Windshield wiper cover
The effect of front and rear wipers on airflow varies from vehicle to vehicle. Some vehicles are designed to keep the wipers out of the airflow when they are in the off position. Some people remove their wipers but others always want the availability of their wipers. For people that want to keep their wipers they can place a aerodynamic cover on the bonnet which extends the hood to the point where the wipers are out of the airflow.
One of the additional effects of the wiper cover is it covers the fresh air intake at the cowl.
Restricting flow into the intake there may be similar to the concept of a grille block: better to send air around the car than through it, unless you need the air.
Instructions for mod
There are many different ways to make a cover for the wipers. One method is described below
- Get some metal sheet that is as wide as the cars bonnet, the metal doesn't have to be too thick just thick enough to be able to hold a screw head. (0.45mm thickness worked well)
- Work out the gradient of the metal with respect to the car bonnet, this will be used to make wedges that will hold the metal at the right angle and to cut the metal sheet to the right dimensions. The metal gradient can be worked out by placing something flat between the water jets and the wipers, this will be close to the line of the metal sheet
- Cut the metal sheet so that it covers from the windscreen wiper water jets up to the wipers themselves, take into account the fact the metal will be raised to deflect the air over the wipers. Note: this step takes some time and the metal can be trimmed later on after doing later steps.
- Cut some wedges which will be fixed to the metal sheet and raise the metal up from the bonnet at the correct gradient. The wedges can be either plastic, metal or wood (if wood is chosen it should be a type that isn't effected much by water). The wedges may have to be different gradients or lengths depending on where on the metal sheet they are to go.
- Fix the wedges to the appropriate places on the metal sheet, likely at least 4 will be required to keep the sheet up depending on the thickness of the sheet.
- test fit the sheet to the bonnet, check that the gradient is correct noting if the wipers are still going to be in the air flow. Test out the wipers operation, check that the wipers can clear the metal sheet and that the water jets clear the metal sheet. If its desired to be able to open the bonnet without removing the wiper cover check that the bonnet can open without the metal sheet or the wedges hit the wipers or the windscreen.
- Make any changes to wedges or metal sheet based on the previous tests, keep testing and changing until your happy.
- Fix the metal sheet to the bonnet. This can be done with pop rivets or screws or many others.
- Fix each of the wedges to the bonnet, if this is not done the metal sheet will flap in the air flow.
- Paint the metal sheet and wedges if desired
- Tape or gap filler can be used to smooth out the gaps between the bonnet and the new metal sheet.
Note: the above method will likely cause scratches and holes to be put into the bonnet so if you want to be able to sell your car at some point you may need to modify this method.
Please enter your user name and any relevant data in the table
|User Name||Car Make, Model, Year||Cost of Mod||Time to Perform Mod||MPG Before Mod||MPG After Mod||MPG improvement guess||Instruction Link|
|Saand||Mazda, 626, 1991||$10||3 Hours|
|Echo-Francis||Toyota Echo 2005||$10||2 Hours||1.5% MPG||Echo-Francis Whiper Deflector|
Problems / Consequences of mod
Poorer visibility due to more windscreen area being blocked
Some crap get stuck in the enclosed area, and snow can be difficult to remove.