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Hi Clark,
Every Lancair is a little different, some are much faster then others. I can only assume that it has to do with the building, rigging, weight, wing, engine mods and even pilot technique.
This cold air induction is sure not for everyone and I'm not trying to recommend anyone doing all this work, but it is an option for Lancair owners to try something new and looking for a little edge or someone building a new engine.
In my case I wanted to remove the whole bottom of my cowling. It was way to big and heavy from allot of very bad repairs from a previous owner. This was my accuse to do this and I wound up getting involved with ECI at Oshkosh on this project. I'm glad I did it and I'm very happy with all the benefits I've gained. But to me this Lancair is about experimenting, learning and having a blast doing it. What other aircraft can you get so much for so little?
To answer you question about leaning, I usually run my EGT's at 1380 degs. They are very balanced at these temps. All my probes are at 3 1/2" from the port and I've moved the injectors around ( and some others ) to get these temps. I rarely fly at high altitudes unless I'm going cross country. My fuel burn at a 200 knot + cruise is around 9 to 11 gph. Pulling back it will go into the 7's, WOT at sea level (31 MAP's 2700 RPM ) I see as much as 16 gph. I don't like saving a dollar to burn up cylinders. That's just me. I'm not a lean of peak kind of pilot.
One trick is put a small aluminum plate in front of the #1 injector so the air pressure from the left cooling inlet doesn't force more pressure in the injector aerator, the other three do not have this problem.
Randy Stuart
LNC-2
----- Original Message ----- From: Clark Baker
To: randystuart@hotmail.com
Sent: Wednesday, February 13, 2008 10:47 AM
Subject: Re: [LML] Cold Induction
HI Randy,
Thanks for the color. I didn't mean to imply anything; just wanted to add my experience. Great to see you have those kind of speeds. I am 1,250 and have the MT 3 blade prop, so that is likely 5kts there. Also, hate to see people part with ~$4,000 and be dissapointed if they didn't see +10kts.
It is always iteresting to see what others are up to. Do you run lean of peak and how balance are your injectors (ie, what is the gph spread from first to peak to last to peak)?
Clark
On Feb 13, 2008 1:08 PM, Randy <randystuart@hotmail.com> wrote:
It's hard to get your LNC-2 past 200 kts., that seems to be the wall on the design for these rockets. There's about a dozen of these Lancair's in my area so it's easy to compare data from one build to another. Getting past the 200 kt barrier is the hard part. Adding HP is exponential, takes allot of ponies to get a few more knots. So you have to look elsewhere to get speed. Weight, straight airframe, rigging, drag. This includes cooling drag, flap reflex, balance, just to name a few. And since everyone of our Lancair's are different there's no real hard data and set ways to build. You just have to ask and experiment... That's the whole point.
My LNC-2 is on the lighter side, about 1150, and I have small cooling inlets, flap reflex, direct RAM air, electronic ignition, small wing tips, small landing gear, small tail. When I do my flight testing I'm using a calibrated Micro Encoder for TAS, CAS, DA and a Garmin 430W to get accurate ground speeds and winds aloft. I also use a VM-1000 for all my engine monitoring.
As I said in my posting about installing the ECI cold induction system, I did do more then just add the cold induction. It certainly makes HP and a better performing engine, no doubt..... But it also allowed me to cut allot of weight off the front and the cowl, make the cowl much more aerodynamic, create a better RAM air system and change the cooling differential. This all adds up to more knots and a better flying Lancair.
An obvious change is in the bottom of the cowl, looking at the before and after pictures, you can see how the airflow now "holds" the nose up instead of the old cowl adding drag. This helps take the pressure off the tail, kind of the effect of reflexed flaps. Doing this allows the airframe to go faster. Less drag = More speed. The tail is drag.
More RAM = More HP. The least amount of air you force into the cooling inlets = Less drag. Performance exhaust = More HP. More HP + Less Drag = More speed.
These are just a few of the many changes and mods we can do to increase performance and have a better flying Lancair.
Randy Stuart
LNC-2
-- Clark Baker
mobile: + 1 917 558 5567
home: + 1 646 964 4159
bakercdb@gmail.com
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