Steve_A
I've always wondered why most people leave them near stock. 

 
Just big, fat, reliable torque i'd guess.

track_mr2
I ran 6 48mm ITB's on a 3.1litre stroked L series engine. You need to be quiet careful around the throttle body design and sizing as I used speed technology/efi hardware equipment with is quiet pricey however they run taffer bores etc...that create more power. Also and more importantly each throttle body had its own throttle stop as the twisting in the steel shaft is enough to through the idle out of balance. They are very sensitive I even had to change linkages to spherical ball type as the play in the cheaper linkages were also enough to through the sync out. I had to also run a custom main linkage that ramped at 40% initially before full to make the car perfectly drivable otherwise I wouldn't get enough throttle control. ITB's can be quiet fiddly to get right.

Thanks for the info. Do you have any data on the itb's against the standard manifold. Its ok that's its a different engine but more interested in characteristics of the change.
Was it used on a street car or circuit car?
Did they shift the throttle bodies up the manifold to suit a particular cam or application or where they simply fitted close to the inlet for streetable driving?
 

Steve_A
Can't wait to see how this turns out! I want to put a 2GR in my 2 and I've always wondered why most people leave them near stock. Have you considered boring the cylinders? You need a sleeve kit and the capacity can be increased from 3.45L to 3.68L
 
Try contacting the guys at Monkey Wrench Racing, they've got alot of experience with the 2GR and should be able to give you a good indication of how much power you'd gain from port work etc.
 
Here's a link to the sleeve kit - http://www.monkeywrenchracing.com/product_info.php?cPath=318&products_id=1586 
and the 2GR specific page - http://www.monkeywrenchracing.com/index.php?cPath=318 
 

Steve_A
Can't wait to see how this turns out! I want to put a 2GR in my 2 and I've always wondered why most people leave them near stock. Have you considered boring the cylinders? You need a sleeve kit and the capacity can be increased from 3.45L to 3.68L
 
Try contacting the guys at Monkey Wrench Racing, they've got alot of experience with the 2GR and should be able to give you a good indication of how much power you'd gain from port work etc.
 
Here's a link to the sleeve kit - http://www.monkeywrenchracing.com/product_info.php?cPath=318&products_id=1586 
and the 2GR specific page - http://www.monkeywrenchracing.com/index.php?cPath=318 
 

Hello Steve,
I will not be going down the path of oversizing the bore as its a expense I'm not interested in due to the cost of playing with the turbo for the last few years. You don't really need to update the bottom end as the standard bottom end is a proven package if you intend to stay below 11:1 compression and 7500rpm. This is where I will be running so it will be rebuild but with standard internals. The cost of sleeves/piston/rods and install is 5k which I am not interested in spending for not a lot of gain. The car will be under 1100kg with fuel and driver so I can for go the 20kw gain of the overbore with the weight reduction. 
I have seen some tricks on two brutal which will be used. LS main bolts for instance will be used. The clutch master clutch I have in the car is the top end race unit so this will also help with performance. May also try one or two other things with the bottom end but no news on it as yet.
 

track_mr2
I really don't know how using stock style throttle bodies on a  ITB setup would work. Are they cable driven? Most factory throttle bodies are cable driven, so you would need to run a the main cable system to some kind of winch system to pull the throttles open?
One of the throttle bodies would need to have the TPS mounted on it where the others wont.
If you are leaving the injectors in the origional factory location and just getting ITB that are basically a buterfly, there are a lot of cheap custom made options for billet buterflys. They have individual throttle stops and are very compact, also have mounts for ram tubes. The EFI Hardware stuff has the injector tube moulded in as they are usually used for webber carb to EFI conversions, thats why they are pricey. Also mounting the injectors as far from the cylinders as possible gives better atomisation and gives better power.

I believe they are talking about the Factory 4AGE 20V Blacktop ITB's which solve all the issues you raise and are commonly used in ITB conversion for many other motors (4AGE 16V, 1UZFE, 3SGE)

 
The 4AGE ITB's can be sourced for $100-$200 a set, which is cheaper then a single individual ITB from EFIHardware.

kameleon
The above are good points and that is why i talked Steve into using stock style throttles for ease of use (linkages that work out of the box for instance) this will give him less headaches and we all know Steve has had so many headaches i am suprised his head has not yet exploded :)
 
I know how much of a ba$tard it was to set up some EFI hardware gear on a BMW 6 cylinder...... The products are quality items though.

Yes, exactly Trav! Just pulling down the 3SGTE yesterday 'wound me up' with memories of the painful path I went down. Its still not over as it will be inspected and 'more than likely' new rings fitted before assembly and sale of the engine. I was going to but it back in the car after the rebuild then tune and have a drive but decided to simply get it out my hair.
It would be a mad street/trackday engine but not for circuit work.
 
The 2GR will produce great results with the standard manifold with a 1UZ throttle body so this is still and option.
But, the itb's is a great little project. Do the Toyota itb's have the injector fitment on the throttle body?

Knightrous

track_mr2
I really don't know how using stock style throttle bodies on a  ITB setup would work. Are they cable driven? Most factory throttle bodies are cable driven, so you would need to run a the main cable system to some kind of winch system to pull the throttles open?
One of the throttle bodies would need to have the TPS mounted on it where the others wont.
If you are leaving the injectors in the origional factory location and just getting ITB that are basically a buterfly, there are a lot of cheap custom made options for billet buterflys. They have individual throttle stops and are very compact, also have mounts for ram tubes. The EFI Hardware stuff has the injector tube moulded in as they are usually used for webber carb to EFI conversions, thats why they are pricey. Also mounting the injectors as far from the cylinders as possible gives better atomisation and gives better power.

I believe they are talking about the Factory 4AGE 20V Blacktop ITB's which solve all the issues you raise and are commonly used in ITB conversion for many other motors (4AGE 16V, 1UZFE, 3SGE)

 
The 4AGE ITB's can be sourced for $100-$200 a set, which is cheaper then a single individual ITB from EFIHardware.

I have been looking for the 48mm, but cannot find any. There are plenty of 45mm units which based on a chart I have found, will manage the output I can get from the head combo I looking at. 45mm are $200 a set.
The efi hardware is great, but its really aimed at higher budget engines. Its 5k for the 2GR. Way out of my budget.

This is what I have in mind


 
If I can get the mold sorted, I can have a manifold casted for under $500. Now who has that 3D printer..

B24
If I can get the mold sorted, I can have a manifold casted for under $500. Now who has that 3D printer..

Send me the motor for a few weeks and I'll see what I can do ;)

They do look like a good option price wise. They look paired up though, so do you need to cut one pair to split them on each bank? For reference 6 48mm on a  3.1L were slightly bigger then necessary. The correct size for me to run would be 6 45mm throttle bodies but that was 3.1L with a single over head cam. So on a 3.5l quad cam 48mm should be about right, maybe even 50's are doable..I think you'll still find some challenges using the 4AGE setup but they will just be small things, like pedal feel through spring return rates, syncing issues etc...but I'm sure you'll be able to find solutions for them as they pop up. I have noticed some other V6 ITB kits for sale that are just above the 1k mark for things like VQ53's. Possibly one of these kits adapted to the 2GR might an option if the 4age setup doesn't pan out. 

The 4AGE 20V ITB's separate into individual units once removed from the manifold. Each ITB has an adjustment screw on the linkage joiner to allow adjustment to sync them properly and a return on each throttle. Here is an example of how someone use joined 6 of them together for an RB20DE