larger T-body

[87cabriolet]

What is involved in swapping to the larger VW t-body in an 87 cabriolet? I have the larger TB but the tops are different and the shafts are also different sizes. How do I make this work?

[Fourt1thirty]

Porting the intake (or getting one off a late Audi 4000 4cyl which has the right sized hole), getting the right throttle body (usually Audi 5000, you'll need one for throttle switches and the same size shaft as the 1.8L one), and installing it.

It's not the high power adder you'd hope. In fact it really doesn't help a stock motor very much at all. The restrictions are the cam, the ports in the head, and the exhaust manifold (if you have the "toilet bowl", the 4-2 manifold flows great).

[87cabriolet]

well, maybe you can help me out, I had a 5000 and the top pieces didn't work and instead of trying to swap them i went back and swapped it for a vw one with a slightly different top. Its top didn't work right so i said i guess I have to change the shafts and now I can't seem to get the bottom spring right because the screw holes are on the wrong side every time I think I have it right. Is all hope lost or am I just missing something? I hope that I am not out two throttle bodies.

As far as the intake mani, I don't know that much about those little engines, just started looking at them when my g/f bought hers because I am the mechanic for us. The thing dosen't line up that great to the intake mani so i guess it is the crap one. What is a better one to put in there?

Thanks
j

[Fourt1thirty]

Late Audi 4000 or late VW Fox intake (probably 86 and later, but look before you buy anything).

As for the throttle body, the proper one will have a shaft that you can pretty much just bolt the Cabriolet linkage to. Although I've done a few of these I've never really figured out which car has the "proper" throttle body. MK2s didn't, and I think the problem with some of the 5000 ones is the cruise control.

[87cabriolet]

how much does a late model 4000 intake cost, and what should I look for?

as far as the t-body, I am just going to have to get one back together, the shafts were different lengths on both that I got so I tried to swap with the one that was origanlly on the car and then it got messy.

with the inake mani and larger t-body, there will be a noticable difference in accel. right?

[87cabriolet]

ok, i am going to buy another audi 5000 T-body because i don't want to waste anymore time on trying to get the springs right on what I have torn apart. I should be able to just move the top peice around or something, but I know not to deal with trying to swap the shafts again and I know that the top from the orignal has a different shaft so I am going to just try to flip the piece that is on there the other way or something similar. Does this sound right or am I messing up again?

[87cabriolet]

Originally Posted by Fourt1thirty

Porting the intake (or getting one off a late Audi 4000 4cyl which has the right sized hole), getting the right throttle body (usually Audi 5000, you'll need one for throttle switches and the same size shaft as the 1.8L one), and installing it.

I think i am just going to dremel out the intake manifold that I already have being careful not to get to small on the one side.

Originally Posted by Fourt1thirty

It's not the high power adder you'd hope. In fact it really doesn't help a stock motor very much at all. The restrictions are the cam, the ports in the head, and the exhaust manifold (if you have the "toilet bowl", the 4-2 manifold flows great).

What does the

Originally Posted by Fourt1thirty

"toilet bowl"

and

Originally Posted by Fourt1thirty

4-2 manifold

look like? Will a 2" aftermarket exhuast system make much difference with the TB and matched intake/TB opening or is the exhuast manifold that restrictive?

[Fourt1thirty]

All you should have to do to the linkage is remove the nut, pull the top linkage off, put the one on from a Rabbit throttle body, and put the nut back on.

As for the exhaust manifold. '83 and later most all MK1s came with the toilet bowl which flows horrible. All MK1s prior to that came with a 4-2 manifold and a dual downpipe. If there aren't 2 tubes coming off your exhaust manifold you have a toilet bowl.

The manifold you want is from an '81-'82 gasoline powered MK1. Anything else wont have a hole for the O2 sensor.

[87cabriolet]

I had originally tried to swap just the top, but the rabbit's linkage was taller than the shaft it was going on. The bottom piece of the rabbit was also much larger in diameter than the one it was going on. I just bid on another tb from ebay, I am going to try and start over. I will also try and locate one of those exhuast manifolds.
Thanks again.

[87cabriolet]

These are what you are talking about right?

http://cgi.ebay.com/ebaymotors/ws/eB...e=STRK:MEWA:IT

http://cgi.ebay.com/ebaymotors/ws/eB...e=STRK:MEWA:IT

I am going to try and bid on one of them tonight if they are the right kind.

[Fourt1thirty]

bingo

[87cabriolet]

ok, so I have a better exhuast mani on the way and a new TB, I took all of the old stuff off and began inlarging the tb opening for the larger tb. The inside of the intake mani is coated with a heavy um, hard to explain. It isn't really a film becuase it is super thick and just on there, like a heavy dirt. I can see it goes all the way into the engine, what is this form? The car has like 158k. I am going to clean the intake mani before putting it back on but there doesnt seem to be much that I can do for what goes into the head.

[Fourt1thirty]

Blowby... it's cooked on oil. A result of the cars milage and shitty gas.

[racerx]

I used a t-body from a 16v Scirocco which is just as big as the Audi one, it fit fine on my MK I Scirocco, I just had to bend in the sheet metal a little bit near the linkage since I have the 17 mm taller "tall block" 2.0 liter.
-Rich

[87cabriolet]

so in changing the exhuast manifold and downpipe to the higher flowing model am I also going to need to get a different cat that has the o2 sensor bung? The o2 sensor was previously on the back of the exhuast mani at the downpipe.

still waiting for parts to arrive...