I was talking to my local shop that just built my custom turbo setup and they were telling me they could build me custom intake manifold to go over ITB's and it would work with my turbo setup. What do you guys think?

 

i read somewhere that toda did something similar with a skyline. if you do have somekind of airfilter over the throttles.

 

It will have a common plenum over the inlets on all of the ITB's, the air filter will be at the turbo's inlet.

 

I think you will get better response and torque with this setup. It will be an expensive setup and slightly more difficult to tune.

Skyline GTR has 6 individual throttle bodies in stock form. Most people ditch the setup for a single large throttle body with heavily modified cars because of difficulty of tuning. However my friend kept the individual throttle bodies and add a larger plenum on his race car because his tuner made it work. He said that he got better midrange torque and response with this setup.

Ikeya (?spelling) make this for the JDM S15.

Should be interesting to get a comparision of the gain in the S.
If you have the money I would say go for it.

 

A estimate in price is about $4,500 installed for ITB's and custom intake . I wonder if the gain would be worth it with my current setup. Also, would it be mandatory to port and polish my motor in order to keep up with the flow coming from my turbo and new ITB's?

 

I think you'd find it is one of 'law of diminishing returns' things. A lot of money for not much gain. You also have a few issues with tuning as you can no longer use a MAP signal and instead rely on TPS and other sensors.

 

Honda Tuning has a comment on this in the last issue, they say tuning is such a bitch you wont believe,high vacuum @ idle is switching to high boost at WOT and it simply never works 100%..but it can be done.