General Forums => Aircraft and Vehicles => Topic started by: TryHard on June 22, 2020, 09:59:07 PM
Title: P47D11
Post by: TryHard on June 22, 2020, 09:59:07 PM
Is this P47D11 Razorback jug fitted with the early war "toothpick" propeller or the paddle prop from late war jugs in aces high?
I don't notice much difference in climb performance between the D11 and D25
Another intresting thing I noticed with P47M/N at Military power 2800 RPM 54" MP The engine burns 580 GPH of fuel, however with WEP engaged bringing us to 2800 RPM and 72" MP fuel consumption actually drops to 552 GPH. This is backwards right? how is more manifold pressure aka airflow through the motor (thus more fuel required to keep the same airfuel ratio even with meth injection) need less fuel?
Title: Re: P47D11
Post by: Nefarious on June 22, 2020, 10:06:53 PM
Is this P47D11 Razorback jug fitted with the early war "toothpick" propeller or the paddle prop from late war jugs in aces high?
I don't notice much difference in climb performance between the D11 and D25
Another intresting thing I noticed with P47M/N at Military power 2800 RPM 54" MP The engine burns 580 GPH of fuel, however with WEP engaged bringing us to 2800 RPM and 72" MP fuel consumption actually drops to 552 GPH. This is backwards right? how is more manifold pressure aka airflow through the motor (thus more fuel required to keep the same airfuel ratio even with meth injection) need less fuel?
I'm pretty certain the P-47D-11 does not use the paddle blade prop. There's been a lot of conversation about it here.
You can fly the P-47D-11 in Blitz Week - We are running a special scenario event - Blitz Week - Saturday Nights in July!
July 11th, 18th, and 25th at 10PM EST/7PM PST/0200 UTC in SEA2
From America's Hundred Thousand, it seems like the paddle blade started with the D-20. The climb performance of the D-11 is just a little lower than the D-40, even so.
Don't know if D11s were retro-fitted.
From that graph it's hard (for me) to tell the actual difference, because of the strange x-axis numbering, but it appears to be 200-300 fpm at altitudes under 20k. Nothing to sniff at.
- oldman (and thanks for the graph!)
Title: Re: P47D11
Post by: RODBUSTR on June 24, 2020, 05:41:36 PM
somewhere about -23 they got better props too.
Title: Re: P47D11
Post by: RODBUSTR on June 24, 2020, 05:46:03 PM
also jeff ethel said that if you tried to do anything but go straight in a p 47 at under 135 mph you were a fool... not here. but maybe jeff didn't know what he was talking about.. have a great day
Title: Re: P47D11
Post by: Mongoose on June 25, 2020, 08:20:09 PM
Another intresting thing I noticed with P47M/N at Military power 2800 RPM 54" MP The engine burns 580 GPH of fuel, however with WEP engaged bringing us to 2800 RPM and 72" MP fuel consumption actually drops to 552 GPH. This is backwards right? how is more manifold pressure aka airflow through the motor (thus more fuel required to keep the same airfuel ratio even with meth injection) need less fuel?
It's an old topic but this puzzled me as well - one of the Corsairs has the same characteristic. Hitech's answer from 2009 was that "we found out the water cooling of the air let them run a leaner mixture, while at the same time increased efficiency do to lower inlet temperature. Hence more HP for less fuel."
The combination of huge fuel and efficient WEP was the N's secret weapon - on the deck it could WEP almost forever and was faster than anything that had similar range.
Title: Re: P47D11
Post by: Hajo on July 29, 2020, 02:32:16 PM
D11s' were retrofitted with paddle blade props in field. Gabby's D11 was fitted with them in the field as were others.
Title: Re: P47D11
Post by: TryHard on July 29, 2020, 07:37:17 PM
It's an old topic but this puzzled me as well - one of the Corsairs has the same characteristic. Hitech's answer from 2009 was that "we found out the water cooling of the air let them run a leaner mixture, while at the same time increased efficiency do to lower inlet temperature. Hence more HP for less fuel."
The combination of huge fuel and efficient WEP was the N's secret weapon - on the deck it could WEP almost forever and was faster than anything that had similar range.
Right thats all well and good, water-meth injection allows you to run a slightly leaner air fuel ratio and more ignition timing to achieve more power with a given amount of airmass. However we know that we always have to add more fuel with more air even with the same air fuel ratio to keep that ratio consistent.
Manifold pressure = pressure of the air coming into the cylinders and directly related to the airmass the motor is consuming at a fixed RPM. More manifold pressure = more airflow More RPM = more airflow
If you know about ideal gas law or are familiar with "speed density" fuel injection systems you know where this is going.
54" manifold pressure (11.8 PSI of boost) going to 72" manifold (20.8 PSI of boost). Even with the charge cooling from water meth that allows you to lean the mixture maybe 1 point of air fuel ratio. Thats still 33% more airflow through the motor and as such requires 33% more fuel to go with it
Title: Re: P47D11
Post by: Hajo on July 31, 2020, 11:25:34 AM
According to some sources the Paddle prop on the D11 allowed it to climb 300ft./min faster then with the standard prop.
Title: Re: P47D11
Post by: CptTrips on August 03, 2020, 09:08:31 PM
I thought this was interesting watch:
Title: Re: P47D11
Post by: bozon on August 17, 2020, 02:25:01 PM
Is this P47D11 Razorback jug fitted with the early war "toothpick" propeller or the paddle prop from late war jugs in aces high?
I don't notice much difference in climb performance between the D11 and D25
Another intresting thing I noticed with P47M/N at Military power 2800 RPM 54" MP The engine burns 580 GPH of fuel, however with WEP engaged bringing us to 2800 RPM and 72" MP fuel consumption actually drops to 552 GPH. This is backwards right? how is more manifold pressure aka airflow through the motor (thus more fuel required to keep the same airfuel ratio even with meth injection) need less fuel?
Most if not all razorbacks were eventually retrofitted with paddle blade prop. The 56FG had theirs at the beginning of 44.
The paddle blade adds a lot of climb rate and acceleration. You don’t notice this when testing vs the D25 because the 25 is heavier and draggier (bubble canopy and wing pylons). Besides being heavier empty, the D25 carries more fuel, so 100% in the D25 is more weight of fuel than 100% in D11, which is what the charts use, and this eats away the advantage that the prop gives the D25.
Title: Re: P47D11
Post by: save on August 24, 2020, 08:36:29 AM
Not trying to off-rail the P47 discussion, but most plane types had variants that could be refitted within their own series. Axis pervs like me would cry for NO2 injection ""zusatzeinspritzung", available from 1940.
Title: Re: P47D11
Post by: Morpheus on August 26, 2020, 11:26:17 AM
That D11 was alaways very fun ride! has kick butt guns 8x50s and even turned with MOST of the heavily used spit rides out there. I was ever scared to get into a low and slow turn fight in just about any furball that I dug myself into! This ride could turn and even stall fight with darn near any ride in this game. I mean from AH1-AH3. Just sitting here and replying makes me almost want to set my HOTAS up and start fighting and dying for the fun in a good furball. this ride never brought a boring and time to log off or Alt F4 from the game in needs for a fun furball right.
Title: Re: P47D11
Post by: Wiley on August 26, 2020, 11:37:55 AM
I came to love the D11, I would really love to see what the paddle prop variant would feel like. Low fuel and with flaps out, it surprises a LOT of people. The paddle prop would likely surprise quite a few more.
Wiley.
Title: Re: P47D11
Post by: drgondog on September 20, 2020, 07:15:47 AM
From that graph it's hard (for me) to tell the actual difference, because of the strange x-axis numbering, but it appears to be 200-300 fpm at altitudes under 20k. Nothing to sniff at.
- oldman (and thanks for the graph!)
Paddle blades were fitted in January 1944, beginning with 56th FG... well in advance of factory equipped P-47D arriving in ETO.