i have seen this mentioned in a few threads, but can't quite figure out what it is.... and searching for TB mod doesn't tag anyhting due to the way the search engine is setup.

thanks in advance!

EDIT:

1996 dodge b2500 van, 3.9l v6, automatic

 

Not sure what year nor what TB type your van has, so I can't provide any input.

 

oops, i edited it

yeah, that info would help

 

If you have a good shop-vac and a good dremel tool, the job is easy with a steady hand.

When the air-housing is taken off, the top of the TB is exposed. Looking from the inside of the van via the dog-house removed, the TB will have two distinct barrels openings. Each opening has a front and rear circular wall. The front circular wall that faces the front of the van needs to be ground all the way down to the base flat surface of the TB. Whilst grinding, maintain a constant shop-vac suction.

The grinding will also need to be very smooth and nearly polished. Add a small radius around the edge going into each barrel. When done, clean up everything.

A Fastman TB costs more to do that to simply do it yourself. Also, the rear walls of the barrel are needed to help control the IAC.

 

ah... thanks for the info....

what is involved with taking it off to do it? haven't had the doghouse off in quite a long time.... to the point of back when i helped my father in law try to diagnose a misfire years ago, back when he owned it

will i need some sort of gasket?

also do you have any pictures? i am unclear on what you are refering to as polished other than it being burnished enough to look mirrored, and once i get it there, do i need to seal it? usually you seal raw metal -- but i assume you don't on this?

i don't feel comfortable with trying to grind on it, and hoping i can suck all the junk back out

 

There are only four bolts that hold the TB to the intake manifold, so it is very easy to remove. You'll also need to disconnect the throttle cable, transmission detent cable, IAC connector, TPS connector and MAP connector.

I would whole-heartedly advise against performing the drilling modification with the TB on the manifold. That's just asking for trouble. In some cases the TB gasket stays either on the TB base or the manifold base and will be undamaged -- in this case you may re-use it. If the gasket tears a new one only costs a few bucks from the auto parts store and most places should have it in stock.

If you do the TB mod please post some before and after pics!

 

oh it's getting done i will take pics

as far as pictures go, stev, i looked into your other thread, and only saw red x's for the pics... are there any other pics that anyone can direct me to to see what this looks like?

i wont be doing it still on the car... i'm way too paranoid for that

 

Stev - what is the realized benefit to the engine after the front half of the circular wall of the TB has been ground away and polished as you described?

 

......

 

Cool, thanks. Now I am puzzled about how grinding the rear circular walls of the TB would (or could) have any effect on the engine idle since the IAC (ostensibly) is infinitely adjustable. If the airflow across the top of the TB is changed at idle shouldn't the IAC compensate as directed by the PCM?