Part 1: The Knob

The shift knob that came on the A4 when I bought it was awful. Because of its inferiority I decided to spring for my favorite interior piece, a stainless steel sphere shift knob! I've wanted one for years and this was my chance. Stainless knobs are near impossible to find in a sphere, while aluminum, titanium ($$$$$), and plastic are readily available. Even then, finding the correct thread pitch is difficult. After contacting a knob manufacturer about the Audi thread pitch (which I confirmed is 12x1.5 with a nut of the same size) I was in business. Now that I've got it its a bit too heavy for my tastes, powdercoated aluminum or some flavor of stock knob is what i'm thinking.

 

The TWM knob is 2" across.  This interface is just fantastic, perfect size for your hand. Perfect shape for several different positions. Silky smooth. Honestly though, I do NOT reccomend a heavy knob on this linkage, it simply amplifies whatever play there may be left in it and doesn't bring anything good to the table in return.

Part 2: the shifter

The stock shifter is butter smooth with a nice mechanical undertone but there is a lot of slop side to side and the throws are enormous. A shifter kit solves part of the problem. There are about a dozen of them out there ranging from an e-bay model to 200$ premium models. The main differences seem to be how much linkage is included and the adjustment of the throws. Having been burned by ebay on a regular basis I decided to spring for the B&M short shifter. I chose the B&M because it replaced the most rubber of any kit that I could find at the time. There is an even better one out now that eliminates the plastic cup that holds the shift lever itself.

This is a detail of the quality machine work on the stainless shift lever. You get what you pay for.

Here is the stock decrepitude with the push down reverse mechanism and the autozone shift knob minus the boot. Ah, if it had only come with a stock knob!!  

I had one hell of a time getting the old assembly out because of these they were mostly stripped and lock-tited in.

The stock shifter is plastic. If you just want shorter throws and you don't mind the slop just drill a hole in that colar on the right below the existing bolt ( when upright - so in this photo to the lower left of the bolt at the end of that tab). Then remount the colar in that hole and you're done, for free! That plus you can get a 12x1.5 (or 12x1.25 if you want to use a toyota or subaru shift knob) die and die the shift lever further down sawing off the excess to make it shorter, also almost for free.

All assembled, just needs to go in the car. You will be working in tight quarters but it's not that bad. I chose the middle setting for throw. I'm getting used to the pure awesome of a Miata shifter so I could have done the shortest setting and been fine though. I'm not going to take it out again.

Finished product:

The finished product. The action is beyond wonderful. The knob is knob-tastic! The stupid push down reverse is eliminated. The end result was well worth the cut knuckles, the multiple tool and hardware trips, and the expenditure. Time for a new shift boot though, ugh!

Part 3: The Selector rod

The B5 A4 selector rod goes from the shift mechanism in the interior to the rod going into the transmission. On early B5 A4's this part has a complex rubber uv joint that introduces easily a 1/4"+ of noticable vague rubbery feel at the shift knob. There are several ways to fix this most annoying piece of the B5 shift linkage. You can convert to the later selector rod, though an upgrade in and of itself it still has a rubber joint. On this revised selector rod you can replace that rubber part with a solid block of metal or buy a pre-made metal piece. Lastly, the route I took, you can buy a universal joint and custom fit it to the selector rod yourself.

The premade metal insert for the updated style is 100$ (for literally two tubes welded together) and the metal for a block to drill out to make my own insert was going to add up as well. If you have the new style joint and access to scrap metal by all means just cut a block to size and drill two holes in it to replace the rubber piece, perhapse with some thin ptfe or nylon washers and some grease to keep it smooth.

I decided to replace the whole stupid Audi UV joint. Mcmaster carr to the rescue, they sell uv joints galore. The cheapest (not the best quality) option was to get a low torque pin and block joint with the right bore sizes to slide onto the audi's linkage. It's too short but a 2"x5/8" coupler and a 5/8" clevis pin fixes that. All of that costs less than buying the updated selector rod, let alone the extra stuff. I don't recomend this route though, buy a better uv joint or get the updated rod, I am having quality issues with this joint.

I drilled(17/64) and tapped(8x1.25) the uv joint for the stock set screw. The other side I tapped for a 4mm x.70 bolt (1/8" drill for the holes). Any play at that point in the linkage translates to a whole lot at the shift knob. The pin I got from lowes racing and just sawed to length. The selector rod is just over 5/8" so I had to bore out my coupler a little on that side. The set screws on the coupler are pretty tight but if it fell off you'd be in trouble so i put in two more 4mmx.70's for peace of mind. I later replaced those with some m6's instead for better durability. It may take some adjustment to get it all in the right place so a helper is very helpful once you get all the pieces loosely in place. If you want a more pnp u join get one that's about 4 1/2" long with 5/8th bores (and zero play). The rod going into the transmission is a bit smaller than 5/8 so a sleeve would be ideal or a u/v joint with smaller bores to be drilled to size.

If you want to be rid of that last bit of removable play in your otherwise excellent shifter this is a must do modification. For me this was the last piece in the puzzle to having a solid shifter in a car that comes stock with 16 mounts, a vague clutch, a ridiculously heavy flywheel, a long throw 80's-tall, sloppy shift mechanism, and, when I bought it, a horrible shift knob. This interface has been by far the most difficult to address! Now, for crying out loud, onto the next ones!

Part 4: misc info

Tuning the engine there are several things to address. The stock intercooler heat soaks immediately at stock boost so it is a definite bottleneck. It's small, has plastic end tanks, and no exit for the air going through it. The cheapest route to fix this is to buy a quality core off of EBay along with a piping kit and some quality constant torque hose clamps to make your own setup. The best course is to buy a pair of aftermarket custom side intercoolers (AWE makes a nice kit) leaving the front of the car for the radiator and ac condenser. Although, you may prefer this space for brake ducting.

After you have that, the clutch, and the exhaust sorted out the next bottleneck is the turbo. Its pathetically small even for a 1.8l. The easiest fix is to put a slightly bigger Borg Warner K04 in there with larger injectors and a GIAC fueling chip.

The best, but at this point most difficult, route is to get an ATP Garrett GT28RS turbo kit, bigger injectors, and a standalone ECU. This of course requires dyno time and a lot of $$$$.$$, hopefully GIAC will take care of this problem by making a PNP GT28RS fueling chip for the appropriately sized injector for the 1.8T. Several people are now making working GT28 kits, 034 motorsports, unitronic/revo, etc. and those are probably the best route for this engine now.