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Hey Matt, in one of the previous post you've mentioned you were going to try using an automatic trans instead. Have you tried using GM's auto trans such as 6l80e or something similar?
 
Discussion starter · #23 ·
Hey Matt, in one of the previous post you've mentioned you were going to try using an automatic trans instead. Have you tried using GM's auto trans such as 6l80e or something similar?
When I was building my race car I tried to test fit a 4l80E and it was crashing into the trans tunnel way too much. Since then I've seen one of my customers swap in an auto so I know it works it just requires a great deal of hammering the trans tunnel.

Matt
 
Discussion starter · #24 · (Edited)
I may not have all the answers for the automatic transmission swap but I will shed some light on the manual T-56 and TR6060 variants. The key issue here is purchasing the right transmission so that the shifter lands in the OEM Lexus shifter hole properly. I've always used the F-body t-56 1998-2002 Camaro/trans am transmission and have found it requires a small amount of notching towards the front of the opening. (I'll post a picture of this here later)

This picture illustrates the the tail housing and shifter location differences between 3 of the most common T56 transmissions. Its easy to see why the F-body trans works so well for the IS300. For those of you that don't know the Corvette places the transmission the rear of the vehicle using a "torque tube" to connect the engine and trans. This would require even more unnecessary spending.

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Without going into a lengthy explanation I'll share some part numbers to delete the Skip shift and reverse lock out feature on the T-56 trans. Not only are these features annoying but they don't fit in the Is300 trans tunnel very well. The list of parts is short and cheap.

Reverse Lockout Delete:
Dorman 555-086

CAGS Delete:
Dorman 090-040

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Planning to make some serious power or drag racing on slicks? The T-56 has some weak spots in stock form. If you're planning to make over 500ft lbs of torque I suggest you look into the viper mainshaft upgrade or the next Topic. The TR6060 found in the newer Camaros and Cadillac CTS-V models. The CTS-V trans being the stronger of the two. These will require some work to make them fit but I know it can be done. RPM did the trans for my drag lexus project.

Info on the Tr-6060 can be found in this link, you'll also the the "Tremec Magnum TR-60606" which may offer some nice shifter location options for a good price.
http://www.hotrod.com/how-to/transmission-drivetrain/1301cct-tremec-t56-magnum-transmission/

CTS-v and Camaro lengths.

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This is my modified CTS-v tr-6060 with f-body tail housing.

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This would be a good time to change the clutch since the stockers don't hold much power. I've chose the stock LS7 clutch and flywheel combo since this clutch is known to hold good power while retaining stock driveablity, not too hard on the wallet either.

Clutch and pressure plate: 24255748
Flywheel: 12571611

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Even if you got lucky enough to find a 5 speed is300 you'll still need to upgrade the master cylinder to a 7/8 bore.

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Discussion starter · #25 · (Edited)
When it comes to the mounts you have a couple choices. You can make your own assuming you have the tools, skills and time necessary to do so. Word of advice the stock Is300 engine isolators are weak so avoid using them if you build mounts yourself.

I'm partial to this kit. The hard work is done for you and includes all mounting hardware.

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You'll also need a driveshaft, these can be made to your spec locally or purchased from the site above.

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I've confirmed ABS relocation is NOT necessary but it does help to clean up the engine bay substantially if moved. The LS1 ecu is big and bulky with no real protrusions for mounting. For years I've mounted mine in the stock battery location to do so you'll need to relocate the batter to the truck.

This battery box is a nice choice. Taylor part number 48101
http://www.summitracing.com/parts/tay-48101

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I know I touched on the fact that the Miles per gallon and coolant temp gauges will no longer be working. However I've found the use of this inexpensive Scangauge to be quite convenient. Not only does it display a digital signal of what the GM ecu is reading but you can also read codes and reset the ecu on the fly.

Amazon.com: ScanGauge II Ultra Compact 3-in-1 Automotive Computer with Customizable Real-Time Fuel Economy Digital Gauges: Automotive

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Discussion starter · #28 · (Edited)
Now onto the part everyone seems to fear "the wiring". After looking at some of my old build threads I can see why this part may look intimidating. Truth be told its actually incredibly easy.

I've taking the liberty of making a "flying lead harness". This harness will utilize all the factory Lexus circuits available on the ecu header connector while also tricking some of the circuits to work with the GM ecu.

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GM Ecu pinouts and body harness connectors can be found on here.
http://lt1swap.com/wiringharness.htm

Is300 wiring can be found in this link but I highly suggest purchasing the Lexus wiring manual if you're serious about wiring.
http://www.2jzgarage.com/2013/04/is300-wiring-diagrams/
http://www.2jzgarage.com/2013/04/lexus-is300-ecu-pinouts/

These are my go to books.
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Keeping with the theme, the 1998-2002 Camaro and Trans-Am F-body wiring will be the only harness I'll cover.

The color coding on my fling lead harness matches the Gm wires as close as possible. These connections are made on the body harness side of the GM wiring harness.
Found here: http://lt1swap.com/ls1_wiring_harness/2000_connectors.htm

Pink = Switched 12v
Orange = Constant 12v
Brown = Check engine light
Green= Data stream output to the OBD2 port
White= Tachometer

Hook up the pink and orange wires and your car will run. Imagine that..

I've highlighted the circuit required. Some of these are for the a/c system I'll cover later.
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Image

Image

Image

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I'll go through all crucial GM wires and label them making my connections easier. This is what you should end up with following the guide above.
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The GM body harness connectors. If you have the opposing side of these connectors you can use them for the splice.
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I used a Deutsch dtm connector to make my 11-12 connections here.
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My harness plugs directly into the stock lexus ecu header connectors. With enough length to run these wires nearly anywhere in the engine bay. With the F-body harness I typically install it where the battery sits.

Image


Some additional wiring will need to be performed in the stock Lexus ecu location. The park position switch will need to be jumpered (if an auto chassis) and the reverse lights. Send these wires to the ecu locations with the rest of the jumper harness. It would take too many pictures to illustrate every step of this process.

For the 2001:
EA1 Jumper pin 2 to pin 6 (Park Position switch)
EA2 Pin 2 (Tacho)
J1 Pin 3 feed power through reverse switch to Pin 2 (Reverse lights)

For 2002-2005:
EA1 Jumper pin 2 to pin 6 (Park Position switch)
J1 Pin 3 feed power through reverse switch to Pin 2 (Auto Reverse lights)
J1 Pin 2 feed power through reverse switch to Pin 1 (manual Reverse lights)

You will actually need two additional wires from the Lexus ecu location to the GM ecu location. These are the Pin J1 reverse light wires. Basically a power to the reverse light switch (GM) and a return power to the reverse lights (Lexus).

You can see EA1 in this picture and also the white connector to the left of EA1 is the J1 connector.
Image


Once my wiring is complete I tuck the connectors down the old ECU box vent hole in the body.
Image
 
More more more! :approve:
 
Now onto the part everyone seems to fear "the wiring". After looking at some of my old build threads I can see why this part may look intimidating. Truth be told its actually incredibly easy.

I've taking the liberty of making a "flying lead harness". This harness will utilize all the factory Lexus circuits available on the ecu header connector while also tricking some of the circuits to work with the GM ecu.

Image


GM Ecu pinouts and body harness connectors can be found on here.
Wiring Harness Information

Is300 wiring can be found in this link but I highly suggest purchasing the Lexus wiring manual if you're serious about wiring.
http://www.2jzgarage.com/2013/04/is300-wiring-diagrams/
http://www.2jzgarage.com/2013/04/lexus-is300-ecu-pinouts/

These are my go to books.
Image


Keeping with the theme, the 1998-2002 Camaro and Trans-Am F-body wiring will be the only harness I'll cover.

The color coding on my fling lead harness matches the Gm wires as close as possible. These connections are made on the body harness side of the GM wiring harness.
Found here: New Page 1

Pink = Switched 12v
Orange = Constant 12v
Brown = Check engine light
Green= Data stream output to the OBD2 port
White= Tachometer

Hook up the pink and orange wires and your car will run. Imagine that..

I've highlighted the circuit required. Some of these are for the a/c system I'll cover later.
Image

Image

Image

Image

Image




I'll go through all crucial GM wires and label them making my connections easier. This is what you should end up with following the guide above.
Image


The GM body harness connectors. If you have the opposing side of these connectors you can use them for the splice.
Image


I used a Deutsch dtm connector to make my 11-12 connections here.
Image


My harness plugs directly into the stock lexus ecu header connectors. With enough length to run these wires nearly anywhere in the engine bay. With the F-body harness I typically install it where the battery sits.

Image


Some additional wiring will need to be performed in the stock Lexus ecu location. The park position switch will need to be jumpered (if an auto chassis) and the reverse lights. Send these wires to the ecu locations with the rest of the jumper harness. It would take too many pictures to illustrate every step of this process.

For the 2001:
EA1 Jumper pin 2 to pin 6 (Park Position switch)
EA2 Pin 2 (Tacho)
J1 Pin 3 feed power through reverse switch to Pin 2 (Reverse lights)

For 2002-2005:
EA1 Jumper pin 2 to pin 6 (Park Position switch)
J1 Pin 3 feed power through reverse switch to Pin 2 (Auto Reverse lights)
J1 Pin 2 feed power through reverse switch to Pin 1 (manual Reverse lights)

You will actually need two additional wires from the Lexus ecu location to the GM ecu location. These are the Pin J1 reverse light wires. Basically a power to the reverse light switch (GM) and a return power to the reverse lights (Lexus).

You can see EA1 in this picture and also the white connector to the left of EA1 is the J1 connector.
Image


Once my wiring is complete I tuck the connectors down the old ECU box vent hole in the body.
Image


Sorry to jack this thread, but i'm getting desperate. Currently i have a 1.5jz non vvti with a OEM 2jz Ignitor which has a rpm output coming out of it, can i wire this directly to the E4 pin 16 or do i need the cam or crank signal wired into the stock ECU to have the stock is300 ECU output the RPM signal? or is the RPM an analog signal i can feed into the stock IS300 cluster from my 2jzgte igniter? here's my link and my thread i started with no luck :( 2002 lexus is300 Tach/rpm signal & coolant gauges )

Thanks in advanced!


I can't find this info anywhere, for the tach signal is it an analog input to the cluster or does the stock is300 ecu have to translate it to the cluster via MPX/can-bus type signal?
 
I can't find this info anywhere, for the tach signal is it an analog input to the cluster or does the stock is300 ecu have to translate it to the cluster via MPX/can-bus type signal?
That member has not been on the forum sense 2017. Old dead thread. You should continue on the thread you started. MPX translates.
 
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