please, i already searched. i found some people saying it is 3" with no taper, some say it tapers to 2.75" at the TB, others say it tapers to 2.5"... can anyone clear this up for me, inner diameter if possible. thanks

 

With a ruler i got 2.75 and it does taper. Probable from 3 inch

 

thank you! is the 2.75 the inner diameter or the outside diameter?

 

inside

 

good news. thats about 70mm if anyone was curious

i am thinking that a stock intake arm into an ericks 68 tapered to 66mm throttle body, into the AEBS manifold with 65mm intake port would be a good all motor setup that would flow better but wouldnt hurt air velocity too much, the whole setup is tapered from 77mm to 65mm.

match that with a *good header, highflow cat and exhaust, flywheel, fd, camgears, and a tuned obd1 hondata delivering optimal fuel... possibly looking at some impressive power from only bolt ons.

i will be putting this setup together after i see the proof that the aebs manifold is all it is hyped to be... if not

i'll supply results as well. before and after with the tb and manifold vs stock.

honestly, i cant wait

 

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i am thinking that a stock intake arm into an ericks 68 tapered to 66mm throttle body, into the AEBS manifold with 65mm intake port would be a good all motor setup that would flow better but wouldnt hurt air velocity too much, the whole setup is tapered from 77mm to 65mm.
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You actually want the intake arm to be about 33% more cross sectional area than the TB. The decrease in diameter helps speed the air velocity so it is beter suited to make the sharp turns into the IM runners.

 

if the ID of the intake side of the arm is exactly 3" or 76.2mm diameter, the cross-sectional area is 4560.4

67% of this would be 3055.5 making the ideal diameter of the intake manifold opening 62.4mm stock for the itr is 62mm.

by opening the intake port up to 65mm the area becomes 3318.3 which is 27% less than the intake arm. a difference of 6% from stock...

assuming that 33% is the ideal size would a 6% decrease in air velocity but increase in air volume hurt more than it would help on a modified motor?

why is j's intake so large on the tip? wouldnt this throw off the balance and theoretically decrease efficiency?

 

It's big so it can suck in more air.

 

but if that is the case then a larger tb would be effective as well.

the j's intake would speed up the velocity, but it is not in proportion to the 33% ideal ratio, the air would be moving too fast. it seems that by increasing the intake port/ tb size to the proper proportion with the j's intake tip, it would make it much better.

can anyone else confirm that 33% is the ideal ratio? or this useless.

 

The 33% ideal ratio is a figure Larry from Endyn has used for a while. It is not the only factor in the whole intake design. The idea is simply that the TB is sized accordingly to the your intake manifolds plenum size and runner design, so that shouldn't be changed. The intake should be slightly larger at the TB opening so that the air will increase velocity so it can make the turn into the runners easier.

The rest of the design and how it effects intake velocity, is designed around when volumetric effeciency occurs in relation to the rpm band.

 

Yep 33% is the figure that team integra quote

 

i wonder if the aebs manifold different plenum and runner design requires something different... no way to know i guess, i will call the company at some point and ask some questions dirrectly... see what they have to say about it.