924Board.org

[CBass]

Hey guys, you may remember reading my posts about the VW 52mm twin butterfly throttle body with throttle potentiometer.

I bought one for my Rabbit(2.0 16v swap with megasquirt), and on a whim tried it on my collection of 924 manifolds. No way it will work with the 931 manifold, which I determined earlier from measurements.

It bolts onto a '77 manifold with no clearance issues, but no clearance between the bottom of the TPS and the runners.

It is so close on an '80 manifold that you can get the cap screws started, although they are tight. It will fit if you skim a little off of the runner for clearance. I'm going to give this a whirl with my spare '80 manifold and see how it goes. If it works out, I may just stick one of these on my car.
Then again, I still have that GM TPS and another 52mm throttle body from a MK2 jetta.

No pics for the moment but it bolts up, throttle linkage pulls in the right direction. you will want to take the piece of the linkage that the cable attaches to off of your 924 and put it on the VW linkage assembly. Connector is a standard AMP 3 terminal male connector.

These throttle bodies are somewhat sought after by the VW community, as they are how the VW guys do their megasquirt, so they can be a little expensive on Ebay. If you're at the local pick an pull, they come off of early 90's 4 cylinder Passats with automatic transmissions. Manual cars do not have the TPS, just contact switches for idle and WOT.
_________________
'81 931 in various states of assembly

[CBass]

Wow, did the EFI craze die while I was gone? I at least expected *some* response to this.
_________________
'81 931 in various states of assembly

[endwrench]

I never saw the post! It is good info and will make life a lot easier for some who try to convert to EFI. Nice find!!

Todd
_________________
'79 924NA. Rebuilt 9.5:1, MSDS header, Mega Squirt Injection, MJLJ-EDIS Ignition, 1.6L Whipple Charger and Intercooler, 10lbs Boost, 944 Trans, Custom HD Clutch.
"simsport" said....superchargers are better than turbos its official!....

[Chrenan]

[Raceboy]

What??
Chrenan, I was posting pics of my engine, and there was a turbo actually attached to it!

And I plan to convert my wifes N/A to Megasquirt.... Initially I wanted to install Motronic, but that makes a lot of hassle without much improvement.
_________________
'83 924 2.6 16v Turbo, 470hp
'67 911 2.4S hotrod
'90 944 S2 Cabriolet
'78 924 Carrera GT replica
'84 928 S, sold
'91 944 S2, sold
'82 924S/931 "Gulf", sold
'84 924, turbocharged, sold.
http://www.facebook.com/vemsporsche

[Chrenan]

[Porsche924boy]

Wow the EFI craze did die. Yep we want superchargers and turbos. So if you could do a super charger that had built in EFI that woud be neat.
_________________
What i own:
1995 Ford F150 Eddie Bauer 4X4
1995 F250 PowerStroke Diesel

Auto Technician Diploma
Diesel Technician Diploma

[endwrench]

Chrenan, Chrenan. What have you done?

[CBass]

If you're converting a naturally aspirated car to forced induction, you're going to have to do something about the engine management regardless. EFI is cheap and most effective. If you're wanting to boost, it's because you want performance. An EFI forced induction system is going to make more power and be more streetable with fewer issues once tuned than a CIS forced induction system.
_________________
'81 931 in various states of assembly

[Chrenan]

Completely true. On an N/A, there must be gains as well when converting to modern injection and ignition besides the obvious advantage of dumping the aging CIS. Hotter multiple spark combined with exact fuel management must be worth a few HP?
_________________
1987 951 - M193 Version for Japan

[Raceboy]

[CBass]

[Raceboy]

CBass, it's most probably due to compression height difference between some years of 931. I don't know specifically what years (perhaps Series 1 & 2?), but Racing mentioned that in one of his earlier posts....
_________________
'83 924 2.6 16v Turbo, 470hp
'67 911 2.4S hotrod
'90 944 S2 Cabriolet
'78 924 Carrera GT replica
'84 928 S, sold
'91 944 S2, sold
'82 924S/931 "Gulf", sold
'84 924, turbocharged, sold.
http://www.facebook.com/vemsporsche

[CBass]

The pistons look to have the same dish as the 1980 7.5:1 US spec pistons. IIRC those come up very close to the deck.
_________________
'81 931 in various states of assembly