[VeilsideTT]

I have a 94TT Auto with an SBC-ID boost controller. That controller has a little boost time graph so I can see boost throughout my whole pull. Everytime I hit it from a stop my boost falls to 0psi or even vacuum during the 1-2 shift. Is this normal? I know traction control limits boost during shifts but during all other gear changes (2-3, 3-4) my boost only falls a few PSI. Is there something wrong with my car or is that normal for autos.

 

[RSA Supra]

I can't say for sure, but it sounds pretty normal to me.

In a turbo car w/ an automatic the boost will actually spike during shifts. Toyota tried to limit this to protect the tranny, turbo's, etc. The traction control essentially lets of the gas during shifts, and the BOV vents boost. During the 1-2 shift, the engine's not loaded that much and the Bov probably vents most of the boost off sucessfully. In higher gears then engine is loaded more, boost is higher, etc. and so its probably not getting rid of all of the boost in those gears.

 

[VeilsideTT]

Thanks. I'm glad to hear it is probably normal.