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Are Speed Mods for Real?
(Currently my Comanche cruises routinely over 180mph and frequently approaches 190mph {TAS} even at over 10k msl, confirmed with my gps. Is this normal?)
- 17031
- ICS member
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- Joined: Tue Jan 20, 2009 9:44 pm
Actually, based on 260's I've seen race, I'm not surprised at the performance you see. Some are just faster than others. Obviously you keep yours in good condition from an engine perspective and it is in good rig. Way to go - always happy to hear about good flying Comanches.
Patricia Jayne (Pat) Keefer ICS 08899
PA-39 #10 Texas
N3322G- ICS member
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- Joined: Thu May 08, 2008 1:58 pm
- Location: Fort Worth, Texas area
With all that said, once all that is done, then check out the speed mods. Depending on your average flight length, the best speed mod may be more fuel. Cutting out a stop will cut your block time by about 45 minutes or more. Next, put hubcaps on your plane if you don't have any. Add the Lopresti Speed Spats and Slipper. Add K2U gap seals for the flaps and Ailierons. If you have a 3 bld prop, add the wing root fairings. All of that will get you another 5mph top end, but it will get you more if you slow down your indicated airspeed. Where the speed mods shine are mostly at high altitude where the IAS is lower, and TAS is higher, and the percentage gain is greatest. That is the efficiency gain.
-Zach
Zach Grant L1011jock- Technical Advisor
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What have you heard about rigging the alerons and flaps to -1 or 1.5 degrees? Cost nothing and is supposed to increase speed a bit.
- Tony Scarpelli
- ICS member
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Re: Are Speed Mods for Real?
Funny, for a while, i put most of the mods on, but still flew at peak, limiting my airspeed.
Lately, I've ran at 75 ROP on the leanest cylinder, and speeds increased more than any of the mods could do...
just a thought, spend money on fuel, keeping temps cooler at same time, and go faster.
steve
N8632Y- ICS member
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- Location: N14 South Jersey
Re: Are Speed Mods for Real?
Dave Pyle ICS 730
- nbaker
- ICS member
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Re: Are Speed Mods for Real?
We have a 260B with the Johnston tips and no other mods. The paint's good, tires fair..........sorry that's another song......anyway we have a new airspeed indicator as well. First, I think an accurate air speed indicator does more for consistent landings than the tips. Speed, speed, speed....We fly long legs at 9500-10500 all the time and we are usually about 450 lbs under gross at take off. On level off at cruise (2300rpm, wot, 100 rop, 12.5gph) we see 185 mph with standard or near standard conditions. As the fuel burns off we do see 2-3 mph increase. We often fly these legs with twinco friends who have the same tips, and all the k2u gap seals, and they are loaded the same (except they have to fill their aux tanks) trust me they are no faster and they are burning 2-3 gph more.
Good luck, Don
ps Steve what's wrong with you, you're gonna get the LOP police after you with fool talk like that.....
- 9089P
- ICS member
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- Joined: Wed Jan 07, 2004 7:01 am
Re: Are Speed Mods for Real?
Your PA30 friends should double-check that the gear selector is in the "retract" positon .......54Y typically trues out around 195 mph at 8000 ft with the throttles fire walled and the props set to 2400, 75 degrees ROP, just a shade under gross. I've seen TAS as high as 200mph. These speeds are verified by the air data computer.
PA 30B N7954Y
Jody Brausch- ICS member
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- Location: Huron, OH
Re: Are Speed Mods for Real?
impressive!
I've run peak, and ROP, and the difference is about 5-7 kts....fuel of about 0.5-1.0 GPH
Running 75 ROP at 6500ft 24"2450rpm 30.52 1C 9.0/side GPH i have IAS 158 TAS just over 171 kts or 196 MPH...
big difference is a combination of the sun and the moon, temps, fuel, etc...it's nice to get there, never fast enough...
steve PA30
N8632Y- ICS member
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- Location: N14 South Jersey
Re: Are Speed Mods for Real?
I think we are talking apples and oranges here, at 8k and your settings you are at 75% or perhaps more (I don't have a twin power chart), at 9500 and 2300 rpm we are only making 65% and I sure my friend was doing the same. By the way what are you burning at your settings?
Don
- 9089P
- ICS member
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Re: Are Speed Mods for Real?
No argument there....the 260 wins hands-down on the fuel efficiency meter. My Dad had a '65 260, and that was one sweeeeeet airplane. Fast, efficient, great ailerons, not to mention the beautiful lines. Can't ask for much more than that. To be honest, after having flown behind one fan for twenty-some years, I just had to have a twin, and I must say that the twinky could not have been a better choice for me, and my family. Now if I could only get those arrivals just right.....
Steve,
54Y's fuel burn is just a little higher than what you experience, burning just about 9.2 to 9.3 gallons/side 75 ROP @ 8000. Not as efficient as what you're seeing, but it knocks the snot out of feeding a 310 or a Baron.
PA 30B N7954Y
Jody Brausch- ICS member
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- Location: Huron, OH
Re: Are Speed Mods for Real?
For fun we will have to compare your plane to Maggie. At 10K is am burning about 14 gph and would expect 185-190 mph.
Kristin Winter- ICS member
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- Joined: Tue Aug 09, 2005 5:21 pm
- Location: Northern California
Re: Are Speed Mods for Real?
I have my twin tricked out thanks to Mr. Speed King, "The Great HANSMIESTER". They seem to work for me. I now claim to be faster than him. This is because I just installed a new set of LoPresto nose bowls. I have copied almost all his other mods. I can honestly say I am getting 174 knots TAS at 75% pwr. My plane still needs paint and a couple of other things.
Jeff
- jeffrey aryan
- ICS member
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- Location: Chino, CA (So-Cal)
Re: Vibration
I have a PA-30B with approx 5800 TT. I currently have all speed mods on it as well as tip tanks. There is a slight vibration at as soon as I rotate and it continues during cruise. any thoughts?
- DBpa30b
- ICS member
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- Joined: Mon Jan 12, 2009 4:38 am
Re: Are Speed Mods for Real?
Welcome - I saw this is your second post. You might want to start a new thread with this as the topic.
Just click on Board Index in the upper left, then click the category and then click on NEWTOPIC which is just below the category. This way it will get the focus you want vs being under the Speed Mod discussion.
I have some thoughts and I'm sure others will chime in as well.
Patricia Jayne (Pat) Keefer ICS 08899
PA-39 #10 Texas
N3322G- ICS member
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- Location: Fort Worth, Texas area