I’ve been really quite sensible with Project RS4 up to this point.
Most of what I’ve done to the car has involved maintaining it, addressing common issues and weak points, improving upon them and actually making the car look more OEM than when I bought it two years ago.
I knew when I bought the car that this was never going to be a crazy, highly-modified project – firstly because there’s not a huge amount that you can do to these to make them better than factory, and secondly I didn’t want to remove the car too far from OEM because I really like how they are in standard form.
However, after these last few tweaks I can safely say that this is the best that Project RS4 has looked, sounded and driven during my ownership.
As I covered in my last update way back in May (RIP Summer 2019), the next item on my list was to modify the stock exhaust to free up a bit more power and release some extra noise. But before that, there were a couple of maintenance items that reared their heads and needed immediate attention. The car had developed a couple of frustrating creaking sounds over the summer, one of which made itself worryingly apparent when driving the car over to France for the second round of this year’s Drift Masters European Championship.
On a side note – this was the first time that I’d taken my own car over into Europe and it’s infinitely more convenient and enjoyable than flying. This was just a quick drive-in, drive-out job for the one event, and obviously I neglected to take a single proper-camera photo of my car in the beautiful French countryside.
These phone snaps are my only evidence.
I do need to take more overseas drives in this before the UK crashes out of the EU in a spectacular and regrettable fireball, so I best get my skates on. Thanks, Boris.
Noise number one came from the rear and was an easy fix – the rear diff carrier bolts had worked their way slightly loose so, during a visit to Driftworks in Birmingham, the lovely lads at Dynotorque next door just nipped the bolts up and the problem went away. One to keep an eye on though.
Noise number two had us scratching our heads, however. I had the car in at VRS Northampton for an oil service and MOT and they diagnosed that the front upper arm bushes were shot and needed replacing. Rather than waste money on blueprint parts or throw cash at OEM replacements, a quick email to my friends over at 034Motorsport in California and I had a set of their Density Line upper control arms on their way to sunny Blighty.
For essentially the same price as OEM arms (once import tax is accounted for), and arriving quicker than I could get to the local Audi parts desk, the 034 arms are made to OE quality but feature slightly stiffer durometer rubber bushes that are free from any voids for tighter and more precise handling.
Back at VRS and the lads simply unbolted the old arms, threw them in the bin and then bolted the 034Motorsport arms in place, ensuring that the suspension was compressed to normal ride height before tightening up the new arms. Easy as that.
While the front KW Variant 3s were off the car I took the time to make a couple of tweaks to the bump and rebound while giving the suspension a general check over. It’s been on the car for around 18 months now and 15,000+ miles, but there’s no signs of any obvious issues or wear.
Frustratingly, the weird creaking noise was still present upon the test drive, however with the play in the front arms sorted it became more obvious where it was coming from – the front subframe bolts needed nipping up slightly and the issue was solved. I’m not sure if this is a common issue or not, but again one for me to watch.
When you’re super familiar with how a car feels on the road, doing as much as changing some worn bushes can make the world of difference. I’ve pretty much replaced every arm and bush at this point with either new OEM items or 034 Motorsport upgrades, including the gearbox mount and rear diff mounts, and the car feels mega to drive right now.
There’s potential to upgrade the motor and snub mounts with 034 items too but for now I’m going to stick with how it is as it feels fine at present.Loud Noises
With the maintenance jobs sorted it was back to Dynotorque in Birmingham for the exhaust tweaks. These are the same guys that do the bulk of the fabrication for the assortment of crazy Driftworks project cars (including their nutty LP640 R-GT road car project, a current favourite of mine right now), so modifying an exhaust would be painfully simple for them!
The 4.2-litre V8 in the RS4 sounds pretty good out of the box, however a bit more growl never hurt anyone. A previous owner had disconnected the rear exhaust valves so that they were in their ‘open’ position permanently – this gave the car a nice note but it lacked a bit of character and was a bit quiet still.
I didn’t want anything too anti-social or anything that was going to be droney on long drives, plus with the fairly-standard power I’m running I didn’t need to upgrade to a larger diameter system, so I knew that modifying the OEM system to my liking would be the best way to get the sort of sound that I wanted.
Step one would be to do away with the factory pre-cats in the downpipes. These restrictive 400CEL pre-cats are positioned painfully close to the headers and ditching them is the single biggest performance upgrade that you can make to the OEM exhaust system. Plus, leaving the main cats in place further down the system ensures that the car still passes emissions testing during MOT (the annual ‘your car is legal’ check here in the UK).
The most cost-effectively route that people tend to go down is to remove the downpipes from the car and ‘gut’ the pre-cats, leaving an empty chamber.
My issue here, however, was that the flexi section on the OEM downpipes hangs frustratingly low to the road, and mine had been torn to pieces, so essentially the bulk of my downpipes were scrap.
Just when I’d resigned myself to the fact that I needed all new downpipes, a custom pair came up for sale second-hand, that had not only had the pre-cats completely removed and straight-piped (the ‘gutting’ process still leaves an empty chamber which isn’t ideal for flow), but the flexi sections had been relocated to the top of the downpipe, moving them well out of harm’s way and creating a bit more ground clearance.
As removing the pre-cats can throw up a fault code, these custom downpipes had also had the main cats spun 180-degrees, moving the lambda sensor further down the system. Not my work nor idea, but ideal for what I needed.
After fighting with some very awkwardly-placed downpipe bolts for a bit, and the old pipes pretty much falling in half, the new pipes went on.
The Dynotorque boys progressed onto step two – removing the central resonator and installing an X-pipe in its place. The internet will tell you various pros and cons between installing a H- or X-pipe on V8s, but the concise version is that X-pipes tend to be better for scavenging exhaust gases and free up marginally more power, especially at the top end.
H-pipes provide a bit more low-down torque at the expense of top end power. However I decided on the X-pipe here purely based on how I wanted the car to sound – X-pipes make for a bit more of a ‘racey’ sounding note whereas H-pipes make it a bit more bassy ‘American-V8′ sound.
While they did this, I made myself less of a nuisance and got out of their way. Dynotorque’s party trick is taking big GM LS engines and fitting them into cars that didn’t have V8s to start with.
It’s always a fun game to wander around their workshop and guess what’s packing a V8 and what isn’t – there are some real wolves in sheeps’ clothing that are created here!
And when you’ve completed that you can always wander next door to Driftworks and ogle at the delights in there. I still need to shoot a proper feature on Phil’s RWB Promodet Japan 964.
Back next door, the OEM centre box was cut out and a pre-fabricated X-pipe welded into place before being mated to the rest of the system. The result is a system that sounds just a bit louder than OEM when cruising, with a bit more noise at low rpm and idle, without being too ‘boomy’.
There’s a nice raw, rasp to the sound at WOT and it absolutely screams at high RPM. I’m very happy with how it’s turned out, but I’ll let you form your own conclusion.
With this job done I find myself getting pretty close to the list of things that I wanted to do to the car during my ownership. There’s a few cosmetic and quality of life modifications that I want to make before winter, and I still back and forth with changing the wheels for aftermarket on a weekly basis, but for now I’m enjoying just getting out and driving the thing, while making the most of the precious few days of good weather we have before the cold sets in.
The next update will be a small one, and might be the last significant changes that Project RS4 receives. It’s not going anywhere just yet, but I already have my eyes on what I want to replace it at some point in the future…