mchrono

Not 100% sure here but I know in other applications it may not provide a sufficient damper against harmonic crankshaft vibrations, leading to bearing and possibly even crankshaft failure.

neanicu

Don't do it,you're gonna mess up your engine! I believe AP also said it won't fit because the tail of the crankshaft is different. Even if you don't believe AP's regular marketing direction these days,just speak with a very good engineer,experienced technician etc : they will tell you that crankshafts are precision manufactured assemblies that are balanced to perfection. That is why it is EXTREMELY IMPORTANT that what you change on the tail of the crankshaft to also engineer on the nose of it,keeping the crankshaft in perfect balance! ESPECIALLY on high revving performance engines! To top it all off you might be introducing internal vibrations in the spinning assembly causing rear main seal/front main seal oil leaks...and worse case causing engine internal damage.

groundhog

No need for one in a 500HP road car - it's not a 100HP TR4.

Todd B

here's a quick read on harmonic type issues you could encounter with a light weight fly wheel on the 4.0l engine.

http://performancedevelopments.com/p...enginefailure/

sl951

The weight of the OEM dual-mass flywheel (991.2 GT3 - 6 speed) is 25lbs.

It's made by LUK who is the Porsche vendor for all 9A1 flywheels.
25-27.5 lbs - is the weight range for various 9A1 dual-mass wheels. I'm not sure what the new Speedster is, but I don't expect it to be significant.

Single mass flywheels - are roughly half the weight (13 lbs).

Any 9A1 flywheel, going all the way back to 2009 will fit on this 4.0 DGG engine (same bolt pattern and diameter).

Petevb

If true 80 grams is 1%- pretty trivial. You’d want to look at the location of the weight as well- if it’s closer to the center it will improve response.

The noise certainly adds character but so does added responsiveness IMHO. Even if it doesn’t contribute significantly to lap time...