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Discussion Starter #1 (Edited)
What I hope this project will bring to the table when it is finished, similar results to what we have seen in the 80mm TB swaps fabs. But with these possibilities below:

  • Placement of your own Cable driven TB wherever you want
  • With the above this gives the user the possibilities of Dual TB's and ITB's (Individual throttle bodies)
  • The possibility to tweak the linkage cam (RED part in pics) (lobe) to advance, slow/speed up the throttle body butterfly opening
  • The slave linkage cam will be replaceable in the future based on users needs
  • Full OEM function (cruise, traction control) should be retained, as all the sensors and main components are still present
  • Will require to do throttle body coolant delete/bypass, and extending sensor cables
  • Launch control should still function
*This project is geared to retain OEM functionality, because of this it will require an OEM TB donor

This is for the mechanical guts transplant, this will keep my costs down. I believe the disassembly is pretty straight foreword anyone with some mechanical knowledge and proper tools could disassemble the OEM TB


I will give a little teaser of current progress.

Reverse Engineering of OEM TB system almost complete, main section as can been seen in pics below is done, CAD model pretty much complete, soon to come prototype and test fit of OEM components to see if all fits, few custom parts will have to be made.

Then of course a cable cam and a slave DBC TB :) of your choice :D

=== update 8/29/2013 ===

For those who could not visually see what was described, I added mock up pictures showing quick mockup CAD files of the other components

you can see that on the right side of the pictures the regular driver cable goes to, the center CAM cable goes to a slave TB :cool:


=== update 9/5/2013 ===

I decided to put up some pics of the work that had to go into reverse engineering the TB for this project, what you see is 3 pics of an is300 TB machined a number of times to allow for dimensions to be obtained for CAD model.

Initially I was going to use these parts to make my own kit, I still can, but I found out that its easier to machine and have everything match up perfectly and reduce some parts that are not needed for the function since this is not a full TB anymore, also a fully machined block can have some space savings which is quite critical for the installation of this unit in the engine bay.

=== update 9/6/2013===

small update went and took better measurements of the actual parts, before it was just quick visual mockup, now the lengths are pretty close. The overall length from tip of one side (plastic motor/actuator) to the OEM throttle cable cam-flat part is 10.6in long, I know I can shave 1.1 inches currently, so that is 9.5 inch unit, that is much more slimmer then OEM.

I measured the OEM throttle body length and its at 11.5in +-.25in, the throttle body cable to the firewall is about 6-7in depending at what height you measure it.

So I figure that few inches shaved by simply angling my unit will keep me at the OEM throttle body cable position, this way not having to mess with it much. I will have to get creative on a mounting system for the unit, I do not think I will mount it to the intake system, most likely to the engine cover or something near by? otherwise a standard will have to be devised if going to intake system? Any ideas?

The way I am going about installing this unit is 180 deg flipped of OEM throttle body, so were you see the black cover on your car its flipped on other side to the firewall.

=== 9/20/2013 ===
Had a bit more time to play with the model, had chance to pull some rough dim from the Petal Position Sensor (PPS) side of the TB housing. I believe the best OAL (Over all length) will be 9.75"

=== 9/27/2013 ===
While working on the model, and setting up program for the main housing, I started to do research about the slave throttle body cable that I would need.

For more details: Post #22

=== 10/5/2013 ===
Today Managed to get some time to finish up the CAM file and generate CNC g-code for the main housing. Was able to put in a bit of work and I am very happy with the results, aside from some machining/tooling issues the housing was completed.

The very first thing of course I went to do a test fit, as you can see in the pics, I put the OEM parts into this new machined housing, it was quite exiting to prove out my reverse engineering, which in itself was quite a challenge, dealing with a casting. It was nice to be able to have it done on the first try, I have to say I was a bit skeptical myself, as I know the small changes that had to be done from CAD to CAM to make it work. Then having to go and machine it was a complete different story, and whole ball of issues challenges in itself.

I will start to put photobucket or other picture sharing site, as I won’t be able to put all of the pictures, at least not in this main thread. I recorded a small video with my phone in one hand and rotating the housing unit with the other as best as I could.

Next up, will be CAMing the 2ndary housing and the bracket.

For more details: Post #23
Housing assembled and being tested for fit and function - YouTube

=== 10/12/2013 ===
So I had a chance to put in sometime into the project. Finished up 2ndary housing CAMing, and had time to setup and machine it!
Next up will be the mounting bracket.
For more details and pics: Post #29

=== 10/23/2013 ===
Been busy this week, but managed to finish both housings! and the bracket, I managed to have the shaft split, and even the CAM machined, though not done.

So I got to test fit the main assembly, it all works good, did not get a chance to put the gears but I did that already in other thread. I still have to finish the CAM and the shaft.

Once those are done and I get more dimensions from the test parts I will make adjustments and improvements, but everything should still be functional in current state.

I had a chance to through the whole unit into my engine bay, sorry that its pretty dirty and pics taken with phone at night.

I will throw a few ideas for placement, though real testing will be done when I have chance to take off OEM TB and y-pipe, then Ill have more pics!

For more details and pics: Post #39

=== 10/26/2013 === MAIN UNIT COMPLETE
Had chance to work on the project a bit, and worked on the CAM and shaft. Both are now finished and are the last main components.
Next up will be brackets for the OEM throttle cable and the slave CAM, as well as thoughts on mounting the whole unit in the engine bay.
Once the brackets are done and mounted I will assemble everything like OEM, I have done partial installations of the guts for all the processes/test fits. Soon though it will be a final install.

Afterwords will put it on the car and disconnect stock OEM TB electronics and sensors, leave the TB alone, connect a CAM on the OEM TB and connect the cable from this unit. Then test things out!


=== 11/11/2013 === MOCK TEST FITTING
This weekend I decided I could find some time for this project. I figured that I could do the mock test fitting in my garage. So I apologize for the hmm cheap improvised mock up for installation.

Took some time to take off my intake and TB, then jumped right ahead to removing some of my OEM TB parts. Once that was done I put the OEM TB stuff on my unit and went ahead trying to find a home for it under the hood.

After some time, I felt pretty defeated, every place I placed that seemed to have room I was short on room just a few inches or something was bulging out at some place and caused interference with the unit.

I finally realized and had to come to a compromise.
BAD news is there is but only 1 way to put this unit with only 1 type of setup that would allow for full plugin play, all other ways require a new extended throttle cable. Which was a bummer as I was really counting on placing the unit in such a way that you could get away with using the OEM throttle cable.

Good news if I plan on going FFIM all I would have to do is placing this unit right were the stock unit was and all the cables and throttle cable would work.
The other good news is that if your not going FFIM but with a larger TB and Y pipe, and keeping similar to stock intake configuration then I did manage to find a spot for the unit. You can see in the pics the mock up cardboard stand and copper wire holding the stock throttle bracket, and before anyone asks yes the hood does close!

As far as brackets are going, im sticking with the OEM one for the OEM side and making my own for the slave CAM side. I still need to make a bracket for the OEM cable bracket? haha if you can call that :p

As for the OEM cable replacement I would guess anything over 35in would work? as stock is 19-20in long.

For more details and pics: Post #47

=== 12/24/2013 === TEST DRIVE!
I'll come back and add more details, its been quite the ride with a lot of small changes back and forth on a number of area's. I finally did find an aftermarket throttle cable that is long enough for this setup and comes almost close to OEM fitting at the firewall, just need to cut plastic part a bit to open up, and use OEM rubber gourmet instead of the aftermarket one.

I finally went with the idea of using standoffs of off the valve cover screws and the engine cover stud, the forth point is just a standoff under tension from the others.

Had major issues with the slave throttle cable, at the end I ended up making new support plate that holes the whole setup on those standoffs, and new bracket to face the cable in reverse then what I wanted.

The OEM throttle body is used for testing this whole concept, as you can see no sensors or motors are on the OEM TB, which acts as a regular DBW TB, only cable and CAM connected directly to the butterfly shaft.

Adjusting the set screw and the TPS sensor is a major pain, because I also have to adjust for the DBC TB, idle at cold and warm can be problematic, I will have it all dialed in, then start it up and get the trac light flashing and CEL, going directly into limp mode. I am still learning all of this. Though I wish I did not mess with it because almost on the first attempt I had it running nice, ya it idled a little low but was ok over all.
Had to extend all (3) the sensors and motor cables as can be seen, that was quite the fun…
It is very interesting to watch the ECU control the TB, the video shows the delay that everyone is talking about, also tried the ECS and Snow buttons, but those do more when car is in gear rather then parked without load.

I will still be testing it for a bit, and also probably come up with a support bracket that fits were the OEM TB is, for a FFIM setup?

For more details and pics: Post #51

IS300 Throttle Body DBW to Slave DBC - YouTube


=== 6/3/2014 === Throttle Cable

Just a small share of discovery, that is that the OEM GS/LS 400 VVT-i 98-00 throttle cable works as a perfect direct bolt on for this, its more then long enough, and the quality of OEM throttle cable vs the aftermarket (some random toyota vehicle fit) is noticeable and there is a lot of room for the bend which what is needed for a U
 

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Got my intrest, if the oem idle control can be maintained without the use of additional iacv controled via standalone.

What's the purpose of this, to keep the auto's from freaking out or just throttle responce from a dbc tb?
 

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Discussion Starter #3
Got my intrest, if the oem idle control can be maintained without the use of additional iacv controled via standalone.

What's the purpose of this, to keep the auto's from freaking out or just throttle responce from a dbc tb?
Pretty much the ecu should see it as the regular TB, this is taking the butterfly and placing a cam with a cable connected to an identical cam and cable on a standard dbc TB

This will allow for larger TB, dual TB setup and hopefully an ITB setup :bigSmile:
 

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This would be sweet for sure
 

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Pretty much the ecu should see it as the regular TB, this is taking the butterfly and placing a cam with a cable connected to an identical cam and cable on a standard dbc TB
I'm interested in the development of this, but can you explain the above more clearly?

Are you saying that there are two throttle bodies mechanically linked essentially?
 

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see, if this could lead to the development of a functional ITB setup, I would 100% all over that.
 

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Discussion Starter #7
I'm interested in the development of this, but can you explain the above more clearly?

Are you saying that there are two throttle bodies mechanically linked essentially?
I will do a mock up, of the final assembly unit, for pics will get this out soon

but to answer your question, its yes and no.

All of the stock parts sensors plastic housing etc, are going to be used, only thing is the new housing that I will have and new shaft, along with new CAM that will take the movement of the butterfly and transfer that position by cable to another identical CAM on a regular mechanical TB

So in essence the ECU things its moving the original butterfly, when infact its moving a CAM that is on another TB, so yes its like 2 TB's just the main one will not have any butterfly but just a means of transposing the movement and position to another TB (slave)
 

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Ok I think I get it a little better now... I see how the stock DBW motor assembly could be used to drive a larger throttle body/plate... which is good if you want to move to a larger throttle and keep the DBW system.

I don't see how this would improve the overall feel/response of the laggy DBW system tho. If the motor is still in there actuating the plate, it won't be any faster reacting than before... or maybe I'm missing something still. I'll wait to see more...
 

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Discussion Starter #9 (Edited)
Ok I think I get it a little better now... I see how the stock DBW motor assembly could be used to drive a larger throttle body/plate... which is good if you want to move to a larger throttle and keep the DBW system.

I don't see how this would improve the overall feel/response of the laggy DBW system tho. If the motor is still in there actuating the plate, it won't be any faster reacting than before... or maybe I'm missing something still. I'll wait to see more...
Personally I do not think we can ever change some features of the system when we are tied to the ECU, now maybe with a piggy we can change few things, or we could try and create a non linear CAM that would speed up the response possibly a bit, but honestly there is no way to change it without fighting the ECU and from what I read if you fight the ECU you will throw codes.

I believe we can work with the system as it is, if we can tweak it a little in some area's then it would be an improvement, now going dual TB and moving the TB closer and or going ITB alone is worth it, and will change the overall throttlebody response.


I learned from the people who did the 80mm TB that they got quite a bit more of a response and they used OEM parts, so this should work with the setup that I am going with.

I think I can make a CAM that is nice and linear for the first say 25-50% of opening and then speed it up a bit on the other 50-100% that way even if the ECU controls the rest of it, it will physically move faster the rest of the control.

Now how much can that be tweaked or worked out? before a CEL or some other strange behavior? that is all to be tested and determined, nobody has messed with the TB this much, and honestly I will need the whole community's input, collaboration, insite etc...

I am willing (given the time) to take this project and turn it into a product eventually... :)

--- my rant----

here is my guess. The only way to work with the ECU is to fool it into thinking or giving it what it wants, with that said, I believe some slight tweaking on the mechanical side can be done, but anything else should be with some logic circuit that would piggy specifically with the sensors and the servo motor signals in the TB assembly; I believe that would be the ultimate TB response upgrade, and even then the ECU might have expectations that can not be exceeded otherwise it might through CEL.

I would guess the logic system would intercept the TPS sensor positions, and be able to decoded the ECU's signals to and from the TPS and the servo motor controlling the butterfly, so this logic circuit would need to mess directly with the servo motor to accelerate in a faster fashion then the ecu and yet send the right info to the ECU for it to be happy. Otherwise the ECU its self would need to be hacked and that is pretty much null point IMO.

I have read few forums were people did a DBC mod, and the ECU eventually was not happy not to mention you would probably fry the servo motor, or it would slip. Honestly having taken the whole thing apart the ECU still wins unless you mechanically force and mod the internals, which I think is never a good idea, and the other kit that we see is doing something like that.
 

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Discussion Starter #11
Thats cool.. I just wanted to make sure I understand it correctly.

Not sure if you have seen this or not.. the Toyota DBW patent for the throttle system on the IS300... pretty detailed and complex, but maybe it could help you with some of your ideas.

Someone posted a PDF link on here a while back, but I don't remember where..

Patent US6561162 - Unit for controlling electronically controlled throttle valve - Google Patents
Yes I have seen it :)

I am a mechanical/MFG Eng, im not an EE, so some of the info they might have pertaining to electrical is above my head, I know how to trouble shoot stuff and solder as far as electrical goes ;)

I have a much bigger project that will be revealed when its done and tested, its a grand project thats all I will say ;) Though related to this in a way :)
 

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Discussion Starter #12 (Edited)
added mock up pics, to show visually the whole unit

Thats cool.. I just wanted to make sure I understand it correctly.
Here are the mockup pics that I was talking about, the OEM unit is bulky I will try and replace some other parts to make it more of a slimmed down version, so that it can be placed easier in the engine area near the TB cable without having to modify the cable length
 

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Cool CAD drawings... I'll be watching this lol
 

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Discussion Starter #14
Cool CAD drawings... I'll be watching this lol
I uploaded pics of a real is300 TB that was machined down, in order to get the dimensions and data needed for CAD model generating. :cool:
 

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Very nice idea. Only way I would be happy is to get rid of DBW with auto. If that can be done, I would pay decent price for it. Otherwise there are other options for bigger TB. I will be running 75MM GTE VVTI TB on my FFIM on my setup. I wish I could run any TB and not worry it with auto. Space is one of the biggest issue in IS engine bay.
 

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Discussion Starter #16
Very nice idea. Only way I would be happy is to get rid of DBW with auto. If that can be done, I would pay decent price for it. Otherwise there are other options for bigger TB. I will be running 75MM GTE VVTI TB on my FFIM on my setup. I wish I could run any TB and not worry it with auto. Space is one of the biggest issue in IS engine bay.
This will give option of what I call slave DBC TB. All the mechanical and electrical stuff is used from OEM, plus or minus a few parts ;)

After this kit is done and similar size aftermarket TB is tested, I will try and see how dual TB for NA purposes would work right at the end of stock y pipe, not sure on sizes? keep it at 60mm or 50mm?

with dual TB's the velocities should be much better then one single large TB? though of course its not that simple (we are talking NA, not boosted)
 

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awesome idea! looking forward to the finished product. the DBW TB is one of the few complaints I had about the IS. any idea how much this would cost?
 

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Discussion Starter #18 (Edited)
awesome idea! looking forward to the finished product. the DBW TB is one of the few complaints I had about the IS. any idea how much this would cost?
Cost is hard to say, I have what you see on the front thread, I havent done a prototype yet, also the machining is one thing, then the assembly or the transplant of the OEM parts into this new housing will add labor too, I have no idea those costs yet.

See my other thread for an idea on cost, those are rough guesses though.:suspiciou
 

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Discussion Starter #19
small update: updated asm and got shaft calculations for split

I got a chance to work on this project a bit more, I updated the model so that people can clearly see more details, the linkage slave cam is now in RED, this will drive your slave drive by cable TB :) This cam can be tweaked, the geometry/lobe can be modified according to the users needs, depending on what TB or setup is being used. I believe its possible to tweak this, of course watching your A/F as the ECU will think everything is fine, but we can mess with the mechanical parts now ;)

Also I am happy that no shaft will have to be made, at least by the calculations that I have its possible to remove the butterfly valve and split the shaft, join it with a small wedge that is same thickness as the butterfly shaft and shove it between the split shaft, this would be a safety in case the set screws get lose in some unpredictable situation :jawDrop:

The project is getting more detailed and closer and closer to the prototype phase :cool:
 

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Nice update with the pics.. looking at the concept more, I was curious do you think the stock motor assembly will have enough torque to pull another throttle plate with its own spring? I mean, the place where you have the cam attached is where the throttle plate used to sit, and it does not have an additional spring there stock. So to pull on another cable throttle with its own spring might put extra strain on the motor / clutch?
 
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