Since this project has so many different aspects, I’ve found that its important to work on as many different available parts as possible. It’s easy to assume that you’ll pull all these parts together in a day and everything will be easy but what often happens is that you realize you’re missing a unique sort of bolt or a seal you forgot to order. So while I’ve been trying to ready the engine bay and do a considerable amount of prep on the chassis, I’ve also been getting the Engine/Transmission package pulled together.
While examining the motor, I found that the main crankcase breather hose was starting to disintegrate and collapse. This is apparently a common failure as there was an aftermarket piece readily available for replacement. The piece is from 034 motorsport and overall I’m happy with the quality. The one piece that could be better is the interface with the smaller breather hose that you can see at the bottom of the picture (not connected). The hose clamp just crushes the hose you insert in there – not making the most robust connection. I’ll be thinking about how to make this more secure.
As a part of this general overhaul of the car, I’m replacing the clutch with a southbend stage 2E unit. This clutch is rated for way more torque than the car will make, but it will allow me to abuse it and give me plenty of potential to build into. I removed the clutch, and found the surface of the flywheel in decent condition but I still started to look for some refresh options. In order for the warranty of the clutch to be effective, the flywheel has to be either replaced or refinished.
You can actually see the imprint of one of the clutch packs here on the surface – likely from an instance of when the clutch got too hot and was left released against the flywheel. From calling around local shops, a refinish is about $50 but I found a good deal on a lightweight flywheel with an OEM clutch so I decided to go that route.
A friend of mine suggested that “while you’re in there” I should replace the rear main seal – one of the most important (and problematic) seals for an older engine. Once the car is assembled, this seal is buried and would require a lot of work later on so I had to agree and get this done. Luckily, the design allows for the job to be done quickly and easily. the seal is part of a larger flange that simply bolts on and off with the seal attached.
I’ve replaced another few seals on the intake. These seals are important so that engine knows exactly how much and where all the air is coming in from. If air leaks into the intake manifold from places it is not engineered to, the engine will run lean (more air than fuel expected) and overall poorly since its metering the amount of fuel to inject based on the air flowing through the Mass Air Flow (MAF) Sensor only. I unbolted the throttle body from the intake, scrapped off the old gasket and cleaned up the mating surfaces on both the throttle body and the intake.
The throttle body also had a lot of carbon build up on the butterfly valves. I didn’t take a before picture but some work with a soft brush and cleaning agents like brake cleaner got the piece to an acceptable state. The carbon build up can influence how the engine runs based on how it affects the air flowing through the throttle body. If the carbon build up on these butterfly valves is significant enough, it can impede the airflow as it travels through the throttle body and create this inconsistency between what the engine expects and what it’s measuring through the MAF.
In this project I’ve deleted all California Emissions components (optional on these cars) since this is a purpose built car. Furthermore, I’ve deleted the Exhaust Gas Recirculation circuit that connects the exhaust to the intake. OEM’s did this to help reburn unburnt fuel in the exhaust, overall creating a cleaner burning system. This recirculation however, also introduces a lot of CO2 which is not useful for a good burn. It’s also one more system that would have required attention to get performing correctly again. I purchased a block-off plate for the intake and new gasket to keep it sealed.
Oil cooling is a feature the CQ did not come with from the factory but with the expected abuse on the engine, I want to give the engine and all compoennets & fluids as best of a chance as possible to stay in their typical working temperature range. By cooling the oil, I am taking some strain off of the cooling system and also keeping the oil in its optimal temperature range, insuring its effectiveness. I’ll be able to take an OEM piece from Audi’s performance cars (urS4, urS6) that had a turbo 5-cyl. motor. Here you can see the two different oil filter housings, the new (old) piece on the top has ports for the oil cooler, as well as a spot for the oil filter. You can’t see the inlet/outlet for the oil cooler which are on the backside of the housing. New gasket on order.