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-   -   Mods and new cruise speed (https://vansairforce.net/community/showthread.php?t=132749)

grubbat 12-21-2015 06:22 PM

RVX
 
Lance,
Did you buy the RVX?
Cj

judoka5051 12-21-2015 06:27 PM

RVX
 
Yes I did.

hlangebro 12-21-2015 10:04 PM

Answers
 
Hi guys,
I will get back with some answers. I am on vacation until the 27th

Stroh21 12-22-2015 04:21 PM

Silly Question,

You mention you broke 200mph, but the pictures indicate 140-150kias at 7500ft. Is your reference of 200mph the ground speed?

I mostly ask because I normally see 145-155mph indicated airspeed when I'm flying at 11,500ft with a 200mph ground speed and clam winds. I just want to see how my 8 is performing compared to everyone else. :D

cajunwings 12-22-2015 09:52 PM

Mods
 
[quote=judoka5051;1039195]Here's a couple of pics ("I hope" says the caveman) this is a little different than what I did on the RV8A. The 6 exhaust is angled much more sharply down, so no center piece. The ramp that guides the air out of the cowl is likely as responsible as the 'flow straightener', but I'm too lazy to take the cowl of just to get a pic. Sorry about the dirty bottom... been doing a little acro.


Lance: I'm very interested in the exit ramp, please post a pic when convenient. Don

eddieseve 12-23-2015 12:04 AM

Hey Lance

What performance improvement did you notice with the exit fairing extension?

Cheers

judoka5051 12-23-2015 07:21 AM

Picked up 6mph!
 
I did a before and after within an hour, at the same altitude. So, while not 'scientific' it's close. The plane didn't have anything to direct the airflow out of the cowl (unlike the 8). Just the firewall and a sharp 90 degree turn at the bottom. So I added a ramp that is riveted to the top of the cooling exit and curves up to connect to the lower engine mount tubes. I've read many times in different place that it is important to get the exit air 'headed in the right direction' which makes sense. I added the exit fences at the same time, so I don't know which of the changes made the most difference, but I expect it's a synergistic effect.

krw5927 12-23-2015 07:38 AM

Quote:

Originally Posted by cajunwings (Post 1039524)
Lance: I'm very interested in the exit ramp, please post a pic when convenient.

Me too! Thanks!

smokyray 12-23-2015 08:24 AM

Sweet!
 
Quote:

Originally Posted by judoka5051 (Post 1039196)
The other pic that I thought I posted...


The innovation continues....
Nicely done LL...:)

V/R
Smokey

PS:Glad you're enjoying it!

Barbeau 12-25-2015 10:53 AM

Quote:

Originally Posted by judoka5051 (Post 1039568)
I did a before and after within an hour, at the same altitude. So, while not 'scientific' it's close. The plane didn't have anything to direct the airflow out of the cowl (unlike the 8). Just the firewall and a sharp 90 degree turn at the bottom. So I added a ramp that is riveted to the top of the cooling exit and curves up to connect to the lower engine mount tubes. I've read many times in different place that it is important to get the exit air 'headed in the right direction' which makes sense. I added the exit fences at the same time, so I don't know which of the changes made the most difference, but I expect it's a synergistic effect.

Hello
As my English is not so fluent, I'd like to clearly understand what you did speaking about the "ramp". Could you send us a drawing (very simple).
About fences it's clear, but do you thing it could be better to close the bottom between the two fences, and to have two straight exhaust pipe blowing horizontally.
Have a nice Christmas


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