I think rerouting back into the downpipe and increasing the downpipe/exhaust diameter to 4" is the best option for high powered cars (500rwhp+). I think 3" is very capable for anything under 500rwhp to reroute back into the downpipe, as long as you don't have too much restriction in the exhaust. I have also seen another car on here that ran a completely separate wastegate exhaust system, maybe someone can find that one again? Either way, should be interesting to see what you guys do.

 

I hear ya. I already have my 3" DP and manifold combo so I was looking for alternatives. I'm not really shooting for 500whp but I should come pretty close. My last setup was a T3 35r and it was rerouted. I knew the turbine size coupled with this was causing a bit of restriction. My exhaust is an open 3".

If I could find a solution that just took the edge off the sound, but still provided gains, I would go that direction.

 

I'm probably going to use Turblown's advice and run a small glasspack to keep the noise down.

 

Ive run a glasspack on the wastegate dump it caused a fair amount of boost creep. It kept the noise down in the cabin but wasnt much different outside the car. I was racing at a track with a dB limit at the time that I made the switch and I may have been 1 or 2 dB louder at worse with just the open dump.

This isnt the case for everyone and may be how I have my open dump routed, Ive heard a a few guys open dumps that are f'n loud.

 

I had an open dump and it was ridiculous. I'm thinking also to just make the length of the wg dump pipe as long as possible with a nice resonator on it.

 

^ Looking at resonators also. After searching quite a bit I found that the "mufflers" tend to cause creep and spikes. However, a resonator is a straight through design. The actual flow restriction should be very minimal. I can also megaphone from the flange to a 3" to help flow. From there a nice 12" resonator should do it.

I found a chap over on the Mustang forums that has a 1000hp setup. He made a resonator and it silenced it beyond the sound of the exhaust but had no spikes. Granted l, he was running dual 38mm's and poisons tend to be a little quieter.

 

Im running a precision 46 (or 48??) wg on my street ported gt4094 fed motor.....the open dump on the wg really doesnt bother me much....i kinda like it. Its like having an ugly dog....annoying at first but then you learn to appreciate it for what it is....

Its like the sound of hell coming at the person who just got their *** handed to them by your rotary!!!

 

^ + 1

 

Id agree, ill never trade the sound of my motor screaming boost to hear the **** pipe'd honda next to me

 

You allow hondas next to you? Lol

 

Cuurently running dual 38mm open, and cant stand it anymore. The piercing scream got old quick, plus I would rather not tell everybody in a half mile radius know that I am having too much fun.

 

Not yet, I'm just preparing for the worst

 

I can agree with this perspective as well. I will be running around 23-25lbs also. For average merging and driving, it should be unnoticeable. Hell, wastegate doesn't even start to open until 17 psi.

I will likely explore the resonator idea. I know Lindsey racing sells a nice piece for the Porsche guys.

 

I didnt last one week with my open dump setup. It was just too loud and it is a serious burn here in California.

U guys should really check out the lindsey racing product I posted earlier. Seems like the best choice size wise.

 

I just got my precision gate and I'm excited to hear it with an open dump tube.

Your post was perfect haha!