No power gain from Underdrive Pulley?...

[BrokenLinkage]

Jake- thank you, both for your prior contributions, and for (once again) clarifying the issue, in a thread that I was helping to derail. I respect your decision but wish you could see your way forward to remain active on the forum. My apologies to the OP.

Now for a question, for anyone qualified to answer. The crankshaft pulley bolt is deemed disposable, to be replaced once removed (ie fitting an UDP), presumedly b/c of thread deformation in turning it 90° past the torque value. Does this process imply that no thread locker or other potential lubricant should be used? And has anyone contemplated lightening the rotating shaft a bit by using a harder but lighter titanium bolt?
Please pardon my ignorance if this seems stupid.

[Gelbster]

Yes, because it is a deformable stretch bolt.
This bolt is Porsche part number 900.082.085.09
You should not use a generic grade 8 bolt of the same size:
M16 x1.5 x 60mm -but I suspect a lot of people do and just slap some loctite on it !
The correct bolt and belt (depends on specific pulley diameter)should come in the kit .

Here is an example of what we miss when the experts(not me !!) are not around:

"Tightening the crank bolt is not the issue, but if and when you go in for an IMS swap, or some repairs involving resetting the cam timing, be prepared for a significant up charge as the shop is going to have to remove the under drive pulley and reinstall a factory unit in order to lock the crank at TDC, that is assuming you have not removed too much of the pin boss from the engine cases when you installed the pulley. If you did, the trans will have to be pulled so that the engine can be locked at TDC from the flywheel. Oh, and the latter adds roughly $3K to the bill of whatever else is being done. "
Nobody mentioned this here !!!
And guess what happened when this was posted by a very well respected pro M96 mechanic - people dickered with him. And exactly the same happened when I re-posted this helpful caution. Yup - someone who clearly is not an M96 expert dickers with the wise advice - again ! And the expert patiently explains his point again to help us avoid needless expense.
My point is that without a few experts, a Forum like this is gets filled with irrelevant or uninformed 'comment'. a.k.a. -The inmates run the Asylum.

[njbray]

Sad that Jake Baby will no longer be posting!
I figure that 98% of us on this site are enthusiastic amateurs and have benefitted greatly from the 'pros' who help us out and answer our questions!
I greatly value his wisdom especially as I am having a lot of fun driving around a car that has 'his' IMS, oil plug, filter and about 9 liters of his oil splashing around behind me!

[WorkInProgressK]

Originally Posted by Gelbster

Yes, because it is a deformable stretch bolt.
This bolt is Porsche part number 900.082.085.09
You should not use a generic grade 8 bolt of the same size:
M16 x1.5 x 60mm -but I suspect a lot of people do and just slap some loctite on it !
The correct bolt and belt (depends on specific pulley diameter)should come in the kit .

Here is an example of what we miss when the experts(not me !!) are not around:

"Tightening the crank bolt is not the issue, but if and when you go in for an IMS swap, or some repairs involving resetting the cam timing, be prepared for a significant up charge as the shop is going to have to remove the under drive pulley and reinstall a factory unit in order to lock the crank at TDC, that is assuming you have not removed too much of the pin boss from the engine cases when you installed the pulley. If you did, the trans will have to be pulled so that the engine can be locked at TDC from the flywheel. Oh, and the latter adds roughly $3K to the bill of whatever else is being done. "
Nobody mentioned this here !!!
And guess what happened when this was posted by a very well respected pro M96 mechanic - people dickered with him. No moderation applied.

Where is the nut? Then it's actually called a screw...(open a bags of worms)

Wait. IMS swap but they charge extra for removing transmission? I don't understand, its part of the work.

About the Drama. One specialist does help have good information, but anyone with enough wits to read through information and willing to try different things will manage to save some money and end up with a more reliable car. I am also guilty of asking a specific information, but not after taking 4hrs of my life to search through bentleys and online. I am not expecting the answer, but anything can help me guide to the right information. Jake if he is that good(I haven't seen his contribution yet) should just open a for pay forum like other youtube mechanics to answer questions. Set up a patreon or such. You should expect free forums to have misinformation and you have filter it. This is what I don't like about owning this car. This car is not more complicated then a modern Honda civic. It just have huge failure point. Nissan Road Racing is my place and since the most common engine is extremely reliable and no one can really exploit any weakness we don't have drama talks. We just share our builds and our research on making the fastest nissan we can.

Can we get back to the fact that smaller crank pulleys are not worth it? Why not replace the pulley on the specific accessory rather then the crank on? Water+ powersteering. Done and Done. You can lock and have the non cavitating factor. Everyone is happy.

JFYI before the pitchforks. I might seem that I think I am always right. That is not 100% true. I am an Mechanical Engineer at an early part of my career and I have a very good grasp on anything mechanical. Giving my honest opinion, based on knowledge and experience, might be wrong and I would love to know with examples. I just see it as a mechanical assembly vs seeing it as a 16 year old Porsche.

[JFP in PA]

Originally Posted by WorkInProgressK

Wait. IMS swap but they charge extra for removing transmission? I don't understand, its part of the work.
.

Re read what the quote says; if we are doing an IMS retrofit, and have to spend extra time (such as removing the small pulley and installing the factory unit) locking the crank because of a smaller crank pulley and a mangled pin boss, it is going to cost you. We have actually had to remove a transmission to lock the crank from the flywheel end when doing some cam timing work on a car that had the pin boss nearly entirely removed and the crank bolt was rounded off when the small pulley was installed. There was no other reason the trans was pulled as the car already had a retrofit done, but the customer had to shell out a lot of unnecessary $ because of what we needed to do to get the cam timing set. So just watch how much of the pin boss you cut away, and don't bugger up the crank bolt; it could become costly down the road..............