Tech inspections before competition

[Jordan_CSM]

So, we are a new team. We've never done tech inspection before. What does it entail? We would like to go through it at least twice by ourselves before we actually get to competition. Is there a checklist somewhere that I was not able to find?

As of right now, we only have a body to make, and that should be done this week. After that, final shake downs and tech inspections.

And yes, I did a search on the forums here before posting.

[Jordan_CSM]

aww gees. Excuse me. it's on the sae website. Which I guess I just never browsed.

[TMichaels]

You may download a video about scrutineering from one of our workshops. Two of our scrutineers demonstrate the technical inspection with the 2006 car from Rennteam Stuttgart. The video is from 2007, so quite some rules might have changed or become obsolete, but it gives you an overview about the whole process and shows in detail what the scrutineers are looking for:
https://www.formulastudent.de/...01_Scrutineering.wmv (https://www.formulastudent.de/fileadmin/user_upload/all/2007/academy/20070507_DIT/FSG-Academy07_DIT_P01_Scrutineering.wmv)

The size is 295MB and the total video length is 80mins, so it may take a while to download.

[MarkSchaumburg]

Make sure several people (independently) go through the tech inspection form and check the car for compliance with every single part. While they try to be as consistent as possible, each tech inspector will vary in experience and will sometimes interpret rules more strictly then others, so make sure that if you choose not to immediately fix something that you have the means to do so at competition. There is definitely an "art" to getting through tech and getting through it quickly. As a first year team, your goal should be to make it through tech/brake/noise and compete in every event. I would fix every problem you find, regardless of what it might do to the performance of the car.

[Jordan_CSM]

As a first year team, your goal should be to make it through tech/brake/noise and compete in every event. I would fix every problem you find, regardless of what it might do to the performance of the car.

That is exactly our goal. It was from the start. We are having a few issues with our brakes right now, but we should be good on noise.

[TMichaels]

Originally posted by Jordan_CSM:
That is exactly our goal. It was from the start. We are having a few issues with our brakes right now, but we should be good on noise.

Don't underestimate noise. I have seen countless teams failing noise. Mostly because their measurements deviated heavily from the official meter. Make sure to have a plan B and C for noise.

[Jordan_CSM]

Originally posted by TMichaels:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Jordan_CSM:
That is exactly our goal. It was from the start. We are having a few issues with our brakes right now, but we should be good on noise.

Don't underestimate noise. I have seen countless teams failing noise. Mostly because their measurements deviated heavily from the official meter. Make sure to have a plan B and C for noise. </div></BLOCKQUOTE>

Honestly, I am a bit worried about our testing methods, and I've definitely thought about how the testing methods may differ, so we are hoping to get to use some of Colorado State's equipment on top of ours. That should help us out a little bit.

[RobbyObby]

Originally posted by Jordan_CSM:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by TMichaels:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Jordan_CSM:
That is exactly our goal. It was from the start. We are having a few issues with our brakes right now, but we should be good on noise.

Don't underestimate noise. I have seen countless teams failing noise. Mostly because their measurements deviated heavily from the official meter. Make sure to have a plan B and C for noise. </div></BLOCKQUOTE>

Honestly, I am a bit worried about our testing methods, and I've definitely thought about how the testing methods may differ, so we are hoping to get to use some of Colorado State's equipment on top of ours. That should help us out a little bit. </div></BLOCKQUOTE>

You need to make sure you test it outdoors in a wide open area, as it will be at competition, so echoes don't interfere with the reading.

Honestly, the fact that you even have and are using testing equipment before competition is more then most teams can say. I would recommend practicing a worse case scenario as it might be at competition. Get a few solid readings to see where you are at, then try and do everything you can to bring the level down by 2-3 dB. Even if your equipment says you're only at 106 dB, try going down to 104 dB by using a different muffler, adding more packing material, or playing with the engine mapping. That way if you get to competition and you test at 112 dB, you know exactly what you need to do to bring it down. Also remember, the sound requirement is 110 +/-0.5 dB (Or at least it is here in the states. Not sure if it's consistent between competitions.) So you only need to test at 110.5 dB. And on a log scale, 0.5 dB is a considerable amount. In 2011 at West we passed at 110.5 dB, and the volunteer said it was the highest he'd seen a team pass the sound test at. Just keep that in mind.

Also, for those teams who run a side exhaust, you are allowed to remove a wheel if you think it is affecting the reading. Not many many teams realize this.

[Pennyman]

Potential showstoppers seen at MIS from my experience that may not be explicitly obvious from the tech checklist:

1. expired driver's restraints
2. vertical/horizontal template compliance
3. New headrest area/adjustment rules
4. chain guard coverage over chain (especially with full tub)
5. location of over-travel switch such that it doesn't shut the car off during the brake test
6. "correct" safety wiring of critical bolts
7. noise, as it's been mentioned so eloquently by Robby here http://fsae.com/groupee_common/emoticons/icon_smile.gif

[Warpspeed]

Sound pressure measurement need not be that difficult, but there are a few things to consider.

First is that the measurement is logarithmic, a 1db difference is 10% change which is a lot.
If you had a thermometer or any instrument that read +/- 10% you would think that was horrible.
But sound pressure to 1db accuracy is very good.

Conclusion, even a low cost budget sound level meter can work pretty well if used intelligently.

Don't trust your ears. The "nature" of sound and how objectionable it is can make it sound a lot louder than it really is.
A really cool exhaust note may sound nice but end up being way over the limit.
Use a low cost sound level meter.....

As already said, make the measurement outdoors well away from any reflective vertical surfaces.

You don't need a dead quiet environment to make a fairly accurate noise measurement. As long as the background noise is perhaps more than 20 db below what you are measuring, it will introduce negligible error. Twenty db is 100 times which is plenty of margin.