I want to make an LFA style air box for my is350 with velocity stacks. I have some ideas from the inside a guitar for the sound. My question is does anybody know the size of the intake ports to the lower intake manifold in millimeters?

thanks,

Brian

email: crowell.brian809@gmail.com

 

Very curious to see where this goes! Not too many folks will have a lower intake manifold just sitting around where they'd be able to pull those #s, but you can get lucky.

 

Velocity stacks can increase the volumetric efficiency of the engine, but changing the length of the intake runners also changes how the wave tuning in the intake tract works. The variable valve timing also plays into this. Chances are it won't make a huge difference one way or the other, but there is the chance that you will create a "dead" spot somewhere in the RPM band. I'm assuming you plan on using the stock upper intake manifold and TB? I'm not sure how much space you have in the plenum, but I would still suggest using the shortest velocity stacks you can find, and while you are in ther spend some time porting the runners as well. Also the filter and intake before the TB have a much greater effect on sound than the manifold so I wouldn't expect any change in sound.

 

Perhaps something like this?

https://www.clublexus.com/forums/per...m-in-love.html

 

I always wanted to take a veloicty stack and put it where the opening goes on the F-sport lower air box.

 

I'm going to keep the stock lower and build a custom upper..

 

That is going to be a big project. I'd take some inspiration from the IS F intake manifold rather than the LFA. The LFA has individual TBs inside a common plenum, the IS F has some great velocity stacks cast inside the plenum and a single TB:

 

Wow. This is new and interesting. Subscribed. I look forward hearing more. Keep it up.

 

I'm adding some other sound tuning stuff in the enclosed air box. I will keep the original design..

 

looks awesome! keep the good work