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Rad blind experiment

Hello,

I read with intrigue this post, however there is one thing that concerns me more so, and that it the fact that you would be affecting the performance of the MAF and that as we know does have a significant effect on the performance of diesels. your thoughts on this would be appreciated
 
If I read that right do you mean that due to drawing in warmer air it would reduce performance.
The air intake is to the O/s of the grille so that's why I left that section exposed, in addition the blank is inside the grille so air can still flow through and channel off to the intake unrestricted.
I need to take measurments but the intake could possibly be under greater pressure as the air cannot pass through the blind.

After I had completed a journey I felt the intake ducting just after the MAF and it was stone cold.
 
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What would be cool is if you could make the slats in the front part of the decorative grill open and close similar to a set of window blinds.

Radblindgrille.jpg


That way air should be deflected over the bonnet when they are closed.

PS, and fit some machine guns instead of those headlamp washers :D
 
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>>and that it the fact that you would be affecting the performance of the MAF

Actually, no. The MAF measures Mass Air Flow, and so the air density changes caused by temperature changes are automatically taken into account by this kind of sensor.

Older air flow meters, like those used on K jetronic, L jetronic, and earlier Motronic systems would read in error as air temperature changed.

This automatic compensation for temperature effects, and the quicker response of a small filament compared with the inertia of a flap are the main reasons this type of sensor is now almost universal.
 
As far as cold air for the intake goes, you only want cold air for max power at full throttle, for good mid range and tractibility you want warm air into the intake anyway, so blocking the feed isnt a massive issue for normal driving.
 
I was thinking about that ages ago. If 320CDI and petrol cars have same grille, surely mine is too big? :)
But well, I tough that Mercedes Engineers know better what then I do and I'm not car mechanic so left the topic alone.

Also, I was too lazy to even try it! But now... possibly if I will find something to blind 60-80% of grille then I might do it! Especially as I'm doing 100 miles a day.. every day!

Cheers
Chris
 
Didn't old Rolls Royces have grills with thermostatic slats that closed up in the cold?
 
A heated steering wheel, I could really go for one of those!!
 
Bobby Dazzler said:
I wouldn't expect the turbulence to increase significantly though, maybe even reduce. The air passing over the bonnet wouldn't accelerate more than usual, and the greater stagnation would likely smooth the radius and therefore the path of air passing over the bonnet.
Might just be more noticeable given the damp/wet conditions of late. ;)
Click to expand...

I did think of the conditions but have driven the car for some while and it seemed different.
In case I didn't explain my self very well, I didn't mean the general airflow over the bonnet, that appears smoother if anything, I specifically meant the emblem caused rain splattering up the bonnet. I wonder if previously because there was lower pressure and a tighter radius for the air to negotiate there it had less effect.

Thanks for your comments.
 
I've said this before on here, but in my first aerodynamics lecture opened by saying something along the lines of "If I had a pound for everytime someone asked me...".

His point was that outside of a tunnel, lab or CFD package then even experts can only guess due to the dynamic effect of all sorts of things coming together.

I still raised my hand and asked how much downforce would be up for grabs if I fitted a diffuser to my Corsa. Wouldn't have been worth asking if it was an LS or sumfink, but mine was an SRi which makes it wurfwile. :D
 
Aerodynamics are very complicated, as a lot of my friends build VERY fast RWD escorts we are finding out some interetsing things, the mk2 RS2000 could be ordered with the sloping front which reduced drag and they have a slightly higher top speed than the flat front ones, which in turn are more aerodynamic and a bit faster than the mk1's, as they are now hitting speeds of well over 150mph its becoming obvious something is happening to them at high speeds because the mk's need less power to hit 160mph+ than the mk2's do.
 
x332race said:
Found this which seems to indicate that an automatic blind is fitted to the E320
Click to expand...
So basically those blinds open below 50mph or above 97 degrees C coolant temp - which suggests they would nearly aways be closed on the motorway.

Tried my own expermient today - perspex sheet leaving about 1" gap at the top and the drivers side. Car was fine on the way to the motorway and temp was around the usual place and on the motorway with the speed limiter set to 75mph. I could detect that the temp was about 1/2 a needle's width higher (82C instead of 80C say). This afternoon I was on the way to pick up Neilrr's tyres so after exchanging the goods in a Sainsbury's car park I whipped the block out and drove back home - temp guage assumed it's normal position.

Stability seemed unaffected - both ways lorries were having no affect, so can report anything there.

MPG - well I've just filled up, so I'll put the block back in and do the whole tank this week to see if there is any noticable difference.

Anyone know what temp the electric fans normally cut in? Would be interested to test in heavy traffic to observe the effect (but would like to know when I can expect the fans to cut in). I may take a carrot to work tomorrow to see if the underbonnet temp is warm enough to get the vicous fan to cut in.

The lower bumper grille is full blocked on my 202 - thinking ahead would the better design be to open up the lower grille and fully block the upper one. Thus forcing more air over the car and less underneath (working on the principle this would reduce the amount of some of the air in front of the lower grille that is getting forced under the car at present).
 
popuptoaster said:
Aerodynamics are very complicated, as a lot of my friends build VERY fast RWD escorts we are finding out some interetsing things, the mk2 RS2000 could be ordered with the sloping front which reduced drag and they have a slightly higher top speed than the flat front ones, .
Click to expand...

Weren't all genuine MKII RS2000 sloping fronted.? That was one of the fundamental differences between them and lesser RS and Sport variants.

I haven't any figures for MKI and II Escorts but the MKIII Escort had a drag Cd of 0.4, which is the same as the Capri MKIII.
I can't see the older Escort being any better, if as good.
It's going to take a heck of a lot of power to make that go fast without aero mods to improve it.
 
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Dieselman said:
Weren't all genuine MKII RS2000 sloping fronted.? That was one of the fundamental differences between them and lesser RS and Sport variants.

I haven't any figures for MKI and II Escorts but the MKIII Escort had a drag Cd of 0.4, which is the same as the Capri MKIII.
I can't see the older Escort being any better, if as good.
It's going to take a heck of a lot of power to make that go fast without aero mods to improve it.
Click to expand...

There were RS2000's and there were RS2000 Customs. Custom was sloped front. Ordinary was flat front.
From memory Cd for MkI Escort was better than MkII.

Hope i am right with Custom......

230K
 
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DM, I spotted a comment on the forum linked by your post #40 that indicated the energy value per unit volume of "winter" biodiesel was approx 15% lower that that for "summer" diesel. Do you know if there is a similar difference in summer and winter "normal" diesel?
 
230K said:
There were RS2000's and there were RS2000 Customs. Custom was sloped front. Ordinary was flat front.
From memory Cd for MkI Escort was better than MkII.

Hope i am right with Custom......

230K
Click to expand...

I used to drive for Ford at the back end of this era before we swapped to the Sierra Cossies, All MK2 RS 2000's were sloped front but you are correct there was a standard and a custom version, the custom version differed as follows.

It had fish net recaro's, full door cards,clock & pod, 6 x13 alloys, boot carpet, and the panel around the rear lights was black.

Standard trim had Mexico door cards, steel wheels and the back panel was the same colour as the body.

However at it's launch in 1976 all cars were what was later to become the custom spec.

Still a member of the RS ownners club and had every RS model they have ever made and still do some consultancy for Ford Motorsport.

this is a good link for RS info

http://www.rsownersclub.co.uk/car_info/menu.htm

Some fond memories of that car.
 
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