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polizei polizei is offline
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Join Date: May 2007
Location: Collegeville, PA
Posts: 1,367
Help me choose the next steps for my EFI Turbo Conversion

Hey Guys,

I did a pretty basic turbo conversion on my '87 Carrera a few years ago. I've since decided to move forward with an aftermarket EFI conversion. I've been collecting parts over the past few years, and I'm getting closer to starting the project work back up! Here's a quick recap on some of the internal mods that I've already completed:

1. ARP Rod Bolts
2. Supertec Head Studs
3. 930 Cylinders w/ 8.0:1 Pistons
4. Twin Plug Carrera Heads

One of my constraints for the conversion is that I'd like to keep the body 100% stock. I'm keeping the Carrera tail and A/C. There's plenty of debate on the topic, but I've decided not to shoehorn an air-to-air I/C under the tail. For better or for worse, I'm going to follow the lead of fellow Pelican thechiller and use a water-to-air I/C. I'm probably going to install a large under-body radiator in conjunction with a wheel-well radiator w/ a high flow fan. It adds weight and complexity, which are acceptable to me.

I have an Electromotive TEC3-R engine management system with a twin plug direct fire ignition that I picked up for a decent price. I don't have much in the way of the fuel system sourced yet. I've got new Bosch 55 lb injectors, and I'm planning to upgrade to a Bosch 044 fuel pump. I've got a set of AMS custom made headers w/ a T4 flange (thank you YermenCars!). I'm leaning toward a Precision SC6262 Turbo w/ T4 .68 A/R hot side. The guys at AMS have had success with the headers/turbo combo on turbo Carrera conversions, so I'm inclined that direction. My goal is to achieve 500 HP w/o exceeding 18 PSI. From what I've read in this forum, conservative opinion is that you should flame ring the heads after 1.2 BAR of boost, as they tend to lift off the cylinders. I'm not looking to set any records, so I'd prefer to play it on the safe side.

I'd like to hear your input on my build plans. Am I missing anything that I should be considering? A few specific questions I'd like to run by you guys:

1. Will extrude honing my intake manifold be beneficial even if I don't port the heads given that I'll be dyno tuning the car? How about porting the intake manifold? Is that different than extrude honing? I'd prefer not to tear down the entire top end for further upgrades.

2. I've heard of several TurboKraft builds that are running 964/993 twin knock sensors. I believe the stock 993 bridge is used on one of the cylinder banks. Can this bridge be installed w/o tearing down the engine? Or does it require that the cylinders be machined?

3. What do you recommend in terms of the fuel system for my setup? Do I need to replace the stock fuel pressure regulator, fuel lines and fuel injector rails?

4. What else? I'm sure there's something I'm missing

The car is in the shop right now getting a suspension refresh and upgrade. Stiffer torsion bars and Bilstein Sports. Big brakes coming in July.

Thanks for help!
Andy - 1987 911 Carrera Coupe

Last edited by polizei; 06-24-2011 at 04:19 AM..
Old 06-23-2011, 06:48 PM
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