Background information:

JDM Evo 9, stock ECU, FP Red Turbo, Hallman MBC, 90 Octane etc.

Take a look at the two virtual dyno runs in the attachment. These graphs were created using logs taken while the car was on a dynojet dyno. As you can see the spoolup and peak torque is significantly different between the two runs. THese are back to back runs with the second run being the one with the much higher torque and faster spoolup. The thing that has me confused is that the only changes made to the map were some minor fuel map changes. No timing adjustment, no Mivec adjustment, no knock and no boost controller adjsutment. So what caused the car to behave so differently?

I am ruling out Virtual Dyno/Evoscan error as the dynojet graphs show the same difference although the numbers are not exactly the same (I actually played around with the occupant weight in Virtual Dyno to get the numbers to read closer to the dynojet numbers). The actual Dynojet numbers were about 370hp and 330 Tq for the higer torque run.The actual numbers are not important though.

I am thinking that a malfunction with the Mivec could be causing this or maybe an acutator problem. Please weigh in with your opinions.

 

Your boost curve moved to the left hence the difference in the tq/power curve between the two runs. Its mostlikely mechanical (boost leak, stuck wg flapper door) not exactly sure. Id take it in and have looked at.

 

Yes, I realize that it built the boost sooner resulting in the higher torque. You might be right though, maybe the flapper is not always closing properly.

 

maybe it's the dyno eddy brake.

 

VD needs to be used on the road not dyno. Loads the car better and factures in wind ect..

 

I could be a multitude of things. A boost leak or an exhaust leak pre turbo could cause this issue. My car did the same thing and it turned out to be an exhaust leak between the turbo and the manifold.

 

I only used VD to determine if what I was seeing on the dynojet was correct or not. The dynojet shows basically the same difference. I am not concerned with the exact numbers but I am concerned with why the car behaved so differently between back to back runs.

 

The thing is the car did a couple of runs with the boost response and torque basically like the lower of the two curves. Then the next run showed the higehr torque. The torque stayed like that for the following 2 or 3 runs and then it dropped back to the lower curve for the following 2 runs. We took it off of the dyno after that.

I don't expect that a boost leak would exist, then fix itself and then reoccur.

 

These graphs are confusing.

 

You are confusing the curves.

 

It almost looks like the red run was in 3rd and the blue run was in 4th with the way the boost curve is with that FPRed. That would also explain the higher torque and lower horsepower on the blue run compared to the red run. Maybe he didn't realize what gear he was in?

~Chris@MooreAutomotive

 

i think if he through this 3rd gear data into 4th or vise versa he will have huge different in power the run detail says both were done on 3rd gear.

 

I was thinking that also when we were on the dynojet, but VD proves that both were in 3rd gear. If you plot one curve in 4th and the other in 3rd you get screwy numbers.

 

I would say mechanical problem with flapper/ actuator as well.

 

yeh it's either flapper problem or dyno load