You can make your own cutout Aby. Source a used wastegate from a IX ur VIII turbo and "T" it into where ever you get your current boost signal. This route will result in a much faster reacting valve then the QTP with motor that takes a couple seconds to full open/close.

 

^ yeah, i was thinking that too....especially after reading about all the motor failures.....mechanical would be a lot better....

Pegasus, can you post a picture of your set-up please?

 

The only concern I had about this valve setup was a vacuum line eventually weathering and cracking. To help protect it from the weather, I ran the vacuum line that is exposed under the car through another larger piece of vacuum line. This should keep it from weathering and thus prevent any issues. The valve and everything else is all stainless steel. There are no bearings to wear out.

It acutally starts to open at 5 psi and is fully open by 11 psi. It opens pretty fast once you get into WOT. You can't miss the noise once its open. It sounds mean as hell! It doesn't close very fast so you don't have to worry about it closing inbetween shifts. I tested mine on my work bench when I got it using my compressor and 15 psi of air.

The only negative is there is a slight rattle from the valve at idle. There is some loose tolerances in the valve. That is why it rattles slightly. Its not horrible, but still present. I figure its a small price to pay for having a quiet system that will still allow big power gains. I don't hear this rattle while cruising or driving at all.

I bought the Y-pipe off of ebay, but had to take it to an exhaust shop to have the flange changed. The 3 bolt flange on the cut out is a standard header flange.

Here ya go:

 

Aby,

Here is a link to an already pre-fab'd wastegate activated exhaust valve:

http://www.atpturbo.com/root/releases/release091004.htm

 

Also, Pegasus, you can run a nice stainless braided line to replace your vacuum line if you are worried about the heat or buy some DEI shielding that can slip over your existing line.

 

Cant you just tighten down the actuator arm which would increase the preload and help keeping it from rattling?

 

The microphones in your phones are all different so the comparisons will be hard to make from this thread. A couple of things that might make the data in this thread a little more meaningful would be to state the phone and application that you used to measure the sounds levels.

For the outside test, we should decide on a position and an orientation for the phone mic. What I mean by position is should everyone be measuring the sounds levels 20 inches directly behind the exhaust outlet (which would expose the microphone to strong directional pulses) or slightly to the one side of the exhaust outlet (to be more of a measurement of the dispersing sound). What I mean by orientation is should everyone be pointing the mic directly towards the exhaust outlet?

For the inside test I think that we also need to agree on a setup.I would recommend the following for consistency's sake. Windows up, radio off, fan off, and phone laying on center console with mic pointed up.

Thoughts? We should compile and update the first post. Can spreadsheets be uploaded onto here?

 

This one is no longer available.

Also thanks for the heads up the stainless steel braid. I might have to look into that.


Yes but that its not that type of slop. It is side to side slop. Since there are no bearings. I'll have to double check though to make sure its all tight, but when I checked it on the bench it was solid tight when closed.

 

The app has a lot to do with it as I downloaded two different apps and get two different readings. Doesn't matter anyways as this thread seems to have wondered into a completely different category.

 

Excellent points. Even though I own a SPL meter, I've been hesitant to contribute to the thread knowing how these things work. Looking at the posted results, sans Aby's, there's no way to be sure that we're comparing apples to apples. I wouldn't really have an issue with it if we were doing this for fun, but folks may reference the results in their individual purchasing decisions.

 

Absolutely.

I think it might be more relevant if the readings were before/after exhaust change, but still, no telling how much a phone mic can pick up.

Still, I appreciate the efforts. It's definitely at "your own risk" to decide based on this thread, but I guess it is better than nothing, and IMO, better than youtube clips.

 

I used this

https://market.android.com/details?id=kr.sira.sound

Driod X. 20 inches away, phone flat, dispaly up, mike end towards exh.

3" buschur DP, 100cell cat and Fujitsubo Rm01a exh

72 @ stock idle (800 RPM??)
90 @ 3200 RPM.

Overall seemed to read much higher than the sound seemed.

It was in the low 40's in a dead quiet room inside.

So far I consider it useless.

I did manage to cover my phone with condensation and little black spots of gunk though.

 

??? why do you say the readings are higher than seemed? so you used a sound measuring device before with your car?

here are results of a 100% stock exhaust w/264 hks cams + 2 other set-ups, while using a proper sound measuring device.....the in-cabin values arent that far off.

these results are of my car back in '06.



once again, i know that phone mic's vary, let alone multiple other variables...

this thread was a means of using a common device to assign a sound # vs "oh, thats so loud" or "my exhaust is as quiet as stock"...

come on guy's, how many times have you read contradicting impressions / opinions about the same product..

consider the cell phone app is a 3rd party tester.

 

The chart that came with the phone app claims very quiet room @ 20, while it was reading 42. I just don't think it is going to be a good comparison tool from one person to another. May be good enough for before and after, but only if it is linear in it's error (again, between different phones/apps). Have read certain reviews of people who downloaded different sound level apps and them being off by 20db between them. So which app is right?

 

^haha, that sthe whole point 20 vs. 42..... quiet room vs quiet room....

i know that in my office, ~5:40am, nobody in-making noise, talking & such, the omega sound measuring device was reading 39 while the phone app was reading 40!

This phone app isnt an acid test or replacement for proper devices.

btw, what cams are you running?