• Garrett T3/T4 hybrid turbo,

• Custom tube header

• 3" 304 stainless downpipe, in car

• Adjustable wastegate

• 3" exhaust beginning from wastegate entry, 3" catalytic converter, single 3" Borla muffler

• Turbosmart single-stage boost controller with electronic solenoid

 

One of the advantages to doing EFI is getting rid of the airbox and opening up room for a header in the future. After getting what I could out of the K26 and stock exh. manifold (about 15psi or so), I decided to upgrade the turbo and exhaust manifold. Going to a smaller turbo like a K24 is not really an option, it would just be too small and restrictive to help make power in the 300hp range. An RS2 turbo would be a good all around turbo on the street, but its price makes it a poor value, plus you are still stuck with the stock exh. manifold.

Since I was going to fabricate an exhaust header anyway, I was freed up from having to use old, outdated 70's technology KKK turbos. Since Garrett turbos are on the forefront of turbo tuning these days, there are plenty of people constantly trying to improve on impeller and turbine design to extract every last bit of efficiency and flow out of these turbos, especially the T03 and T04 line of turbos. A really good option for a street turbo is a T3/T4 hybrid, giving the quicker spoolup of the T3, but the compressor flow capabilities of the T4. With this turbo I estimate power output of up to 400+hp and very good efficiency (lack of intake air heating), and full boost by about 3K RPM. See my thoughts on turbo selection.

Turbos can be sourced with the K26 hotside housing allowing direct fitment to the stock exh. manifold and downpipe, but since I was building a new header anyway, I figured I would use a Garrett hotside as more information is available about them than any of the KKK turbos.

T3/T4 vs. K26	Turbo Front	T3/T4 hybrid turbo	Turbo on head w/o Intake Man.

 

In order to fit a turbo like this, much adaptation of oil and waterlines must be done. All lines use AN fitting and stainless braided hose

Block Oil Outlet	Block Oil In	Support Bracket/oil in	Turbo Water	Complete

 

Other Audi Turbo Options

• Majestic Turbo does a K26 upgrade where they trim 10 degrees off the exhaust turbine, and add a K27 cold impeller inside the K26 housing. Cost is $600, a great option for the money and bolts right in.

•2Bennett and others offer a K27/26 hybrid turbo that spools up much more quickly than a straight K27, but can flow a lot of air using the huge K27 cold side housing. Retail is about $1300 for one, a great turbo, but for the money there are better options. Water and oil lines need modification.

•Turbonetics and others offer the T03/T04 turbo, available with ceramic ball bearings. A great, modern turbo, probably the best on the market. They make it with a K26 hot housing so it bolts up the factory manifold, but requires extensive modification to the oil and waterlines. Cost is $900, or about $1400 with BB.

•034efi offers KKK/Garrett hybrid turbos, any Garrett center section and cold side with the K26 hotside for a direct bolt up to the factory exh. manifold and downpipe. A great option if you don't want to rip apart the engine compartment but want something much more efficient than the stock KKK units.