Building an IS350 6MT
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Joined: Apr 2009
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From: California
Jeff
Thread Starter
Joined: Apr 2009
Posts: 5,211
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From: California
In regard to the mounts, the subframe did not need to be removed, the engine was raised a bit to get the mounts out and the new ones in. Should have just done it when the driveline was out. Oh well.
Car has had about 40,000kms on it since the swap, I've been driving it this winter for the first time since the swap... it's been fun.
Jeff
Car has had about 40,000kms on it since the swap, I've been driving it this winter for the first time since the swap... it's been fun.
Jeff
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Joined: Jul 2016
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From: UT
The engine is the same either way, it's just the ECU that is different. That said, using a non-VDIM GS350 ECU in an 06-08 IS250 for the swap would likely be the way to go. You'll still need to figure out a way to get it reprogrammed to not be upset about that pesky lack of a transmission to control.
Jeff
The second-gen GS guys are having really good luck with this little emulator module that wires in to the ECU and tells it sweet nothings about the auto transmission, allowing them to swap in manuals with no errors. I imagine something like that could be made for the 2IS, but it’s not nearly as common of a manual swap platform, so I don’t know who would be willing to commit to developing it.
Not to derail Jeff's build thread but if someone wanted to start a new thread exploring what is needed to trick an AT TCU into thinking it has valid inputs, lets open a discussion. That is not to say I plan on taking a leap. I don't. But I am open to participating in a group discussion.
/return
Jeff, what's on the the horizon for 2019?
/return
Jeff, what's on the the horizon for 2019?
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Joined: Jul 2016
Posts: 518
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From: UT
To hijack further, from what I understand the emulator designed for the 2GS (and also the SC300/400 and 1IS) has a circuit that satisfies the ECU’s check for operating shift solenoids. That’s easy. What it also does is returns an input to the speed sensor circuit based on the engine RPM. It essentially provides data consistent with being locked in one gear in order to prevent the engine control from pulling timing during a “shift.” All of it works in conjunction with the neutral start switch.
What some SC guys have done is removed their solenoids from the AT valve body, left them plugged in and just wrapped them in protective plastic and left them under the car. If they pin the wiring harness for D mode they tend to feel odd lumps in power delivery when the ECU tries to “shift.” But if I remember right, pinning it in “2” or “L” causes the ECU to freak when the speed sensor signal goes beyond the selected gear’s threshold. And pinning it in “N” doesn’t engage peak engine management, I.e. ignition timing is not mapped the same as when in “D.”
I’d be down to see another thread for this, I love learning about how these ECUs manage their lives.
*I don’t actually know a whole lot, I’m just regurgitating what I’ve read*
What some SC guys have done is removed their solenoids from the AT valve body, left them plugged in and just wrapped them in protective plastic and left them under the car. If they pin the wiring harness for D mode they tend to feel odd lumps in power delivery when the ECU tries to “shift.” But if I remember right, pinning it in “2” or “L” causes the ECU to freak when the speed sensor signal goes beyond the selected gear’s threshold. And pinning it in “N” doesn’t engage peak engine management, I.e. ignition timing is not mapped the same as when in “D.”
I’d be down to see another thread for this, I love learning about how these ECUs manage their lives.
*I don’t actually know a whole lot, I’m just regurgitating what I’ve read*
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Joined: Apr 2009
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From: California
I've actually been considering building a 'box' that did something similar, but programmable for various transmissions/expected inputs, it would make swaps much, much easier. But that's a future project.
Nothing big on the horizon for 2019 except some wear and tear replacement pieces and a new set of wheels. We'll see.
Jeff
Nothing big on the horizon for 2019 except some wear and tear replacement pieces and a new set of wheels. We'll see.
Jeff
Jeff, in post 280 where you installed TRD bushings and ISF sub-frame mounts, did this eliminate wheel hop? Well assuming you had wheel hop.
As best I can tell the F-Sport 350 has the same sub-frame mounts as the IS-F. Most everything shows the TRD differential mounts as discontinued but this may be a good time to us polyurethane.
Thanks
As best I can tell the F-Sport 350 has the same sub-frame mounts as the IS-F. Most everything shows the TRD differential mounts as discontinued but this may be a good time to us polyurethane.
Thanks
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Joined: Apr 2009
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From: California
I didn't have any bad cases of wheel hop that I can recall before changing the bushings, but the TRD bushings definitely helped keep the rear end more planted. I actually had them installed first and noticed they helped a bit, then had the IS F subframe bushings installed a couple of weeks later. I didn't notice as much of a difference with the subframe bushings. The TRD mounts would likely not work with the IS350 differential anyway, so you'll need to look elsewhere for those.
While the 2011+ F-Sport and Sport Suspension models share the subframe bushings with the IS F, the IS F does still have different differential bushings. I'm sure they're a bit stiffer, but still liquid filled. I'd look to other sources if you're looking for increased stiffness from the bushings.
Jeff
While the 2011+ F-Sport and Sport Suspension models share the subframe bushings with the IS F, the IS F does still have different differential bushings. I'm sure they're a bit stiffer, but still liquid filled. I'd look to other sources if you're looking for increased stiffness from the bushings.
Jeff
I've actually been considering building a 'box' that did something similar, but programmable for various transmissions/expected inputs, it would make swaps much, much easier. But that's a future project.
Nothing big on the horizon for 2019 except some wear and tear replacement pieces and a new set of wheels. We'll see.
Jeff
Nothing big on the horizon for 2019 except some wear and tear replacement pieces and a new set of wheels. We'll see.
Jeff
FWIW I did a project like this for my street bike. In short Yamaha limited ignition advance in 1st, 2nd, and to a much lesser extent 3rd gear by comparing the CPS signal to the final drive to tell the ECU what gear the bike is in. I made a circuit that made it think it was in 3rd gear and up. However with all the data on a single data line, it also hacks with the reported speed and distance on the multi-function meter / speedometer so i removed it. The hardest part was trying to mimic the output from a hall like sensor where the voltage goes up exponentially with shaft speed as it induced errors the ECU didn't care for. The ECU can be flashed but they want $600 USD to throw a couple of ignition maps at it so I declined.
I know this project would be huge but it opens up the possibilities to do some fun swaps if done right.
//
As for housing bushings, yes, I know the 250 housing is different but went looking for TRD parts for the later housing which Lexus seems to put in just about everything 2013 and up. Likely just go with poly as it's not likely to need maintenance like a suspension bushing wanting lube every 9 months.
Thanks for you're input.
Who wouldn’t! I think there would be more is350s out there if it come with manual transmission from factory. I’m sure that’s why many people chose a g37 over an is350 because of the manual. Lexus lost out in a big opportunity there.
