Advice Please - Upper Grill Block (first aero mod)

[Arragonis]

I have managed to get some thick but flexible plastic using Ikea - its cuttable and bendable so it should be easily shaped. My plan is to fit an upper grill block to my Fabia. The upper grill comes to pieces easily and I can replace the slatted part with my plastic easily.

The engine is the familiar VW TDI 1.9 unit so the upper grill also has the air intake on the left hand side (viewed from behind the wheel, i.e. looking forwards).

First question is, do I need an opening to allow air into the engine ?

Assuming the answer to that is yes, then my plan is to start by drilling holes in the plastic where the intake is. That should allow air into this area but not disturb the superbly smooth airflow I am planning If that seems like its not enough or I get a power / FE problem then I'll open these holes up into vertical slits again with the idea that the air is flowing vertically at this point so some can divert smoothly into the intake.

After this is sorted my next plan is to cover the fog lights under the bumper at each side. I have to allow an opening on the right hand side (again viewed from behind the wheel) as in this car space is at a premium so the intercooller is actually just ahead of the RHS front wheel. There must be a gain in shortening the flow to the IC but thats a longer project. There is a grill "looking" part in here but apart from the IC intake its all blocked up, so its a waste and could be smoothed.

Underneath the front the bumper extends to just ahead of the front axle line with skirts (roughly 1.5 inches depth) in front of each front wheel.

Part C of this masterplan is to look at a lower block but the engine being so big and the car so small most of the space at the front is basically radiator - its bigger than the engine. It must be there for a reason so I'll go for a 1/2 block first and monitor stuff before doing anything more serious.

Thoughts, suggestions, abuse ?

Cheers

A

[Thymeclock]

Originally Posted by Arragonis

I have managed to get some thick but flexible plastic using Ikea - its cuttable and bendable so it should be easily shaped. My plan is to fit an upper grill block to my Fabia. The upper grill comes to pieces easily and I can replace the slatted part with my plastic easily.

The engine is the familiar VW TDI 1.9 unit so the upper grill also has the air intake on the left hand side (viewed from behind the wheel, i.e. looking forwards).

First question is, do I need an opening to allow air into the engine ?

Where is the intake orifice located now? As long as it can access air (meaning it is not blocked by anything) it should be OK. If it is mounted to the grille itself (but it's unlikely it would be), you might be able to disconnect or shorten the tube. Usually the intake orifice faces downward or at some angle to avoid rain and debris from entering it, and usually it's not at the grille itself, but merely in the engine compartment.

I just spent several days making and installing a lower grille block and a large under body air deflector for my new '09 Aveo. I'm finishing up making an external, detachable, upper grille block for it as well. I plan to start a new thread with details and photos soon.

[COcyclist]

Arragonis, I have an 04 Golf TDI and it sound like a similar layout to yours. I have used an upper grill block year round with no overheating issues, even climbing mountain passes. Everything I have read says letting a diesel breathe easier helps power and mileage. I did not block the engine air intake at all. My grill has horizontal slats and the one that feeds the intake air is wide open. I use pipe insulation over the lower grill slats in winter to block off some of them. I block some of the intercooler for faster warmups in winter but usually pull those out before long climbs. The Scanguage shows the intake air temperatures really ramp up when the engine is pulling hard under boost.

[lunarhighway]

blocking the radiator should be find, but restricting engine intake does not seem like a good idea. based on my own experience, it may even counter the effect of the grillblock. but every car's different