Stuck with a tired IS300 automatic, a weak W55, or a clunky R154? Looking for faster shifts, better drivability, and a transmission that can actually grow with your power goals? Want trans-brake launches and the ability to clutch-kick? The ZF 8HP swap kit for the Lexus IS300 is the upgrade you’ve been waiting for.
Our kit allows you to run the modern ZF 8HP transmission behind your 2JZ-GE, giving your IS300 lightning-fast shifts, incredible durability, and a truly modern driving experience.
Using an 8HP45, really?
While developing our 2JZ adapter plate for the Dodge 8HP70, we also examined the Dodge 8HP45 from a V6 RWD Charger to see if it could be a good, budget-friendly alternative. We purchased one and created a variation of our adapter plate to fit the Dodge 8HP45 (or 845RE as Chrysler call it) as well. Right away, we noticed a few differences: the bellhousing bolt pattern isn’t identical to the 8HP70, and the transmission mount also varies slightly. Overall dimensions, however, are very similar. The bellhousing size is nearly the same, so there aren’t any major clearance advantages.
With the 8HP45 sitting in the shop, we wanted to know how it stacks up against the 8HP70 — which has proven extremely capable. So we decided to install the 8HP45 and push it to its limits to find out how strong it really is.
The 2JZ build
For this car, we aimed for a typical setup we often build at the shop for around 550 whp. The IS300 that we bought was a rolling shell without engine and we had a 2JZ-GE non-VVTi engine from a MK4 Supra. The 2jz was torn down, fitted with new rings and bearings, and upgraded with ARP head studs. We also installed a 2JZ-VVTi oil pump to add the integrated trigger wheel and crank sensor, since the non-VVTi 2JZ-GE relies on an electronic distributor and does not have a crank sensor from the factory. We fitted a hall cherry sensor in the head for the cam sensor and used our 2jz-ge distributor block off plate to seal the distributor hole.
List of modifications:
- MaxxECU Sport ECU relocated under the driver seat
- 1ZZ Ignition coils
- 1000cc Injectors with Radium Direct Mount Regulator
- Perfect Tuning Intake Manifold with GM Electronic 90mm Throttle body
- BorgWarner S366 Turbo with 44mm Wastegate
- Custom 3" Intercooler and piping
- Walbro 450 lph fuel pump
- Battery relocation in the trunk
The 8HP installation
The Dodge 8HP70 and 8HP45 are very similar transmissions. Their overall length and external dimensions are almost identical. Some 8HP45 units use a 3-bolt driveshaft flange, while others share the 6-bolt flange found on the Dodge 8HP70. The transmission mount is also similar, with only minor differences, and both models use the same oil pan.
The Lexus IS300 transmission tunnel is quite small. When we developed our CD009 swap kit a few years ago, we had to bang the tunnel significantly to clear the larger CD009. Especially around the shifter area. In comparison, the Dodge 8HP has a more compact casing, so it fits the IS300 tunnel much more easily and require only minor tunnel clearancing.
The tight area is near the firewall. The bellhousing on both the 8HP70 and 8HP45 is large but tapers quickly. To simplify the installation and increase clearance, we moved the engine forward by 5/8 inch using our custom stainless motor mounts. With this setup, the fitment becomes straightforward and much cleaner.
Here are the pictures showing how the 8HP fits in the IS300 tunnel and the areas we had to modify for proper clearance.
We designed the transmission mount (which is different than the Dodge 8HP70 by just a little) and we went with our usual 3.5" Aluminium driveshaft but with 1310 joints because it's a direct bolt on on the OEM differential. The other option for bigger setups is the 1350 driveshaft but it requires the 4 bolts diff adapter available on our website.
MaxxECU Sport? Why not go with a MaxxECU Race?
Yes, definitely the Race is a better choice for a 6 cylinders like the 2jz. With the drive by wire throttle body, it's not ideal but it works because we're quite limited on the analog inputs. The other big advantages of the MaxxECU Race is the knock inputs that the MaxxECU sport doesn't have.
We designed our CANBus shifter module for the Perfect Tuning sequential shifter and were able to use this module for the shifter and as a port expander. We also designed a CANBus Knock Module that we are currently testing.
Finally ready for the dyno!
More to come.... Stay tuned.
Lexus IS300 Gets the ZF 8HP!