BBB and Ported Intake question

[pejohnson]

I have a hypothetical question. If I was looking to buy a used Gen I or Gen II or found one at the local junk yard, how would I go about determining if the intake had BBB's or a ported intake? I am assuming I would need to take a caliper to measure, remove something on the intake and measure it. Sounds like a pain hence my question. Also what are the factory diameters?

 

[rubydist]

if you have ever looked inside the stock intake, you know the typical casting roughness.

if you pull on off at the jy, and its smooth inside, you can easily conclude it has been ported.

you need to actually dis-assemble the intake to get to the butterflies to see if they are larger.

 

[jayro]

Stock butterflies are 39mm BBB are 41mm. If you pull the intake and visually examine it you should be able to see the difference.

 

[zblackbeast]

Like it was said, if you've seen stock ports and stock butterflies, you can EASILY tell BBB's and a ported intake just by looking.

 

[LOUDSHO92]

SHO Shop notched the limiter for the BBB's when they made them. An external reference to look for.

 

[SHO_OFF]

Will get pics up in the next few days. Just got my Ported intake with BBB's back from Powdercoating, and have a stock one laying around. Will take comparative pics for everyone!

 

[kevinspann]

First sign to me is a missing set of intake horns. You can see where they are sandwiched in between the intake and the butterflies. Also if the intake is dirty and stock, along with the rest of the car (I've never come across a modded SHO yet).

 

[zach44102]

Stock butterflies are 39mm BBB are 41mm. If you pull the intake and visually examine it you should be able to see the difference.

Incorrect, stock butterflies are 38mm. BBB are 40mm.

Just look for casting marks on the inside of the intake. if they are there then it has not been ported.

 

[jayro]

Incorrect, stock butterflies are 38mm. BBB are 40mm.

Just look for casting marks on the inside of the intake. if they are there then it has not been ported.

Memory must be going........

 

[zak]

Stock butterflies are 39mm BBB are 41mm. If you pull the intake and visually examine it you should be able to see the difference.

SHOshop made some 41 mm ones. Vast majority of the rest are 40 mm. I am working on some 42's

 

[jd4242]

SHOshop made some 41 mm ones. Vast majority of the rest are 40 mm. I am working on some 42's

Can the ports be ported that large to take advantage of 42mm?

 

[zak]

Can the ports be ported that large to take advantage of 42mm?

Its a cross sectional area issue. If you subtract out the area of the centerbar even a 41 mm SHOshop BBB has less flow area than a 38 mm extrude honed short runner. That is why a few have gone to no butterflies - but that hurts torque in these small displacement/heavy car applications.

 

[jd4242]

Its a cross sectional area issue. If you subtract out the area of the centerbar even a 41 mm SHOshop BBB has less flow area than a 38 mm extrude honed short runner. That is why a few have gone to no butterflies - but that hurts torque in these small displacement/heavy car applications.

Oo didnt even think about the cross bar on the butterfly. Can you half shaft them or are they already? Yea no butterfly would seem to be only good with a car thats above 4000 all the time or FI.I would like to see mine open a little earlier say 3200-3500 to make the transition easier.I find when they open in turns or windy roads that my inside tire looses traction, but sure springs and new tires will solve that

 

[zach44102]

You can not go bigger than 40mm. 42's are impossible using the original housings. 41mm leaves a wall thickness so thin the heat and hose clamp would warp the housing.