Spec 911 class questions

[Phil Gilsdorf]

Hi guys, I'm in the process of building a spec 911 to race with PRC next year. I was hoping there were some folks on here that could impart some wisdom on a Spec911 newb.

915 transmission, is there any consensus on which 2nd and 4th gear is preferred?
2nd gear 18:33 or 18:32
4th gear 26:25 or 26:26
Is the a preferred limited slip setup?

Suspension, I have coilovers on the car now, so I'll have to go back to the drawing board. I heard there was talk of mandating a minimum ride height, which will affect my options. Spindle height on the front struts, +19mm or +30mm?

Is everyone running 24mm front and 31mm rear torsion bars?

Brakes
With the relative low grip of the 7 and 8 inch toyos, how critical is the brake package? preferred setup?

Any insight is greatly appreciated!
Phil

[Mahler9th]

Hello Phil:

I haven't run in Spec 911 so I cannot answer your questions directly. Howver, several NorCal Spec 911 racers visit and contribute to these forums. I am sure several will chime in. If you do some searches, you can learn about their choices and identify opportunities for further on- or off-line communication. You may also be able to access the Porsche Racing Club (PRC) forums and communicate with current and prospective racers.

As you may know, the largest group of Spec 911 racers participate with the PRC here in NorCal, and the competition is engaging, fun and fair. Several shops build and/or support Spec 911 race cars, including but not limited to Jerry Woods Enterprises, The Stable, Rothsport, Carl's Place/900 Series and Reno Rennsport. And of course there are quite a few folks that "do their own thing."

The rules have been stable for quite a while and you can download the 2014 version from the PRC web site. Usually the new rules for the coming season are published in final written form between November and January, so stay tuned for those. I think changes for 2015 have already been decided and are accessible in the PRC forums.

The PRC has a rules committee, and an elected Spec 911 racer represents the class participants, engaging them throughout the year. The class rep is usually also a kind of ambassador for Spec 911, so if you have questions, I am sure he will try to help.

PRC also has a Compliance Steward, and he is also an important resource if you have questions about rules choices and interpretations.

I helped create the PRC and was the point person on rules for the first decade+. Folks have made a wide range of choices in the some of your areas of inquiry for a variety of reasons. Our local culture is one in which much information is shared pretty freely, and folks have respect for choices made by others. However, since competition is involved, there will always be a little "secret sauce" held somewhat tightly by individuals and/or shops.

And of course it is somewhat difficult for written rules to capture all details, so I highly recommend leveraging resources like the rules rep and the compliance steward if you have questions.

Our local racers have and have had a wide range of developmental and maintenance budgets, but there is a pretty clear understanding of which key choices lead to performance potential that can allow a skilled and experienced driver to run up front. And in general these things can be achieved in the mid-range of budgets.

Good luck with your build and feel free to ping me if I can help.

[Mahler9th]

I should add that of course it can be highly beneficial to actually study some Spec 911 race cars and engage shop owners and/or racers in person, so details can be discussed. For shops, this can be much easier than telephone conversation.

And of course, since you are planning on racing in NorCal, you may want to study the past few years of racing results to identify resources involved with the development and maintenance of the car and drivers with whom you wish to compete. In the latter case, you should note that there are some local resources for coaching that several drivers have leveraged. Happy to point you in some directions on that as well if you so desire.

[juanbenae]

according to the rules doc the 2015 rules package has been updated--

http://www.prc-racing.com/uploads/PRC%202015%20Rules.pdf

where in california are you located? id be happy to spend some time doing a walk around my car if you are near the so bay.

look forward to seeing you on grid & in paddock next season.

toby

[Phil Gilsdorf]

Thanks for the feedback guys. I was originally planning on building this car to SVRA ST 2.5L specs but after talking to Carl from Rothsport at the PCA race at Road america this year, I was sold on making this into a spec 911 car. I talked with Rich and Jerry at JWE initially about doing the engine. I'll probably use them for track support, but I decided to build the motor myself. My car has some history, racing in socal SCCA since the late 60's (wolfgang Maike), so I want to stay with a period look and feel. EFI is no doubt the winning solution for the best power, but I'm going with MFI to try something different and period correct.

I'm in San Francisco, so Toby I'd love to swing by your garage sometime and pick your brain.

[Mahler9th]

Sounds like you are on the right track.

It might also be good to stop by the Stable in SF and visit with them as well. They provide services to a cadre of experienced and accomplished Spec 911 racers.

[Matt Monson]

Based on my sales, I would say that the 1.78 2nd and the 1.00 4th are the preferred ratios. JWE and Rothsport pretty much exclusively run my LSDs and gears in the cars they build. You will also want to look really closely at your 3rd gear. 2nd and 3rd are the gears that wear out and fail. We are talking about 30-40 year old gearsets here, and while they aren't cheap, most of the guys at the pointy end of the field have rebuilt their gearboxes using my new replacement gearsets for reliability reasons.

Regards,

Matt

[ZOA NOM]

Welcome to the madness, Phil. I'm across the Bay in Livermore. Hit me up any time, even if you're headed to see Toby. I'd love to join you.

[Eagledriver]

Tall second gear and short fourth gear is best.