ITB manifold

[LXI 87]

Currently getting the parts gathered up for High Comp 16 valve build. The guy building the engine isn't happy with the ST throttle bodies and T3 adapter. He isn't happy with the angle of the T3 unit he says he would like more angle on the inlet to get a better swirl effect. He is looking at Suzuki GSXR 1000 K5 throttle bodies and making a custom manifold. Has anyone any experience with ITB's other than ST ones and also does anyone have any feedback about T3 manifold?

[yoshimitsuspeed]

Is he reshaping your ports to have the same angle? If not then you will just be disrupting airflow.
What is your power goal?

[oldeskewltoy]

The BEST adapter I've managed to see is the one below....




This type uses the entire ITB system...




and not just mounting the throttles on to an adapter...





The adapter (top 2 photos) uses the entire Toyota throttle body system... and manages a mild (few degree) angle.

[gotzoom?]

Where might one acquire such a trinket, OST?

[oldeskewltoy]

Where might one acquire such a trinket, OST?

Tony - "gaijin_rokurunner" told me he saw it on YJ... It isn't that tricky... I'm sure it could be made simply enough... begin with both gaskets... align the intake ports, and viola......

[burdickjp]

Basically, if you're paying for this, you won't get a lot for your money going elsewhere. If you're devoting your own time, what is it worth? What's your power goal?

Though I haven't had one in my hands, the best I can tell is that comparatively there's not much wrong with T3's solution IF you incorporate a vacuum block. AE101 throttles have been the staple of almost all ITB kits for a long time. Toda used them until recently, I'd presume because supplies are drying up.

One thing to consider, though, is that many would consider AE101 throttles a bit large for most 16v builds. Depending on your powsr goals, you may want smaller throttles.

[yoshimitsuspeed]

Where might one acquire such a trinket, OST?

I can make you one if you are willing to pay the price

[gotzoom?]

I can make one too, but I figured it would be easier to just pay $300 for one.

[jondee86]

[offtopic} A long time ago when I first looked at doing the ITB conversion, I did
a bit of research on what adapters were available. First I wanted to use the whole ST
manifold as per the OST pics above... but no-one was selling adapters, and I had no way
of making one. So then I looked at the T3 adapter, and read that the inlet and outlet
sides of the adapter did not blend the angles very well, and that some porting would
be needed to get it to flow decently. RS Chita had a much nicer manifold, but wouldn't
ship them outside of Japan, so in the end I just made my own inlet manifold from tube.



What I really wanted was this, but there is not enough room to fit them on a RHD car



It's my opinion that it is better to have a bit of distance between the butterflys and the
valves, to let the airflow settle. And a nice smooth transition from throttle bore to
port shape, with the intake runner matching the angle of the port. [/offtopic]

Cheers... jondee86

[gotzoom?]

Thanks jondee. That's exactly what I was thinking about. Did you waterjet the flange on the itb manifold side? How did you arrive at the tube length of the adapter manifold?

[oldeskewltoy]

Cheers... jondee86

bet that might just fit on LHD.....

[burdickjp]

bet that might just fit on LHD.....

bet something similar would look good on a certain specific smallport.

[MisterJerk]

bet that might just fit on LHD.....

bet something similar would look good on a certain specific smallport.

which may or may not have been built by loynings...

[jondee86]

Did you waterjet the flange on the itb manifold side? How did you arrive at the
tube length of the adapter manifold?

There wasn't a lot of science involved I made a simple CAD drawing and had
both the flanges waterjet cut. Then I used aluminum scaffold tube, which I calculated
to have the right diameter to match the intake ports when squashed down. Put a curve
in it with a pipe bender which partially collapsed the tube into almost the exact port
shape. Cut the U-bends in half, then a bit of massaging in a press and good enough.

The length was pure chance... I just needed them to be long enough clear some of
the stuff on the intake side on a RHD car, and tilt the throttles up a bit. Due to some
brain fade at the time of welding up, the TPS ended up in front instead of at the back,
as I had intended. But happily, that mistake actually working in my favour... space is
awful tight at the rear of the head.

I did look at the calculations for tuning the intake tract for a particular rpm. But came
to the conclusion that when the engine is required to work over a wide range of speeds
and space is limited, the harmonics you are trying to catch are not significant. If you
have the room you can experiment with stack lengths. I have finished up with very
short stacks, and they work well. Probably because I have more inlet runner length.

Cheers... jondee86

[jondee86]

bet that might just fit on LHD.....

Just about bet on it And I'd be surprised if you didn't already have the sump
and cam covers tucked away at the back of the shed !!!

Cheers... jondee86

[oldeskewltoy]

cam cover is HEAVY... and offers me nothing.

[xBigDope]

Hi jondee86.

Would you be able to send me the dimensions you used for the flanges.?? Or even better the cad files
Wanting to do the same, and get them cut out. But cant seem to find the correct measurements.
Cheers

[xBigDope]

Hi jondee86.

For some reason i cant reply in the messages.
email is derek@reformedridez.com
Would be much appreciated!! Cant wait to run ITB's!!

Cheers