Throttle body to Air filter adapter

[nkemp]

Seems that one of the problematic parts when converting from Bosch CIS to EFI is adapting from the stock (if using) throttle bodies to the stock (if using) air filter. The Distributor can be gutted, parts can be cobbled together and parts can be fabricated but it is always nice if OEM parts can be reused. Here may be some parts that may help.

A number of years ago (12+) I pulled some parts from various cars ... just in case. Here are pictures of one:
IMG_4992.jpgIMG_4993.jpgIMG_4994.jpgIMG_4995.jpg

The parts are from a VW of unknown model with Bosch CIS.

- The round part fit over the Fuel Distributor where our filter fits. As such, if you turn it over it fits right on the DeLorean air filter. This part can be used to make a nice 90 degree bend from the filter towards the throttle body
- The tube is "oval" for all practical purposes and the ends measure about 3.75 x 2.25
- The other end has rubber adapter that measures about 3.75 x 2.25 on both ends. It also includes a number of ports one of which could be used for IAT, the other could be used for an idle air filtered air source.

HELP... Can someone, who has the TB sitting outside the car, measure the throttle body's inlet side (CIS Distributor side) and reply back? Hopefully it will be about 3.75 x 2.25! I need to keep mine running for a while or I'd provide the measurements here.

Clearly the VW assembly will not work as is. But it doesn't take much to imagine how the middle tube could be adapted. Or a custom tube could be created to fit between the two boots. Even if the round boot is the only part used it is still a nice part to use.

The VW part numbers (taken from parts)
- Oval air filter adapter 067133357
- Tube 067133373
- Oval adapter 067133649

I also pulled a Volvo air tube (# 127 651) that fit on the Volvo's CIS Fuel Distributor. It is rigid plastic and as such does not slide over the DeLorean air filter but could be used if a sleeve was used to connect to the DeLorean filter.
IMG_4997.jpgIMG_4998.jpg
Lest someone thinks that the mounting tabs will work if flipped and used under the DeLorean air cleaner... they won't. They are not symmetrical (mirror images) and when the part is flipped thy will not fit. Also, this part may not fit between the runners and will require lots of further fab work. It is included for completeness... maybe someone wants to play with one.

[dmc6960]

HELP... Can someone, who has the TB sitting outside the car, measure the throttle body's inlet side (CIS Distributor side) and reply back? Hopefully it will be about 3.75 x 2.25! I need to keep mine running for a while or I'd provide the measurements here.

I can tonight if nobody else does. I still have both the air meter assembly and throttle body sitting in a box in the garage.

As an added bonus I could bring both items with me to the orchard this Sunday for a real test-fit.

[nkemp]

Bringing them to the orchard would be great!

Nick

[Spittybug]

I'm watching this one eagerly! The only reason the "stock" EFI setups have to keep their fuel distributor assemblies is to provide connection for the odd geometry between the slightly downward facing throttle body and the horizontal plane of the bottom of the air cleaner. We've looked to find a >90* boot that would mate to the air cleaner and the face of the TB with no luck to date. Given the confined space, rubber would be the preferred method. Being able to totally remove the fuel unit while keeping the stock manifold and air cleaner (we shown the addition of fuel rails isn't a problem) makes for a very clean install, less weight and much better access to the distributor.

Would love to see you succeed on this one! I Googled that part number and found this:

Elbow at meter on top of air box.P/N - 067-133-357 (CR)
Fits:
1979 to 1993 Rabbit Convertible & Cabriolet
1979 to 1984 Jetta
1979 to 1984 Rabbit Pick Up
1975 to 1984 Rabbit
1974 to 1989 Scirocco

and this: http://www.busdepot.com/air-intake-boot/

[nkemp]

AFAIK, this part would work to make the 90 degree bend. I have not tried installing it on the intake manifold but I don't think height will be an issue. Here is a picture with the part slid on the DeLorean air filter (upside down... downside up):

IMG_4999_2.jpg

It slides on nicely and a hose clamp may be all that is needed to make a secure & air tight connection. If not, a bit of little RTV would do the job. Being a circle it can be oriented in any direction.

The RED circle highlights a rib that if removed would allow the boot to slide on farther. I think it is currently on far enough to get a good clamping surface. If/when I do it I'd remove the rib to get it on farther just in case.

My concern is still the connection to the throttle body and I anxiously await the dimensions. It would be SOOOOO nice if the other boot would fit.

Nick

[Spittybug]

I measured the oval on the fuel distributor end. 4 1/4" x 2" Now, that is the internal dimension of the hole, the throttle body has a rubber gasket that presses up against this face. So, to go over the "mouth" of the TB it would have to be bigger, say 1/2" in both dimensions?

[nkemp]

Hmmmmm. It will be interesting to see how it fits or not on Jim's pieces this Sunday. I'm not optimistic.

Your measurements are more accurate than mine were... I measured the inside of the rubber couplers which are somewhat of a moving target (also, my notes said 3 1/2 and I typed 3 3/4). So I just measured the plastic tube external dimensions and it is pretty close to 3 5/8 x 2 1/4. The tube has a lip on the end and the parts do not fit real tight past the lip...just right.

BTW ... the outside diameter of the 90 degree boot when installed on the tube is 3 7/8 x 2 1/2 (not including the lip). I still think the boot gets us more than half way there.

[nkemp]

Finally I found a picture of the backside of the throttle body... where else but eBay (http://www.ebay.com/itm/1981-1982-De...-/120975789278) They show it with the rubber coupler attached.

So is it fair to copy a picture from eBay and post it here?

It has been a while since I took that part apart and it is different than I recall. It needs a flange to attach to the throttle body. As such, the VW rubber adapter will not fit nicely to the backside of the throttle body.

[Spittybug]

Too difficult to speculate on these kind of things. We need to wait for your test on Sunday.

I have a full manifold/TB/Fuel distributor laying in the workshop that I would be willing to play around with if you want to send me the boot, but I think you're fully equipped to do the same, aren't you?

[nkemp]

Yes... I think I can use Jim's parts. And once it snows I can use mine :-(

Nick