from the 1992 100 to the 97 A4/A6/Cabrio and there is one throttle body that outflows all others stock and therefore would also once bored or bored/sleeved due to it's inherent larger primary bore aft of the primary butterfly.

In over a year and a half I've had access to 3 of these and every one shows the same 28-32 more CFM of air over and above all others. Actually every other unit from 92-97 flows within 4-6 CFM of each other in stock, clean form. And among them theres no clear winner as the 4-6 MAD (mean average deviation) seems to be arbitrary and due to casting tolerances (variances) more than any design feature.

I kept the testing "blind" as I didn't want to know what application this TB is for and still don't know. All I know is it's part number and it's for an automatic transmission car.

I've wanted to build a "racing" throttle body to play with along with the ported/polished intake manifold but wanted to start with the clear flow winner as my base platform. Didn't hurt my feelings at all to find the reason this one flows better will remain intact once converted as it's below the butterflies and in the casting... I can't make another one flow this well below the butterfly shaft with any amount of machine work due to an entirely different casting used on this throttle body in that area. Above the butterflies remains unchanged and is the same as all other throttle bodies so any/all other typical TB mods can still be done the way they alwys have.

And as I said I don't even know what Audi this throttle body is for. Doesnt really matter since I just happen to have one. But in case you guys wanna go looking in junk yards it's part number is: B6 291 078 063 T and like I said it's for an automatic tranny car. But all auto TB's easily transfer to a manual tranny car. It's making a manual TB try to fit a auto car thats a MAJOR project! And it'll flow 12-15% better than the one you're using now, no matter what model Audi you have without any modification whatever.

Just wait till you see this lil beauty prepped for race! All-out, no holds barred RACE! I'm gonna lose a little low-end but at 2800+ RPM's this thing is gonna BREATHE!! By far and away my most extreme and radical design yet.

If so, the number would be more like "078 133 XXX"

It would a center prefix of 133.

Damn!

but they all have an extra prefix/suffix added on in their body stampings.

But because I buy my TB cores in bulk, usually 6-12 at a time I'm never sure whats in the box part number-wise or what they came off of.

I would guess that Mance possibly got a non-12v TB from whatever engine whose TB served as the template for our 12v TB's.

It appears likely that Audi used an existing TB design for the 12v and then modified the primary valve's bore without reducing the size of the valve. No sober engineer would design a TB with a valve larger than needed and then use a smaller bore leading to it?!?!

I suspect the original design of our TB came from the early V8 or another large VAG engine and then got scaled down to match the 12v's airflow needs.

I currently have 11 throttle bodies in-house. Of those 11 I have 5 different part numbers as listed here:

B2 211 078 061 A*
B5 215 078 063 K
B5 129 078 063 K
B6 304 078 063 K
B6 291 078 063 T*

* indicates auto tranny configured TB's.

These are a mix of 90/A4/A6/Cabriolet and 100 series throttle bodies. The "T" throttle body which is the "good" one is the third one I've tested and I only accept throttle bodies from my source that are from the above listed cars so I doubt the salvage yards slipped a V8 throttle body in on me. Tho I do remember at one time wondering if the 4.2 throttle body was bigger and seeking one out. For some reason I never ended up with one so it must not have presented anything surprising or appealing as compared to the 2.8 throttle bodies.

Is funny that ETKA doesnt show the same part numbers that are stamped on the TB castings even if the prefix/suffix markings are dropped. But I seem to also remember something like this happening early-on when I was trying to compare the throttle bodies from different cars so I could do exact replacement TB's as those returned to me. But I gave up that ability early on since I couldn't tell tho there are some subtle differences between pre-96 and later TB's especially as it relates to throttle cable hookups on the throttle bodies.

but are all an " XX XXX 078 XXX X" instead. And even if we drop the prefix/suffix we still end up with a "XXX 078 XXX" part number. We could have a huge nightmare on our hands trying to find the year/model Audi that this TB lives on.

blowing thru the outer primary venturi exterior walls then re-sleeving to desired I.D. This one is no different than the others above the butterfly shafts. Thats why it can accept all the normal mods and still have a larger exit venturi below the primary butterfly.

Just some suggestions

I know this because this is the third one thats come thru here and two of those were exchange units sent to me by people who had S3 conversions sent to them.

We shouldn't be making this any more complicated than necessary. It's a North American 2.8 12V car. The biggest problem is ETKA doesn't list the same part numbers that are stamped on our throttle bodies... but that doesn't mean we ALL have european or diesel throttle bodies. Even the ETKA part numbers for my A4 and my sons 90S are different than the part numbers stamped on our throttle bodies.

Most TB's I have in stock right now are exchange units I've received after sending S3 conversion TB's to people. All these people sent me the throttle bodies that were on their cars. None of them sent me diesel or european throttle bodies.

We just have to learn how to decipher the ETKA as it relates to TB's. We must also realize that any/all early part number TB's may well have been superceeded and that this particular unit is no longer available. But it would still be nice to find them in a salvage yard via their application.

133 is VW/Audis code for TB ever since they started making parts years ago. The chassis code would be the first three numbers (058, 078, etc..)

In every VW/Audi part number the center 3 digits is made up of a main group x** and the subgroup *xx eing the X's.

So any part number like this:

*** 1** *** : Would be Engine and clutch applicatios.

*** 2** *** Gastank, pipelines, exhaust

*** 3** *** Transmission

*** 4** *** Front axle differental, steering..

33 is the Subgroup for pretty much the whole intake system in any VW or Audi such as aircleaner box, MAF, hoses, etc.. (Most every part anyway). There may be some clips and stuff that fall into a body main group of 8**.

I think Im going to put together a page for everyone to fully understand Audi/VW part numbers, maybe a FAQ page for AW. Afterwards, you would probabaly be able to guess any part number just by year make model and placement.

do not fit the ETKA criteria with anything close to a "078 133 XXX" type number stamped on the TB castings? I mean it's not just the one on my car, my sons car, my exchange units which came from A4's and 90's, but everyone thats reporting numbers.

Further why is 078 a constant but not the 133 that you're saying Audi specifically gives to throttle bodies?

There has to be a MAJOR supercession that occured recently that superceeds all previous part numbers for TB's with 9-digit numbers. That would seem to be the only thing that makes sense since all throttle bodies excluding auto/manual are directly interchangeable for pre 96 and post 96 2.8 12V engines.

Thier part number system will never change.

What I think is that maybe your looking at manufactuer stampings. Most of Audi/VW throttle bodys dont have part stampings or castings. The only ones that I have seen are on the new ones with plastic backs on them, and even then the numbers are printed on the plastic and not stamped or casted into the metal.

Im sure anyone here would be happy to take a look at ETKA and verify the different part numbers for the 12v TB through the years. I would do it now but one of my co-workers are on the VW PC putting in a stock order.

Is to have everyone possible get the numbers off of thier TB and post it with the make/model and *VIN* of thier car.

With this information, we can then correlate TB applictions. Someone with the same year and model with only a few VIN digits away may have more relative numbers on thiers. Those numbers could refer to lots of things, build dates, plant numbers/locations, mold numbers, even serial numbers.

The hard part is trying to figure them out. Probabaly impossible. ;(

form the same year/model Audi this one came from. It may be from a car that was only available as an auto or it may be that it was offered on a manual car but that I just havent had one come thru here yet.

Once we find the car it came on from Audi we'll know which throttle body to go looking for next time we need one, be it for conversion or just as a replacement.

Until we zero-in on some more clues that point us in the right diection we have to be VERY carefeul what we exclude from the search lest we mistakenly omit one potential/possible success.

It's just a hunch but it's a reasonable one based on some measure of an educated guess gleaned from the TB's I've seen to-date.

I'm gonna go with a 1995-1997 A6. Probably more specifically a 96 or 97 A6. I'm doubting a 95 due to the throttle cable hookup on the 3 I've seen use the 96 & later throttle cable pulleys on the throttle bodies.

This theory also lends itself to an "auto only" application as the 96/97 model year A6's were auto only. The 95 was offered as a manual but coupled with the throttle cable issue and my having seen none of these in manual spec lends creedance to the later year/auto only line of thought.

The third consideration is these were large, heavy cars. Audi might try to speed them up a little to show a better 0-60 time. The quattro sedan weighed in at a hair over 3700lbs and the wagon a hefty 3900lbs, fully 400/600lbs heavier than the A4's of the same two years. Given these facts and the actual units I've seen and tested the 96/97 A6 would seem the logical starting point for finding the application for this higher-flowing throttle body.

May or may not work out but I gotta start somewhere and the A6 seems a better choice for the above reasons than anything else I can come up with.

I have looked at our 1996 A6 AUTOMATIC TB, and it just did not look the same, mruhahahahhaha, hmmm, next question, could i put on one of my many, yes i have 5 tb's in my posession. But can i take one of my 4 5spd's and put it on the 4 spd auto?

MAJOR PITA to convert a manual TB to fit an auto car." You would have to drill/tap the throttle body to hold the auto micro switch and one of the pulleys to mount a step-down lever on to activate the above switch.

Still there is no visually perceptable difference between the two throttle bodies other than on the primary bore outlet. You can't see that outlet while it's on the car thus you wouldn't see any physical differences while your A6 unit is on the car other than the auto step-down (passing gear) device and electronics.

However you should be able to get the numbers stamped into the side while the TB is on the car near the EGR valve and just below the TB base vac nipple. If it's B6 291 078 063 T then our lil mystery is solved.

Ive started to gather some part numbers to thier applcations and so far theres only three different TB's.

For every year Cabriolet, 12v 100, 12v A4 and A6 all the 5 speeds use the same unit, 078 133 063K

The Autos are using 078 133 063T and 063L which are split by VIN except on the A4 which only uses the 063T. Yup, only two different units for the A4.

The only car I havent looked up yet is the 90 and thats only because I was forced to get back to work. But Ill be back on it tomorrow. Afterwards, Ill post up a full list of every unit and its appliction.

Mance, I have to get you a copy of ETKA. ;)

Only thing is that my mom just brought it to get a lower ball joint. Im going skiing tomorrow so can't do it. But ill see if i can get it either maybe tomorrow or thursday.

PLEASEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE WITH SUGAR ON TOP AND SPRINKLES.