Just Another (Turbo) Build

[rb6freak]

Before you all get your panties in a bunch, just note that these dyno results are preliminary as my tuning is not yet complete. Mustang dyno. It's called the heart-breaker dyno for a reason. I personally am not displeased with the results as the car feels great and I've already stomped a 2013 STI on WG spring pressure alone. This is about as best I'm going to get on the stock exhaust manifold. I'm confident that the new PTuning header will relieve a lot of back pressure and allow me to get smoother curve and better numbers.


91 octane

Red - HP
Blue - TQ
Green - PSI




Red - 91 octane 7lbs WG Spring, conservative, reliable, steady tune.
Blue - 91 octane 7lbs WG Spring, pushed quite a bit without running crappy timing.
Green - 91 octane 7lbs WG Spring w/ boost solenoid, max safe boost with this setup.

[King Tut]

Interesting how different the boost plot is with the boost solenoid. I don't understand how it allowed the turbo to spool quicker.

[rb6freak]

Originally Posted by King Tut

Interesting how different the boost plot is with the boost solenoid. I don't understand how it allowed the turbo to spool quicker.

I'm not an expert, but taking a guess I would say it has to do with the volume of air being drastically reduced when the solenoid is active. Almost 4 feet of 5mm ID tubing to be specific. Its all complicated stuff. It doesn't actually start spooling sooner, it just spools faster due to WG spring staying shut vs partially opened.

Again I'm no expert, just a guess based off my reading.

[King Tut]

I guess. I would be pissed with a wastegate performing like that.

[rb6freak]

Originally Posted by King Tut

I guess. I would be pissed with a wastegate performing like that.

I think that's just the nature of a single boost reference line on a WG. At least, the dyno charts I've seen with an added solenoid are about same as mine.

[AllDayJonRay]

Yea, that's what you get. Wastegate springs are just that: springs. So as boost starts to build, the spring starts to compress a little at a time, cracking the WG open and allowing some exhaust gas to bypass the turbine. And this gradually increases as boost increases, which means boost will climb gradually, and a little slower than with a solenoid installed. Its not the WG performing poorly, its just how WG's perform.

When you put a solenoid in-line and set it to 'spring pressure', it stops any manifold pressure from reaching the WG before that set pressure, so the WG doesn't crack open early or gradually, and you see a slightly steeper and slightly earlier increase in boost on your curve.

[King Tut]

I didn't notice any difference like that when I added a solenoid to my wastegate, but I also was targeting a higher PSI than my wastegate spring as well.

[AllDayJonRay]

Yea, a different target boost level will make a difference for sure. Also keep in mind that such a difference is easy to see on a graph, but not very likely noticeable on a boost gauge during live driving, or with the butt dyno.

[rb6freak]

Just another step closer to track readiness. Brake package arrived and will be installed shortly. PTuning header and oil cooler should be here and installed in the next month or two.

[rb6freak]

Photos and video, enjoy.

[ame]http://youtu.be/gJhyAKN-AWI[/ame]

[sw20kosh]

Originally Posted by rb6freak

Before you all get your panties in a bunch

This dyno reads like 15% lower than a dynojet I believe so you are right at 280-290 whp at 9 psi... on a dynojet. My panties are def not in a bunch!

[sw20kosh]

Originally Posted by King Tut

I didn't notice any difference like that when I added a solenoid to my wastegate, but I also was targeting a higher PSI than my wastegate spring as well.

Wastegates will start to crack open while you are building boost.

He gained better spool because the solenoid prevented the wastegate from seeing any boost untill the target psi was achieved. A non-bleed MBC will do the same like the HALLMAN PRO RX.

You are saying that your wastegate stayed shut the whole time untill the spring pressure was achieved? Or are you saying that when you converted from a MBC to a solenoid type you didn't notice a difference?

[King Tut]

Originally Posted by sw20kosh

Wastegates will start to crack open while you are building boost.

He gained better spool because the solenoid prevented the wastegate from seeing any boost untill the target psi was achieved. A non-bleed MBC will do the same like the HALLMAN PRO RX.

You are saying that your wastegate stayed shut the whole time untill the spring pressure was achieved? Or are you saying that when you converted from a MBC to a solenoid type you didn't notice a difference?

Wastegates will start to crack open as they see the PSI their spring is rated for. If you have a 15 psi spring in there you can guarantee it isn't coming close to opening as you build 2 or 3 psi. I used both an MBC and an EBC with solenoid and had the exact same boost curve with both, but I was using a 9 psi spring and targeting over 12 psi. I am just saying that if your target psi is close to the wastegate psi, then I could see getting a poorer boost curve when running just off wastegate with no boost control of any kind, but his example seems very extreme to me.

[sw20kosh]

Originally Posted by King Tut

Wastegates will start to crack open as they see the PSI their spring is rated for. If you have a 15 psi spring in there you can guarantee it isn't coming close to opening as you build 2 or 3 psi. I used both an MBC and an EBC with solenoid and had the exact same boost curve with both, but I was using a 9 psi spring and targeting over 12 psi. I am just saying that if your target psi is close to the wastegate psi, then I could see getting a poorer boost curve when running just off wastegate with no boost control of any kind, but his example seems very extreme to me.

I'll check my logs to see if I have the same effect he does when adding boost control to this waste gate. I only see about 5.5-6 psi on this waste gate spring. My target is 10 psi with the MBC.