Stealth grille block VW Golf

[sallen]

Just a quick post to show my new (stealth for the missus) grille block.

I basically used a bit of plastic sheet from an old wind turbine I built a few years back.

I popped the grille off and realised it would hold itself in place once re-mounted on the car. Cut a couple of holes and Bob's your uncle.

Attached is a pic of it off and re-mounted, no change from the stock look.

[gasstingy]

That's a very clean looking install........OK, so I HATE to expose my ignorance, but I thought the purpose of the grille block was to clean up the aerodynamics of the car. If it is behind the grille, by not letting air come into the engine compartment, that is virtually the same thing? I would have thought the shape of the grille would still detract from aerodynamics.

[sallen]

There has been many a thread discussing this.

I think the theory is that the air has nowhere to go so becomes a squashed "cushion" of air that then deflects incoming air much like an "over the grille block" would do. I'm sure somebody will straighten my story here if need be...

I might try a clear block on the outside just to see if there is any better gain. My personal 2 pence is that covering the top grille makes little or no difference as the euro Golf has a huge gaping bottom grille. Unless I tackle that I don't think I will see any significant gain.

To date I have seen only a tiny improvement with slower driving, grille block and high tyre pressures. If I drive everywhere at under 2000rpm I get about 45mpg (imperial). If I drive like a lunatic on the turbo all the time with diesel smoke pouring out the back I get about 45mpg so I can't win.

Also if I go on a motorway journey and drive at 70 I get 45mpg, if I drive at 50-60 I seem to only get a tiny bit more...

Nevermind though, Bottom grille block, DTM mirrors, undertray and intercooler should fix that.

[some_other_dave]

There is also the benefit of the engine coming up to operating temp more quickly, saving the extra fuel that is needed during warm-up.

-soD

[gasstingy]

Thanks, After I posted the question, I found links to the other discussions on grille blocks and read them all. I'll put more effort into hunting down similar threads be4 I have to admit my ignorance:-). I rather like the idea of a stealth grille block.

[COcyclist]

sallen, I have a Mk IV so I'm not positive about the Mk III, but on my car the air intake for the TDI engine is just below the hood (bonnet) between the VW emblem and the left headlight. I am using an upper grill block made of black foam pipe insulation stuffed between the horizontal grill bars, except the top left opening (just right of the emblem in your photo) You might check as I wouldn't want to do anything to restrict intake airflow in a diesel. Incidentally, I use the same pipe insulation split and notched to fit over the grill bars on my lower grill for a partial cold weather grill block. It's cheap, nearly stealth and easily removable in 10 seconds if I start running warm.

[tasdrouille]

Nice, clean looking instalation!

In MKIII cars the intake is in the front fender.

[sallen]

Cocyclist I like the idea of a clip-on, removable bottom grille block. I will have to mock something up like you have used and see if I get gains. So far no mods / driving changes are giving me gains. So would be nice to finally see something substantial