Intake question

[Jon3sgte]

Does runner length matter much on the 5SFE? would it be benificial to get the filter as close to the vent as possible? Also, most people are running a standard cone filter. I have seen smaller filters which in theory should improve flow. Would a bigger throttle body be a benefit or a waste of money? What works out best?

[Medusa]

Yes, runner length does make a difference, albeit not such a big one. IIRC, about a foot and a half or so is the optimum runner length.

Please explain your theory on a small filter improving airflow. A larger filter has greater surface area for filtering, and a larger area available for flow. How is a smaller filter better?

I do not know if a bigger TB would be better, I know if you use one that is too big you will have throttle response issues.

[Jon3sgte]

i guess i cant argue with the surface area of the filter. lol Does the element itself matter such as: K&N style VS a foam element?

[328FTW]

Originally Posted by Jon3sgte

Does runner length matter much on the 5SFE? would it be benificial to get the filter as close to the vent as possible? Also, most people are running a standard cone filter. I have seen smaller filters which in theory should improve flow. Would a bigger throttle body be a benefit or a waste of money? What works out best?

No idea how good of a match runner length is on the 5sfe but remember the runner length is only the bit from the intake port to the bit where it enters the intake plenum. Runner length is not dependant on plenum length/size that is something different. Larger volume plenums usually increase top end power but decrease low end torque. After the throttle body the intake length doesn't add much of a factor compared to the other parts of the intake so the main goal is getting cooler air from outside the engine bay rather than the hot air from around the engine and especially the exhaust.

Also a bigger filter with more area works better but only up to a point and after that it is just wasting your time. As for the larger TB I wouldn't say it would make a big difference unless you went turbo, the 5sfe doesn't rev out really high like the 3sge and my 3sge TB doesn't have any problem keeping up at 7k infact it pulls to redline and shouldn't be a limiting factor. That should be enough to take in and answer the question

[Medusa]

^I guess I should have clarified. When he said runner length I think he was talking about the length of the intake tubing from the filter to the TB. I forgot to clarify that point. I do remember somebody had dyno'd an MR2 MKII with an intake about a foot and a half long, an open intake (no filter) and a filter attached directly to the intake. The long intake had the most power.

[1993MR2NA]

"Larger volume plenums usually increase top end power but decrease low end torque."

I just installed a ram air intake and it feels like I've lost something. It makes a lot of noise, but seems more sluggish when I hit the gas at around 30mph. Someone told me the computer might need to be adjusted to deal with the increased air flow (more air needs more fuel)? Would adjusting the timing help with this?

Thanks in advance (no timing pun intended!),
Jerry

[TomsMR2]

you have less air flow because you installed a big gigantic long intake tube. theres more volume to fill before air actually enters the engine.

[Jon3sgte]

does that tube have more volume than the stock airbox and tubing???

[Medusa]

For an N/A you don't need anything bigger than a 2.5" intake tube. For a turbo, 3" is good unless you have a gigantic turbo. But not many people run a turbo big enough to need anything more than 3".

[1993MR2NA]

I think I put a 3" tube on my 2.5" intake port, but the tube is MUCH shorter than all the stuff that the stock cold air intake used. I was amazed at how much space I got after removing all of it.