After doing some research, I found a few options to muffle the noise of open dump wastegates.

I know re-routing the wastegate is the best way to kill the noise, but for my own reasons (for one, my xs engineering cast manifold setup and situation isnt great space wise) I am trying to avoid that as of now.

Option 1:
although pricey, it looks nice seems to be of quality. I wouldnt mind paying 150 for it if it actually cuts down the noise.
http://www.lindseyracing.com/LR/Pors...A-951-WGM.html



Option 2:
Buying a old porsche turbo wastegate muffler *stock* which came on several of the cars. cheapest I can find used and who knows what condition is about $120.
http://www.ebay.com/itm/PORSCHE-TURB...#ht_500wt_1287

http://forums.pelicanparts.com/porsc...e-muffler.html


More porsche custom wastegate muffler pics:
http://forums.pelicanparts.com/911-9...e-muffler.html

Another option I was thinking is junior dragster mufflers since they are not restrictive and skinny. Only prob is, the only 1.75 inch one I could find costs ~$350.
http://www.borla.com/products/produc...?cat=5&type=73

Final option. possibly extending the wastegate tube its self may decrease the noise level or at least make it more pleasurable to hear.
http://www.google.com/products/catal...ed=0CF8Q8wIwAw

I dont really have a decent option here for silencing the noise, anyone else have comments or ideas?

 

another interesting find. this seems to be the best option if I can manage to fit it. It doesnt seem restrictive.
http://www.ebay.com/itm/Flo-Pro-3302...ht_2801wt_1139

 

Joe,

We sell this unit; http://www.turbosource.com/ProductDe...e=TS4-10-51661

22" body, 26" length, 2" in and out...

 

thanks Elliot, didnt see that on your site and def looks like it will really work well and make things quieter.

 

Has anyone considered using a SuperTrapp type muffler? Would be very space-efficient and not terribly expensive.

 

I read that a lot of DSM guys use that, or consider it but it looks extremely restrictive. It may or may not be, im just judging it based on the way the design looks.

 

ill like to revive this thread. Now that my single conversion is just about done, Im looking more into muffling the open dump. For now its setup as a dump until I figure out a reasonable method.

Elliot was nice enough to share a link with a 2 inch muffler, which I purchased but I wasnt able to fit it by any means with my specific setup. If it did fit, it def would of been awsome.

Now im just curious how the supertrap style will work.. the concerns with that are the heat resistant capability and most importantly the backpressure caused by it.

Im really eyeballing this as well. I just dont know if it will fit though.
http://www.lindseyracing.com/LR/Pors...A-951-WGM.html

Maybe Ill post pics of my underbody and you guys can chime in for some ideas.

 

I don't understand how you have room for an additional muffler for the waste gate, but not enough room to route the waste gate back to the down pipe.?!

 

Recirculating the wastegate in to the exhaust can contribute to a loss of power. At least that's what I've been told by a few people now.

 

I do have room to recirculate. I am choosing not to due to many reasons.

 

There is a locost that runs a turbo BP 1.8 that has a motorcycle muffler on the wastegate tube

 

I was thinking an FMF muffler for a large displacement dirt-bike might be a good option. Can even buy one with a spark arrestor if it doesn't add too much backpressure.

 

its not a bad size.
FMF Powercore2 Shorty Silencer RM250 03-07 - | FMF Exhaust at Bob's Cycle Supply

But for the price it may be better to still stick with the lindsey racing one.
working link..
Google Image Result for http://www.lindseyracing.com/pics/LRA-951-WGM3.jpg

 

My WG is routed back into the DP, but I did try a temp WG muffler with a small
SuperTrapp. It did not work. I used the SuperTrapp: Performance Exhaust
with a pipe size that matched my Tial 46mm WG.

If I reduced the plates to make the sound reasonable, it restricted the flow and boost creep. If I opened it up to prevent boost creep, it was as loud as if it was not here.

 

Thanks for the info. I suspected that those supertrap's would cause creep. Im honestly just trying to find the smallest 2inch muffler/resonator at this point.

 

I had been using open wastegate for over a year and I finally got around to routing it back into the downpipe. I used 2" piping and gradual bends and it routes in right into the bend where it levels off into the mid pipe. This thread had me searching for mufflers but I have a friend who owns a muffler shop and it ended up costing me next to nothing to do it. As far as I can tell, I can't feel any power loss. If anything the car feels faster because you can actually floor it more of the time without worrying about unwanted attention. I have my dyno sheet from last January and am waiting for it to cool off in a few months to compare now that it's recirculating. I did 418whp at 18psi and I will see what it does at similar temps for comparison. I'll let you guys know in case you are thinking about quieting down an open dump.

 

thanks man, that will be really good info to have for comparison. I honestly dont mind losing ~5-8whp. People keep telling me the loss is sometimes around 15-20whp. Well just wait and see.

Also, how far down the dp did your re-route?

 

I tried a SuperTrapp with the maximum number of disks - still got boost creep.

It's for sale if anyone wants it.

 

Sorry if I am a bit late. I was doing a Google search for the a wastegate muffler and came across your thread. I had an idea I thought I would share that you may not have thought of or knew about. Do a search for 2 stroke motorcycle mufflers. They often have very small inlets like we need for a wastegate and many can be cut to length. You can also custom make them out of carbon or titanium if you want. I'll be doing this type in my 911 when I start building my piping.

Again sorry if I'm late, I just joined in order to post this for you.

Cheers,
Scott

I tried to post you a link but because I do not have enough post count I am unable to do that. So, just look up ebay item number 230829178035 this is just for reference purpose only. Many of the 2 stroke motorcycles are GREY MARKET (UK spelling) motorcycles not sold on the US market so parts are kind of slim but you still can find them. You can also check BARF.COM or bayareariders.com cant remember which. Its a motorcycle forum in CALI where grey market motorcycles are huge. I restored a really rare V4 grey market motorcycle and they were a big help. Also, you should be able to find one used on that forum unless you want a new one which I'm sure you can also find.

sorry for the rather long 1st post.

 

Here is a pic of my setup. I actually got a little less boost creep and a more consistent boost curve, I think because there is more even pressure on both sides of the wastegate. Will post dyno sheets in a few weeks.

 

Thanks for the info! I checked the muffler on ebay and it is pretty slim. just be looking at the pics it does look like it smalled than 2inch for the inlet so it prob wont work with my/most setups. Ill look for others however. Also for $155 shipped, Im again debating on using the lindsey racing one which still seems to be the smallest and best option. I attached anothe pic.

I will hopefully get around to taking some undercar pics this weekend and draw out a design. I have very little room to work with so size is most important. If I can fit anytime I will prob re-route it.

 

Nice setup, it maybe be a bit too close, not far down enough and cause some backpressure. Eitherway im looking forward to your DYNO results.

When you say you get less boost creep, are you comparing to the supertrap setup you have? or just free flow dump. Most ppl claim to gain creep when backpressure is added to the wastegate exhaust.

 

after getting the car tuned (without dyno) and driving the car for a couple days, I decided to just re-route the wastegate. The noise was just stupid.

My welder has a dynojet so I decided to do a before and after all on the same day. The result was a 20whp loss! I have the dyno and should post them up shortly.

**NOTE** something is seriously wrong wtih my setup as my td61 from turblown is reaching 15psi at 4500RPM! and I only made 330whp on the dynojet. So i basically lost hp switching from stock twins to single with added lag. I'm extremely frustrated.

 

dyno


331 (3rd gear) and 345 (4th gear) were with open dump. Rest are 4th gear and re-routed

 

I have been weighing my options for a wastegate muffler also. Anyone have success with them?

OP, test your wastegate to insure it isnt sticking open causing your turbo to overwork. I had this issue when I was producing low numbers.

What were your intake temps?