Speed Mods

Discussion in 'Avionics and Upgrades' started by jstrahan, May 17, 2018.

  1. jstrahan

    jstrahan Filing Flight Plan

    Joined:
    May 17, 2018
    Messages:
    5
    Display Name:

    Display name:
    jstrahan
    I am considering buying a Piper Archer and was wondering who does better speed mods, LoPresti or Knots2U. Although I am a long time pilot, I have never owned an aircraft before and would appreciate some advice. Thanks.

    (the year of the Archer would be somewhere from 1975-1994)
     
  2. Checkout_my_Six

    Checkout_my_Six Final Approach

    Joined:
    Mar 4, 2007
    Messages:
    7,878
    Location:
    Maryland
    Display Name:

    Display name:
    Check_my_Six
    buy a faster plane....much cheaper speed mod.

    For thousands of dollars (AMUs) spent....I can't imagine getting more than 5-6 more knots.
     
    MBDiagMan, TCABM, wsuffa and 3 others like this.
  3. Timbeck2

    Timbeck2 En-Route

    Joined:
    Nov 4, 2015
    Messages:
    4,804
    Location:
    Vail, Arizona
    Display Name:

    Display name:
    Timbeck2
    Isn't Knots2U just a reseller of other manufacturers' mods?
     
  4. tawood

    tawood Pattern Altitude

    Joined:
    Sep 22, 2015
    Messages:
    1,654
    Display Name:

    Display name:
    Tim
    I truly don't think it matters...as an owner of a very mod-loaded Piper...they hardly make any noticible improvement. As @Checkout_my_Six said, buying a faster plane is waaaaaay cheaper. The only mod on my Piper that I think makes a noticeable difference is the Powerflow exhaust. All the fairings, gap seals, wing tips, etc, don't change anything if you don't change the prop, and these Pipers need the lower prop for a decent climb so you really shouldn't change it.
     
    Last edited: May 17, 2018
    James331 likes this.
  5. steingar

    steingar Taxi to Parking

    Joined:
    Feb 6, 2007
    Messages:
    25,132
    Location:
    Land of Savages
    Display Name:

    Display name:
    steingar
    The best speed mod for an Archer is to sell it and buy a Mooney.
     
    Last edited: May 17, 2018
  6. Chip Sylverne

    Chip Sylverne En-Route

    Joined:
    Jun 17, 2006
    Messages:
    4,241
    Display Name:

    Display name:
    Fear is the poison of our lives.
    I bought a Comanche with just about every LoPo mod on it. Instead of 155kts I get 165. Bought it that way, wouldn't spend the money if it were my own. Looks cool on the ramp though.
     
  7. jstrahan

    jstrahan Filing Flight Plan

    Joined:
    May 17, 2018
    Messages:
    5
    Display Name:

    Display name:
    jstrahan
    I got my commercial in a Mooney M20J in 1985. They seemed a bit cramped. I prefer Pipers.
     
    Checkout_my_Six likes this.
  8. Checkout_my_Six

    Checkout_my_Six Final Approach

    Joined:
    Mar 4, 2007
    Messages:
    7,878
    Location:
    Maryland
    Display Name:

    Display name:
    Check_my_Six
    FTFY....:D
     
    JOhnH likes this.
  9. teejayevans

    teejayevans Pattern Altitude

    Joined:
    Aug 13, 2013
    Messages:
    1,790
    Display Name:

    Display name:
    Tom
    Piper Archer:
    Cabin Height: 49”
    Cabin Width: 42”
    Baggage volume: 24 cft

    Mooney J:
    44.5” (lower roofline results in lower seating position)
    43.5”
    17 cft (doesn’t include hat rack, ~2cft, which is limited to 10 lbs).
     
  10. Timbeck2

    Timbeck2 En-Route

    Joined:
    Nov 4, 2015
    Messages:
    4,804
    Location:
    Vail, Arizona
    Display Name:

    Display name:
    Timbeck2

    I'm glad you posted that. I was on the fence. I guess I'll just buy gas.
     
    tawood likes this.
  11. jstrahan

    jstrahan Filing Flight Plan

    Joined:
    May 17, 2018
    Messages:
    5
    Display Name:

    Display name:
    jstrahan
    I guess I’ve been a bit nervous about Mooney’s, ever since that cult was started.
     
  12. Clip4

    Clip4 En-Route

    Joined:
    Jun 27, 2013
    Messages:
    2,761
    Location:
    A Rubber Room
    Display Name:

    Display name:
    Cli4ord
    Or split the baby and get a Tiger.
     
  13. dans2992

    dans2992 En-Route

    Joined:
    Jan 7, 2013
    Messages:
    3,099
    Display Name:

    Display name:
    Dans2992
    Does it have the cowl also? I think that mod was something like $15k.
     
  14. Chip Sylverne

    Chip Sylverne En-Route

    Joined:
    Jun 17, 2006
    Messages:
    4,241
    Display Name:

    Display name:
    Fear is the poison of our lives.
    Yep. Only thing it doesn't have are the wing root fairings. Not the best pic, but you can see how much tighter the cowl is 20170820_175946.jpg from this angle
     

    Attached Files:

  15. wsuffa

    wsuffa Touchdown! Greaser!

    Joined:
    Feb 22, 2005
    Messages:
    21,657
    Location:
    DC Suburbs
    Display Name:

    Display name:
    Bill S.
    Or a Glasair.....
     
    Ray Eaker and James331 like this.
  16. blueskyMD

    blueskyMD Pre-takeoff checklist

    Joined:
    Mar 26, 2015
    Messages:
    234
    Location:
    Allentown PA
    Display Name:

    Display name:
    Bigfoot297
    a folding gear will make nice speed mod
     
  17. kayoh190

    kayoh190 Pattern Altitude

    Joined:
    May 29, 2014
    Messages:
    2,197
    Display Name:

    Display name:
    Kayoh@190
    Wish they had folded the gear on the Dakota.
     
    weilke and hindsight2020 like this.
  18. Checkout_my_Six

    Checkout_my_Six Final Approach

    Joined:
    Mar 4, 2007
    Messages:
    7,878
    Location:
    Maryland
    Display Name:

    Display name:
    Check_my_Six
    Cirrius doesn't fold gear.....low pressure wheel paints and strut shrowds will make a difference.

    BTW....I have FSDO "approved" plans for PA-32 (works for PA-28 too) low pressure wheel pants. $50 gets a copy.
     

    Attached Files:

    Last edited: May 20, 2018
  19. TigerGene

    TigerGene Pre-takeoff checklist

    Joined:
    May 31, 2017
    Messages:
    103
    Location:
    Tyler, Tx
    Display Name:

    Display name:
    TigerGene
    The problem with speed mods and Cherokees is you are limited by the fixed pitch Propeller. Furthermore you are limited by the take-off performance the fixed pitch prop can provide, minimum static RPM and maximum engine RPM.

    So basically you would be souping up a car that has ONLY 2nd gear. It’s only goingvto go as fast as the gear (prop) and engine RPM allow.

    Speed mods on a Cherokee CAN buy you a bit more miles per gallon, but usually not much more speed unless you can change the prop pitch.

    A Cherokee with ALL speed mods completed AND a speed prop is a Grumman Tiger or Cheetah.
     
  20. tawood

    tawood Pattern Altitude

    Joined:
    Sep 22, 2015
    Messages:
    1,654
    Display Name:

    Display name:
    Tim
    FTFY
     
  21. TigerGene

    TigerGene Pre-takeoff checklist

    Joined:
    May 31, 2017
    Messages:
    103
    Location:
    Tyler, Tx
    Display Name:

    Display name:
    TigerGene
  22. tawood

    tawood Pattern Altitude

    Joined:
    Sep 22, 2015
    Messages:
    1,654
    Display Name:

    Display name:
    Tim
  23. TigerGene

    TigerGene Pre-takeoff checklist

    Joined:
    May 31, 2017
    Messages:
    103
    Location:
    Tyler, Tx
    Display Name:

    Display name:
    TigerGene
    Sorry for the misunderstanding. I agree with you 100%.
     
    tawood likes this.
  24. Unit74

    Unit74 En-Route

    Joined:
    Mar 8, 2014
    Messages:
    4,266
    Display Name:

    Display name:
    Unit74
    K2U makes their own speed mods, as does LoPresti. However, LoPresti is far too proud of them. $1k a knot is the going rate. I had all K2U mods on my Archer which resulted in 130 knots true. Worth it for 5 knots? Not really.

    Buy a TruTrack AP with the same money.
     
    Ray Eaker likes this.
  25. NordicDave

    NordicDave Pre-takeoff checklist

    Joined:
    Oct 31, 2015
    Messages:
    346
    Location:
    San Jose
    Display Name:

    Display name:
    NordicDave
    ^^^ What he said. Speed mods are an absolute waste of money and time.

    If you buy EVERY speed mod available, you MIGHT get 5 knots. Other factors like a worn prop or rigging are tangible speed improvers.
     
  26. Checkout_my_Six

    Checkout_my_Six Final Approach

    Joined:
    Mar 4, 2007
    Messages:
    7,878
    Location:
    Maryland
    Display Name:

    Display name:
    Check_my_Six
    Oh....that reminds me. One of the best Cherokee speed mods is getting your flaps adjusted max up. Many (check the TCDS for your SN) will allow a negative 2 degrees up. That's worth 2-3 knots.
     
    James331 likes this.
  27. tawood

    tawood Pattern Altitude

    Joined:
    Sep 22, 2015
    Messages:
    1,654
    Display Name:

    Display name:
    Tim
    I remember an article that said just getting it rigged is good for a couple of knots as well.
     
    James331 likes this.
  28. steingar

    steingar Taxi to Parking

    Joined:
    Feb 6, 2007
    Messages:
    25,132
    Location:
    Land of Savages
    Display Name:

    Display name:
    steingar
    As is cleaning off all the bugs.
     
  29. Glenn D

    Glenn D Pre-takeoff checklist

    Joined:
    Nov 5, 2015
    Messages:
    127
    Location:
    So Cal
    Display Name:

    Display name:
    Glenn D
    Get rid of the coffee can red strobe on the tail, reduce or eliminate antennas, clean up the little things, and that all helps a lot, those easy changes gained almost 5 mph. I added the Laminar Flow nose wheel fairing, and gained about 4 mph, Aileron and elevator gap seals helped with control at slow speed... Will be adding the Laminar Flow main wheel fairings next to gain some more...

    For the flying I do, it is worth the cost.. Doing all the work myself helped with that cost. Being more efficient at a given speed is more important then just pure speed, but is fun to see 160 mph at 2500 ft full power.... not to bad for a little hot rod Cherokee 140
     
    Timbeck2 and Mtns2Skies like this.
  30. MBDiagMan

    MBDiagMan En-Route

    Joined:
    May 8, 2011
    Messages:
    2,562
    Location:
    NorthEast Texas
    Display Name:

    Display name:
    Doc
    Which Piper offers the same speed per gallon as a Mooney? Pushing away from the dinner table will make the Mooney fit just fine.
     
    tawood likes this.
  31. bgmac

    bgmac Pre-Flight

    Joined:
    Apr 10, 2014
    Messages:
    53
    Location:
    Cypress Inn, TN
    Display Name:

    Display name:
    bgmac
    I had a Cherokee 180 with the O-360 and put on gap seals and wing tips. When I did that it wanted to take off on its own, well I saw very little in speed, but much more improvement in control. Then I bought the Commander 112 with the IO 360. More room/speed by 25 kts. Then when I painted black around the windows I gain another 10 kts on the ground. :)
     

    Attached Files:

    Ray Eaker likes this.
  32. tawood

    tawood Pattern Altitude

    Joined:
    Sep 22, 2015
    Messages:
    1,654
    Display Name:

    Display name:
    Tim
    I've never seen a Cherokee tied up like that...why have the front wheel off the ground? (I only do it for maintenance / pants removal).
     
  33. bgmac

    bgmac Pre-Flight

    Joined:
    Apr 10, 2014
    Messages:
    53
    Location:
    Cypress Inn, TN
    Display Name:

    Display name:
    bgmac
    True, I was just finishing an annual and put the wheel and pants on. Thought it looked cool so I took a picture. I'm somewhat of a big guy and I can push down on the back of the plane and tie it down to an anchor in the concrete floor.
     
    tawood likes this.
  34. jstrahan

    jstrahan Filing Flight Plan

    Joined:
    May 17, 2018
    Messages:
    5
    Display Name:

    Display name:
    jstrahan
    Thank you for proving my point. I don't much care about "speed per gallon". The plane should fit me, not me the plane. "I'm not a Marine. I believe in my comfort." (what movie?)
     
  35. MBDiagMan

    MBDiagMan En-Route

    Joined:
    May 8, 2011
    Messages:
    2,562
    Location:
    NorthEast Texas
    Display Name:

    Display name:
    Doc
    What movie what?

    BTW, my wife and I both believe in comfort as well as control precision(I loathe the thought of going back to a cable and pulley aircraft,) speed, fuel efficiency, simplicity and reliability. That’s why we boutpght a Mooney.
     
    flyingcheesehead likes this.
  36. jstrahan

    jstrahan Filing Flight Plan

    Joined:
    May 17, 2018
    Messages:
    5
    Display Name:

    Display name:
    jstrahan
    The reference to a movie is from a line in The Green Berets, spoken by actor Jim Hutton. My only experience in a Mooney was about 20 hours getting a commercial in an M20J over 30 years ago. I didn't like them much. I felt they were more 'cramped' that other similar sized aircraft. "Simplicity"? I didn't see such. As for speed, fuel efficiency, and reliability, my experience was too limited for a definitive opinion as to those items. I also prefer an airplane that is more affordable to acquire since I am in the market to buy my first plane. Mooneys are simply too expensive. I've checked. BTW, my avatar is a picture of the airplane that my youngest daughter is getting her Private in, a 1977 Piper Warrior II.
     
  37. James331

    James331 Touchdown! Greaser!

    Joined:
    Apr 18, 2014
    Messages:
    16,859
    Location:
    Behind you!
    Display Name:

    Display name:
    James331
    That.

    If you mean a short winged RG CS one with the largest engine you could shoehorn into it.
     
  38. Checkout_my_Six

    Checkout_my_Six Final Approach

    Joined:
    Mar 4, 2007
    Messages:
    7,878
    Location:
    Maryland
    Display Name:

    Display name:
    Check_my_Six
    ....it also increases the stall speed by a few, but you're landing with flaps so that brings it back down again. ;)
     
  39. flyingcheesehead

    flyingcheesehead Touchdown! Greaser!

    Joined:
    Feb 23, 2005
    Messages:
    20,109
    Location:
    UQACY, WI
    Display Name:

    Display name:
    iMooniac
    The best speed mod for an Archer is retractable landing gear. IE, an Arrow. Better yet, a Mooney or Bonanza... But of course, faster plane usually means higher purchase price. So...

    The best "speed mod" you can get and still have it be an Archer is to get one of the newer models with the fully faired landing gear. The early ones could have wheel pants, but even if they did, they left the brakes hangin' out in the breeze, among other things. This changed around 1978 or 79, so you want one newer than that.

    This is the kind you want:

    archerpants-new.jpg

    This is the original style - Note all of the uncovered stuff on the inside of the wheel and the much smaller pant:

    archerpants-old.jpg


    Bah. I'm 6'4" and over 300# and I fit in my Mooney better than most any other 4-seat single. "Mooneys are small" is an OWT, unless you're talking about the back seat of a short-body model. But I don't think any of us sit in the back, and my long-body is just fine in the back. The "small" impression can also come from the instrument panel being closer to you, but I much prefer it that way. I used to get a backache on instrument lessons in the Archer from having to lean forward to do stuff on the panel so often. Another place it comes from on the early models is the more-vertical windscreen and its position relative to you - It's in the same position as any other plane relative to the instrument panel, but as I mentioned, that's closer to you. But, I don't spend any time above the glareshield, nor does anyone else, so any space you may have had there is wasted anyway.
     
    Cruzinchris and 5QK like this.
  40. Pilawt

    Pilawt Final Approach

    Joined:
    Sep 19, 2005
    Messages:
    6,069
    Display Name:

    Display name:
    Pilawt
    Constant-speed prop would help takeoff distance, climb rate and high-altitude performance, but not necessarily cruise speed. Through the 1972 model year, fixed-pitch prop was standard and constant-speed prop optional on both the Cherokee 235 and the Cherokee Six 260. On both, book cruise speeds were 2 mph slower with the constant-speed propeller.

    Screen Shot 2018-05-26 at 9.17.54 PM.png

    The change to the bigger wheel and brake fairings was with the 1978 model year on all US-built fixed-gear PA-28s and PA-32s. They do help reduce drag, but they're a pain should you ever be inclined to inspect or service tires or brakes. :mad:

    Oddly, PA-28s and PA-32s built under license by Embraer in Brazil were still built with the old-style fairings well into the 1980s. http://www.airliners.net/photo/Aeroclube-de-Eldorado-do-Sul/Embraer-EMB-712-Tupi/537223
     
    Last edited: May 26, 2018