Anyone considered/attempted ITB's
 

Recently I aquired some (I)ndividual (T)hrottle (B)odies for my SR20DET 240SX that I nearly have up and running. Has any one attempted this or seen any evo's with them. Most of my searching while researching their function had a lot of gripes about tuning and idle, but most were on NA cars w/o plenums.

I got ITB's from a pulsar gti-r and redrilled the flange and the last thing I have to do is flip the plenum with an adapter or re weld it. Most people don't see much for HP gains but have much better response and top end. I assume the minimal power gains are from the increase in throttle area. I went from a 60mm w/ 2826mm^2 to 4 45mm plates totalling 6358.5mm^2. I just got the SR built and am starting to work on the outer power adders starting with the intake side. If the throttle response is that much better I will probably minimize I/C piping with a V-mount and be able to use a large turbo with reduced lag and a broader power band. I would probably apply this to the evo if it is a success on the 240.

I have been working on some subaru roller throttle bodies and have evo on the back burner...which shouldn't be hard once the subies are done.
roller barrel > butterflies

Roller barrel are very nice since there is no throttle shaft in the middle F'ing with the airflow into the cylinder.

To answer your question Justin, HKS did this in their LMP675 cars a few years ago. Sean Glazar did it with his 9 second 2G back in the day. There isnt much power to be found but throttle response does become more bike like. This in itself is reason enough for me to do it but I have another project in mind first before I get to that.

what are roller barrel sounds interesting

There's a 1G Talon in the Vancouver, BC area with ITBs. Throttle response is amazing, but it is hard to tell if there are any gains up top compared to other well designed intake manifolds.

I would guess overall intake manifold and intake runner design will have a larger impact on top end performance than the restriction of a single large (esp versus a Q45 or Mustang style) TB versus multiple bike style throttle bodies.

One of the reasons ITB's have such an advantage is the that the percentage of airflow at any given TPS for a single GIGANTIC air door verus 4 smaller ones. The larger 95mm will flow the same amount of air lets say as 4-45mm but it will also have a lot larger bog zone as it starts to open. Tip in issues in otherwords. Look at motors like the RB (ITB turbo from the factory) or Turbo M series cars and you can see how responsive they are.


Roller barrels- http://pistonheads.co.uk/gassing/top...0766&f=101&h=0

I'm always hunting for better engine response too - JB, if you make this project a reality I'll be very interested :).