Has anyone tried or read about converting a 997.1 TT engine to NA. I ask this cause I have a spare engine and transmission and want to see if this can be done, and if poassible, what power output would i get.. Basically trying to get rid of all trubo related hardware and make it simple. I know it would be better to buy a GT3 or similar than go through the whole process. But i live and drive in India. No access to such great cars.. hence the proposed project.. Appreciate any feedback...

 

Hi Raju,

I'm not sure that would be a good idea as this motor is specifically built for a forced induction application. Typically turbo motors have a lower compression ratio as they are built with some form of forced induction in mind. Lower compression is commonly used to ward of detonation. An NA motor, for example might have a compression ratio of 11:1 or 12:1 whereas a motor built for forced induction might be 9:1.

Without tearing into the motor and changing out the rotating assembly (pistons at minimum) to give you more compression, you will have a motor that might run but will lack power and torque. There will also be the difficulty of what ecu, injectors and fuel maps to run. You won't be able to use the turbo ecu unless it is re-mapped.

If I were you, I would sell the motor - they are worth a fair bit of money - and then get a GT3 motor or NA motor and ecu for your project.

 

cheaper to fix your turbo if you have problems with them

 

@Edgemonty007 thank you for your insight. But suppose if i rebuild the motor for a high compression 4.0L setup and use the required intake plumbing from a GT3 with a SYVECS ECU, would it work? Would it be capable of around 500-550 bhp output.. I already have a heavily tuned, recorded 4.0 L turbo motor which is working great.. This is a project motor for a likely use in a 2009 Cayman S or maybe in my own turbo for track day use..

 

Thank you guys. Have been looking on eBay for a GT3 engine.. and found a few.. Guess I think it is better to buy one of those and plonk them rather than trying to reinvent the wheel... Thanks again..