

Grump...If I cut holes in the hood,the spiders would have nowhere to ice skate ! Maybe bolt an attic fan to the underside ?