Noise control enforcement

[404namenotfound]

I'm going to send an email to the rules committee about this. Before I do that I would like to get feedback from the forum here on what can be done about this.

We all know there are teams that blatantly cheat with sound. Its legal to change engine calibration, and that can make a car louder, but that can only do so much.

My solution is to use tamper tags like those used on water meters on the muffler. That would make it difficult for teams to "uncork" the exhaust after tech. If any team sounds too loud throughout the weekend the tag could be checked on track if they're within a reasonable margin of the noise limit.

Does anyone else have any solutions?

[Mumpitz]

Endurance corner workers should be able to flag a team for being loud in endurance but allow them to keep running. Then retest sound after fuel refill. The station is right there, takes 10 minutes. OK fine some muffler packing burnt up over the weekend give a couple dB of wiggle room but should put the possibility of cheating to rest. If you go through sound test on Wednesday sounding like a lawn tractor and come out Saturday sounding like the Harleys that piss me off all summer there ought to be some eyebrows raised. Would a team be allowed to keep their score if they were found to have a 21mm restrictor at the end of the comp? What's the difference between swapping restrictors and swapping muffler components?

And for anyone that thinks that the noise test is a bs part of FSAE, have fun with that attitude in the working world.

http://www.camaroperformers.com/project-cars/magazine/camp-1005-2010-chevy-camaro-ss/photo_03.html

[mdavis]

I actually like Mumpitz's solution, but I would say that if you fail the post enduro noise test, all of your enduro/fuel points are taken in penalty. Even if the post enduro noise test is 112db instead of 110 to account for muffler packing burning up or something (there's nothing that says you have to run muffler packing, so there could be an argument that there should be no allowance for that), the teams that are cheating would definitely fail at that value.

-Matt

[Chris Head]

The db limit in fsae will always be cheated. We work on these cars all year long, and if running at competition vs not running comes down changing the map a little,you can be sure any team will. You can argue that teams should engineer the engine and exhaust to
pass before arriving to competition but from my experience decibels can be affected by a number of factors outside of the students control. For example, two years ago we tested our noise at least 3 time before competition. Passing by at least 2 db on all occasions. We were running an exhaust that was advertised as being one of the quietest available but upon arriving to competition we failed sound by around 5 db. We took the car back to the pits and tested it with 3 other teams meters getting different readings across each
meter. And as far as racing goes FSAE is one of the quietest. Im not saying that i condone cheating of any kind but maybe decibel ratings should be reevaluated to see if they are appropriate for the engines we are running.

[mdavis]

Chris, changing the engine map is legal. Changing the muffler or adding/removing plugs is not. Teams that do the former are completely within the rules. Teams that do the latter are not. I have no problem with the teams that change maps, but the teams that blatantly cheat by adding/removing physical parts in the exhaust and the resulting changes by the rules committee that punish the teams that make legal changes for the actions of teams making illegal changes that I have a problem with.

-Matt

[LewisKoberg]

Matt,

As opposed to slandering other teams and accusing them of cheating, why don't you simply bring it up with them and voice your concern when you are there at competition. Making false accusations and generally whinging about it is something better left at the grade-school playground.
Furthermore, if you have spent the year designing an exhaust system capable of 100 dB at any RPM and load condition, I applaud you, but do not feel cheated when others focus their time on other things and are content with a solution that allows them to pass under the 110 dB limit, however close.

Lewis

[Jay Lawrence]

This sounds like the sort of thing people would go after when every other aspect of the competition is completely sorted. If you can buy an off-the-shelf, legal for the road muffler and still fail noise (which my team has also done in the past), surely there is something wrong with the noise test?

As for penalties, let's assume a 112db muffler gets 2kW more than a 110db muffler. Anyone have a points value for 2kW?

Seriously, if you think it's too loud, wear ear muffs.

[MarkSchaumburg]

The biggest problem that I see with the sound test is that it is very susceptible to factors that don't affect the overall/ambient sound level you hear on the track.

I agree with Jay though. There are much bigger problems to tackle than teams "unpacking" their mufflers after sound.

[Bemo]

In general I'd say at least in Europe teams should be careful with changing their muffler setup after passing noise. At FSG last year we had a couple of teams rechecked after Endurance if they seemed very loud. There was no team disqualified. At the rechecks minimal violations (like let's say 2dB too loud) were accepted. As you have to accept that the noise testing as it is done is quite inaccurate and it is possible that a car is measured a bit higher without any changes at the car just because of wind and other effects.

It is not surprising that some of the cars seem to be much louder on track than others while using the dBA rating. For noise levels like the noise of a FSAE car dBA isn't consistent to human hearing. Does anyone know if they already used the dBC rating at MIS this year? This should be closer to human hearing.

[404namenotfound]

I like the idea of allowing a bit of wiggle room and doing a second noise test at competition post fuel measurement for teams that sound over 110 dB, maybe give them up to 112-113 to catch the people who are really cheating.

The reason I think this is worth the effort is not because of the power gain from but how much less effort sound is if you know you're just pulling the plug on it after it passes. Its easy to say you're not worried about power in sound or being rules compliant after, stuff one or two plugs in the muffler which really do hurt performance, and then pull them out after sound. At the same time its a lot more difficult to actually design an exhaust that passes sound, especially if you're a single team. That effort could be spent elsewhere. Then it becomes a matter of do you want to spend time building something that''s actually rules compliant or just BS sound. I don't think its right to be putting students in that position given what the goals of this competition are.

I can think of at least one top team at MIS this year that had a very loud single that was significantly louder after sound. If that was just the difference between dBA and dBC that's fine but I doubt that and would have liked to see them rechecked and not cheat if they were.

[Mbirt]

Matt,

As opposed to slandering other teams and accusing them of cheating, why don't you simply bring it up with them and voice your concern when you are there at competition. Making false accusations and generally whinging about it is something better left at the grade-school playground.
Furthermore, if you have spent the year designing an exhaust system capable of 100 dB at any RPM and load condition, I applaud you, but do not feel cheated when others focus their time on other things and are content with a solution that allows them to pass under the 110 dB limit, however close.

LewisSpeaking for myself here, I didn't say anything at FN 2013 after hearing the car ring loud all the way from the practice area to inside the arena because I knew that the off-the-shelf silencer wasn't going to give the offending competitor a performance advantage, especially when exhaust backpressure wasn't the weak link in the competitor's powertrain. The only damage done by a car that had been ridiculously loud at two competitions in a row was that it bolstered the rules committee's switch to the dBC scaling that will likely be used next year. As a nearsighted and friendly competitor, this didn't motivate me to make a big deal about a loud car that posed a threat only to eardrums.

[mdavis]

Matt,

As opposed to slandering other teams and accusing them of cheating, why don't you simply bring it up with them and voice your concern when you are there at competition. Making false accusations and generally whinging about it is something better left at the grade-school playground.
Furthermore, if you have spent the year designing an exhaust system capable of 100 dB at any RPM and load condition, I applaud you, but do not feel cheated when others focus their time on other things and are content with a solution that allows them to pass under the 110 dB limit, however close.

Lewis

Lewis,

I didn't say anything at competition because I personally do not care if you (or anyone else) cheat the noise test. Does it make watching the competition slightly less enjoyable? For me, yes, but I have very sensitive hearing. Again, it's something that I can live with, so I don't really care. The problem I have with it is when the rules committee sees/hears cars on track that are well over an acceptable noise limit, and immediately thinks that the car is in the same configuration as it went through noise (which is per the rules) and therefore the rules must be changed because the car is too loud on track.

As for our exhaust, we had an OTS flow-through (absorption type) muffler that we had run since we switched to a single in 2012 (new parts, but the same model). Our thought process was that there are much lower hanging fruit in terms of performance than spending a lot of time developing a system which may only provide minimal gains. Our theory was "buy a muffler that we know works well, then massage as necessary to pass sound at ~110dBA".


In general I'd say at least in Europe teams should be careful with changing their muffler setup after passing noise. At FSG last year we had a couple of teams rechecked after Endurance if they seemed very loud. There was no team disqualified. At the rechecks minimal violations (like let's say 2dB too loud) were accepted. As you have to accept that the noise testing as it is done is quite inaccurate and it is possible that a car is measured a bit higher without any changes at the car just because of wind and other effects.

It is not surprising that some of the cars seem to be much louder on track than others while using the dBA rating. For noise levels like the noise of a FSAE car dBA isn't consistent to human hearing. Does anyone know if they already used the dBC rating at MIS this year? This should be closer to human hearing.

Bemo,

I cannot comment about MIS 2014, but at Lincoln 2013, our single cylinder was tested for dBA, and once we had a passing reading, they immediately checked the car in dBC. Our dBA value was 110dB, while the 2nd test showed a 119dBC value. To me, there are other things that students can be focusing their resources on than designing a sound suppression system to keep the car at 110dBC that would prove more valuable. Our testing was an off the shelf ATV muffler that costs $275 (IIRC, I could be wrong) and a couple hours worth of tuning on the school sidewalk


Speaking for myself here, I didn't say anything at FN 2013 after hearing the car ring loud all the way from the practice area to inside the arena because I knew that the off-the-shelf silencer wasn't going to give the offending competitor a performance advantage, especially when exhaust backpressure wasn't the weak link in the competitor's powertrain. The only damage done by a car that had been ridiculously loud at two competitions in a row was that it bolstered the rules committee's switch to the dBC scaling that will likely be used next year. As a nearsighted and friendly competitor, this didn't motivate me to make a big deal about a loud car that posed a threat only to eardrums.

This is it exactly, except that I do not have near the engine knowledge that Matt Birt does. I just know there were loud cars, and when we asked them about it after competition (still within a few blocks of the event) they told us about a plug/cheat to the test. It's not the act that bothers me, but the rules committee punishing the other teams because of the actions of a few (regardless of what the actions are).

-Matt

[Mbirt]

For anyone that's wondering, OTS ATV/bike silencers like these:
http://blogs.mcgill.ca/fsae/files/2013/03/DSC_0135-300x199.jpg

typically have OTS "quiet inserts" like these:
http://www.off-road.com/images/content/4.jpg

that can be swapped in when you chose to ride in a noise-enforced area. When an OTS silencer manufacturer's quiet core is used, there is usually no drop in peak power and little drop in power after the torque peak. This means that your FSAE car isn't going to be faster on track when you pull the quiet core after the noise test. It's just not worth it. Here's a test of a YFZ450R quad with and without a quiet core in its aftermarket silencer:
http://i6.photobucket.com/albums/y218/diypunx/OCPDynoquietcore0001_zps16210b06.jpg