That's really awesome, I know the LS guys have been wanting this mod for a while.

now the TCMs are going to be even harder to find, and will keep going up in price!

 

Wow, I have to give you credit for figuring out the TCU. I am one of the LS guys who has forever wished it would be possible to retrofit an IS-F TCU. That said my LS is an AWD. I don't know if that would affect comparability, but knowing my luck I'm sure it would.

The important question is how does it drive? I remember one of the GS460 guys installed an IS-F TCU on his car and it didn't quite drive just right, but the improvements in shift times, etc. were certainly noticable in the video he shared.

​​​​​I hope you were only kidding about not sharing the necessary wiring and pin out info. You can't tease us with something like this and then keep it to yourself! Lol.

Again nice work man. Extremely impressive.

EDIT: TH01 - I think I've identified the extra wire. I've still got to trace it and try to identify what the hell it does lol.
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I was going to include this in my original reply, but didn't want it to be too long.

With regards to your custom intake, which by the way is quite impressive as well. Wouldn't it be possible for Loi to program your tune in a way that only requires a single MAF + IAT sensor? I would think it not impossible to just feed the signal from one to both inputs or something like that. I ask because I wonder how much having both MAFs installed like that might cause some restriction and/or affect the direction and shape of the air, or cause it to be more turbulent. You would think it would be possible to switch to a single MAF because the 2UR in the IS-F and the 1UR in the GS-460 both have single MAF intake systems.

As far as the temp issues you have been having I bet you'd have better results using some kind of molded plastic MAF housing rather than aluminum.

By routing the intake to the brake duct are you diverting some or all of the air that would be going to cool the brake? Are you concerned about brake performance and wear because of this?

Extremely interesting in following your v2 build. I had started to design and source parts for a custom intake system but I started out with the thought of using one of the 2 into 1 split intake pipes from LS engines due to the dual MAF/IAT sensors and the lack of space there in front of the throttle body. I have to say your design is unlike anything I considered. Would be very interesting to know what if any performance improvement was due to the intake itself and not just your tune.

​​​​Please keep us updated on v2!!!! Thanks!!!!!

 

TH01 - is this the pressure switch for the oil pressure warning on the ISF?

 

That's a nice cooler install, what length is it? does it bring up the engine temp being right in front of the condenser like that?

 

Thanks! You're not lying about it being hard finding TCMs and the cost. I believe we're safe for now since GS460 and ISF are rarely seen in junkyards or auto dismantlers. They have the connectors needed to make this swap easy.

 

Thanks! I just started "really" driving the car again today so I'll report back with better info (been 2 days since the install).

Today, I've done about 60 miles of driving this morning, mostly stop and go on my commute and it has been shifting smooth. Also did a couple WOT pulls to merge and it shifts noticeably quicker. I believe it's due to Loi's transmission tune. After I swapped the ISF TCM in, I re-flashed the car. I'm looking at an in car camera mount as we speak. Hoping to get videos up soon.

As far as intake goes, I'm sure Loi would be able to calibrate the ECM to run only 1 MAF. I've tried jumping the wires together when I was making the intake and it ran like crap and sounded like it was cammed haha! Loi did mention that each MAFs have their own map tables, I would imagine he would need to blend the 2.
I just ran it the way I did for time sake.

I agree with a plastic material for better temp management and hoping to make something soon.

I would like to modify the brake ducting to run over the intake pipe and back towards the brakes but I haven't really invested time into that since I may route the intake another way. I'll keep ya'll posted for sure.

Yes, TH01 is the apart of the oil pressure circuit for both TCM's and it is used. Try looking at the LS460 "EO5" pinout

 

Thanks! the dimensions are 23" x 8" x 1.5". I actually noticed engine coolant temps maintain 195*F - 205*F I believe it's because hot ATF is no longer in the cooling loop.

 

 

I apologize in advanced for the length of this reply. Like I said I am very excited to see the progress you've made, as there are projects I've been researching on and off for quite a while. I truly appreciate you taking the time to chat with me. Custom Intake v1 That's interesting that trying to tie the MAFs together made the car run poorly. I wonder if the MAFs are setup in such a way that they are "parallel" and in tying them together it altered the voltage range reported to the ECM. You would think that the overall setup wouldn't be too complicated because the intakes still feed a single throttle body. Like you said I'm sure a tuner could average or sum the dual signals so long as that's all that is going on. I think one possible explanation for why your car ran poorly when you tried to tie them together could be a lack of adequate flow considering you were at idle. I know that the HKS Supercharger Kit kept both MAFs and they were installed one after the other in-line just as you've done with v1. I think it's safe to assume that they had to do it that way though due to the fact that the ECU hadn't been unlocked when they produced and released the kit. It's too bad we can't pick someone's brain at HKS and ask if they would have retained both MAFs or altered the stock setup had they been able to tune the ECU at that time. To be honest I kinda wonder why Lexus chose to use a dual intake/dual MAF setup to begin with. Like I said above it's kinda baffling to me that there are two separate maps considering that both intake pipes feed a single throttle body. Perhaps the ECM relies more heavily on the MAF for fine-tuning. If this is the case I wonder if moving to a single MAF, which would cut the resolution in half, would have negative consequences regardless. I've read about some systems which use dual MAFs so that they can match the MAFs to actual injector sizes. I have to admit that I have no idea what that means. This may very well be a stupid statement, but I wonder if it is possible for there to be one MAF for the port and one for the direct injectors? Or perhaps maybe each cylinder bank? This is an area where I would like to learn more for sure. I'm just not exactly sure where to start. There aren't a whole lot of centralized resources for this kind of information out there. Most of it is scattered across various forums or buried in more obscure corners of the internet. I wonder if it would be worth experimenting with installing an airflow straightener just before the MAFs, or even before each MAF to smooth out the airflow. It should cut down on any irregularities and as far as I know they don't impede airflow in any meaningful way. Of course another possibility would be switching to MAP or speed density tuning. Again this is a bit beyond my understanding at this time, but I'm sure your tuner would be able to give an educated answer. TCU When you installed the ISF TCU did you input the Transmission Compensation Code from the small QR Label on the transmission itself? I seem to remember that sticker with the code on it being located on a part of the transmission that is only accessible if you drop the transmission itself. I wonder if it would even be legible at this point given the age of most of our cars.

I just purchased an ISF TCU on Friday, and it should be here by the end of the week. You would think we should be able to find our current compensation code in Techstream. I would also like to find out if the TCU will be able to "learn" over time and adapt without the proper code. How have things been for you over the last several weeks? Any issues? Judging by the video you shared the shifts seems lightning quick!!

 

I've been MIA with updates and development on V2 intake due to parts availability... and life

As for the TCU, I did not enter the transmission comp code through Techstream. The TCU I installed came off a wrecked ISF. Once I was able to re pin the wire harness to the correct pinout location on the module, I started up the car and it operated as normal. I was told a new part from the dealer will require Techstream to handshake the new module to the car also that we should be able to pull the codes through Techstream.
So far I've driven just under 1000 miles on this TCU with no issues. I would think that a check engine light would have came up by now if the trans comp code was a major issue being mismatched.

I've received an updated transmission tune from Loi and it's even more amazing. I'll try to get video uploaded when I can.

 

Heh yeah life does have a tendency to get in the way every once in a while lol. You have inspired me to start researching and drawing up plans for an intake v1 myself. Even if at the end of the day there's no improvements to performance and I revert back to the stock setup, it will be a fun project and I like proving to myself that I can do something once I set out to do it.
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​​​​​​I agree it only makes sense that we ought to be able to pull our current comp codes from Techstream before swapping the TCU. If anything I think you would have only experienced some minor driveability issues, or at worst maybe it may be a bit harder on the transmission. Good to know it wasn't an issue for you.

That's super exciting news about the new tune. I didn't even think about the potential for further tunability with the TCU. I bet that has been a blast! Looking forward to the new video.
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I've been looking for pictures and a write up on the cold air intake since your car made the rounds on the 460 FB groups lol, glad to have found your build thread.
What was the first trunk spoiler you were running in the earlier pics, the smaller one?
Is the second larger one the Aimgain or the Wald Black Bison or something?

 

Awesome! I'm FINALLY in the process of making a V2 at the moment. Currently just waiting on parts that are scheduled to come in today.

Yes, the first trunk spoiler was the smaller one.
The second one is a 13-17 LS spoiler and my attempt to 1 piece it... it did not turn out that great so i'll be going back to the smaller one.

 

How well did the 13-17 spoiler fit on the earlier model trunk? I've been trying to find if the actual trunk lid shape differs between the early and late model 460.
And what brand was the smaller spoiler of you don't mind me asking? I'm currently on a spoiler hunt and trying to avoid spending the billion dollars and months it takes to get one from Japan.