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Aiight, I know that the title automatically makes everyone come to the conclusion, "no it will not work. ITBs are only for N/A cars!" Well my lil brother came across this website (http://extrudabody.com/Products/ITBs.html) and it almost seems as those its possible (pics at the bottom of the link). The only thing is, would it even be beneficial to a turbo setup? I know I've seen people say that it would (not from this website) but anybody can just say "its beneficial" but it really doesn't work. Well if anyone can let me know if the Individual throttle bodies with a Plenum (not necessarily from the website above) will be better then a top mount from JDMFabtech. Thanks for any help.

 
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I still don't understand how it would work with turbo. How would you route the intercooler piping to the throttle bodies? Also, a good turbo setup is all about flow. A proper intake manifold is designed to distribute the air among the cylinders evenly; not sure how that would work with piping straight off the IC?

 
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you'd almost need a splitter at the end of your IC piping and they would have to be equal length...not sure how you would fit it. Not sure if you would get any gain, but I'm sure the headaches would come almost immediately.

 
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^You would just run a plenum on top of the itbs. RB26DETT have itbs with a plenum stock.

To the OP I can't speak from experience but IMHO the ITB setup wouldn't be worth the money. There's also a guy on honda-tech Tony the Tiger who has a boosted GSR with ITBs. You might want to PM him a few questions if you want more info.

 
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True but they spent a lot of money to make sure that setup worked properly, a one off on a D17 doesn't really seem worth that kind of effort especially when you aren't sure whether or not you will see gains over the JDMFabtec intake. Good luck if you go for it though bro, hope you get some gains.

 
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Here is a picture of a setup, there used to be lots of pics of a B intake like this by tony the tiger on H-T but the pictures are since gone

 
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^^^ thanks tfnaaf for the pics. is that the one from tony the tiger off of h-t? well it was just a thought. i think it would be pretty cool if it would see some gains... i'll try to get with tony the tiger that mister was talking about and if i do i'll definitely post it and let everyone know how it turns out. as far as being worth the money... i think if i am able to do the ITBs myself it MAY (not saying it will be) but it may be just a lil bit more or less than the jdmfabtech one. well, let me do some more research and we'll see what happens.

 
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You just need to add a plenum. As hard as it is to get these things to run right on boost, I wouldnt go crazy with crap like that. You'll have a hell of a time getting it to read MAP, idle and TPS real well. Stick with one throttle, on boost, since you're shoving air in, as long as its there, it works just fine.

 
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thats true boiler! its just a thought!

 
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It absolutely will work. However you will not see any specific gains. Reason being that all n/a intake manifolds are tuned based on intake pulse waves. ITBs allow more precise and less restriced intake based on vaccuum. Pressurizing it nulls pretty much all of the benefits and in some cases can hinder airflow seeing as the butterflys dirrectly in the runners can create turbulance whereas one single TB in a plenum give the intake time to converge and enter the head as smoothly as the manifold will allow.

 
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No that isnt Tony the Tiger's, i found his post but all pictures were red X'd. His looked very similar to that picture thou

 
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And that is what I was looking for... and no one other than Gerry came thru! (Just a figure of speak, thanks still from everyone that helped and gave me their thoughts) I'm still looking to pick one up Gerry. I emailed you a while back and I just seen the other thread on here about Clint and Steve starting I guess a "Group Buy" if you want to call it that...lol. I'll try my best to save up some money if you are able to even bring it down lower than what you emailed me about. I have a wedding to plan by Aug '08... my fiancee is overseas.

 
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Unfortunately that is just not true. When an engine is operating in "vacuum" that just means it's operating at an intake manifold pressure below atmospheric. When we turbocharge it or supercharge it in any way, we're elevating that pressure above atmospheric. This does not negate the laws of physics, if only it did things would be a lot easier. All you're doing is increasing the density of the air via pressure, while this does change the tuning range of the intake manifold minimally, the rules still apply.

It's best to think of intake manifold pressure as Manifold Absolute Pressure (MAP), and the units I like and which are typically used in standalone ECUs are kPa, kiloPascals. 0 kPa would be a perfect vacuum with no air and no pressure, this never exists inside an engine. 100 kPa corresponds roughly to atmospheric pressure, or approximately 14.7 psi. This is the key, there is always pressure, even in your intake manifold. If there was no pressure air would not enter the engine. There is no such thing as "suction" or air being drawn in, it is air being pushed in by atmospheric pressure. A forced induction engine is just that, its pressure levels are simply a bit higher than the normal atmospheric pressure available naturally.

That said, I think you can achieve any flow number regardless of ITB or single throttle body. The ITBS WILL provide superior throttle response because the TBs are so close to the combustion chamber. Air is at full pressure in front of the ITBs and when you open them there is far less time necessary for that air pressure to make its way into the chamber. The flow will be equivalent to a TB of equal flow area. You find the flow area by adding up all four ITB surface areas, pi*r^2 where r is the radius of the butterfly. Do the same with the single TB setup butterfly and compare. Usually ITBs have much more surface area so they can flow more, but a huge TB with proper plenum might have the same flow with less response, but this is often not a huge difference in response.

This all assumes similar runner shape, size, and length, which also has an effect. I think some of the effects of ITBs are negated simply because you have to put a plenum and inlet pipe on the setup with forced induction, whereas with NA the idea is to have no plenum or inlet whatsoever restricting airflow into the runners. So is there an advantage, absolutely, even with forced induction, but is it worth it for most people, not at all. With a large enough plenum and TB, and the right runners you should make just as much power on a turbo engine and only suffer a small loss in throttle response. I wouldn't bother unless you're getting the stuff super cheap and building yourself. Otherwise you're talking a few thousand for a nice ITB setup.

And there is always that pesky MAP signal problem. It will be difficult to tune with a speed density/MAP system, MAF would make it possible but again, that's if you have a plenum and piping going to it to put the sensor on. The other option is Alpha-N which uses the TPS to determine fueling, and it can be made to work well if done right, it can be pretty crude though. The best is Alpha-N at low throttle openings and then switch to MAP only near WOT or under boost, when you have a more stable MAP signal. Obviously only standalones are likely to have this capability, Megasquirt is capable of it but I have never tried it.

Any time you're talking ITBs it really belongs on a race car, not a street car. I didn't even mention until now that the setup can be hard to drive, very touchy, because of the huge amount of butterfly flow area. Modulation will be lacking.

I know this is quite a long post but I hope it is helpful.

 
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Thanks John. I really learned alot with your post. But of course I didn't know much to begin with. But I'm no longer thinking of ITBs although it would be nice to see what type of numbers a turbo with ITBs would produce on our engines regardless of how much money... but I don't have the money...lol. Thanks again!- Jay

 
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Who was that masked man? Nice first post!

 
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LOL.. don't know either.

 
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I'm no engineer but I play one sometimes and I listen to a lot of them. I was actually searching around for ITB and velocity stack pics and info and came across this thread. You'll usually find me on Turboford.org. Now with all that said, velocity stacks like you see on ITB setups are very good to go on each runner inside your plenum, they will smooth out and improve airflow into each runner. The velocity stacks work great even if you don't have ITBs. Like this:
http://www.team-integra.net/images/B...Junplenum2.jpg

 
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thanks john!

 
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dang rufus...lol why you gotta be so harsh...lol just kidding man!

 
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Or like this perhaps?

 
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DAMN gerry looking good..... can't wait til i get my turbo kit going and pick up one of these!!!