Spec Boxster Build

[thstone]

** Laguna Seca Results **

Sorry for the late update on last weekend, but I had a busy week at work. Here are the formal results;

Saturday Race 1:
Qualified 7th of 11
Highest Place: 4th
Finish: DQ (black flagged for excessive sound at 2/3's into the race)

Sunday Race #2:
Qualified 4th of 9
Highest Place: 2nd
Finish: 4th

Overall, I drove and raced well but struggled all weekend with meeting the 92dB sound limit.

I was black flagged repeatedly thru the weekend cutting my practice time to almost nil (2 laps for the entire weekend) and forcing me to qualify while short shifting or staying in the next highest gear to keep the rpm's (and sound) down to an acceptable level.

More on sound to come (and some crazy pictures of what we did to try to mitigate the issue). And of course, racing video!

But when all is said, racing at Laguna Seca is always a great experience since its such a unique track.

Here are a few pic's from the garage...

[njbray]

This 92dB sound limit adopted by Laguna Seca basically means they are not able to host many pro racing events - such a shame! All they need is a few more law suits from nearby millionaires and it could be the end - one day!

[thstone]

Originally Posted by njbray

This 92dB sound limit adopted by Laguna Seca basically means they are not able to host many pro racing events - such a shame! All they need is a few more law suits from nearby millionaires and it could be the end - one day!

I hear you (haha!) and I understand that it is what it is; but 92dB???

The chart below applies to a person within 40 ft of the source. Google maps says that the closest house to the race track is about 3,000 ft away (6/10ths of a mile).

This means that the goal of 92dB is to meant to set the noise level to be the same as a lawnmower from more than a half-mile.

All I'm saying is that it seems a bit low for a racetrack.

[rastta]

Originally Posted by njbray

This 92dB sound limit adopted by Laguna Seca basically means they are not able to host many pro racing events - such a shame! All they need is a few more law suits from nearby millionaires and it could be the end - one day!

Actually they have several - I think up to 7 unlimited sound events per year. The rest are either 90dB or 92dB.

The track is owned by Monterey County. Therefore it's limits are set by the Monterey County Board of Supervisors. The limits were put into place and more aggressively enforced due to actually one guy who inherited his home in Carmel Valley - a group called the Highway 68 Coalition out of Salinas.

I can pass sound by lifting and running supertrapps on the exhaust. Kills power above 4k but at least it allows me to run there. I've been black flagged once while running the trapps at 94dB. Car is normally around 98dB. I only run there one weekend a year with the Audi Club - the rest of the time I run elsewhere where the sound limits are reasonable.

[njbray]

Originally Posted by rastta

Actually they have several - I think up to 7 unlimited sound events per year. The rest are either 90dB or 92dB.

The track is owned by Monterey County. Therefore it's limits are set by the Monterey County Board of Supervisors. The limits were put into place and more aggressively enforced due to actually one guy who inherited his home in Carmel Valley - a group called the Highway 68 Coalition out of Salinas.

I can pass sound by lifting and running supertrapps on the exhaust. Kills power above 4k but at least it allows me to run there. I've been black flagged once while running the trapps at 94dB. Car is normally around 98dB. I only run there one weekend a year with the Audi Club - the rest of the time I run elsewhere where the sound limits are reasonable.

That's good to know. I love Laguna Seca - We have been going to events there for 20 years. When they had the Ferrari historics it was amazing to hear the F1 cars on the track - the noise was echoing off the surrounding hills! You could hear them all the way around the track.

[Chuck W.]

That track was built in 1957 when there was nothing around there. Then they build homes there and complain about the noise. It is like buying a home under an airport runway approach and then complaining about the noise.

[thstone]

So, here is the story of what we did to reduce the sound over the weekend...

Fix #1/Saturday evening

Weld on a pair of SuperTrapp diffuser's to my existing TopSpeed Pro 1 exhaust. This failed sound on Sunday morning and did really reduce the sound level to any appreciable degree. The red goop is thread locker to keep the diffuser bolts from coming loose.



Fix #2/Sunday morning

Cut off the SuperTrapp's, weld on an 8" bullet muffler, and weld the SuperTrapp's onto that.

This solution did the trick! Looked like crap, but met the sound requirement without completely restricting the exhaust flow and killing the power. Good enough to get me up to 2nd place in the race and finish 4th. I'll take it.





And now, since I Frankenstein'd my TopSpeed, I bought a new TopSpeed and will swap it in next weekend to get back to the original racing setup.



In the future, all of this could have been avoided by simply buying a used OEM stock Porsche muffler from eBay and bolting it on before the event. The stock exhaust is very quiet without losing much power.

Thanks to Brad Roberts and Vali Motorsports for all of the support! They saved the weekend for me.

[jsceash]

It's not the only race course that has these crazy restrictions. Lime rock has the same restriction so I can't run there (90db).

[thstone]

Here are a few pic's from last weekend at Laguna...

On the grid, thumbs up, ready to rock!


Leading Paul Young's #17 Dead Pets Racing 911 hard into Turn 5...


Darin Kajoika's #265 chasing me up the hill to Turn 6...


Looking tidy coming out of the turn...


Using all of the track past the bridge on the uphill to Turn 6...

[bkovac]

that suit is just getting bigger and bigger

[thstone]

Originally Posted by bkovac

that suit is just getting bigger and bigger

Haha! Thanks, I'll talk that as a compliment!

[thstone]

Originally Posted by JayG

Glad that was not you and your car in that accident. For a second, I thought you were talking about your car.

Are you going to be at the POC event at Fontana in Sept?

Hey Jay, yes, I will be at the POC event at AutoClub Speedway in Sept - hope to see you there! I'll also be there Friday for practice and coaching.

[itsnotanova]

http://i1114.photobucket.com/albums/k522/thstone/Fix2a_zpscw2xynam.jpg
That pic with the exhaust extensions reminds me of the stinger exhaust people would use on the old air cooled VW's. Part of me gets nostalgic for that look and I start to think about adding one to my boxster

[thstone]

Originally Posted by itsnotanova

That pic with the exhaust extensions reminds me of the stinger exhaust people would use on the old air cooled VW's. Part of me gets nostalgic for that look and I start to think about adding one to my boxster

Wow, I hadn't thought of those in a long time, but yes, you are exactly right!

[JayG]

Originally Posted by thstone

Hey Jay, yes, I will be at the POC event at AutoClub Speedway in Sept - hope to see you there! I'll also be there Friday for practice and coaching.

cool

I'll be there just on Sat with my Son for his first track day.
He will be running the PDS on the infield and I'll be in TA on the roval

[thstone]

Originally Posted by JayG

cool

I'll be there just on Sat with my Son for his first track day.
He will be running the PDS on the infield and I'll be in TA on the roval

Great! I look forward to meeting your son and the infield course is a ton of fun!

[jcslocum]

Is it known where the microphones for testing are located?? We used to run some VERY loud bikes and adding a 90 degree turn would point the sounds away from the mics. They were always placed in a similar spot on the outside of the track, worked for us at the time.

[rastta]

Originally Posted by jcslocum

Is it known where the microphones for testing are located?? We used to run some VERY loud bikes and adding a 90 degree turn would point the sounds away from the mics. They were always placed in a similar spot on the outside of the track, worked for us at the time.

Yes - in the small building at the exit of Turn 5 as you accelerate up the hill. If they are anticipating a very loud group - they will have a roving sound guy who moves to different point along the track.

[thstone]

Originally Posted by jcslocum

Is it known where the microphones for testing are located??

As Joe said, just after the exit from Turn 5 as you go up the hill...

[thstone]

** Weight Update #5 **

Spec Boxster minimum weight with driver and fuel is 2,650 lbs. My goal is to be able to manage the weight of the car by adjusting the fuel load at the start of a race so I am near the min weight at the end of a race (with some margin for error).

Last weekend, total weight was 2,683 lbs with a 1/4 tank of gas. Subtracting 24 lbs for fuel (6 lbs/gallon x 4 gallons), says that the car/driver weighs 2,658 lbs.

If you remember, weight update #4 had the car/driver at 2,654 lbs with no fuel. Then I removed another 16 lbs (11 lbs for the lexan windshield and 5 lbs from my own weight, so I was predicting the car/driver total to be 2,638 lbs - but got 2,658 (or a difference of 22 lbs).

This means that I am experiencing something like 0.83% variability in weights (8 tenths of one percent). My thinking is that this error is primarily driven by different scale accuracy and fuel gauge accuracy but the error budgets don't add up.

Most scales used for weighing cars say that they are accurate to 0.001% which would be around 3 lbs and the fuel gauge might be off by a gallon, so another 6 lbs of error for a total of 9 lbs, But I am seeing a difference of 22 lbs.

So, I plan to reduce weight by another 13 lbs (22-9) to try and account for the variability on the high side and then get another weight check at the next event to see where I stand. At that point, I should be within the measurement error bounds and if I end up being too light, it is easy to add more fuel to be sure that I am at min weight at the end of a race.