Toyotec presents...the effect of ITBs on a bone stock 16V 29/11/11

I think the point is being missed here. I have certainly never seen ITBs controlled with a standard OEM Digi ECU. Has any one else?

 

Chris,

I didn't say I had either....the point I am trying to get across is that there are without doubt many members on the forum whos knowledge on these matters is not as in depth as that of others and I am concerned that they may get a little misled. Original posts that have been made by 'anon' and others about there being no significant benefit of fitting ITBs to an otherwise standard vehicle are in my opinion justified UNLESS said vehicle is also fitted with SEM to enable it to be correctly mapped to the new intake system to harness the potential advantages.

Maybe a better title for the thread would be 'Toyotec presents...the effect of ITBs on a bone stock 16V engine with SEM 29/11/11

 

There is no active intention to mislead that I see here. Why would there be?

I can't see the point you're making!

ITBs go hand in hand with SEM. You cannot run without. So the comparison is one of a standard engine, with ITBS and SEM, against what has been talked about in the past on many occasions, ie countless threads asking "Shall I fit ITBs", followed by "no" answers.

On my reading this thread has moved our understanding forward, at the very least in this particular combination of components

 

I can see above that 'bone stock' is defined under the heading "The project and background" Read the original post !

 

Any confusion is answered in original post by:

Thread going off course.. to be expected on CGTI though lol

 

As soon as you start to research ITBs it becomes very clear, that you would also use an SEM.

 

great info...that makes me happy..im moments away from firing up an unopened ABF on 45mm jenveys and emerald man.

 

A very good point nicely illistrated, when I said bodged I ment poor runner lengths inclusive of other areas. The ones in the first pic that are off the shelf are far to short but this could have been the customers lack of knowledge, im sure with decent ram pipe lengths the problem could be addressed. The last one is very interesting as the torque is really shifted up the rev range, maybe better for track work? if you like it like that. I like to have bags of mid range extending up to the rev limit please. makes pulling out of corners better and you can hang onto gears for longer.

Love the ITB bodies on Eddies build, the ram pipes look like off the shelf items which means easy to get hold of and change, and i really like the fact they are designed for a car - not bike so the rest angle of the butterfly will be steaper and therefore give the driver more modulation on light throttle openings.

 

The vel stacks are bespoke machined 4A-GE 20v "silver top" parts. I do not think the chap makes them anymore though.

 

The information i received to keep achieve maximum torque from ITB's the inlet - valve length is 300mm.

it would be interesting to see the different trumpet lengths fitted on the Test Engine Detailed Eddy to prove the if this is true.

 

The intake runners are tuned to invoke natural supercharging to the inlet valve. The measure of this supercharging for a given length of air column is at least rpm dependant.
The length you are quoting would be suitable for a certain peak rpm but not necessarily ideal to another engine that has different compression ratio, cam timing, port shape, important target torque shape and valve size.

 

In addtions to Ben S' work on 16v ABF plenums, cerips recently posted in his V8 thead a very easy to understand illustration of manifold tuning at work

The lengths are very much tuned to your requirements.

The same ethos for exhausts lengths and collector design which do the opposite - scavenge.

 

Great thread. Makes me think what a proper airbox would change?

 

Only one question Eddie, when is the kit being released so I can start saving?

 

Any news about build thread of these bodies coming up? Would be quite interested

 

Haha...not a commercial exercise I am afraid. Just me finding a solution to a particular challenge using bits and resource that surround me.

Yes, more details will follow when the throttles end up in their permanent home.

 

I've just bought a pair of black top 4age ITB's and was wondering if you had an access to a CAD file or flange picture maybe? Plan on using these in mk2 with Abf in it.

 

I have all information everything to make and install another set of throttles based in these units for a VW. However as this was a team effect, which took many intense hours of thinking and skill to assemble, test on road/track, calibrate and report out, you would appreciate I am not about to start devaluing all the inputs by making every detail public as just yet until we see them work in the environment they are targeted for.
Let us be patient and wait and see what happens in the next phase of the project.

 

I'm agree with you and appreciate time and effort put in development on these itbs. Can you tell what application they intended to go in?

 

Great conversion, looks very tidy!

Any dyno time yet?