50 replies to this topic

[Jim Drago]

We had our call last night (CRB) and the Runoffs talks have started. Laguna presents some unique problems that other tracks don't, mostly with sound. Being the kinder,gentler SCCA of 2014.. We thought it would be good to get some opinions here.

Here is the situation...

Before 9:00 and after 4:00 each day of practice and qualifying must be run under 90 DB ( trying to get hat to 92 DB) We really can't afford to lose all this time during the week or most all classes will need to be combined etc.

The races will be 103DB ( Normal conditions)

The only cars that can make these sound numbers are SM, SRF and FV.
FV cars run a super trap and make the sound
SRF has a quiet muffler they could all use
SM- well here is where the discussion begins.

Many race at Laguna under these sound requirements and have fabbed together something that has worked.


So here is what I would like to discuss and what I was thinking...

Do we "spec" or suggest a known exhaust that will pass the 90 DB or come up with one? Does MBS pass?

If so, do we keep that same configuration for race day as well even though we are allowed to run the cars in "normal" SM trim?


I also think if we qualifying in "quiet" trim, we should probably race in "quiet " trim. That eliminates tuning the car for a race and driving a different car from what you had tested and qualified with. I agree with this as well.

Do we lobby just not to go out in the beginning or end of the day ( not what I think is in best interest of the club)

Any known quiet <90db exhausts out there now that you guys are using? I am sure we can come up with something that is very inexpensive, quiet and fair for all. Just my opinion.


Please add any suggestions/ comments below.


( one question that I do not have the answer for.. What if a car with the spec exhaust fails sound.. I will work on that.)


Jim

[scott sanda]

Jim,

 

You forgot one important point, which admittedly is going to be a bigger problem for the other classes than it is for SM, but it could be an issue for "non quiet" Sm's as well.

 

Sound at laguna is drivers RIGHT, and is not the SCCA standard 50(I think 50) feet from the track. It is also right in the track out acceleration zone of a corner, and is NOT monitored or enforced by SCCA, but by the track/park.

 

I'm curious what the SM's that currently run there do, as it will help me with my AS car.

 

Scott

[Alberto]

Most of the SFR region SM hasn't had too many issues making sound.  Many of us use a setup such as that in the pic below.  TC Design has made many of these.  I forget the brand of the muffler TC uses but it is typically attached to the rear of a Springfield Dyno exhaust.  Others have fabbed their own.  IIRC, TC claims a 1 HP drop on the dyno from adding the muffler he uses when compared to the SD w/o his muffler.

 

Some people also add a 90* elbow coming off the rear pipe to point the sound to the inside (left/driver side) of the track just in case atmospheric conditions (cloud, fog etc) are present that would affect sound levels.

 

 

I'm sure the SFR region board members Brian and Mike have some further insights they can share.

 

fwiw, The presence of the muffler made no difference in power when my weak 107 rwhp 1.6 was on the dyno.

 

Hope that helps.

[FTodaro]

since everyone is going to be at the same disadvantage i would spec a cheap aftermarket muffler #30.00 buy an elbow, i did this and fabbed a bracket that it would slide right in to the stock muffler mounting points. it could be done for 40.00. since this is not going to be long term why not make it cheap to do. I did a set up like that was used to drive an sm to the track on and off in 5 min. 

 

I would not try to plan that SM on run around the time restriction, that could be a disaster.

 

Make it cheap and easy. spec parts.

[LarryKing]

 

If we all buy a low cost exhaust say under $300, you will not have to worry about guys like me buying and building multiple exhausts and coming up with a quiet exhaust that is 1-2 hp better than most everyone else's?

We're suddenly worried about too much development and cost of the exhaust? (just kinda seems like ordering a Diet Coke to go with your Wendy's triple bypass and great biggie fries)

[Johnny D]

Lots of threads on this over the years, search.

Different designs too.

 

An extra 90 helps to get you to pass.

J~

[Mike Collins]

MBS would most likely make sound.  I'm regularly below 90 at multiple tracks but I am 88/89.

[Todd Lamb]

My muffler is going to accidentally fall off on lap 3.

[john mueller]

The best option is to lobby to ensure the BIGGEST RUN GROUP get a sweet-spot time !  

However IMO you'd better plan on the worst even is the schedule says SM will be running at 'normal 103db' times...  Meaning if it's foggy 103bd could come into play (somewhat doubtful, but is possible).

In that case, I'd recommend spec'ing a muffler to fab-something-up like Alberto shows and a complete system (Borla's is damn quiet)

[Alberto]

The best option is to lobby to ensure the BIGGEST RUN GROUP get a sweet-spot time !  

However IMO you'd better plan on the worst even is the schedule says SM will be running at 'normal 103db' times...  Meaning if it's foggy 103bd could come into play (somewhat doubtful, but is possible).

In that case, I'd recommend spec'ing a muffler to fab-something-up like Alberto shows and a complete system (Borla's is damn quiet)

 

That won't happen.  Miatas are far more easily modified to make sound than any other class.

[Johnny D]

Test days, you'd probably have to comply anyway.

J~

[Michael Novak]

a new MBS exhaust will pass and they are relatively cheap. I would guess it will pass as it ages also as it uses a regular muffler. Bonus is that also fit right everytime.

[Mark Drennan]

Everyone who races SCCA in this region already has a "Laguna exhaust".  So, please don't make us spend more money by spec'ing something different.  We've already spent the time and money to meet the requirement.  Now it's your turn.  Welcome to racing at MRLS. 

[Bench Racer]

Ooop's.

[Bench Racer]

My muffler is going to accidentally fall off on lap 3.

The black flag will  upon you.

[Jeff Wasilko]

My muffler is going to accidentally fall off on lap 3.

 

Explosive bolts?

[Sean - MiataCage]

I don't really have any issues racing at the 90db, but I do have issues Spec'ing an exhaust.  I thought that there was some loose agreement that rules were frozen other than weights and plates and this IMO deviates from that expectation.  As others have mentioned above most anyone who has raced at MRLS in the last few years already has their way of meeting the DB numbers.

 

Let's assume you Spec an exhaust for a minute......

 

1. Who will the supplier be?

2. Can they handle the demand?  Look at the SE30 issues NASA has.... It can be troublesome.

3. Will the price be frozen if it's an existing product?

4. Will I need to be buying this exhaust from a competitor?

5. What if it gets damaged at the track during the week and I don't have a spare?  Will everyone need to carry a spare?

6. What happens if it fails sound?

7. When would this exhaust be spec'd?  April, May etc, etc, etc.

8. Are we violating the existing GCR by doing this?  Specifically the 120" or 40" rule?

 

90 db is 90 db, who cares how we get there as long we get there?  Let the market drive the demand for a finished product for those that need one and let the rest of us who have money and time invested into our own systems keep them.

 

Thanks.... Sean

[Sean - MiataCage]

My muffler is going to accidentally fall off on lap 3.

Don't forget to wire the rear defroster to take out the back glass as well..... Maybe lap 4 or 5. 

[Jim Drago]

Good dialogue!

[Todd Lamb]

Rear bumper cover too.....

 

But seriously - if we agree to run some "quiet" exhaust for the sessions outside 9a-4p, and we agree to run said exhaust in the race within the 9a-4p window, we need to agree that if the exhaust is bypassed and/or falls off, regardless of meeting sound rules, it is illegal.

 

I think DDG has some really solid ideas on how big the muffler should be? (oh boy, am I going to get a restraining order against me for saying his name?)