OK, OK now I'm in big trouble. The next stage in the car's development is near. We have just about finalized everything but I hope within a couple of weeks all will be in place for the "makeover". My goal is to increase my power at the wheels from the 240 WHP on 94 octane (255 WHP on 109 octane) to about 290 to 300 WHP range (on 94 octane) depending on the turbo to be used.
I will most likely wait until after my last tracks days to get started on this little project, so possibly in October.
AIR INTAKE :
First I am getting rid of the OEM air intake box and going to this system made by ITG in the UK. This means the car will be running without a MAF and we will be using a "speed density" method to run the car.
Here's the ITG air intake system on a STaSIS race car.
AIR CONTROL:
Since I'm using a new type of air intake, I won't need to re-circulate the air back into the system. We are now going to use a TIAL BOV. We are going to use the regular/smaller model with a stiff spring. We may start with a small opening to reduce the air outflow and work up to a bigger opening if needed.
TURBO SYSTEM :
There were 3 turbos we were looking at for this project. Unfortunately my original front runner is now almost out of the race. I wanted something original not mainstream at first. Something that almost no one else was using. I wanted to go the Mahle/STaSIS route with the IHI VF34 turbo. It is said it produces a bit more power than the GT28RS but even more important it spools up faster, some say up to 500 RPM faster.
However there are some downsides to this turbo. First, you cannot rebuild this turbo. This means if it fails you need to buy a new turbo unlike the Garrett turbos which can be rebuilt. Second and most important because it was designed to be used primarily on Subaru STIs with a boxer engine (horizontally opposed) the turbo's design does not work well on a longitude oriented 1.8T as in the A4. There is an exhaust manifold made by a tuner in the UK to adapt the VF34 to a 1.8T but it is for the transverse mounted version of the 1.8T as in the A3 or Golf. My understanding is that Mahle had to get a custom made adapter to fit this exhaust manifold to the VF34 to change its exhaust flow orientation of the turbo to make it work on the STaSIS cars. This makes for a touchy exhaust manifold to turbo set up that needs constant looking after which I'm not ready to live with.
So now we are down to two choices... The Garrett GT28R (smaller) and the GT2860RS (Disco potato) that APR uses on their Stage 3+. The priority is quick spool up with lots of torque at the bottom end and with more horse power in the higher RPM range (5000 -7000 RPM) than my "special" MTM K04 turbo. In either case both these turbo will have a T3 flange to mate to the exhaust manifold we plan on using unlike the T25 flange (smaller) that APR uses on their kit. After many discussions with several people it was decided we would go with the GT28R. They are confident we can get our goal of 290 to 300 WHP using 94 octane on a Dynapak with this turbo. That would be an increase of 50 to 60 WHP on 94 octane over my K04 and that would be great indeed. They told me to expect a greater gain on 109.
Special thanks to Mike Hood for his inputs and time spent on the phone with me. In the end I did not go with his choice (GT28RS) but if I ever want more peak horse power I can always change the turbo.
EXHAUST CONTROL :
Although Garrett turbos come with internal wastegates it was decided to go with and external wastegate that will mate to the exhaust manifold. We are going with the TIAL V Band 44 mm wastegate.
EXHAUST MANIFOLD :
I want something a bit exotic! Something proven, something well made that will increase the performance level of the car. We are going with a stainless steel equal length tubular exhaust manifold made by Full Race. It also uses a T3 flange. Additionally we are sending Full Race an AIM bung to be installed on their manifold to read accurate EGTs. This will be fed to the AIM Pista for data logging and may even be available in real time in the dash display if I want it.
SYSTEM MANAGEMENT :
All these parts are nice and dandy but you need something to control the "package" and make them work in harmony together. With my current OEM ECU problems with the car I decided to go with a stand alone. This will give my tuner the full potential to tune my car for maximum efficiency and power. There will be several gas type programs, like 91 octane, 94 octane and most likely 109 octane or higher (leaded race gas) since I will be making a custom 3 inch exhaust system without a CAT. I will have a "true" Launch Control and I was told if I wanted a "Turbo Anti Lag" program I could have it too. However I'm not too keen on having it because of what it can do to the turbo and exhaust system. The choice of the stand alone we picked works hand in hand with the AIM MXL Pista data logger which is a bonus too. So here's our choice... The AUTRONIC SM4.
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Originally Posted by mtbrider
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