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Rod Bower's RAM air system

T

Tom Martin

Well Known Member
Over the last month I have been working with Rod Bower, http://www.ramairforhomebuilts.com/ , doing some testing using his system on my EVO Rocket. We first used his standard air box and air valve and for my installation it was not quite right for the 540 engine. The filtered air was too restricted at high power settings and the ram air valve was also a bit undersized.
I use a chase plane, Wayne Hadath in his rocket, to determine the effectiveness of any modifications that I make to my plane. In the past, at altitudes of 8000 feet I used to show half an inch more manifold pressure then Wayne did. When I first installed the RAM air system I was not seeing any real improvement on those numbers compared to my previous system. Rod rose to the challenge and had a larger air box with bigger reed valves made. He also got a larger RAM air valve that has helped with flow. Yesterday Wayne and I did another test and I now have a full inch more MP then he does for an honest improvement of half an inch of MP using the RAM air system. With my previous filtered inlet setup I had not flown beside any other rockets that had a greater MP,so improving on that one is a real improvement.
The filtered take off performance is now on par with my previous system but when you open the RAM door you can feel and hear the difference. Thank you Rod for going the extra mile to make this system work properly with my engine.
 
Tom,

Was this improvement that Rod made something that would benefit all IO-540s, or something unique to your Rocket?

I know that Deems Davis just started flying a couple weeks ago with one in his RV-10.

I'm just curious if this is a one off improvement or something across all I)-540s.

thanks,

bob
 
Bob
I believe all 540s would benefit from the modifications that Rod has made to the system. I know I saw an improvement with his system over my previous setup after he made the changes. I am not sure that any one has flown a stock RV10 system and then compared it with a Rod Bower system. Rod has a nice cowl inlet kit to modify the cowling of RV10. I had to make my own for the EVO and it was a lot of work. I think that his setup might even be easier to install then the stock airbox.
 
I ordered a system from Rod in April for my 7. He told me that he was in the middle of improving it and I would get the first unit for my airplane. It shipped Friday so I'm anxious to get it on the airplane. He also has a molded scoop for 7s and 8s. Don
 
Me too!

I have one of Rod's RAM systems for my -7. Bought it last summer and should know how it works in a month or two.
 
An inch of boost is worth 2% of indicated airspeed.. In a Rocket that indicates 180 kts at 23/23 if you can do that at 9K instead of 8K that means 3.6 kts of TAS gain.

Ole '84 on a 30" day can show 23" at 9K which is incredible boost..... That is the combination of the incredible pitot cowl that Mark built and the Barrett cold air induction system. 23" at 9K is about a 2" boost..... that is 7 kts TAS.... Do you know how much HP it takes to increase TAS by 7 kts???? Answer, a bunch......

Many builders and flyers do not understand the importance of flying at the optimum altitude..... It is a huge benefit to speed and efficiency......

Spend the extra time to get the induction system right.... There are major benefits to be had from cleaning up this area and maximizing the breathing potential of your airplane....


Tailwinds,
Doug Rozendaal
 
Well Tom if you say so it must be true

Our various experiements and similar conclusions cause me to trust what you say. This looks like a major research and development effort for me but you've got me thinking. Larry Vetterman's initial design on the cowl outlet fairing (and closure) with cooling air outlets around the new widely spaced exhaust pipes is another task in the queue. I'll see you in Courtland, Alabama in a couple of weeks and that should be a MOVING experience. The straight line speed dash against Wayne and at least two other Rockets will be something to see.

Bob Axsom
 
Bob
I too am looking forward to the trip to Courtland. This will be not only my first race of the year but my first cross country for the season. Weather issues aside we would like to arrive on thursday so we can have a day to look around.
 
Ram Air For Homebuilts

Tom thanks again for the in flight analysis. This condition was suspected on the 540's and having you confirm really says alot about the actual in flight test. When compared to another friends aircraft in flight it can show even subtle changes.
I became suspicious during a dyno run at LY-Con on a 540 and had already arrived at the same conclusion. Your test of my solution proved to be what the doctor ordered.

I am currently working on a "vertical sump modification" to address the forward facing servo application. The only solution for the 540 is to use the COLD AIR Sump and that can get alot expensive.
I will have the billet prototype sump modification by tomorrow. This will effectively create a low profile 90 degree plenum and address the pressure drop caused by the currently available 90 elbow sold by AIR FLOW Performance. Don at AIR FLOW said there was too much pressure drop for the 540 to use the 90 degree elbow and agreed that this will fix it.

This should provide a good alternative to the expense of cold air induction and compare favorably with forward facing sumps. Way less expensive.

This has been mocked up on a RV-6 and a RV-10 and I have made the molds for the lower cowl modification.

I now have systems for the RV-6,7,8,9 and the 10.

Look for a spread sheet comparison on the various induction choices for the 540 starting with a stock 540 and Van's airbox/filter as a base. This will be done at LY-CON's engine test stand/dyno

Rod Bower
 
Rod,

Did I hear correctly that you have a solution for a vertical intake rv6/7? If that is the case, could you post a picture of it and give a little more information. I have a vertical induction RV7, and would like to convert to AFP injection, and use your intake, but I have been scratching my head on how to do it.

JC
 
John, get in touch with me on my email. [email protected]. You will like the lower cowl mod as it moves the inlet induction ring right up to the base of the spinner flange. I have pictures of the FM-200 install. Rod
 
RB Ram inlet and fairing modification

Tom Martin said:
Bob
I believe all 540s would benefit from the modifications that Rod has made to the system. I know I saw an improvement with his system over my previous setup after he made the changes. I am not sure that any one has flown a stock RV10 system and then compared it with a Rod Bower system. Rod has a nice cowl inlet kit to modify the cowling of RV10. I had to make my own for the EVO and it was a lot of work. I think that his setup might even be easier to install then the stock airbox.
Click to expand...

I have a standard RV-10 intake into the IO-540. I just reached out to Rod for the kit. I will collect data from both systems and let the forum know how it went.
 
rcoleman-10 said:
I have a standard RV-10 intake into the IO-540. I just reached out to Rod for the kit. I will collect data from both systems and let the forum know how it went.
Click to expand...

Yep, excellent.

Filtered vs filtered on the takeoff roll is a direct comparison, given (hopefully) equal conditions.

Be sure to record pressure altitude (set 29.92), OAT, and a true airspeed for anything involving ram.
 
rcoleman-10 said:
I have a standard RV-10 intake into the IO-540. I just reached out to Rod for the kit. I will collect data from both systems and let the forum know how it went.
Click to expand...

If possible, can you post pics / summary of the install? I?m curious about this as well.
 
I wouldn't think it would be a good idea to run un-filtered air unless I was racing and max MP was the only goal. Dirt and bugs do exist above the runway (the dirty air filters I throw away every year are evidence of that).
 
Walt said:
I wouldn't think it would be a good idea to run un-filtered air unless I was racing and max MP was the only goal. Dirt and bugs do exist above the runway (the dirty air filters I throw away every year are evidence of that).
Click to expand...

Next time you're cleaning your canopy, look at any surface on it with the same number of square inches as your engine air intake, and consider that. :eek:
 
This is an old thread, but with the new interest I thought I should give an update. As I am no longer racing I do not need every last bit of MP.
I built an air box that was longer then the bower system. I built the container to fit the largest air filter, with the deepest pleats (more surface area) that I could find.
The filter worked really well with very little loss, if any, in the system, compared to the bower air box. To provide a source of alternate air I used the same sort of inlets on the canister that the original had. I did not need as many holes as this was just to help with that plastic bag on the runway that we worry about. The system would not provide alternate air in an icing or snow situation.
I am happy with my current system as I have filtered air all the time and on less knob to worry about.
 
Thanks Larry.

When Jon and I finish the panel upgrade I might want to fly down and look yours over.

Plus he's mentioned a race to compare our 3 different props :D
 
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