fastfredy

What are the muffler requirements for Club 40? Are there any stated demensions for the stinger opening as was used at the Alabama race? As stated in the race thread the GO was .297 and the NO GO was .303. I checked my stash of stock mufflers and they checked as follows, 3 measured .250 and 3 measured at slightly less at .240. In Texas they are supposed to be stock un-modified with baffles. The mufflers must have been modified to get to a GO of .297 like was stated for the Alabama race?
In addition, I found that the new style cone baffles were about 3 to 400 rpms less and the brand new ones that I have are around the .250 demension []for the stinger?
What demensions will be used at the Waco Nationals and in the future for RCPRO club 40 racing?
Fred French

skull1971

That is a GREAT question Freddy!! and thanks for the rpm info.

THRL-CKER

Let me do some more checking, but you are probably correct the measurment will be given for a drill bit passing completly through the stinger. But just because yours might be a bit smaller does not mean you can drill it out!

I will also give a carberator size also.

These sizes will be given from drill bit sizes so no special gage or equipment will be needed

JohnMcGowan

My Feedback: (15)

Hi Freddy,
the measurements that were taken from Tim's, (aka Battman) new mufflers were used for him to machine the go-no go gauge. I also have a g/ng gauge from him and the go part of the gauge can be inserted into the muffler outlet by about a 1/4 inch, then it stops due to the ID of the outlet being tapered down toward the exit. The mufflers had not been altered in any way beforehand so the measurements that were provided earlier are indeed correct. Remember, it needs to be STOCK and no drilling.
We've only had one guy locally who "tried" to pass thru inspection with a drilled out stinger a couple years ago but he was busted on the spot and was told that he could not run the muffler that day during a race.
This would be the same P.O.S guy who has attempted to cheat at other flying events yet screams out that everybody that beats him fair and square in Club40 is a cheater. You all know who Im refering to. Will wonders never cease?

gefisher

My Feedback: (2)

Man John you didn't have to bring me into this! I didn't think the drill bit was that big.........[X(]

skull1971

Man Gary I'm glad you got in the line of fire for me on this one!!

fastfredy

Thanks John, So what your saying is that the go guage that was used at Alabama was only supposed to go about a 1/4 of an inch into the tapered openning? I believe that this would allow some mods to the actual openning further into the taper? I also found that the NO GO .303 would just go in maybe a 1/6 of an inch. I think that Jim McQuin is correct in measuring the actual openning, at lets say, .250 inches. I also had a conversation with Bob P. and he was thinking like me that maybe a .265 No Go with a .250 Go would make more consistent measurements and make everyone closer to the same size?
I can't get no satisfaction, size does matter!
Fred French

JohnMcGowan

My Feedback: (15)

Thats correct Fred.
I hear you on what you are saying about someone maybe trying to mod the taper on up inside the muffler, but even if they did, what would that gain them if the last part of the taper exit is the correct size. Know what Im saying ?

BarryReade

My Feedback: (1)

It has proven that any mods to the TT PRO 40 muffler slows the motor down. The difference between the plate and cone baffles arenegligible. When Jim Duda did the testing a couple of years ago maybe the the cone baffle was 50 rpm slower. It has been proven that changing the stinger size and removing the baffles slows the engine down.

fastfredy

John, the problem is that the stock hole in the stinger is around .240 to .250 and using a .297 go guage doesn't really check for any mods to the taper. What I would recommend is the .250 for the go and maybe a .265 for a no go. This would give the racer the ability to check there mufflers with the shanks of a 1/4 inch and 17/64 th inch drill bit.
I was using a new cone muffler at Alabama and Hico, I couldn't figure out why I was much slower than at other races. After doing some checking at home I noticed that my new cone mufflers were noticeable slower on RPM. Until then I didn't even know about the cone style of mufflers vs the old waffle baffle.
Consider this, a new TT-40 with the cone muffler is not as competitive. I hope someone proves me wrong, but after 50 years of experience with RC performance engines I know what I'm seeing. Maybe we should consider a larger openning on the cone mufflers to improve performance/competitiveness against the old style mufflers? I say this because the first thing I noticed was the difference in the needle settings which were not as broad a range as compared to the old muffler, this is due to the increased back pressure (the cone)resulting in more muffler pressure.
Let's think about the new guy or the current racers that are out of the old mufflers? Luckily I have 2 of the old ones. Lets race.
FF

skull1971

I know that Jason Oliver had a cone muffler, and whipped us several times.

Bozarth

My Feedback: (15)

Wow! We race Skyraiders here in Colorado and we all voted years ago to fly an extra round instead of spending all that time checking everyone's engine, tach readings, mufflers, etc. It was evident that the winners flew the best course, and no one had an advantage because their engine turned an extra hundred rpms or so. If there is a unknown cheater among us, he/she isn't cheating very well because no one dominates.

www.airparkelite.com

Kurt

fastfredy

Kurt, sounds like you guys are having fun in Colorado. My 12 hour trip to Alabama wasn't very fun because I got my doors blown off and most that attended would say I can fly the course as good as anyone. If your coming to the Texas Nationals then maybe you need to be more competitive and check out the differences in these mufflers. RPM does make a difference along with the RPM unload in the air.
FF

Bozarth

My Feedback: (15)

Sounds like a lot of those guys are ready to start flying 424/426/422! Best of luck to you.

Kurt

Tbatt

My Feedback: (4)

Rick Grim and I discussed what to do about the muffler outlet and decided that a visual inspection works best. If the outlet has been drilled out it will be easily detected due to the surface finish being different. I think that the stock mufflers are bead blasted to give them a satin finish. That would be very hard to duplicate on the inside of the out pipe.

My 2 cents....
Tim

airraptor

My Feedback: (66)

You should rethink that. lol a quick blast would be easy to do on the outlet.

squidman

My Feedback: (2)

One would only have to bead blast the drilled portion. Next !![]

skull1971

Well we had a few caught with their hand in the cookie jar, so to speak.

vicman

My Feedback: (10)

I would be happy to offer bead blasting services to those in need of speed.[>:]

skull1971

I've got three I can send right now, what the approx turn around time?

twitte1

FF,

I was at the Tuscaloosa race also. While I have not seen the offical times, I saw that I ran 1.26 in one of my heats. I know some went faster. I specifically use the cone. I have them in each of my Club 40 planes and my 424 planes. I do not believe there is a big difference in performance.

Trey Witte

JohnMcGowan

My Feedback: (15)

As Barry Reade commented to earlier, Im in agreement that there is just not a game winning difference between the two type baffles. Its basically how good a person can fly the poles as to how he ends up at the end of 10 laps, just my opinion, take it for what you paid for it . You fly sloppy and get outta whack like me sometimes and you get passed and get beat, thats about all there is to it.

Ken Erickson

Sorry that this isn't about mufflers.

I wholeheartedly agree with Kurt. When we started this, we intended/hoped that those who really felt the competitive urges ad proven ability to win would "move up" to 424.

Trouble is, it is going to take someone with access to a field which can support 424 and the willingness to do the work, worry and stress to get club permission and then put together races.

Come on you guys who have been enjoying being the winners in RCPRO Club 40, perhaps it is time to do a little "Pay it Forward" and be the guy who gets "Entry Level Pylon Racing" going in your area. Give the "Hot Sticks" the chance to add 25 to 30 mph to their enjoyment.

As for me, I have worked 5 years to get "Introductory Level Pylon Racing" going here. It is happenning. Maybe we will be able to do 424 in 4 more years. I know the field to do it.

Ken Erickson
RCPRO National Rules Committee Chairman

vicman

My Feedback: (10)

For you guys who blew your stingers oversize I also happen to have a swedge die to bring it back in tolerance.

fastfredy

OK Eric your full of bull again, Jason Oliver was not using a cone style of muffler. Can we believe anythtng you post?
FF