Turning in my man card... I want to make the GTRA quieter... best method? - Page 6

Wess-RA · 11-23-2008, 01:17 PM

I bought everything from Summit Racing

Magnaflow P/N MPE-11366 $69.95 ea.
Supertrapp P/N SUP-544-2503 $71.88 ea (This includes the heat shield)-These are the 5" disks-for higher HP motor upgrades later on. I installed the full package of (I believe it was 12) disks for least back pressure. According to the Supertrapp rep. the 5" disks are quieter than the 4" disks also more tunable on HP vs Torque while balancing Db levels.
Clamp P/N SUP-094-2500 $10.83 ea.

I'm running Laguna Seca tomorrow.(Monday) I'll let you know if I pass. It should be no problem.

Uwe

Wess-RA · 11-23-2008, 01:23 PM

One more thought: I went to a local muffler shop-gave the guy $40 and he let me use his lift and have at it. In the process he stretched 2 short tubes (and slotted one end for the compression clamp) to slip over my exhaust tips and welded the sleeves on to the Supertrapp flange.

I had a hell of a time getting one of the pipes off; literally had to sawsall it off and grind the slip over portion of the cherry bomb full length before it finally would come off.

Typical work for older exhaust systems.

Wess-RA · 11-23-2008, 01:24 PM

One more thought: I went to a local muffler shop-gave the guy $40 and he let me use his lift and have at it. In the process he stretched 2 short tubes (and slotted one end for the compression clamp) to slip over my exhaust tips and welded the sleeves on to the Supertrapp flange.

I had a hell of a time getting one of the pipes off; literally had to sawsall it off and grind the slip over portion of the cherry bomb full length before it finally would come off.

Typical work for older exhaust systems.

Uwe

Wess-RA · 11-23-2008, 01:27 PM

oops-duplicate-the site is running slow today

Craig245 · 11-23-2008, 03:03 PM

I guess great minds think alike. I order the same Supertrap as you, but got the Magnaflow Super Turbo P/N WLK-17784. I picked that one becuase the http://Norcal-saac.org web site suggested that the SuperTurbo's all by themselves may, pass, and then it is no risk to tune quieter with the supertrap. I also have a 450hp 347 in the car. All the parts come on Tuesday so I'll be interested how you did today. I plan on being at the Green Flag event at Laguna on Dec 22-23. Let us know if you actually got a reading. It is only a matter of time before all tracks will have noise restrictions.

Craig

Craig245 · 11-23-2008, 06:22 PM

Oops, that's a DynoMax super turbo muffler that I ordered.

Craig

Wess-RA · 11-25-2008, 04:46 PM

Heres the bummer story-inconclusive at best.
I did a first run while lifting and up shifting to pass the Db test. My buddy in a very quiet turbo-ed NSX got meat-balled on his 1st run. It was a low fog day and I figured that may have contributed to his problem. There were lots of meatballs being flagged. On that 1st run I was thinking how my car was feeling gutless on the high end. (RPM's coming up slowly).

2nd run my car wouldn't go above 2K RPMs about halfway through the run. The exhaust was choking us out inside the cockpit. I exited the track and disgustingly pulled out the disks. Here is what I found:

Look at how tightly the stuffing is packed in-looks like it formed a gasket

I then ran without the Supertrapp for the next 3 runs lifting at the meter station. Its a real drag to let cars you've caught pull away due to lifting.

So the test is inconclusive. I called Supertrapp-they stated that the 12 disks I'm running should be fine for my HP output of 245. At most I could try an additional 6 pack of disks but he didn't think it would help. (It would just be louder) The stuffing he felt was a defect of the Muffler. I then called Magnaflow and they stated that If the car is running rich or if the muffler is too close to the header while not running cats that it could cause the muffler to blow out. I explained that this is the muffler Panoz uses and that it is located the same as all of these cars. (They recommend 5' back from the header, that's absurd) I sent these same pics to him. I will probably have to take the muffler out to see it it is blown out from the inside.

Sorry I can't give a definitive answer on the Db's. I have more work to do to resolve this. Anyone have a similar experience/insight?

Wess-RA · 11-25-2008, 04:57 PM

Laguna Seca took a reading of 89Db-but remember that was with a totally choked off exhaust. Craig who is running the Green Flag event at Laguna Seca? Can you provide me with contact info for that.

Craig245 · 11-26-2008, 11:57 PM

Quote:

Originally Posted by Wess-RA

Laguna Seca took a reading of 89Db-but remember that was with a totally choked off exhaust. Craig who is running the Green Flag event at Laguna Seca? Can you provide me with contact info for that.

Here is the link for Green flag ant Laguna. they run a very nice group, most of them ae part of the NorCal shelby club. I am using a Dynomax super turbo that does not have any filling, just chambers. It can't blow out.

http://www.greenflagdriving.com/

Here is a link to an article about how to meet the noise limits at laguna.

http://www.norcal-saac.org/ot/soundadvice.htm

Craig

Craig245 · 11-27-2008, 05:26 PM

PS: Sorry to hear about your problems, I know how frustrating it is after all the work you put into it. And, no matter what the factory says, the mufflers should not blow out the stuffing so quickly. I would say the muffler was faulty.

The article from Nor-Cal SAAC says that the Turbo Muffler may just barely pass all by itself if you have a cross over pipe, which we don't. So I bought those and the Supertraps for a little extra insurance. I hope that I'll be able to pass. I purchased two slots at the track for my girlfriend and I plus it is a long tow from San Diego. We will have a lot invested for the two days, but that's race cars.

Craig

eric1h · 11-27-2008, 08:45 PM

what happened to the old days when you just crammed some steel wool in the exhaust pipe to quiet it down! :-D

PRO SYSTEMS · 11-28-2008, 11:38 AM

OH I wish I would've opened this thread sooner I could've saved you a lot of money and hassle.

Tow of our cars runs Car Chemistry inserts. The are located right in the pipe (if you use an evac, be sure to put the evac tube AFTER the inserts).

The inserts are made out of metal so they don't burn out AND you can quickly and easily adjust how loud they are right at the track.

Our A Sedan car without them was 105 db with a peak mph at Daytona of 162. With them (very important) located at the very end of the pipe was 95 DB and had the same 162 mph peak and the same lap times.

No they are not a sponsor, I don't sell them and I have no idea who they are but the product works.

Patrick James
prosystemsracing.com

Wess-RA · 11-28-2008, 03:16 PM

Patrick, Is this what you are talking about?

This has to be installed immediately after the header right? I really want the ability to easily remove the restrictors for other tracks. Will this make the 92Db requirement?

Craig, what P/N of the Dynomax are you referring to? I went on line and the ones I looked at also have packing. I was actually given the advice from the Panoz factory that the Magnaflows are what they are using on their Windsor race engines. (11" case length to fit infront of the jacking tube) I also figured this choice would give me the future upgrade path without having to scrap my new mufflers.

Thanks for the Shelby Laguna Link-really helpful. By buddy with the seemingly quiet NSX was really teed off when he kept failing sound. This article confirms our suspicions that it was probably a combo of his high pitched turbos spooling and the high moisture with low fog deck. It looked like a Chinese Fire-drill that day with everyone working their exhausts trying to pass. My friend and several others brought along dryer vent pipes (solid with rotating hinges) to point to the left side of the car. It worked with varying success. This kind of bull detracts a lot of the fun from the day. (Steel wool options were also tried.)

My schedule won't allow for the Green Flag day so unfortunately I won't meet you on this run. I may go to Laguna Seca again on Dec 8th with
http://www.hookedondriving.com/category.cfm?category=1
so I may be able to give you some additional feedback before you go up.

Uwe

PRO SYSTEMS · 11-28-2008, 03:30 PM

[quote=Wess-RA]Patrick, Is this what you are talking about?

Yes that is it....we have long tube headers and straight pipes that run back about to the front of the rear axle. It was 105 db with turn downs.

We cut one of the rings off it (so it was only about 70 percent of its length), then installed them right before the turndowns far away from the header so as to keep away from the strong pulsing section of exhaust and it dropped to 95 db.

Patrick James

Craig245 · 11-28-2008, 04:13 PM

Uwe, This is what I ordered, http://www.dynomax.com/products/superturbo.html, and you are right, there is a wrap of fiberglass. This is the muffler that has passed Laguna, but our cars are a little different. If you read the Nor-cal sheet they have never seen any kind of insert pass the 92 dB limit, but maybe in conjunction with the supertraps they would. Patrick's A Sedan at sebring is just one data point that may or may not apply to the method of measurement used at Laguna. It is a very draconian limit that as you now know is very difficult to meet, and depends on the local weather. It is worth it, though, as it is one of the best tracks on the west coast if not in the country. Once we get it figured out then we won't have to worry about ot again.

So what are you going to try next week? Let us all know how it goes, and good luck.

Craig

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