Yes, I agree, I had an N54 335i for 3 years and modified everything I could except for the stock internals. I ran more than than 500 WHP on that motor without problems except for snapping half-shafts and a slipping tranny, but the motor was well overbuilt for sure. That being said, I had the proper auxiliary sensors installed with data acquisition tied to tune fail-safes to help with safety.

It would be nice to know the level of overhead we are working with when tuning the AJ motors in the F-Type.

 

Now that I've surpassed the 400 mark for both power and torque, it is obvious that there is no purpose in adding more as the clutch problem has been exacerbated. The clutch will not fully engage between shifts during aggressive acceleration, an issue that has been present since day one (2 different clutches). Until the clutch issue is resolved, I have abandoned the idea of adding the over-sized lower pulley.

After investigating the lower pulley options, I ordered the most immediately available option in the desired size (and meeting appropriate design parameters) from Eurotoys. Even though the pulley had entered production, Mike cheerfully and fully refunded my payment today. Now...that's customer service. At the very least, I was expecting a "restocking fee" for a made-to-order item.

Mike, thank you also for providing guidance on how to approach the clutch issue. (That project will be documented on a separate thread).