C Box worth it?

[RudiGreyling]

Hi Guys,

I am considering upgrading my B box to a C box with bigger prop on my 503. I want to know about quantifyable increase/decreases on the same aircraft by just replacing these components. You hear wispers about this and that but no real numbers. I hope someone on this chat group can shed some light:

1) What was your B-box & prop configuration before your upgrade? (Ratio, Prop make and specs)
2) What was your configuration after the C-box and prop upgrade? (Ratio, Prop make and specs)
3) What increase/decreases did you see (RPM in cruise, Vertical Climb speed, Cruise speed, max speed, fuel consumption)
4) Anyhting else you have noticed with your upgrade?

Thank you in advance,
Kind Regards
Rudi

[Junkie]

Also want to do this on my Mainair trike -

For what its worth currently have:
582
B-Box
2.57:1
62" 3 blade warp (small prop to clear wing keel overhang)
Pitched to run 6300 rpm static & 6700 max in the air giving a steady cruise of 60mph @ 5000 rpm
75mph @ 6700 with wing trimmed fully back (or hangpoint fully fwd) Climbout 800- 1000fpm flat rattle, trike loaded with me and 65l on baord.

Now considering an E-Box with starter, as I have GPL (sidewinder) starter setup and getting fedup having to weldup that damned ringear every 100hrs or less - Although motor is mounted on Lord mounts and is as smooth as can be, I do think dumping the B Box for a C Box wil make a big difference (essentialy same as Ebox)

[RudiGreyling]

<SNIP> I do think dumping the B Box for a C Box wil make a big difference (essentialy same as Ebox)

Hi Junkie,

Yes but how much is the R10,000 question?

Regards
Rudi

[Morph]

Yes but how much is the R10,000 question?

About R10,000

[RudiGreyling]

About R10,000

Was going to say the million dollar question, but I tink out of pocket about +/- R10K after box and prop. I would rather have some data before spending ...

[Joninmoz]

Hi Rudi,

I have an Aquilla which originally had a B-box and a Geo-Killy prop. I changed to a C box and a P-Prop. There is a significant improvement in performance:

Climb: (at 3000 ft asl) 500 ft p/m vs 850 ft p/m (one up 100kg pilot).
RPM cruising: 5300 RPM vs 4800 RPM now (one up).

Previously I would not consider carrying a passenger weighing more than 70 kg. Now I easily carry a passenger of 80-85kg, and I still climb at 500ft p/m.

I must say that I was considering changing to a 582 engine but after talking to some of the guys I decided to go the c-box, p-prop route. Cost-wise its R40,000 vs R10,000 (no real argument there!).

I am very happy with my planes performance now and I don't feel that I lack any power with the combination I have now. My advice is to make the change - you won't be sorry.

Regards

Jon

[Smiley]

Hello Rudi

I've spoken to Fred one day about the same topic and he said going from a "B" to a "C" box gives you about a 15% increase in power or lets rather say thrust!!

Where you once with a "B" box could take a pax of lets say 80kg, you can now take a 105kg pax no problem.

I way 111kg and Theo about 105kg and you've seen how we fly. Just don't do this after 10am in the summer.....

My 2c, judging on my planes performance....

[RudiGreyling]

To Joninmoz,
Thanks for the numbers this is the type of data i'm looking for..

To Smiley,
Riaan, yes I know the whispers of 15% increases, but I want hard comparitive numbers of people that have done it.

Any additional numbers?

Thanks
Rudi

[Marius Burger]

Sorry for seeking commercial intrest in your quest for better thrust.... Have good second hand C-box up for grabs.

Marius

072 750 4168

[Duck Rogers]

Sorry for seeking commercial intrest in your quest for better thrust....

Firstly, welcome to the forum :D
Secondly, no need to be sorry...if you don't advertise you'll never sell :D

Duck Rogers

[IFLYHI]

Sorry for seeking commercial intrest in your quest for better thrust....

You sell better thrust

[Duck Rogers]

You sell better thrust

Sure he does....IN A BOX

Duck Rogers

[Duck Rogers]

have an Aquilla which originally had a B-box and a Geo-Killy prop. I changed to a C box and a P-Prop. There is a significant improvement in performance:

You need to tell us what the previous configuration was.

What ratio was the old box? (I presume 2.58:1)
What was the specs on the old prop?
What ratio is the new box?
What are the specs on the new prop?

I'd like to see to what extent the box contributed towards the improvement and likewise the new prop.

With this info we can do some math (with a calculator of course, I'm too stupid otherwise :D ) to give Rudi some more numbers to confuse himself with :D

Duck Rogers

[Duck Rogers]

BUMP....waiting for answers :D

Duck Rogers

[Leprachaun]

Hi Guys , there is no comparison , if you can get a 3, 47 cor e box do it - you need a 72 inch 45 pitch two blade wooden prop or a 72 inch 3 blade composite . Hennie Malan in Pretoria make a good prop for R2700,00 that works just fine - been ther done it got the tshirt . The old 2,57b box is ok , but the cbox or e box is the champ , lower prop speed , more lift quicker takeoff , bigger pax - a different plane - - I will buy your old B box as well a Prop - need one for a spare 503 DCDI - Dont use a 3 or 4 to one C or E box - the harmonics will drive you and the plane crazy - Leprachaun