Speed

[larryrbutler]

I,m proud of the old girl but she is damn slow, Hornton stal and flap gap seals have been installed and fresh 0300.115 MPH at 2550 RPM. Open for Ideas. LB

[canav8]

As advertised.

[W.J.Langholz]

That's 3 mph faster than most.........must be green

W.

[lowNslow]

I,m proud of the old girl but she is damn slow, Hornton stal and flap gap seals have been installed and fresh 0300.115 MPH at 2550 RPM. Open for Ideas. LB

Are you talking TAS or indicated? Which prop do you have?
Most 170s with the "California" prop (between a cruise and climb prop) get 105kts TAS (121mph) at 2450rpm at 4500-7500 msl.

[GAHorn]

It's within specs. But if you really worry about it... the additional effort and money you can spend on the quest for another mph or two can start with:
1-Airspeed indicator calibration.
2-Pitot static system check.
3-remove the Horton.
4-aftermarket turbo-charger.
5- Me-163 jettisionable landing gear
6-....large inheritance....

[jrenwick]

...3-remove the Horton.

The Horton STOL kit doesn't seem to slow a 170 down at all, or at least very little. The larger factor on my airplane is probably the 8.00x6.00 tires sans wheel pants. At altitudes between 2 and 3 thousand, where I do most of my flying, I expect to see 115MPH true at 2450RPM. Where the Horton kit really shines is on climb-out. I wouldn't spend the money to install one, but it would be a real bitch to remove it, and I wouldn't consider doing that. But your suggestion wasn't really serious either, was it, George?

I flight-plan 100KTAS. Three summers ago, on our trip to Alaska and back, I averaged 100MPH ground speed, 8GPH, 12.5MPG. Nice round numbers....

[Fearless Tower]

5- Me-163 jettisionable landing gear

Hey, I like that idea - just need to install the rubber matting at your home field like the Navy tried many moons ago. Only problem is that you need to add the jettisonable prop for that one!

[GAHorn]

[...The Horton STOL kit .... I wouldn't spend the money to install one, but it would be a real bitch to remove it, and I wouldn't consider doing that. But your suggestion wasn't really serious either, was it, George? .....

It was as serious as the rest of the suggestions....

Anyone who wants a FAST airplane...would do well to avoid the wing-strut Cessna's built before 1960, and all their "competitors".

Anyone who wants t o improve the speed of their 170 (regardless of year model) should remember that drag increases as the SQUARE of speed. So if you want to improve speed you've GOT to REDUCE DRAG! Horsepower is the most expensive way to gain speed.

Drag reduction should include:
1- Get rid of unused antennas, and unused equipment, old-radios, etc. 10 lbs saved is REAL savings in every parameter, including speed, useful load, field-performance, fuel consumption.
2- Properly-rig the airframe IAW specs
3- Make cowl and baffle repairs (more drag results from inefficient engine cooling than one might realize)
4- Hide brake lines behind gear struts, install small tires.
5- Seal wing root fairings, and repair any other streamlining/fairings and fairing seals.
6-Repair DOOR and window SEALS and check door fitment (this can be a real tough one)
7- Check propeller specifications for blade length (dia), thickness, chord, profile.
8-Instrument calibrations including Tachometer, ASI and pitot/static system.
9- Wash/Wax/Polish
10-Strip and repaint INSIGNIA RED (couldn't resist)

[W.J.Langholz]

Convert kts to mph Calculator Convert knots to miles per hour with our handy conversion calculator. 1 kts = 1.15077945 mph ..

W.

[GAHorn]

I,m proud of the old girl but she is damn slow, Hornton stal and flap gap seals have been installed and fresh 0300.115 MPH at 2550 RPM. Open for Ideas. LB

If your ASI and TACH are accurate...depending upon the altitude you took those readings, you may be underpropped.... what prop do you have? and what other conditions existed? (weight, altitude/temp)

[170C]

My '56 C-172 w/ convention gear, Horton STOL & aileron gap seals (no flap gap seals) is a 100 kt/115 mph cruise. I do think the Horton item may slow it down some, but as has been posted before, 888A is a bit slower than comparable B model 170's (and A models) I have flown with over the years. My prop is a 53". Hate to admit but I don't recall exact rpm for the 115 mph cruise under 7500 feet. I use my gps for accurate ground speed reference. Don't be too concerned about your speed. You are in there with the best of them. 170's are not speed demons

A bit of green paint might increase speed

[Glenn]

I plan on 98kts. Recent retiming (mags were off by about 15-20*) has given me better GPH and seemingly better acceleration once I level off. It feels faster but I can't confirm that yet. May not be a rocket ship but it sure is faster/more fun than driving. Especially since my main source of transportation cruises about 60mph on level surfaces. I plan on removing the huge Narco ant this month so maybe I can bump it up to 99kts.

[minton]

How many of you check the mag "E" gap before timing to the engine? It's nice to have a healthy spark!!

[flat country pilot]

I,m proud of the old girl but she is damn slow, Hornton stal and flap gap seals have been installed and fresh 0300.115 MPH at 2550 RPM. Open for Ideas. LB

How fast do you want it to go?
You have 115mph, you want 125, 130, 135?

I would like mine to leave the ground in 250 feet. Probably not going to happen, but I could use the short take off.
Should have a cub or a maule I guess but they are not a 170.

If your looking for 180mph, a mooney would be nice. A mooney 231, M20K, gets what 200kts?
That's pretty fast, but its not a 170.

My two cents is 5 or 10 more MPH won't make a big difference for you.
I fly my 170 for what it is and that's pure fun. It will fly coast to coast and have fun doing it.

Bill

[blueldr]

Check the accuracy of your tachometer. Are you sure you're really makinh 2550 turns per minute?
I had a buddy with a 180 HP Tiger that claimed it was the fastest Tiger going. He borrowed my tach checker and found that his tach was 150 rpm low. At an indicated 2450 he was turning 2600.