Transmission( valve body upgrade)
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Lexus Champion
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From: North Carolina
Transmission( valve body upgrade)
Any thoughts on a valve body upgrade for the 2IS. I noticed at the track this past weekend that the car was smacking the limiter in auto mode. In both ECT power and normal. I have no wheel spin. The tranny just doesn't shift fast or hard enough to make a quick gear change.
Last edited by HKS350; Nov 14, 2007 at 11:33 AM.
Mine does that on occasion, but it's rare, and it always learns to shift earlier the second time. The challenge I see with upgrading the valve body is that it would probably wind up causing the transmission to shift way too early since the transmission's ECU would stil initiate the shift at the same point. For example, In 1st gear, the ECU probably initiates the shift at 5900 RPM so that it will complete by 6400 RPMs. In 2nd gear, it would initiate the shift at probably 6200 RPM so that it will complete by 6500 RPM. If you upgrade the valve body, then you might find that the peak RPM you could reach might fall to 6300 RPM in any gear. That would suck since the rev limiter is above 6700 RPM.
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Joined: Jun 2007
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From: TX
I just wish there was something to make the actual shifts faster. I have noticed the couple of times that I have been to the drag strip that i set the little red light to come on @ 5800 RPM or 6000 RPM and when I shift "manually" it still goes up to redline before shifting. I bet we could all pick up a tenth of a second if we could get fast crisp shifts...
Pole Position
Joined: Sep 2006
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From: Smoggy, CA
A valve body upgrade would be sweet. Toyomoto did mine in Miami on my 2001 IS and it made a world of difference. No more hanging at redline, or having to let of the gas for shifts to occur (with turbo / nos). The ecu shouldn't have an effect on whether the vb upgrade works well or not.
There are a couple of places that made electronic shift kits for the old IS that could probably do the same for our car's, although, the mechanical ones are much firmer and work at higher torque levels.
There are a couple of places that made electronic shift kits for the old IS that could probably do the same for our car's, although, the mechanical ones are much firmer and work at higher torque levels.
The ECU would have an effect since it is what controls the valve body. If the ECU continues initiating shifts at lower RPMs, then a modified valve body might just cause the shift to occur too early.
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Lexus Champion
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From: North Carolina
A valve body upgrade would be sweet. Toyomoto did mine in Miami on my 2001 IS and it made a world of difference. No more hanging at redline, or having to let of the gas for shifts to occur (with turbo / nos). The ecu shouldn't have an effect on whether the vb upgrade works well or not.
There are a couple of places that made electronic shift kits for the old IS that could probably do the same for our car's, although, the mechanical ones are much firmer and work at higher torque levels.
There are a couple of places that made electronic shift kits for the old IS that could probably do the same for our car's, although, the mechanical ones are much firmer and work at higher torque levels.
Last edited by HKS350; Dec 11, 2007 at 07:42 AM.
Pole Position
Joined: Sep 2006
Posts: 248
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From: Smoggy, CA
That's it! I had the TBKO ESK with the green switch. In either case, both of them (electronic / mechanical) didn't make the car shift earlier or anything - just firmer and quicker. It was great and made having the turbo worth while on an automatic.
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