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Discussion Starter #1
Hello every body....how can i customize the timing of autotrans gear shifting? My car is 7mge engine and the gear controler is lexus se300.
 

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Blue Thunder
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Get an aftermarket ECU. What is an SE300? You mean ES300? Or SC300?
 

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Discussion Starter #3
Thank you for responce. Sorry i mean es300... my car has seperated controler for gear. How can i choose another car gear controler?
 

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Arman,

is there something wrong with the transmission TCU? what are you trying to achieve by replacing the TCU?

There are no drop in replacement for standalone aftermarket TCU, the ones that are available will have to be wired in completely AND you will have to understand some transmission basics (how many solenoids, amperage draw for solenoids and convertor lock up). It is not a small thing to try and accomplish.
 

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Discussion Starter #5
Hello figgie....the gear shifting is too fast.. for example the first gear changes when the car reaches 20km/16ml with full throutle
 

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7M Fanatic
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I hold my trans in first, and it will actually run up to my 8500 rev limit.
The trouble with that is there is a small delay between when I move the lever to second, before it actually shifts into second.
I had to shift at about 5500, and the delay would then actually shift at the 8500.

I used a shift light to know when to shift from 1st, to 2nd, so I could hit 8500.
The other gears all shift when the engine ECU said to shift, which the shift points were bumped by changing the clock crystals in the ECU.
This was not on an ES300 trans, but the original A340E with an IS300 pump, and overdrive assembly behind a built 7MGE.

This may not work on an ES trans, as I know in the later autos they started playing with more computer control of converter and clutch lock up to get what seemed to simulate more gears.

A340E shifting at 8500 rpm
Noticed I just missed the 1-2 shift on this pass, as it bounced on the rev limiter just a little.
After adding the shift light, it would just hit the rev limiter a little less, so that the engine would just come off full power for a millisecond while the trans shifted. Helped tearing the bolts out of the torque converter, and crank shaft a little.

Finally called it quits on this trans due to no one being able to build a true high stall converter for it.
the most I ever got from anyone was about 3200, which was way to low for this engine.
I really needed something up around 5000 due to the mods.
 

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Discussion Starter #7
Actualy i made a cut switch on the way of speed sensor signal so i can hold the first gear as much as i want then turn the switch on and tcu start to read the signals and change gears...this way i could make drift mode.
 

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There aren't many computers that can control the automatic transmission. The easiest is the stock computer, but then you can not change when it shifts. A 'suprastick' (I'm not sure if it is still able to be purchased) will allow you to manually shift your car with buttons/paddles.

If you have the ECU from another car, in your car, and it isn't shifting right, it's because the sensors are different between the two cars.

A standalone ECU (like the ProEFI) will be able to control the automatic transmission, and you can change shift points that way.

Unfortunately there aren't any options in between.
 

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Discussion Starter #9
There aren't many computers that can control the automatic transmission. The easiest is the stock computer, but then you can not change when it shifts. A 'suprastick' (I'm not sure if it is still able to be purchased) will allow you to manually shift your car with buttons/paddles.

If you have the ECU from another car, in your car, and it isn't shifting right, it's because the sensors are different between the two cars.

A standalone ECU (like the ProEFI) will be able to control the automatic transmission, and you can change shift points that way.

Unfortunately there aren't any options in between.
Thank you
 

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back in the day

Ian (IJ.) ran a PCS TC2000 which is now superceded with the TC2800.


today there are numerous companies that sell standalone TCU.

TCI Auto/FAST (Fuel Air Spart Technology)
Holley
numerous companies are starting to support the 6speed, 7 speed and some are even supporting the 8 speeds.

the trick is to understand how the transmission works and than any TCU can be made to work with them (assuming the TCU has enough outputs and each output can support the necessary current)..
 

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I hold my trans in first, and it will actually run up to my 8500 rev limit.
The trouble with that is there is a small delay between when I move the lever to second, before it actually shifts into second.
I had to shift at about 5500, and the delay would then actually shift at the 8500.

I used a shift light to know when to shift from 1st, to 2nd, so I could hit 8500.
The other gears all shift when the engine ECU said to shift, which the shift points were bumped by changing the clock crystals in the ECU.
This was not on an ES300 trans, but the original A340E with an IS300 pump, and overdrive assembly behind a built 7MGE.

This may not work on an ES trans, as I know in the later autos they started playing with more computer control of converter and clutch lock up to get what seemed to simulate more gears.

A340E shifting at 8500 rpm
Noticed I just missed the 1-2 shift on this pass, as it bounced on the rev limiter just a little.
After adding the shift light, it would just hit the rev limiter a little less, so that the engine would just come off full power for a millisecond while the trans shifted. Helped tearing the bolts out of the torque converter, and crank shaft a little.

Finally called it quits on this trans due to no one being able to build a true high stall converter for it.
the most I ever got from anyone was about 3200, which was way to low for this engine.
I really needed something up around 5000 due to the mods.
Is this not the same transmission in that is in the A80 TT Auto cars? I thought they made custom converters up to 4400RPM for them now.
 

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No, it was a hibred, part early A340E, part later SC300.
But the problem was that a converter that will do 4400 on a boosted engine, even if the boost is low, will not do that on a high strung NA, which probably isn't making stock torque at that rpm, where as the boosted is actually making more.
Stall rpm is directly related to input torque.
All behind me now, as I have went very close ratio 6-speed. Clutch engages at any rpm I want it to, and engine rpm drops only 1500 between shifts.
 
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