Dyno test with helper spring on wastegate.

[bemis]

After hearing about the "helper spring" idea for the wastegate, I decided to do it myself. At first I hooked up the helper spring in conjunction with the ball and spring boost controller. It brought the boost up, but I still had boost spikes and fall offs. BAD for a 15-18lbs. boosted non-intercoolered engine running on meth/water injection, which has a small latency before it takes effect. So, I decided to remove the boost controller completely from the lines and just setup the wastegate to run off the helper spring. This made a huge difference. The boost doesn't spike and it stays where I set it.

Here's what the boost looked like with a ball and spring boost controller, before the helper spring. The boost was set to about 18lbs.

HP on the left, PSI_g(boost) on the right.



And here's what the boost looks like with only the helper spring on the wastegate. The boost was set to about 14lbs.



Thanks Ellis AutoWorks for letting me use their kick ass dyno to do some seemingly pointless tests.

Peace!

[FlawleZ]

Interesting. Which MBC are you using? I'm glad I'm not the only one who is taking their sweet time to intercool their Z. :?

[bemis]

I'm not using any MBC, just a helper spring on the waste gate.

[Jason84NA2T]

I noted exactly the same thing when adding yet another helper spring last time I dynoed. The boost onset point didn't raise nearly as much as it did out closer to redline. Meaning the boost was more stable and "flat"

My stock actuator now holds 24PSI rock steady to redline, but the maf voltage maxed well before that and I have to correct it by other means.

Also interesting to note that at your peak power each time, the 2PSI difference made 11hp. You can see how the compressor efficiency is falling off at that boost level.