MFI protractors not needed says Porsche Product Information Circular. Comments?

[David E. Clark]

[David E. Clark]

Any comments from the evening MFI crowd?

[Zeke]

It's kinda like what I have been saying. Once you set the pump rod, the length of the push rods is determined by how far forward or rearward you can move the throttle bodies on the studs and sthe same for the pump itself on its mount. That, and where the throttle levers rest after idle adjustment. IOW, there isn't a lot you can do do move things around significantly once you have the 114mm..

Now, I said significantly. I'm not going to dispute what Grady Clay and Warren (Early-S-Man) have posted before. There is room for making small adjustments given the tolerance of the pump rod (+-2mm) and the other movements. The protractors seem to be more of a varification than an overall adjustment tool.

Now, Grady talks about something regarding the cross bar and the ratio of push. So, it would seem that you can get a liitle more rich at part throttle, or a little more lean. But, I thought that was what the pump adjustments were for.

The whole MFI business is splitting hairs. If everything is in top notch condition and properly calibrated, I'm sure there's room to find the pinnacle of performance. But, so many perameters contribute that it is a daunting job.

And, WOT is WOT and hopefully all parts are WOT when you are there and kicking ass. Speaking of that, if you read Tyson Schimdt's comments on the subject, he submits that the system runs inherantly lean at WOT, so it is wise to have things set up rich if you are at the track.

[Grady Clay]

I’ll go look and if I can find this publication and other contemporaneous ones.

My take is this is P+A’s response to not having technicians system wide who could properly use the protractors. The result was to instruct to set everything at its Factory idle stop and then simply adjust the links so all come off the stops at the same time. Not a bad idea and is part of CMA.

The difficulty comes at just off idle and part throttle. I don’t think this is an issue at full throttle.

I think better training would have been a more satisfactory solution.

For today setting MFI, I think the protractors are critical for proper set-up. There has been too much opportunity for linkage mischief in the intervening years.

Best,
Grady