toyota 1gr 76mm throttlr body

[Crazy Drew]

Originally Posted by wu_dot_com

im curious as to your insight as to how to properly implement ITB for this car?

looking at the two existing designs, having an inline ITB with long intake runner just dont make much sense in the performance aspect as an optimization design.

having 2+2 ITB with mechanical linkage that actuated by a common motor does eliminate the long intake runner issue, but also dont make an optimize design. since 1. parts have to be in close tolerance to one another which drives up the cost. and 2 you lose the ability to individually adjust the TBs (this is a weaker point because the existing ECU was probably never program to take cam position and knock reading for individual throttle position adjustment).

ideally a perfect ITB package that would work great would incorporate a plenum with single MAF or individual MAF, single / individual O2, 4 electronic throttle with controls. the controller can be one integrated circuit that does it all. d each electronic throttle body can be mass produce with much cheaper per unit cost. The control programming for a single O2 application is much simpler because the controller would only have to worry about synchronizing each TBs.


i would like to pick your brain as to the work around of alpha N mode. other than an alpha N tune, or compensated MAF with plenum or individual MAF that feeds the sum of MAF readings to the existing ECU, what are some other remedy that are currently being use for correct fuel metering?

MAF is ancient technology as well. Really, all you needis crankshaft position, MAP and throttle position. Even throttle position is questionable as one of the engines I worked on used only MAP and a hall effect for the crankshaft position. It wasn't ideal and far from what I wanted but the chief designer liked the simplicity in it.

I explained the MAP issue a little in my post that went up shortly after you posted this. If I were to make ITB's for the twin I'd run something like a -6 AN hard line from each manifold runner to a vacuum accumulator for MAP reference. You want the accumulator to change vacuum quickly but not be large enough to allow too much air to pass between the runners through the system.

[fooddude]

@Crazy Drew:
Thank you for your shared knowledge and insight. I guess the biggest hurdles to make it function properly is syncing ecu to work with them, sensors, electronics, etc.

Can you please give your opinions on the 2 pics of the BRZ/FRS's with ITBs (the burgundy one and white one) and from what others have said about them? ...particularly, and similarly to your recent post, about MAF ..in that, many seem to be in doubt that this white car would even work properly.
http://www.ft86club.com/forums/showt...?t=7939&page=4


White car problems: If you look closely, it is using the oem throttle body mounted directly on top and center of the engine...but only for its' ETC (electronic throttle control). I guess they just hacked it up and ran linkage from the ETC to the ITBs. Also, instead of figuring out how to measure MAF from all 4 ITBs, they merely only ran 1 MAF on only 1 ITB (the bottom left ITB in the pic). Would only 1 MAF on 1 ITB work? ..and I guess frankensteining/hacking the oem TB/ETC to run hardware linkage from it looks like it might work..?

Burgandy car: Idk if anyone noticed this yet..but, it has been converted to an older style cable controlled throttle (as seen in the middle of a video at the carshow) and not an ETC any longer. How does one convert to an older cable style throttle without ecu problems? ...new ecu perhaps?

Blue car: I guess this one doesn't have any problems at all, since it seems to be running healthy. Would love to hear your insight on this too though...those roller barrel ITBs look interesting.





[ame="https://www.youtube.com/watch?v=ctyBOEk3L9Q"]Subaru ITB - YouTube[/ame]

(you can see the cable at 0.33 right in the middle of the stacks)
[ame="https://www.youtube.com/watch?v=kZoPhhcmr1M"]Gorgeous FRS with ITB's - YouTube[/ame]

[Turdinator]

@Crazy Drew top info, thank you.

An idea I have had bouncing around in my head for a little while is that packaging and control of a twin throttle setup might be easier for the FA20 than ITBs. Something like the Ferrari V8s use with a plenum per pair of cylinders. What would you thoughts on something like that be?

[Malt]

I'm just curious, but why are you guys going on and on about ITB's when the throttle body isn't the limiting factor to begin with. What do you hope to accomplish with an ITB setup that the stock TB and manifold can't accomplish?

Seems like a gigantic waste of time/money to me.

[fooddude]

Originally Posted by Malt

I'm just curious, but why are you guys going on and on about ITB's when the throttle body isn't the limiting factor to begin with. What do you hope to accomplish with an ITB setup that the stock TB and manifold can't accomplish?

Seems like a gigantic waste of time/money to me.

*drumrrrrooolllllllll*.....................

[fooddude]

Originally Posted by Turdinator

@Crazy Drew top info, thank you.

An idea I have had bouncing around in my head for a little while is that packaging and control of a twin throttle setup might be easier for the FA20 than ITBs. Something like the Ferrari V8s use with a plenum per pair of cylinders. What would you thoughts on something like that be?

Great idea.

But, I think you'd have the exact same problems in making it work since the pair would still be far away from each other since it's a boxer, and you still have to figure out the MAF/density/etc setup (albeit 2, instead of 4) and how to make the ecu work with it.

I think besides the obvious and easier hardware hurdles.. the biggest difficulty to make it run properly is ecu compatibility/tuning and syncing and making all the sensors work, etc. Anyone can get a blowtorch and fab up some pipes/flanges/etc to mount them and make them look pretty ..but to actually make them work properly comes down to electrical/ecu/tuning knowhow. Feel free to correct me if I'm wrong.

[Crazy Drew]

Originally Posted by Turdinator

@Crazy Drew top info, thank you.

An idea I have had bouncing around in my head for a little while is that packaging and control of a twin throttle setup might be easier for the FA20 than ITBs. Something like the Ferrari V8s use with a plenum per pair of cylinders. What would you thoughts on something like that be?

You're welcome, I'm glad to share it as long as people are willing to learn.

It'll work, I'm not sure it'll work well though only testing in expensive software I no longer have access to, or real world testing would tell. My past analysis of it though says it's not worth the effort. The problem I see with it though is that you would approach choke flow (Fun fact, air reaches choke flow in the intake at Mach 1 and can't exceed it, you really only want this to occur at the valve) of the throttle body much easier with two small throttles rather than one large one. This is because both cylinders on one side fire in succession of each other. It works on the Ferrari because the Ferrari is a single plane crankshaft, meaning all of the crank journals are 180 degrees apart from each other rather than 90 degrees like in a conventional v8. It actually runs like a pair of 4 cyls on a single crankshaft rather than as one 8 cyl. To make it work well on a boxer you'd need a massive crossover tube linking the two plenums together essentially nullifying the intent of two separate plenums other than for packaging reasons.

Originally Posted by Malt

I'm just curious, but why are you guys going on and on about ITB's when the throttle body isn't the limiting factor to begin with. What do you hope to accomplish with an ITB setup that the stock TB and manifold can't accomplish?

Seems like a gigantic waste of time/money to me.

Because mid-range. It may only gain a handful of power in a peak power application (especially on an otherwise stock longblock). It would however gain significant power at just about every other RPM. It would also allow the opportunity to work the resonances to tune out the torque dip inherent with this engine. With Cosworth opening up the door to some hardcore engine parts it would be even more beneficial in providing a better engine "package" compared with the OEM intake.

Originally Posted by fooddude

@Crazy Drew:
Thank you for your shared knowledge and insight. I guess the biggest hurdles to make it function properly is syncing ecu to work with them, sensors, electronics, etc.

Can you please give your opinions on the 2 pics of the BRZ/FRS's with ITBs (the burgundy one and white one) and from what others have said about them? ...particularly, and similarly to your recent post, about MAF ..in that, many seem to be in doubt that this white car would even work properly.
http://www.ft86club.com/forums/showt...?t=7939&page=4


White car problems: If you look closely, it is using the oem throttle body mounted directly on top and center of the engine...but only for its' ETC (electronic throttle control). I guess they just hacked it up and ran linkage from the ETC to the ITBs. Also, instead of figuring out how to measure MAF from all 4 ITBs, they merely only ran 1 MAF on only 1 ITB (the bottom left ITB in the pic). Would only 1 MAF on 1 ITB work? ..and I guess frankensteining/hacking the oem TB/ETC to run hardware linkage from it looks like it might work..?

Burgandy car: Idk if anyone noticed this yet..but, it has been converted to an older style cable controlled throttle (as seen in the middle of a video at the carshow) and not an ETC any longer. How does one convert to an older cable style throttle without ecu problems? ...new ecu perhaps?

Blue car: I guess this one doesn't have any problems at all, since it seems to be running healthy. Would love to hear your insight on this too though...those roller barrel ITBs look interesting.

(you can see the cable at 0.33 right in the middle of the stacks)

You're welcome.

White car - Hacking up the TB to run the ETC to actuate the throttles is honestly an easy way to make this work with the OEM ecu. The original TB mounting holes could easily be repurposed for mounting of the entire assembly and provide a solid setup with no movemement compared with the ITB's. 1 MAF on 1 TB isn't ideal but it works, especially if you're trying to run a non-SD tune with ITB's and not utilizing a plenum. You'd just have to scale the MAF accordingly for the rest of the engine. 400% would be a decent starting place however the proximity of it to the velocity stack needs to be taken into account as it's very different in conditions than the OEM intake tube. This is a pretty trivial thing for any tuner to do.


Weld's burgundy car (jesus I love that thing) - A conventional cable setup wouldn't be too big of a deal to figure out. I can only speculate though since I have no knowledge of the FA20DI fuel injection arcitechture, only general fuel injection. The ETC should be servo controlled, or at minimum stepper motor (once again, it's not 1990) with a potentiomenter providing feedback to the ECU. I'd need some time with the car and an oscilliscope (don't have one) to really determine how the signals are passed back and forth between the ETC and the ECU. That being said, it wouldn't be too difficult to install a TPS/Potentiometer to provide this same input back to the ECU. It should be looking for confirmation that it has opened the TB as much as the ECU has commanded it to. As long as this input is satisfied and the throttle pot on the accel pedal is retained the ECU wouldn't know if the ETC was opening the throttle or if a cable is. I highly doubt the ECU is actively monitoring it's outputs for current (amperage) consumption except in the case of it exceeding it's limits. One thing to note about this ITB setup though is the large amount of bends that's in it as the runners snake their way up to the TB's. As a good general rule of thumb you'll lose 1% of your potential flow for every 90 degree bend, assuming everything else is equal.

The Blue STI - Pretty neat setup they have going on. It should be very responsive even with that fairly large turbo. It appears to be running on a Speed Density tune leaving them without needing a MAF. Or, at least, I didn't see one. Barrell throttles are intersting in that they provide a way for the intake path to be 100% obstruction free when the throttle is open however they're a manufacturing nightmare. The parts have to fit together extremely well and a high surface quality is needed to prevent binding of the system and air leaking between the barrel and the body. We like to think our intakes are contaminate free, but in the real world they aren't. Reversion in the intake (remember me talking about the pressure wave travling back and forth) does a fantastic job of gunking up stuff. Since there's large rotating surfaces in the barrel throttle there is more potential for contaminates to get between the barrel and the body. With a conventional throttle body these surfaces are much smaller and less prone to buildup.

I personally like slide throttles a whole bunch. If I ever get to be a bajillionaire I'll spend all of my time building top notch n/a engines with slide throttles. If you're unfamiliar with them they're similar to the Barrel in that they're 100% obstruction free when fully open, but have no rotating parts. The throttle blade is pulled or slides out of the way of the intake path. You can create a design in the throttle blade that also makes it open at a negative exponential rate, meaning at low throttles it takes more throttle input to open the blade than at high throttle input.

One thing to remember with all of this is that regardless of ITB style or how it's tuned each runner will still have to be synched to the other. This requires a manometer with one tube for every cylinder to be able to accurately measure vacuum in each intake port simultaneously. Without doing this you could run into potential power problems or failures with the cylinders making uneven power with each other.

If I could get my hands on a reasonably priced FA20 engine to mock up a full ITB setup I'd love to have one. Last time I checked they were almost $8000 though for a used one through any local wrecking yard. Since my twin is a daily I'd need to be able to install a new intake a tune in a day, two at most. I wouldn't be able to be without a car for months on end while prototyping something. I like Weld's idea of having the throttles in a single location in relation to the engine however I'd like to see it packaged a little differently.

[fooddude]

@Crazy Drew:
Good stuff teacher, hehe

You def sound like the most truly knowledgeable person on this website in regards to ITBs. Hopefully one day you will make, and we will all get to see, your work and prototypes for the FA.

Btw..so in summary, the easiest setup to make ITBs work with the oem ECU is the white car(1 MAF on 1 runner + hacked up oem TB/ETC), correct?

[mike the snake]

I wonder if someone could utilize the stock plastic manifold, and fab up a tricky ITB setup. Seems like you could fit some butterflies, fab the rods and linkage, drill holes through the manifold and fit some bushings and O-rings. You'd have your common vacum source then and you could use the stock MAF but also have ITB's.

[Crazy Drew]

Originally Posted by fooddude

@Crazy Drew:
Good stuff teacher, hehe

You def sound like the most truly knowledgeable person on this website in regards to ITBs. Hopefully one day you will make, and we will all get to see, your work and prototypes for the FA.

Btw..so in summary, the easiest setup to make ITBs work with the oem ECU is the white car(1 MAF on 1 runner + hacked up oem TB/ETC), correct?

Thanks, maybe one day I'll get the chance to put my knowledge to use on this engine. You're correct about the white car being the easiest way to run the OEM ECU on ITB's. It would have no idea that it's not running a factory engine.

Originally Posted by mike the snake

I wonder if someone could utilize the stock plastic manifold, and fab up a tricky ITB setup. Seems like you could fit some butterflies, fab the rods and linkage, drill holes through the manifold and fit some bushings and O-rings. You'd have your common vacum source then and you could use the stock MAF but also have ITB's.

That might work however manufacturing would be rediculous difficult. You'd have to assume there's no manufacturing inconsistencies in runner cross sectional area where you chose to put the butterflies. The OEM plenum is also way undersized for an ITB setup and bonding the bushings to the plastic intake is incredibly difficult. Not impossible but difficult.

[michael336]

My adaptor is finished, but the car is in paintshop right now, can't install it......

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[wtrxprs007]

Originally Posted by michael336

Attachment 81158Attachment 81160Attachment 81161

My adaptor is finished, but the car is in paintshop right now, can't install it......

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wow.. O_O

i must say it looks interesting so far.. wonder how it would be when its done

[fooddude]

Nice welds..you have a very good fabricator.

[michael336]

Finished the paint job today. Made two holes in front for ram air. And diy side fender. And fill up the gap for the bodykit.

Will work on the big throttle and new intake tomorrow

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