I would guess that the Porsche bolts are very high quality but perhaps not to the ARP standards. If anything, I'm guessing the ARP version is going to be slightly heavier.

One way or another, I can't believe there is a performance difference. Reliability would be the only improvement I see possible.

It will be interesting to see what cgtexas finds out about availability of replacement bolts.

Where do you draw the line the replacement hardware? If I need to replace damaged head studs and use Gr 8 hardware in lieu of factory hardware, have I violated a rule? What about other bolts on the engine or other places in the car?

I think the concentration here should be on rotating mass and preventing people from reducing the mass of the rotating assembly. Other than that, quality of hardware used should be free IMHO.

944Racer72 wrote:


Rules state the following and describe the intent and how to validate an aftermarket part.


Also general bolts will be treat with basic common sense. Hardware with in the engine will be consider with more detail. Remeber upgrading for relaiblity is some what slipper slope. We have done what we can in the rules to address the known issues in reasonable cost effective fashion. By this point the rules are some 8 years old and nearly all of know issues are addressed in the rules. We do not have specific allowance for certain parts because stock works in those areas. If you see something that is needed for reliablity, but is outside current allowances we can discuss and evaluate it based on the normal rules change process.

WOW!!!

Too early in the year for rules creep.

Is there was a weak link in theses engine we did not know about?

Was really just checking before I used them as I had some I picked up cheap. Wasn't asking/looking for a rules change, just seeing if they were allowed in the existing ones.
I didn't want to run afoul of the rules. It just surprised me that you can't find OEM bolts.

cbuzzetti wrote:


No, I believe the stock rod bolts are reliable. The question is whether they are available. If not, then an alternative replacement is needed.

I have no interest in a new rule to allow ARP bolts if the OEM can be sourced for a reasonable amount.

Pelican lists more than 100 of the OEM bolts in stock, so I don't see that as an issue at this point.

Though these bolts themselves are a very small issue, they do bring up the point that our rules once contained this statement:



If ARP rod bolts are the same weight, I would think they meet this standard, and cars were built to these rules. There are good reasons why this is no longer in the rules, but it does have a legacy, and "fixing" some of these issues, were it required, might be very difficult.

I suspect there are quite a few cars with this sort of hardware in them out there.
Something we'll need to chew on a bit...

The PCA added a rule for 2011 that specifically allowed non-OEM nut and bolt hardware, provided it did not weigh less than stock [likely to address this issue].