Wednesday, February 22, 2012

Dyno (Days) Again!

Back at Global Motorsports Group for the second round of dyno tuning. The first results came out unsuccessful, so hopes were high that the clutch job and tightening of the wastegate actuator would bring expected numbers. 
You can see in the picture below, The Electronic Boost Controller on the driverside fender is recieving a boost source from all the way across the motor to the intake manifold. The boost source tells the boost controller to pressurize the wastegate spring. If the source is too long the signal is delayed. This may cause what we have repetedly been seeing, a lost of boost at springs maximum pressure (crack pressure). So the spring that came with the Forced Performance 20G is holding 15psi when it cracks.
The boost pressure is written in green on the y-axis of the map. AFR's in black. Eng. TQ. Blue and Eng. HP in Red. After playing with the boost controller we got it to crack at 17psi. Boost pressure falls rapidly to 14psi and creeps back to 17pounds. When the boost drops power drops. This is only 226HP. 

I decided maybe the boost controller and wastegate actuator would work better with a clear boost source straight from the compressor housing on the turbo. So I drilled a hole for an 1/8npt tap. I went with an 1/8 nipple for the push on hose fitting. 
After doing this we put the car back onto the dyno, and the response was sooner but the same boost drop was occuring. So abouth to throw in the towel, I made a call to FRSport and picked up an 18lb. wastegate actuator spring before they closed on Tues. night.
I had to fabricate a bracket so I made a template and Wed. morning I cut the bracket out of aluminum. 
Make two to be safe! 
The Outcome. Well this is a base tune with lots of potential. There is still the boost controller that needs tinkering with to get the boost to hold sooner. This is 296HP. My dyno time ran out here. Thanks to Stephen Ruiz for being so patient.


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