A buddy at the local club has DL-50 with stock muffler now with about 4 gallons. I posted vid in last DL thread ofthe DL on his 17 lb 88 inch EF Yak.

Last weekend he added a EComposites cf tuned pipe with Karl Muller header.

First try and the Vess 23A gave him 7950.....it almost launched his plane and his 13 yr old son[X(] out of the driveway.

He is still working out the mid range smoothness....will play with props and header length and report back.