If so, thoughts?
If not, thoughts?

Regards
Adolfo

We were competing in an air race where engines had to be stock but airframes could be modified with STCs. My Mom would put on a mod to see if the aircraft top speed was improved. If she determined that the mod had any speed improvement, it stayed - don't know if she got the advertised speed improvement. She was pretty sharp on this and holds the record for the most pilot-skilled cross country speed air race victories. The reason I share this is a lot of people go for these mods to fly faster and the plane did fly faster, I just think that if you are going to spend money, it is better to add fuel tanks because anytime you can pass on a fuel stop, that is a huge time saver and therefore the best speed enhancement.

We have aileron and flap gap seals, wing root fairings.

The rudder seal went on and slowed our PA39 twin down so it came off.

Twins are notoriously hard to get a smooth landing out of. Either it was these mods or the tip tanks but husband and I both noticed the Twin was easier to land smoothly after these additions. I'd like to think we got better as pilots but it is more likely to be the mods.

Hope this helps.

Clarence

Raced a 400 once at max power at sea level - had to learn to move my finger faster!

Not looking so much at increased speed, although I'll take it, it's more on improved handling on take-offs, landings and reduced stall speeds.
Oh, and yes for the looks

Adolfo

For speed, I would recommend reversing your brakes if you have not done so. That is the mod I got the most out of. Also the slipper in front of the nose gear.

I don't think any of the mods will change your stall speed much. I have all of them except the vortex genorators and dorsal fin.

Mark

However, he is the the most knowledgeable person about speed mods.

Go to: http://www.hdneubert.com/
then: Presentations
then: Reno 2002

Copying those should keep you busy for about 5 years and then at that point you will only be 17 years behind Hans -- he is still developing.

All the best!
Jim