Best muffler?

[aspemo]

At the moment there is no way that I can drive my car on the track.

The sound level is to high, around 110 db.

Now there is a relatively short muffler, my builder constructed it by him self. The lumen from the turbo is 4" and its straight trough pipe, central in central out.

How would you construct a muffler , so that you get max effect and as silent as possible. I have to reach 95 db to be able to drive the car at the track.
The turbo is placed in the center line of he car. So there is limited place for a muffler.

Magnaflow?

Appreciate all inputs.

[lr172]

My experience is that the Dynomax Ultraflow and Magnaflow are about the best from a flow standpoint. Dynomax is very open with their flow figures and will give recommendations for a given engine size. If I recall, it was CFM = 2.2 X CID. I think the 3" mufflers will flow close to 550 CFM. These will easily pass track requirements. They also sell race versions that flow twice this with higher DB. You will need to see their site for details. I think they list the DB ratings.

Magnaflow uses a better packing material that should keep the volume constant for a longer time. The fiberglass will wear out and become louder over time. This happened with my Dynomax on my big block Chevy.

I have a dynomax 2.5" on 3.2 Turbo and it is very quiet. I would actually like a little more voume and will possilbly go with a small case to raise the db.

Good luck.

[aspemo]

Originally Posted by lr172

My experience is that the Dynomax Ultraflow and Magnaflow are about the best from a flow standpoint. Dynomax is very open with their flow figures and will give recommendations for a given engine size. If I recall, it was CFM = 2.2 X CID. I think the 3" mufflers will flow close to 550 CFM. These will easily pass track requirements. They also sell race versions that flow twice this with higher DB. You will need to see their site for details. I think they list the DB ratings.

Magnaflow uses a better packing material that should keep the volume constant for a longer time. The fiberglass will wear out and become louder over time. This happened with my Dynomax on my big block Chevy.

I have a dynomax 2.5" on 3.2 Turbo and it is very quiet. I would actually like a little more voume and will possilbly go with a small case to raise the db.

Good luck.

So if I understand you correct , the best option for me would be the Dynomax to keep the sound as low as possible?

[David]

You may have very limited choices with a central turbo location. Can you post a pic under the bumper so we can see what you have to work with.

[DonE]

Here is my exhaust that I made from a magnaflow using 3 inch stainless pipe and a v-band mount. The muffler is a center/offset design and fits perfectly in the stock location using the stock strap mount. You'll also see the O2 bung at the 12 o'clock position just after the turbo.

[lr172]

Originally Posted by aspemo

So if I understand you correct , the best option for me would be the Dynomax to keep the sound as low as possible?

No. These are recommended for maximum flow at reasonable volume. You need to research the mufflers, as case design and size (i.e. amount of packing) will have a big impact on volume, without necessarily impacting flow.

You should do some research at Dynomax's site regarding db and flow then figure out you options, given your target db. You will find many choices that reach 95 db.

I used this one on my 3.2 turbo conversion. It fit well and exits the drivers side. I's also very quiet. However, it is 2.5", so not sure it is the flow you are looking for.

http://www.magnaflow.com/02product/shopexd.asp?zone=main&id=8045
good luck.

[aspemo]

Originally Posted by 125shifter

You may have very limited choices with a central turbo location. Can you post a pic under the bumper so we can see what you have to work with.

By the way what do you think of Super Trapp?

[David]

Originally Posted by aspemo

By the way what do you think of Super Trapp?

We always called them Super Crap

You have a muffler. Next?

Seriously, you may have to reduce your exhaust ID to get more muffler packing in there or make a 180° bend and go out the driver side, but it doesn't look like you'd have enough room.

This is what I have http://www.burnsstainless.com/cgi-bin/order.py?action=add&part_number=SM-350-625-17**

It's realatively quiet but I haven't been measured.

Burns also makes a muffler that has an X-brace across the ID with some metal scrubble stuffed in. It looks a little restrictive for a turbo car, but you may not have any choice with the sound restriction.


Another option, which a few racers I know do, is to back off the throttle when you go by the sound meter.

[aspemo]

Originally Posted by 125shifter

We always called them Super Crap

You have a muffler. Next?

Seriously, you may have to reduce your exhaust ID to get more muffler packing in there or make a 180° bend and go out the driver side, but it doesn't look like you'd have enough room.

This is what I have http://www.burnsstainless.com/cgi-bin/order.py?action=add&part_number=SM-350-625-17**

It's realatively quiet but I haven't been measured.

Burns also makes a muffler that has an X-brace across the ID with some metal scrubble stuffed in. It looks a little restrictive for a turbo car, but you may not have any choice with the sound restriction.



Another option, which a few racers I know do, is to back off the throttle when you go by the sound meter.

2 stage Muffler? Do you think that it will take down the sound to an acceptable level?

[RarlyL8]

If reducing the sound level is 100% of the goal you have options.
The center mount turbo will not allow a long muffler to sit in the conventional position. Run a pipe from the turbo outlet and do a 90 bend around the passenger's side of the engine toward the front of the car. Place the muffler along the bottom/side of the engine with a stubby tailpipe pointing towards the ground behind the rear tire.
That should hide the sound pretty good. Add the waste gate pipe to that system.

[aspemo]

Originally Posted by RarlyL8

If reducing the sound level is 100% of the goal you have options.
The center mount turbo will not allow a long muffler to sit in the conventional position. Run a pipe from the turbo outlet and do a 90 bend around the passenger's side of the engine toward the front of the car. Place the muffler along the bottom/side of the engine with a stubby tailpipe pointing towards the ground behind the rear tire.
That should hide the sound pretty good. Add the waste gate pipe to that system.

that was a good ide. But there is a small problem, the oil-pan, sits in the way.

Of course I can move it, but the cost is pretty high. So any other suggestions to solve the problem a little cheaper that to rebuild all oil lines.

If there is no other way to go around that problem then I have deal with it.

Burns 2 stage muffler, is that a better option than Magnaflow or Dynamax?

The price is much higher.

[RarlyL8]

The muffler needs to be a 5" round body like the ones I have. It will fit down low but will not hit anything that the tire will clear as it is close to the tire.

Another (cheap) option is to use a heavy short secondary muffler from a big truck like a Dodge Ram. These mufflers are 3" diameter ID and very short and squat with inlet on top and exit on bottom. Very heavy with lots of packing material. You can hang that right off your turbo and point the tailpipe under the engine towards theground to kill the sound. I do that trick with waste gate dump pipes, it works well.