Hi Fellas,

Just finished up with a 4.0L Build on a customer's 996 GT3 track car.

Is an all bore 4.0L, 997 cup heads, 996 street cams (customer's preference for budget), 997 4.0RS plenum, Dundon Race Headers and 997 Cup muffler.




Dundon 4.0L 996GT3 over 300lbft of torque and 420whp!

 

Please say hi to Charles for me.
Joe

 

Wow, it pulls all the way to 8K. Nice work.

Is this the 4.0L upgrade kit for the 996 you mentioned a couple months ago (reliable, not too crazy expensive and reasonable RPM's), or is that one still to come?

 

There's the stuff you do to the inside that keeps it reliable, it's the stuff you combine it with and tune it that makes it pull to 8k! We have a 4.0RS plenum on this one combined with Dundon race headers and a custom Dundon tune. Before the car was tuned all the parts yielded 388whp. After the tune a consistent 420whp.
If you're interested fall will be here in no time, send the car out and we'll get it all fixed up!!

 

nice build! o/t question. would the decklid from a 996 gt3 fit a turbo? looking to do a wing on my turbo

 

So the stock cams were re-used?

How about the Ti-rods? Were those re-used as well? Some seems to replace the factory rods when re-building. Just curious.

Definitely would love to do a 4.0L build in the future!

 

Yup, stock cams and the Ti rods were used after reconditioning. No need to replace with a heavier steel part when the Porsche rods are so nice. If it was a 4.0L stroker, then we would have to replace the rods, have steel and Ti options for that as well!

 

How many miles on the engine before the 4.0 job?!

 

55k, has been a track/pca race car for a while, leakdowns came in at over 20% on some cylinders so it was time for a rebuild!

 

Is the stock cooling system up to the challenge?

 

Has 3 radiators in the front like 997's and 997 Turbo's making way way more power than this!

 

Looks as if you're using wheel hub dynos. What's the difference in readings at the hub vs a drum dyno? How does a reading at the wheel hub compare to crank HP?

 

Hub dynos are a bit safer, no traction issues from tires, no variations due to tires etc.

The bottom line is calibration, in the end a dyno is a tool, like any other. Our dynapack 4000 hubdyno reads similarly to the dynojet we have done a lot of work on previously. It's about 15% loss vs crank hp.