Here are the RHD ITB measured flow rates at 28" and aproximate maximum power potential per cylinder when placed in the high velocity section of the intake runner.

The ultimate size of the runner is proportional to the total air flow requirement which in turn is linked to the power output of the engine, so by this theory we can use the power level as an indication of the size that is required not the engine displacement.

2010年5月9日 · The selection of an ITB size is then a compromise between these multiple design choices. The Jenvey FAQ provides some recommended ITB sizes based on HP per cylinder. This information suggests that a 40mm ITB setup would be more than sufficient on an M10 for all but a 200HP race engine.

2024年1月30日 · Recommends a 57mm for a stock long block and 60mm for a built K20. If he says it, it must be the truth.

2021年3月29日 · I cannot recall the source of this information, but I distilled this effort to determine how much HP is available for an x diameter of throttle body for ITBs. Per the following web site, this may be helpful: The table below can be used to help estimate the correct size ITB 40mm 265cfm 61Hp 350-500 cc/cyl

2004年11月3日 · ITBs of a given size, say 40mm, will out-flow a carb of the same size due to no restrictions like venturis, main jet stacks etc. Typically a 40mm carb works great on a 2056cc motor where you're turning up to 6KRPMs. Knowing that, I would consider 38mm ITBs and possibly 40s, but no higher for a 2056cc.

2018年10月4日 · RHD sells 40mm and 42mm, it's known that you obviously don't want to go too big on throttle size. I assuming these are too big for 2.7 with a 272. Anyone have some thoughts?

2005年8月26日 · The port size is equivalent to a circle of ~46mm diameter. So 48mm ITBs are plenty and good for driveability. ITBs with a 50mm diameter will also do fine, above that im not sure how much that would help you, and you would lose some drivability.

2007年10月6日 · I know GSXR 600's are something like 42mm/38mm, but is there any site or resource that lists all the sizes? I'm looking for something along the lines of... in this thread in this sub-forum in the entire site

2011年4月29日 · If you want to max out port velocity near 300 fps at redline with an isolated runner intake, I suggest individual throttle blades of 2.25" (57.15mm) diameter. 3.2729 sq. in. intake runner cross section will net you 292.29 ft. per sec. average port velocity @ 7,200 RPMs.