Slow4’s S4 Avant was back in for a few things.
First item on the list was some torn and leaking CV boots. The left front inner CV boot had split and the both of the rear outer CV boots were leaking fluid past the back of the boot. Along with all the other CV boots were old and getting really soft so I changed all eight CV boots. Here is the left front inner. I have posted up a bunch of these lately it seems.
Second item on the list was changing out his Koni Shocks and H&R lowering springs for H&R coilovers.
Fronts with the H&R coilover on the left and the Koni shock/H&R lowering spring combo on the right:
Rear with the H&R coilovers already installed:
In preparation for the following items, I took the front bumper off.
Then took the core support off.
Third item on the list is a weird coolant leak that would only show up at odd times. He had said that it wouldn’t always happen but occasionally he would walk out to the car and there would be a puddle under the driver’s side front of the engine. I had pressure tested the cooling system before taking the front end off and I didn’t notice any drips. Once I had the core support off the only thing that looked like it had coolant residue around it was where the thermostat joined the water pump. Which is a good thing because there is a ton of coolant lines and places where coolant could be leaking on that section of the car.
Once I had the thermostat off it was obvious that the seal was leaking. Great, that is an easy and cheap fix at this point since so much stuff had been taken off already!
Now we get to the meat and potatoes of this job. Item four was to install my old V1 long tube headers on Slow4’s S4.
Here is a reference picture from when I took them off my car. Slow4 wrapped the headers in DEI Ti header wrap but in this picture the headers just have the old ceramic coating that I had sprayed on them.
The installation notes for installing these V1 headers say to remove the engine or that it must be lowered substantially. Well I have installed these headers on my car and a different set of V1 headers on another B6 S4 without removing the engine so why start now. First I had to remove the fully catless stock downpipes. Then the engine was supported from the top with an engine support bar on both rear eyelits. Next the subframe had to be lowered as far down as it can go so it was just hanging by the lower control arms and the transmission crossmember. Also took off the driver’s side engine mount with the upper bracket, AC compressor, serpentine belt and tensioner, alternator, along with disconnecting a bunch of hoses, electrical connectors, vacuum lines, etc. This is the engine hanging from the engine support bar.
Then lowered substantially:
Finally I tilted the engine to one side at a time to install the headers. Kind of a scary thing if you have never seen it done before.
The stock exhaust manifolds on these B6/7 S4s suck at flowing the exhaust out smoothly. Just like most people would expect for factory exhaust manifolds.
Front of the driver’s side:
Side view of the driver’s side exhaust manifold:
After the driver’s side exhaust manifold was removed:
Fed the V1 headers into place on the driver’s side:
Just to give you guys an idea of how tight of a space that these headers are in, take a look at the most rearward bottom two studs and nuts that tighten the headers to the cylinder heads. Those two studs and nuts are just below the exhaust ports for cylinder 7 and 8. There is no room to get a socket and ratchet on the closer of the two nuts. Don’t forget that the shaft for the AC compressor driveshaft is right below this as well. Which is further restricting the amount of workable space. The more rearward nut needs a unique combination of a short 10mm socket, wobble/universal joint, extensions, and a lot of patience to get tight. These headers require just about every different 10mm tool (from short/deep sockets, long/stubby/bent wrenches, to crowsfeet) to tighten all the nuts on each side. Also the headers are pressed up against the gear drive unit for the accessories on the back of the driver’s side of the engine.
Once the driver’s side of the headers was bolted on then I put everything back together on that side and tilted the engine the other way so that I could work on getting the passenger’s side of the headers in. Here we have the passenger’s side exhaust manifold still on.
Passenger’s side exhaust manifold taken off. This side was actually more of a PITA then on my car or on the other B6 S4 that I installed this type of headers on. For some reason the engine would not hang as low as it did on the other cars.
The passenger’s side headers installed:
Let me back up a step though because I had to remove the passenger’s side engine mount and upper bracket to tighten the lower nuts. When I went to put the engine mount and upper bracket back on there wasn’t enough room to get the bracket into place. Okay, a few minutes with my hand grinder and the correct grinding wheel for aluminum solved that.
How tight of a fit that it is between the passenger’s side engine mount upper bracket and the headers.
Next up is item five on the list. The Fast Intentions catback that is on Slow4’s S4 was necked down to stock so that needed to be modified to be a true 2.5 inch exhaust all the way back. I had already cut off the lower necked down portion with a sawzall.
To make the transition to a true 2.5 inch exhaust he got some slip on joints attached to about six inches of 2.5 inch pipe. I cut the excess pipe off after double checking my measurements a few times and then TIG welded the slip on joints onto the catback portion of the exhaust. The picture below is while I was welding on the first slip on joint. The foil over the ends is to prevent the argon backpurge from escaping out and the other ends of the pipe have foil over them too but they are not pictured. The hose that is going into the slip on joint supplies the argon gas for the argon backpurge.
After I welded those two joints on I put the catback portion of the exhaust on and then installed the catless mid-pipe sections of the V1 headers.
Close up picture of the slip on joints with the catback portion reinstalled. My welds look pretty good if I do say myself.
The catless mid-pipes attach with slip joints on one end and V-bands on the other so they are easily swappable. Slow4 got a set of mid-pipes with high flow cats from me too but he had me install the catless sections for now.
Okay, we are into the home stretch. The last item on the list was to install an automatic serpentine belt tensioner instead of the factory manual serpentine belt tensioner and roller system.
Factory manual belt tensioner and roller setup:
Automatic tensioner setup:
Finally I put everything else back together. Adjusted the ride height to 24-3/4 inches from ground to fender all the way around. Then changed out the wheel spacers that were on the car from 5 mm in the front and 10 mm in the rear to 3 mm in the front and 5 mm in the rear. This is the end result.