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Finished - Throttle Body DBW to slave DBC with OEM function - TEST DRIVE and VIDEO!

36K views 73 replies 19 participants last post by  Drutort 
#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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#47 · (Edited)
BAD and GOOD news

So here is the mock setup that I have that should work if I was to go stock intake path with say bigger TB.
The bad news is that to go any other way besides FFIM you would have to change the stock throttle cable, and along with needing a slave TB cable. Of course it would also be required to extended all the wires, was already expected from the start.

The good news is that if I was to go FFIM then I would not have to mess with the OEM throttle cable nor the wires.

I thought about a possibility to grind the OEM round nipple to be a barrel type and use it as slave TB cable, otherwise will need 2 throttle cables.

The issue is that the only reasonable placement of the unit that is not FFIM requires a throttle cable that does a U bend and that requires for it to be much longer. Stock is around 19-20in? I am guessing would need an extra foot or so, probably 35in throttle cable would work. This set up would require some stand off base to hold the unit as seen by my quick dirty cardboard mock up.

As far as brackets go, the OEM side of the CAM I am sticking with the OEM cable bracket, just need an adapter bracket? and then for the slave CAM I will make specific cable bracket.






The OEM bracket will be a little lower, but the hood did close just fine from what I could tell.




Of course if I was going to go FFIM then this unit would simply stay were the OEM TB is and require no rewiring and stock OEM throttle cable will work.
But for now I plan to get the cable brackets and support mounts all designed and machined, once everything fits for a final test fit, I will then go and disconnect the current OEM TB and use it as a test TB slave in DBC, pretty much taking off the sensors and servo motor, and placing a matched throttle CAM


===update===
actually now when I searched ebay, I forgot that a throttle cable with a 90 degree metal bend would work for this and it would probably have to be only 25in long
 
#48 ·
I haven't read this whole thread but have a few questions. The stock system, as I recall (it has been several years since I last dug into it), reads your mechanical input with a TPS and then the ECU tells the stepping motor to open or close and uses another TPS to monitor when the real TB is open to the correct position which then tells the stepping motor to stop. If I recall, the fuel delivery is linked to this second TPS. Does your system some how fake out the TPS signal somehow so that the ECU doesn't lag the fuel delivery?

I need to go back through that really old thread that I was contributing to, to remember how the stock system actually works.

I am super excited about this project. This laggy DBW makes driving the car on the limit of traction very hard as you can't move the load between the front and rear tires at the instant you need to.

Thanks for your efforts on this Drutort!
 
#49 ·
If I recall, the fuel delivery is linked to this second TPS. Does your system some how fake out the TPS signal somehow so that the ECU doesn't lag the fuel delivery?

I need to go back through that really old thread that I was contributing to, to remember how the stock system actually works.
This part interests me about the fuelling side, i have had a bit of a search around to find out more and read a little bit on it but didn't read anything definite about which is controlling. If you can please find the one you are thinking of i would be keen to read more on it :bigSmile:
 
#51 · (Edited)
The top cable in the pic is the OEM, the last one is an aftermarket one that I used. The cable over all is thin, and doesn't seem like they had the nylon lining inside, which sucks, because with that bend you feel a bit of a jagged if not like grinding/rubbing, if I put it straight or a small bend it works ok and smooth. I put a bit of oil and grease and it helped, I guess a long quality cable is good? or this one works fine with small bend, seems the nicer cables with nylon lining can with hold a bend and function perfectly smooth.










 
#52 · (Edited)
I did a few test drives, I got it dialed in better so far, I guess I forgot that cause of SRT intake and the R-ECU it was always pretty low on RPM's

Its also pretty neat to see the ECU move the Slave throttle CAM...


Here is a video of it in action
http://youtu.be/1ZUgzc055O0
 
#54 ·
So far I have a little over 100 miles on it :) everything is running good, tired cruise control all perfect

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#55 ·
good stuff, does seem pretty responsive.
in for while driving videos
 
#57 ·
Why do you need driving video? the car drives for 95% exactly as it did before :)

I can put up a video but all your going to see and hear is an IS that is close to stock, an IS with SRT intake, aftermarket ypipe and muffler.:suspiciou
 
#58 ·
yesterday, I discovered a vac leak, it was a hose that through the zip tie tension (you can see the zip tie in the video and can guess which hose it was heh) and heat from the engine slipped off, but there was a minor leak as well, a hose that I changed due to the OEM one cracking while I was taking more then I needed to of off the intake lol. All is fixed the OEM clamp was not tightening enough, so I replaced it and now I should have no leak, and my idle is back to normal :cool:
 
#60 ·
Good work! Great to actually see someone follow thru with an idea like this.
 
#61 ·
Thanks.

Oh I started to use Instagram too.
@Drutort To follow this project #is300DBWtoDBC
 
#65 ·
Thanks :)

I've been having fun at seeing ppls reactions to it in person heh

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#72 · (Edited)
throttle cable from GS/LS 400 VVT-i 98-00

Just a small share of discovery, that is that the OEM GS/LS 400 VVT-i 98-00 (not 100% on the years) 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

This tip was given to me by someone who needed this setup for a customer of theirs, they went and searched and it seems that OEM is the best way to go, and I agree

Here is a pic of it installed on a turbo auto is300 (rebuilt auto, and now I think lots of work on the engine as well) they had a lot of work put into the car and ironically had gotten stuck on the TB issue when throwing a large aftermarket TB, and of course the DBW to DBC was the solution heh, the car is setup with FFIM and a ebay large TB

sadly they only provided me with 1 in process pic thus far of the car :erm:
other pic shows stock throttle cable vs the GS/LS 400 vvt-i
 

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#73 · (Edited)
DBW to DBC on auto IS300 dyno pull over 500 rwhp!

BTW check out this video of this crazy auto IS300 which has to be the Worlds first IS300 VVT-i AUTO with aftermarket throttle body and FFIM setup that is running with standalone along with factory ECU, pulled off over 500whp! heh

of course the boost was baken back down to reasonable 300ish not to blow up the auto trans




RaceLAB.net
 
#74 ·
FYI after nearly 2 years and still same electronics and all is still running good (this is on my DD) :grin:
 
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