Audi UR Quattro Rally Build

4 minute(s) of a 357 minute read

Week 17 of the Storage Unit Rally Build: A Sharp Intake of Breath

We’ve been back and forth on what to do about an intake system for the car for ages. We’d like to have our cake and eat it too but we just can’t see a way to get there. This is what we’d like to have:

As used on the works rally cars. It looks iconic and sucks air from the high pressure cowl area where, conveniently, there are louvers in the hood above for that very purpose. There are a few problems with this. Firstly we have a MAF sensor to incorporate in the intake track, ideally in the stock location as we have an aftermarket U shaped intake tube that houses connections for all kinds of other bits and pieces that we need. This really doesn’t mate up to that.

Secondly, if we did this it really would have to be made of carbon Kevlar to pass muster and making one from scratch would be very expensive and time consuming. You can, in theory, buy one but we’ve heard it’s of dubious quality and it still wouldn’t mate to our MAF sensor.

We tried prototyping an alternative route to the cowl that goes down the bulkhead to an existing 3” hole before doing a 180 into the passenger compartment and back up through another existing hole in the cowl. We think we could terminate this into an oval shaped pancake filter with a lid. It would probably work and we think we could make it look half decent but our fear is that it would just look like a poor substitute for the original.

We could just whack a bloody great cone filter on the end of the MAF sensor and declare “job done” but there are a few problems with that too. It would be sucking air from right next to the turbo and also be right under the hood louver that lets hot air out of the engine bay and, not great, water in. So we dismissed this too. Here it is mocked up with a small filter.

We looked at modifying some OE intake boxes but they don’t seem to be suitable either.

So we’ve settled. Settled on another U bend with a cone filter behind the headlight. This is not under the louver so should stay dry and it gets a good cold air feed from the grill and light surround. We also think we can shield it from the engine bay quite easily and, although it is a bit rigged it will hardly be visible so it doesn’t matter if it looks it.

If nothing else it will do to get the car running. Maybe we will revisit this later, or not.