The Muffler Baby

[andrewd]

id just like to know who gets to play with all the muff out there?

do you buy your own, or go crazy and design it yourself?

cause i can see this is a problem for ALL the teams, well maybe all, what types of muffler do you use etc

ciao

[andrewd]

id just like to know who gets to play with all the muff out there?

do you buy your own, or go crazy and design it yourself?

cause i can see this is a problem for ALL the teams, well maybe all, what types of muffler do you use etc

ciao

[jack]

turbo's not only make good mufflers, but add power too!

jack @ WWU
http://www.etec.wwu.edu/

[Daves]

Dboi, the most popular muffler is the Yoshimura, and they have a discount for FSAE teams. If you search this forum for "muffler" you will see their advertisment. It's about $178 for a Yoshi.

Other popular mufflers are Vance & Hines, Hindle, stock Yamaha, Supertrapp, stock Suzuki, and Micron.

For more information from the people of this forum, please see Topic: Noise Testing Results (Muffler Comparison) (http://fsae.com/eve/forums?a=tpc&s=763607348&f=125607348&m=9906028253)

http://www.letu.edu/formula

Formula Photos & Links (http://what3542.5u.com/dave/fsae/formula_photos.html)

[Daves]

Jack,

The rules do state that a muffler is required, so I hope you are using a muffler in addition to your turbocharger.

http://www.letu.edu/formula

Formula Photos & Links (http://what3542.5u.com/dave/fsae/formula_photos.html)

[James Waltman]

Rule
3.5.5.1 Muffler Required
The car must be equipped with a muffler in the exhaust system to
reduce the noise to an acceptable level.

Definition from Dictionary.com:
muffler: A device that absorbs noise, especially one used with an internal-combustion engine.

Our device that absorbs noise is a turbo. The rules don't say that the muffler has to have baffles or fiberglass packing. We just need to be able to meet the noise requirements outlined in the rules.

James Waltman
http://dot.etec.wwu.edu/fsae/
Vehicle Research Institute at
Western Washington University

[Daves]

Just in case, please ask SAE if a turbo constitutes a muffler before you get to competition and find out you have to plug one of your outlets and use your naturally-aspirated muffler with your turbo.

Another item I've wondered about are "tire warmers." Do they consider the radiator and exhaust tire warmers? Can these be used to heat the tires?

http://www.letu.edu/formula

Formula Photos & Links (http://what3542.5u.com/dave/fsae/formula_photos.html)

[Mechanicaldan]

http://fsae.com/eve/forums?a=tpc&s=763607348&f=125607348&m=8716047225

As I stated in the above post, Ebay is great for finding mufflers cheap.

Other than for the true learning experience, I think making a muffler is a waste of time. Spend the time making the rest of the exhaust header and system, but buy a muffler.

Here's a tip if you haven't thought of it. Use the stock primary runners from a stock header, and them make your own collector. The stock collectors usually have internal perforated sheet for noise reduction and weight addition. Just cut it off and start from there. It's best to make a jig for the head end so the pipes don't move, and use something to clamp and hold the 4 tubes together at the other end.

Cyclone Racing
www.cyclone-racing.com (http://www.cyclone-racing.com)
Iowa State University
Project Director

[MikeWaggoner at UW]

Muffler required; they should just bring an emergency aesthetic muffler if it's required. A real one would add too much weight.

Muffler tire warmers; I'd be nervous about using them, since some tires overheat in hot weather and long drives; this is also when the car would be at peak heat producing capacity. Also, since you can't fare the wheels wouldn't you end up with heat concentrations when static?

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by James Waltman:
_Rule
3.5.5.1 Muffler Required
The car must be equipped with a muffler in the exhaust system to
reduce the noise to an acceptable level.

Definition from Dictionary.com:
muffler: A device that absorbs noise, especially one used with an internal-combustion engine._

Our device that absorbs noise is a turbo. The rules don't say that the muffler has to have baffles or fiberglass packing. We just need to be able to meet the noise requirements outlined in the rules.

James Waltman
http://dot.etec.wwu.edu/fsae/
Vehicle Research Institute at
Western Washington University <HR></BLOCKQUOTE>

[Daves]

For the exhaust tire warmers, you could use a 90 degree elbow that you can aim at the tires only on cold days. For noise testing, angle it at the ground. For hot days, angle it at the ground or up away from the ground vertically. As long as the parts do not change, it seems like it would be legal (unless it's considered a "tire warmer." The other tire could have the engine jacket water radiator blowing hot air onto it. A drawback would be if you have flames coming out of your exhaust like many schools do.

http://www.letu.edu/formula

Formula Photos & Links (http://what3542.5u.com/dave/fsae/formula_photos.html)

[jack]

everybody assumes that FSAE cars run cold tires all the time--i dont really know why. the back tires should be really easy to warm up at the begining of any event: spin the wheels!! the problem is FRONT tire heat! its the front tires that dont warm up enough--relative to the back tires, until the car has been run for a while.

that is why we have decided to put our radiators in front of out front wheels. http://fsae.com/groupee_common/emoticons/icon_wink.gif

jack @ WWU
http://www.etec.wwu.edu/

[A Reinke]

from the other topic:

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>As a rant, the sound test is complete and utter bullshit. Hardly any Gixxers could pass the test because the RPMs were so high. Many schools that passed the test(with Gixxers and other engines) were not at the proper RPM, as per my ear tachometers. Anyone else notice this?
<HR></BLOCKQUOTE>

i hate this event too. if you accidentally rev OVER the limit set, and go past 110 dB, you fail. and you can't set your limiter for the number they give you, and floor it, cuz it'll fail too! http://fsae.com/groupee_common/emoticons/icon_mad.gif

we used a 2001 Gixxer with a SSR-2 Vance and Hines carbon fiber. repacked it, and it still failed...had to make a baffle from an aluminum plate to pass.

~Adam

[Big Daddy]

I have a question. What happens when your engine redline is 2000 rpm lower than what that formula tells you your engine will be tested at. If your engine will not physically reach that limit what do they do????

"A woman is a lot like a beer, they look good, smell good, and you would run over your own mother to get one." Homer Simpson

[andrewd]

yes we noticed that too, they say its tested fast weighting,

which by now we know means averaged over time

and this time bracket is quite long,

if you have no limiter set, then whats to stop over revving? and hence more dbs

[Belo]

I'm sure this noise test should be discussed seriously because they way they do it really is a joke... We went from 136 dB to 108 last year in Detroit by using steel wool !!! which is about 400 times quieter!!! it was good quality steel wool I might say hahaha

Drive it thru the carwash!!!

[Charlie]

How exactly is it a joke? Are you saying they are just totally wrong with thier measurement or what?

I think the noise test is very valid and works well. If you have a rev limiter below the required RPM test range, you have to remove it, plain and simple, to pass noise. If you can't hold your RPM steady for a few seconds, you have tuning problems.

-Charlie Ping

I just need enough to tide me over until I need more.

[Sam Zimmerman]

Of all the events, I do not see where the sound test would be considered a joke. What is a joke, though, is the number of people who show up for competition and are unable to pass it. Just like the brake test, it is clearly outlined in the rules and should be put to rest well before the time competition rolls around.

Having said that, there was more than one team who obviously used steel wool last year and had it blown out before the end of the autocross. The real joke would be if the event organizers failed to black flag all of these teams like they promised they would in the team captain's meeting.

Sam Zimmerman
Vandals Racing (http://www.uidaho.edu/~racing)

[Big Daddy]

My question was that I know of a 600cc v-twin that redlines at 5500rpm. When I did the numbers in the formula it said that it would be tested at 8950 or somthing of the sort. If you revved that engine to that rpm you would have a connecting rod embedded in the asphalt. So how would they treat that, an engine that cannot be physically run at the required rpm.

"A woman is a lot like a beer, they look good, smell good, and you would run over your own mother to get one." Homer Simpson

[Charlie]

Seeing as the formula is based on piston speed, I find it really hard to believe there is a disparity that large. I guess I'd have to see the example engine and your calcs. I don't think there will be an engine with a stock redline below the RPM test limit.

-Charlie Ping

I just need enough to tide me over until I need more.

[Ryan Schoffer]

pretty easily - think of the piston speed n a car engine, that uses large pistons and has a 'low' redline

Vehicle electronics leader

www.ucalgary.ca/fsae (http://www.ucalgary.ca/fsae)

[Big Daddy]

Calc. Test Speed= (914.4X1000)/(2Xstroke)
First off let me say I was a little off in remembering my numbers as it was a while ago when I first did the calcs.
The stroke is 77mm on this engine. Therefore
914400/154=5937rpm round that and its 6000rpm for the noise test.

From the factory this engine is not suposed to run over 3600rpm that is the factory recommendation. With severe modifications you can push this to 5500rpm. An engine builder said that he would not run it over 5000rpm for more than a few seconds.

With modifications this engine is still 500 rpm short of the required limit. Also what happens if a team can't afford to modify this engine and can't rev it over say 4000 in stock trim?????

In this case I would hope that the judges would realize that it is physically impossible to rev the engine that high without failure and allow you to test at your rev limit.

"A woman is a lot like a beer, they look good, smell good, and you would run over your own mother to get one." Homer Simpson

[Andy K]

Don't know what the big problem is... we designed and built our own CF/SS muffler. Not too complicated either. It's a stubby little thing at about 8-10 inches in length, but we passed with flying colours.

Then again the turbo may have helped... http://fsae.com/groupee_common/emoticons/icon_wink.gif

Andris Kanins
McGill Racing Team
2002/2003 Body Design
2003/2004 Suspension

[Belo]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Charlie:
How exactly is it a joke? Are you saying they are just totally wrong with thier measurement or what?

I think the noise test is very valid and works well. If you have a rev limiter below the required RPM test range, you have to remove it, plain and simple, to pass noise. If you can't hold your RPM steady for a few seconds, you have tuning problems.

-Charlie Ping

I just need enough to tide me over until I need more.
<HR></BLOCKQUOTE>

I m not saying the test itself is a joke I'm saying the way they measure it isn't precise... If you don't agree can you give me a logical explanation on the fact that we had a 28dB difference between 2 tests??? I personnaly don't get it... and the angle and distance from the exhaust can have a great effect on the results shown by the type of sonometer they use...

Drive it thru the carwash!!!

[Daves]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>From the factory this engine is not suposed to run over 3600rpm that is the factory recommendation. With severe modifications you can push this to 5500rpm. An engine builder said that he would not run it over 5000rpm for more than a few seconds. ~ "Big Daddy" <HR></BLOCKQUOTE>

I have never heard of a motorcycle engine with such a low redline. Was it made for a motorcycle? What engine is this? You said it's a 600 cc V twin. Even a Ford Mustang revs to 6000 rpm.

http://www.letu.edu/formula

Formula Photos & Links (http://what3542.5u.com/dave/fsae/formula_photos.html)

[Mechanicaldan]

SAE Mini-Baja motors rev to 3600. Also lawn mowers, garden tractors, etc...but they also make 8-20 hp. http://fsae.com/groupee_common/emoticons/icon_frown.gif

Cyclone Racing
www.cyclone-racing.com (http://www.cyclone-racing.com)
Iowa State University
Project Director

[Big Daddy]

yeah but Harley v-twins dont rev that high it all has to do with cylinder arrangments.

"A woman is a lot like a beer, they look good, smell good, and you would run over your own mother to get one." Homer Simpson

[aem8927]

This is true Big Daddy, but you also need to remember that the HP numbers posted by these great Harley engines as not near as much as that by the sport bikes. That along with Harley's refusal to run anything short of, shall we say a normal firing order, makes those things a "pig" to ride. As a motorcyclist I would never ride a Harley for that reason alone.

Now as far as your engine choice goes, the Briggs ohv v-twin, may or may not be the best fsae choice. However I am willing to bet that if the build quality of your fsae car is anything like the independent rear mini-baja car you built last summer, we all have nothing to worry about.

Adam

Proud Alumni of TTU FSAE

[Charlie]

if it's 'factory recommended' to run 3600 RPM, it's likely governed to that and sounds like an industrial engine. They can rev much higher than thier almost 'infinite steady state life' speed. I took a 5 HP 1 cyl Briggs to almost 10k and there are guys running higher too.

That said, if you end up in that situation, you can probably get an OK from the rules committee BEFORE competition through the normal channels-- I wouldn't count on getting one at the competition.

-Charlie Ping

I just need enough to tide me over until I need more.

[Big Daddy]

Adam,

I guess its nice to hear from you but I can't really tell through all that sarcasim. But your right about that engine choice you see there are some teams out there who try to push the edge of automotive design by trying off the wall ideas. Like Queensland, or the school with all wheel drive but you see the reason most teams dont try new things is because of people like you who make fun of thier designs before you even know if they will work or not. My engine choice is based off simplicity rather than horsepower. Its air cooled, weighs 65 lbs with an ally fly wheel, can put our 65 hp with carbs and a fixed ignition(imagine what it will do with fuel injection and electronic ignition), plus this thing has more torque at 16 hp than alot of the formula cars already have. Those are just a few reasons. Now bashing my independant rear suspension car that is just distasteful. I have said nothing about the formula team at TTU and I believe that you are just jealous that in my three years on Baja I have 3 First places, 1 Third, 1 Ninth, and 2 Mini Baja Team of the Year awards. Me and some of the other team just wanted to try something different to push ourselves as engineers is this wrong I seriously doubt it, as most professionials I have talked to about funding have liked the idea tremensly.

Charlie,

I agree with what you said but these twins are a different animal than singles. The 5000rpm line was given to me by Clements Racing who builds the baddest cart engines in the nation. They blew a couple up at 6000rpm and this is with billet connecting rods and fordged pistons. So I believe I will take thier word for it. http://fsae.com/groupee_common/emoticons/icon_wink.gif

"A woman is a lot like a beer, they look good, smell good, and you would run over your own mother to get one." Homer Simpson

[aem8927]

Big Daddy,
As I read back through my post I realize that what I said may sound like I was making fun of some of your formula team's choices, on the contrary, as far as I'm concerned you can choose to run any engine/drive/suspension/whatever combination you want. I was more saying that I dislike Harley engines, and think Harley is a bad comparison for this competition.

Now as to the assertion that I am jealous of your team's wins in mini-baja, yeah probably, but only because of the ease it allows that team to do the things it wants to do through its notoriety within SAE. That being said I am not envious of the fact that the same car is built year in year out by that same winning mini-baja team. Also I was only saying what everyone in the shop, even on you team, was already saying.

Adam

Proud Alumni of TTU FSAE

[Big Daddy]

I may agree with you one some level but the fact remains that I (and a few other people) share an off the wall idea that we plan on making a reality. Will it win FSAE I doubt it, will it win Mini Baja I doubt that too but will it turn a few heads at both competitions I think so. The only thing that both competitions require is that you finish all events to place in the top quarter of the field. That is what I am persueing, not to win but to broaden my own horizions as it relates to SAE and cars. Sorry that we got a little off topic. Adam we can continue this in a private topic I will set up. This ISN'T the place to air our differences. http://fsae.com/groupee_common/emoticons/icon_biggrin.gif

"A woman is a lot like a beer, they look good, smell good, and you would run over your own mother to get one." Homer Simpson

[Test Driver]

BD

Do you have pictures of your car with the Briggs up anywhere? Sounds interesting to me. Are you using a CVT? If so, what kind and how much weight will the CVT add?

Ramon

[Big Daddy]

I am working on posting some pics, yeah uses a cvt and a belt drive which the pulleys are being made now


Here try this.....

http://www.imagestation.com/album/?id=4288072767&congratulation_page=Y



"A woman is a lot like a beer, they look good, smell good, and you would run over your own mother to get one." Homer Simpson

[This message was edited by Big Daddy on January 08, 2004 at 10:04 AM.]