White Dog Racing SMIC Install

A few weeks ago I had flow tested the White Dog Racing side mount intercoolers and found them to perform very well.

Today I worked on installing the intercoolers on my B5 S4 so that I could take some temperature measurements.

I figured the installation should be relatively quick seeing as how they are very similar in size to the Silly Rabbit Motorsport intercoolers, but I was wrong.

White Dog Racing B5 S4 Side Mount Intercoolers
White Dog Racing B5 S4 Side Mount Intercoolers

What should have been about a 90 minute project stretched out to almost four hours.

White Dog Racing driver side B5 S4 intercooler
White Dog Racing driver side B5 S4 intercooler
White Dog Racing passenger side B5 S4 intercooler
White Dog Racing passenger side B5 S4 intercooler

The problems I ran into are attributed to the height of the end tanks, just a bit more than the SRM ICs.  Also the tabs that are welded onto the end tanks to help hold them in place are not long enough.  The result is that the highest point of the end tank causes interference when reinstalling the headlights.

As a reminder, you’re probably reinstalling the headlights as the LAST step of putting everything back together.

WDR SMIC Driver Side Headlight Interference
WDR SMIC Driver Side Headlight Interference
WDR SMIC Passenger Side Headlight Interference
WDR SMIC Passenger Side Headlight Interference

My first mitigation effort centered on filing down the corner slightly where the interference was occurring.  When that failed to completely resolve the issue I pulled the bumper back off and removed the bolts that were holding the IC end tank tabs and then pushed the IC down as much as I could and then reattached the bolt without passing through the end tank tab.

The frame rail is right below the upper end tank outlet pipe and doesn’t allow for much downward movement, but at this point every millimeter I could get was worth trying for.

Parts were reinstalled and I was able to get the headlights in, but it was a tight fit.

As I went to reinstall the belly pan I found another issue.

WDR Driver Side SMIC
WDR Driver Side SMIC
WDR Passenger Side SMIC
WDR Passenger Side SMIC
WDR SMIC Belly Pan fit
WDR SMIC Belly Pan fit

The bottoms also extend down further than what I had with the SRM IC’s, to the point that re-installing the belly pan was not possible.

I set the belly pan aside and finished replacing the lower bumper grills then drove the car off the ramps.

In the coming days I plan to begin recording intake temperatures produced by the White Dog Racing side mount intercoolers.

Fuel Filter & Pump Swaps

The silver S4 got a new fuel filter and fuel pump.

Audi B5 S4 Fuel Filter Swap
Audi B5 S4 Fuel Filter Swap

Neither of these is a task I enjoy doing, and when the fuel filter started leaking gas after being tightened to the advertised torque I was not happy.  Finding that I could not fit a wrench between the banjo fitting and fuel filter had me even more steamed.  Unable to find a suitable wrench I had about resigned myself to shopping for a new wrench with a thin body when I thought I might be able to get a good grip on the fuel filter with an oil filter wrench.

That hunch turned out to be a successful idea and the extra little bit of tightening the banjo bolt stopped the gasoline leak.

This car is also receiving a fuel pump upgrade with a ProjectB5 setup.  The fuel pump turned into a bit more effort than the “drop-in” name would suggest.  For the life of me I could not get the pump holder to engage with the basket.  This is the fourth time I have swapped pumps in one of these S4s and the first time I have had a hard time getting the pump in place, other than the first when I had not yet purchased the Schwaben fuel pump removal tool.

After 45 minutes of trying, and cursing, I decided to pull the pump out and try to figure out why the darn thing would not lock in.  Comparing it to the recently removed stock unit I noticed that the sock on the bottom of the PB5 pump seemed to to extend a little further than the stock part.  I pulled out the calipers to measure and sure enough the PB5 setup extended down 17 mm further than the stock part.  While the location makes it hard to be conclusive about the cause, it seems likely that the added length is preventing the fuel pump holder from descending far enough into the basket for the notches to engage properly and hold the pump firmly in place.

The next hurdle was a do-over on my part as I forgot that Audi wires the fuel pump backwards, the RED wire goes to the negative post and the BLACK wire to the positive post.  I wired up the normal way and got nothing when I tried to start the car.  Out came the pump so I could swap the wires, but happily upon re-installation the car started right up.

The car is on the base tune but is looking pretty good thus far.

CP Initial Boost Profile
Initial Boost Profile

 

Accordion to Brake Booster Modification

The Silver S4 I have worked on has the Brake Booster hose arrangement that joins the Accordion Hose, Intake Manifold, and Brake Booster by a 3-way junction.

Accordion to Brake Booster Lines
Accordion to Brake Booster Lines

The new intake setup consists of the 034 silicone hose to replace the stock accordion hose thus doing away with the grommet that allows for the connection to the accordion hose.  Like most places inside the engine compartment space is tight around where this hose is located so that leaving capped off parts is undesirable, as well as a potential source for leaks.

I set about modifying the hose to run direct from the intake manifold to the brake booster connection at the firewall.

Using a knife I removed the connecter that attaches one end of the stock line to the intake manifold, intending to reuse this part.  The stock part that connects the line to the brake booster is not a check valve, but one is needed so that boost does not reach the Brake Booster.

The connector that goes to the Accordion Hose is a check valve and it could be re-used, but in this case the car has 150k miles on it and I prefer to put a new check valve in place.

Brake Booster Check Valves
Brake Booster Check Valves

The other part needed for this job is some hose.  I felt the best option was this stuff as it consists of an interior rubber lining, a metal mesh wrap, and a fabric covering.  Air tight and strong to withstand vacuum.

Brake Booster Hose
Brake Booster Hose

The part numbers are:

  • Brake Booster Check Valve –191611933F (Comes up as a part for a Porsche)
  • Brake Booster Hose – N0203901

The check valve goes in one end of the hose, to attach to the firewall, and the other has the connector for the intake manifold.

Brake Booster Check Valve
Brake Booster Check Valve

Audi B5 S4 Information and Testing