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jons911 jons911 is offline
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Join Date: Oct 2015
Location: Jacksonville, FL
Posts: 158
For the money on a 911 engine, you'd really struggle to beat going turbo. Say you splurge a bit on parts going turbo: Brian's headers for $2700 and GT3071r turbo (internally gated) for $1000. You'd still need a fuel pressure regulator and a new chip, but if you kept boost low, you could run without an intercooler on your current engine. Or get an intercooler for few hundred for some piece of mind and a few more pounds of boost (I would definitely recommend this).

If you go big bore and already have 3.2 cylinders to send in, that used to be about $600 for bore and plate. Plus new pistons, which at JE are now up to $1800. If you don't go twin plug, you'll be limited on compression. Then, you'll want a different set of headers to improve airflow through the engine. A set of SSI are like $1000, but you might want bigger primaries. On top of that, you're looking at minimum some engine tear down, which incurs its own costs. And to end, you would want a new chip.

Both setups would probably get a new muffler and chip, so that evens out. The turbo comes in around maybe $4200. The big bore comes in around $3400 plus rebuild. But with the turbo, you could easily have 300hp. Without a compression bump on the big bore, the displacement gets you around 6% plus whatever you pick up with a freer exhaust and better tune. Say it all adds up to 15%, that's only 250hp. Upgrading down the road is where you really see a difference. For an extra $2500 or so for pistons, injectors, and fuel pump, your turbo setup is now good up to around 400hp where I've been told the 3.2 cams top out. For NA, you'll need twin plug, new cams, and high compression pistons (cams/pistons are min $2300), and even then you're only looking at like 275-285hp if I remember correctly.

This is a pretty top level look at the two builds. I'm by no means an expert, so if others see errors, I'll gladly fix them. There's always those odds and ends that add in to the price, but I think these are the big ticket items you'd be purchasing.

'79 Copper 911 SC
'88 911 Carrera
Old 04-09-2019, 08:37 AM
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