Throttle Linkage length - 1971

[Xhab]

To complete the post we found with my mechanic there's 2 Réf. for Throttle Bellcrank / inverted lever, Réf. : 901.423.027.03 (1969) / 901.423.027.02 (1968) which correspond to the same Throttle Linkage Réf. 901.423.026.03 (1969) / 901.423.026.02 (1968)

There's a difference of length and angle on the lever which explains the difference in length of Throttle Linkage :

[SFE]

1969 is a very special year !
You really have to deal with both 68 and 69 PET...
And of course Porsche OEM have no clue about it.

[edmayo]

Porsche changed the bell crank leverage when they went to MFI. It was to provide greater leverage for the increased resistance of the MFI throttle system.

[SFE]

Porsche changed the bell crank leverage when they went to MFI. It was to provide greater leverage for the increased resistance of the MFI throttle system.

Hello Ed,
So you mean all MFI cars should have the bell crank leverage circled in red (even early MFI cars) ???

[edmayo]

What you have circled should be for carbs, they have the shorter arms. Less leverage. Is that your .02 bell crank ? I see very few cars that come in that have full throttle. Most people have trouble understanding how a bell crank works. The entire system has to dealt with, starting with the pedal return stop on the pedal cluster, get that wrong and you never get the rest correct.

[Simonjjb]

What you have circled should be for carbs, they have the shorter arms. Less leverage. Is that your .02 bell crank ? I see very few cars that come in that have full throttle. Most people have trouble understanding how a bell crank works. The entire system has to dealt with, starting with the pedal return stop on the pedal cluster, get that wrong and you never get the rest correct.

I learned from Ed that you have to start from the front and work your way back...

[SFE]

To be clear, when my friend Xhab ordered a throttle linkage .03 it was too long and it was probably because his lever was the .02 (the one which is not circled on the picture).
So regarding the lenght of those throttle linkage it seems you need the lever circled in red to fit with the .03 throttle linkage.

But if you say it's for carb, then the truth is elsewhere !!!

[Flieger]

Planning a rehab of the pedal cluster and throttle linkage on my '71 and came across this thread. I was just wondering how best to pop the ball joint apart (is it simple as using some leverage or is there some sort of clip to remove?) but now I'm wondering if I'm getting full throttle. My car has MFI but has the shorter bell crank. It seems to have plenty of power but I don't drive other early 911s, and my car has seen a lot of things over the years that I don't know about. What's the best way to tell if I'm getting full throttle?

Right now I'm chasing what seems to be excessive friction in the system which I think is either pedal bushings or something to do with the linkage (which looks to be kinked). I'm planning to replace the center tunnel linkage- I had just replaced the bushings (which were missing) the other day but that seemed to make things a bit worse actually.

[gled49]

Just a little fyi.

[Flieger]

Oh wow! Which one should I have? It looks like I've got the one on the left.