Intake Rubber Piece ??

[SHOBound]

I noticed that when I took the intake apart, the rubber has very small holes. Has anyone cut into these to make them flow better ? Just wondering

 

[wood_e]

What are you talking about? I assume you mean the intake boot (tube).... if you have holes in yours you should replace it...

 

[SHOBound]

No, the intake tube above the sprocket cover, I took it off and I noticed when it was off, the rubber hoses that connect the tube to the rest of the intake has a small hole that is probably half the size of the tube. You would think would restrict the flow of the intake charge. I dont know if all the rubber hoses that hold on all the runners are that small diameter in the center but if they are, I bet a ton of flow could be had by cutting them out !

<small>[ March 01, 2004, 09:45 PM: Message edited by: SHOBound ]</small>

 

[Mr Anonymous]

Do you think Yamaha was just being generous by providing the extra rubber, or maybe they designed them that way?

I suspect they were designed that way for a reason. Some people have opened them up, some have left them alone. I don't know that anyone has ever done a before/after dyno to see if there was any noticible difference.

 

[yamahaSHO]

Yes, there has been before and after dyno's... No gain was attained... Only a louder intake.

 

[billyshoe]

If you're discribing the crossover tube on the pass. side if the car, its purpose looks to be equalizing the flow thru the plenums and would probably be best left unmodified. It may be a expansion chamber. Anyway, alot of thought went into the design of this intake and it is most likely serving its purpose well enough on this particular piece. It works pretty good why mess with it.

 

[Yamaha V6]

The diameter of the rubber piece, as well as the diameter of the crossover tube itself varied over the years. There's a large dia. tube with a small dia. rubber, and a small dia. tube with a larger dia. rubber. Mix & Match at your desire.

 

[revhardSHO]

The Subaru SVX uses a similar crossover intake system (mind you, it looks nothing like the SHO intake). It has dual plenums (H-6 piston configuration) that are joined via a 55mm (i think) butterfly valve at the opposite end from the TB. At low RPMs (below 4K) this valve is closed so as to increase low end torque, At higher rpms this valve opens, equalizing flow for a decent HP gain up top. So there is a theory behind this.

Even shaving the rubber for more flow wont help much with the stock crossover. The crossover tube passage is to small in diameter for any gain, partially due to the interference with the timing covers and also the cut-outs for the DIS wires. To maximize flow you would need larger diameter tubing. Of course, in the end, its probably not worth the time/effort/energy, but what the ****?! Just an idea thumb

The diameter of the rubber piece, as well as the diameter of the crossover tube itself varied over the years. There's a large dia. tube with a small dia. rubber, and a small dia. tube with a larger dia. rubber. Mix & Match at your desire.

From 89-91 yamaha used the small dia. tube w/ the larger dia. rubber. From 92? up to save on casting costs, yamaha used a large dia. tube and small dia. rubber. I think.

-hey did you check if you have the titanium front pass. panel?