Turbo Hood Mod Update
Did a lot of research on heat extraction and quickly discovered that just about every factory installed turbo from any manufacturer had some form of heat extraction.
Must be a reason, considering ambient summer temps in most parts of the USA far exceed U.K. and European temps, which can cause problems.
Decided that venting is necessary for performance and durability as the W124 engine compartment is "sealed" with the bottom pan.
Want to stay with a W124 "period" look, prefer a metal part that would just bolt on.
The original Chevy Lumina Z34 louvers would work, but not so keen on the louver orientation. They also would require a bit more then just a hood cut out.
Searched quite a bit and came up with the 1989 Pontiac Sunbird Turbo GT louvers.
More a "period" appearance and mount over a cutout with studs going through the hood sheetmetal.
They are flat so should fit the hood with no problem.
Have ordered them from GMParts.com, price for the pair is $55.00.
After I receive them I'll decide whether to locate side by side on the raised center portion of the hood or right over the turbos and intake on the lower section of the hood.
Found these pix of an install on a Fiero hood...

Last edited by Eliot; Aug 6, 2007 at 06:17 PM.
Potential problem is not in directing airflow to the turbos but to extract the heat that the turbos produce.
Heat has no where to go but up against the hood.
Plenty of cold air intake, and engine operating temp stays below 90C even in +90F ambient.
Just trying to reduce the under hood temp to prolong the life of everything !
Twin turbos produce more under hood heat then even the NA M119......
Potential problem is not in feeding air to the engine, but not extracting heat produced by the turbos...
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I have seen one noticeable problem, and that is with the A/C.
Today it was about 96 degrees.
If I start the car, turn the A/C to max, let it idle for a few minutes until engine reaches operating temp,ithe A/C blows nice and cold.
If I start the car and immediately drive, it takes the A/C about fifteen minutes to reach a cold point.
I'm assuming the A/C compressor is fighting the extra heat produced by the turbo that begins when I drive with a partial boost.
I will be painting the car early next year so I'm "experimenting" with various body mods.
Anything I do will be kept in the "period" look of what "tuners" in the early 90's did.
Also looking at possibly insulating the turbos with more then just the heat shield.
I would think a louver placed in a low pressure section of the hood over the turbos would drop the engine bay temps considerably.
Oddly enough and most fortunately the engine temp never reaches 90C even on the hottest day.
Even putting a resistor in to turn the aux fan on at a lower temp, it has yet to come on.
The cooling system was flushed and refilled no more then every three years since the car was new.
Also considering installing a manual boost control to step the boost up to about 9-10lbs from the fixed 7lbs.
Not worried about detonation as I can reset the fuel map with a lap top.
If I do this I will dyno first and tune on the dyno.
I'm amazed at how much power the Merc inline engines can put out.....who needs a V8 !!!!!
The Best of Mercedes & AMG
Not worried about detonation as I can reset the fuel map with a lap top.
If I do this I will dyno first and tune on the dyno.
I'm amazed at how much power the Merc inline engines can put out.....who needs a V8 !!!!!
I have a manual boost controller,If the hose blows the boost does not exceed the wastegate spring pressure in my case 5psi--get a boost guage,and air fuel ratio monitor...I have both but they look hideous and I am looking for something that matches the interior better....your A/C sounds like it might be low on freon,,,those factory hoses can withstand quite a bit of heat before it starts to affect cooling
Don't require a guage or the ability to adjust from drivers seat.
Once it's set, it's set....decide to change then it's back to the dyno !!!
Dealer checked the A/C when they did the last service at 62K miles in the early spring.
Charge was fine at the time.
Also still running the "old" freon, never converted over.
Don't require a guage or the ability to adjust from drivers seat.
Once it's set, it's set....decide to change then it's back to the dyno !!!
Dealer checked the A/C when they did the last service at 62K miles in the early spring.
Charge was fine at the time.
Also still running the "old" freon, never converted over.
I have seen one noticeable problem, and that is with the A/C.
Today it was about 96 degrees.
If I start the car, turn the A/C to max, let it idle for a few minutes until engine reaches operating temp,ithe A/C blows nice and cold.
If I start the car and immediately drive, it takes the A/C about fifteen minutes to reach a cold point.
I'm assuming the A/C compressor is fighting the extra heat produced by the turbo that begins when I drive with a partial boost.
I will be painting the car early next year so I'm "experimenting" with various body mods.
Anything I do will be kept in the "period" look of what "tuners" in the early 90's did.
Also looking at possibly insulating the turbos with more then just the heat shield.
I would think a louver placed in a low pressure section of the hood over the turbos would drop the engine bay temps considerably.
Oddly enough and most fortunately the engine temp never reaches 90C even on the hottest day.
Even putting a resistor in to turn the aux fan on at a lower temp, it has yet to come on.
The cooling system was flushed and refilled no more then every three years since the car was new.
Also considering installing a manual boost control to step the boost up to about 9-10lbs from the fixed 7lbs.
Not worried about detonation as I can reset the fuel map with a lap top.
If I do this I will dyno first and tune on the dyno.
I'm amazed at how much power the Merc inline engines can put out.....who needs a V8 !!!!!

http://www.owendevelopments.co.uk/pr....asp?prodId=22
Any good for your installation ?
I'll contact them and also do a Google search to see if I can find a similar product in the USA.
Most times you have to wrap the turbo and the end result although efficient is not attractive.
Might make me change my mind about venting the hood !!!
Less heat out of the Turbo means cooler underhood temps which allow the intercooler and intake and pressure piping to be more efficient and make more power.
Also less stress on any component under the hood as the turbos generate a whole lot of heat.
Keep in mind the W124 gas engine wasn't designed to be turbo charged and the primary kit installs were common in the U.K. and Europe.
Both climates with summer temps no where near what just about any place in the USA attains









