4k Powerband...

[Jeeves]

Now, I've searched and only really come up with a wealth of contradictory info.

I own a 1994 V6 Camry XLE w/the 1mz-fe and the stock auto/stall in it. I'm not looking for power so much as looking for answers to why at 4k there's an immediate and hugely noticable gain in power. I know it's not the auto's fault, while they're totally ball-less below 4k, I've been told the 5spd's have a good amount of ummph to them.

Some have said that it's the cam profiles, others have said it's due to head design, yet others mention over-sensitive knock sensors. Is there actually a good answer to this question? Thanks.

[terrastrife]

ACIS valve opens at 3900rpm, shortens the intake run length for hi end power, when its closed, the longer intake is better for low end. with some form of piggy back ecu or some ecu hack you can lower the valve opening to closer to 3200rpm which will smooth it out a bit better.

the valve is ocnnected to the plate the blocks the left side of your intake manifold.

search for ACIS if you want more info.

edit: cleaned it up, im sleepy.
edit again: toyota autos are quite good, you should try another manufacturer, they suck real bad (my tacho needle is too slow changing into 2nd) :P loose something like 5nm torque and 20whp because of hte auto, take off is slower becasue the stick has shorter gearing.

[Toysrme]

^ Actually the ACIS valve closes to increase the length of the runners.
Which in-turn promotes higher horsepower.
(longer runner, higher velocity, more stuffed into the cylinder, more power)

The Auto isn't to blame. What you loose in performance before the torque convertor locks up is helped by torque multiplication on launch so. eh. It's slower stock to stock, but they're not bad.
It's not head design LoL! FE head/cams produce much more power in low-mid rpm ranges than GE head/cams.

over-sensitive knock sensors.

Maybe, but I would pretty well doubt it. The biggest thing about ignition timing is the throttle responce you get with it, not so much power increase. If it is overly sensative, if would just respond a little slower as you open the throttle, and you'd lack a few horsepower, not a lot of it!




I think it's more the way the cams are setup for your engines stock. They really lack power down low.
I'm sure it is more pronounced on the 1mz's as you lack a lot of torque down low.
Ratko's (with Tony speculating at the time a knock sensor was overly sensative





Go HERE To learn about cleaning your ACIS valve. While you're in there, clean the entire upper intake chamber as well. it's going to be caked with EGR.

[Jeeves]

Does anyone make EGR block off plates for the 1mz? W/the 1994 not having OBD2 I shouldn't have any issues blocking it off...

Thanks for all the info by the way.

[Toysrme]

No but it's not that hard to do. If it's piped like the 3vz-fe, you simply ditech the EGR pipe that uses a JIC fitting to hold the pipe in the manifold and seal it from leaking.

When you ditch the pipe you can go to a nut & bolt house that sells JIC fittings and have them give you one you can bolt down and cap the EGR with.


All it takes to seal the intake side of the EGR is the thinest piece of metal you have with some sealant on it.




Note that unlike an older OBD-I car, you can't totally ditch the EGR system as the ODB-II car has to have it on the car.