One of the mods I'm planning for my 4AGE is ITBs. I was thinking about doing that maybe a year from now but I just noticed some 20v blacktop ITBs selling for a decent price on the local forums. Any reason to go with any of the modern sportbike ITBs over this?
I'm planning to use a Megasquirt to run an alpha-N setup at first and eventually move to blended setup with dual MAP sensors.
I'm also thinking about variable trumpets (controlled by the MS if possible, else the Race Capture) but running R6/R1 ITBs would only save me a little fab work in this case.
Just an opinion, but definately Toyota parts on this one. I've geeked out on this quite a bit, and that's what I think.
I didn't look at 20V parts because they were more expensive at the time. I don't know about now.
I doubt a 20V intake is a perfect fit to a 16V head, so you'd either need to modify it, or purchase a manifold that does. I think T3 sells one.
Fitting GSXR600 ITB's to my 16V required fabricating a manifold, and changing the spacing between #2 and #3 TB's. The GSXR injector holes had to be plugged, the secondary throttle (air valve??) needed to be removed and the holes plugged. The throttle cable thingie needed to be changed to fit the Toyota cable.
The GSXR TPS is a piece of epileptic poo that cannot be filtered adequately by Megasquirt. I ended up fabricating an adapter to run a GM TPS.
The TPS is on the opposite end of the throttle shaft from the cable, so there is some delay between what your foot does and what Alpha-N needs to see. Running Accel-Enrichment off of MAP solved that quirk.
If I were to do it again, and was willing to spend more (my Locost is on the more affordable end of the spectrum), I think using factory Toyota parts, and less head-scratching and less fabricating would be a better way to go.
For Lethal Locost #2's Duratec 2.0L, I'm going to try and fabricate my own ITB's because I am that stupid.
Well that settles that, I'll pick up the Toyota ITBs. I've seen some adapter plates for sale before.
Found one from Techno Toy, but it's made for the AE86, I'd have to make sure there's enough room to run it on a laterally mounted engine:
https://technotoytuning.com/toyota/ae86/4ag-individual-throttle-body-adapter
GameboyRMH wrote:
Found one from Techno Toy, but it's made for the AE86, I'd have to make sure there's enough room to run it on a laterally mounted engine:
https://technotoytuning.com/toyota/ae86/4ag-individual-throttle-body-adapter
It is best to use the entire ITB assembly, then it is to use just the individual throttles..... also I've seen (MR2 application) that the T3 adapter interferes with the coolant plumbing
Jubiride, and a few others make an adapter that allows the user to adapt the entire ITB assembly to the 16V head
This keeps the ITB assembly intact... providing better vacuum resources
Any I can order online? I've been googling around and have seen some others mentioned but can't find any place I could order them (other than Jubiride's general contact info on their Japanese website).
GameboyRMH wrote:
Any I can order online? I've been googling around and have seen some others mentioned but can't find any place I could order them (other than Jubiride's general contact info on their Japanese website).
http://www.jubiride.com/shopping.cgi?cl=PO&pg=2
Ah thanks. I guess the "straight" model has the ITBs sticking horizontally out of the head and the "diagonal" model has them pointing upwards. Google Translate calls one a "wings agay" model, dunno what that does 
Acquired ITBs yesterday. The base plate is a big unsightly thing that would eat into precious head-to-firewall clearance. Assuming a proper T3-style adapter that has all the cooling passages, are more built-in vacuum ports the only advantage of using the entire assembly?
In reply to GameboyRMH:
You might check to see how much room the T3 adapter requires, before you just chuck the OEM one.
I'm nowhere close to chucking it but the size of a Jubiride-style 16v-20v adapter plus the OEM base plate is making me look carefully at the options.
I'll overlay pics of the two with the bolt holes lined up later, should give an idea of the relative sizes.
Subscribed.
On a slightly left-field note - gotta love Jubiride's tagline
"For the Reckless Drivers"
Here is the best comparison I could make with the pics available, with the Jubiride's flange leaned up against the t3 and "passing through" it. Looks like the Jubiride is thinner, the question is by how much.
GameboyRMH wrote:
Here is the best comparison I could make with the pics available, with the Jubiride's flange leaned up against the t3 and "passing through" it. Looks like the Jubiride is thinner, the question is by how much.
Want to make sure you are measuring apples to apples and not oranges...
The T3 unit is going to be thicker because it adapts just the throttles. the Jubiride unit is likely thinner, but requires the entire ITB assembly... NOT just the throttles
Yeah that's what I meant, and I just went and measured the base plate and it's a good 7cm thick in all, so it's looking like I'll have to make the T3 adapter work. Vacuum stuff I'm not too worried about, there won't be a need for much of it with most things being MS-controlled. I'd connect the 4 runner vacuum ports to a vacuum manifold and attach an IAC valve, MAP sensor (eventually), dizzy advance (temporarily) and any miscellaneous doodads to that.
The only thing I'm not sure about is the throttle cable, I guess worst case scenario I could get an adapter plate fabbed up to attach the stock lever system.
Bump with new question: Is hooking up the vacuum system on ITBs really a cross between rocket science and witchcraft? Will I end up with low vacuum if I don't use just the right layout?
I was going to hook up each runner into a vacuum manifold and run everything off of that, but I've seen some suggestions to keep the "high flow" items like the brake booster, PCV system and the IAC valve itself away from the "sensor" items like the PS and AC hookups, and of course MAP sensors.
Also it's looking like I'm going to use a custom adapter in the style of the T3 adapter, I've seen a lot of complaints about the throttle and vacuum attachments being on the underside of the system on the T3 adapter, it looks neater but it's a PITA, so it's better to have the ITBs facing the other way. Plus import duties will make a custom adapter cheaper.
I can't help on that one - my Locost isn't really blessed with accessories.
Bump for the work surfers.
