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I know we all hear the rumor that the JZZ30 ECU (Soarer) is supposedly more aggressive. I just ordered a JZX90 ECU for my Cressida, because it will fit in the glove box much better than the JZZ30 ECU will because of the plug locations on the box. (My Cressida has a JZZ30 Soarer set).
So my JZX90 A/T ECU arrived today, so I installed it and took it for a test drive. I noticed that the shift points are more aggressive with this JZX box than the JZZ box, which is understandable. The thing that suprized me was that my maxium boost was only 8psi. So I was like WTF?
So I pull off the side of the road, switch back to the JZZ30 ECU, and test again. Now I am back to building 10psi max. Now I am really wondering if I am reading the boost gauge right, so I pull off the road again, put the JZX ECU back in, test drive again, and only 8psi. (I am currently running NO boost controller BTW).
So based on just my boost readings, there is about a 20hp (2psi) difference between the JZZ30 and the JZX90 ECU (with the factory hardware, no boost controller)... but what I don't understand, and no one has been able to explain to me why my boost is being effected just by changing out ECU's? I mean aren't the wastegates vaccum controlled? Or does the ECU have some way of controlling the vaccum on these engines that hasn't been documented yet?
I mean yes I know I can (and I plan to) install a boost controller in the next week or so, but I'd like to understand WHY there is a boost difference between the 2 computers... Anyone have any ideas or wisdom they'd like to share with me?
Thanks!
So my JZX90 A/T ECU arrived today, so I installed it and took it for a test drive. I noticed that the shift points are more aggressive with this JZX box than the JZZ box, which is understandable. The thing that suprized me was that my maxium boost was only 8psi. So I was like WTF?
So I pull off the side of the road, switch back to the JZZ30 ECU, and test again. Now I am back to building 10psi max. Now I am really wondering if I am reading the boost gauge right, so I pull off the road again, put the JZX ECU back in, test drive again, and only 8psi. (I am currently running NO boost controller BTW).
So based on just my boost readings, there is about a 20hp (2psi) difference between the JZZ30 and the JZX90 ECU (with the factory hardware, no boost controller)... but what I don't understand, and no one has been able to explain to me why my boost is being effected just by changing out ECU's? I mean aren't the wastegates vaccum controlled? Or does the ECU have some way of controlling the vaccum on these engines that hasn't been documented yet?
I mean yes I know I can (and I plan to) install a boost controller in the next week or so, but I'd like to understand WHY there is a boost difference between the 2 computers... Anyone have any ideas or wisdom they'd like to share with me?
Thanks!