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What is the max shave head limits?


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I have a Porsche 944 that will be joining the spec race soon. My question is" What is the max head shave limits that one can do on a spec 944 engine with out going over the specs for racing? Also what will it do to compression on the engine.



83 944

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We don't as of yet have shave limit on the head. We may in the future however.


What we do have is a max compression allowance of 11:1.


Motors stock are 9.5:1 for 83-87 and 10.2:1 in 88.


I would advise to NOT shave the head. Power gains from a shaved head are inconclusive. Shave heads may result in greater risk of headgasket failures. This also inconclusive.


Best bet is to have the head cleaned and made flat with min material removal. Run the car like that and you will be fine in terms of power and will yield the best reliablity and lowest costs as you can run on 91 octane pump gas.


Rich where are you located?

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I drive around town on 87 octane, and race on 89 octane. I run the higher octane during racing in case there are any hotspots in the combustion chamber or anything else that might cause pre-detonation.

Like Joe says, I'd keep it close to stock for reliability.

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I have my head shaved but not as far as some of the others. I have about 10.2-10.5 CR and there is still room for cleaning up if need be. I've seen some heads shaved flat and they still don't put out 11:1 CR. Besides anything you gain is on the very top end and you lose it lower. It's like robbing Peter to pay Paul. Have you head redone to specs and I'm sure you'll notice the difference. Plus make sure everything else is good. My DME had an issue as it ran fine but did not produce much HP. Since swapping it out my car runs great now. But like Tim says keep it stock for reliability. All of the top running cars are probably within 5-8 HP of each other so there really isn't anything to be gained by spending your money there. Drive baby, drive!!!

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So willow springs in you backyard!



Take a look at the website in my signature. It lots of good info on the class.


Tim Comeau is the Series Director over there and can get you number graphics and can help with details on getting going. I can issue you a number as I have a listing of those already taken.


Most of us on this board are pretty good at sharing set-up information. Our intent is to to have the cars equals so that creates tigher field to racing with with and more fun.



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Rich, Great to have another new driver in the series! Welcome!

Have you read the rules well?

Having never seen your car, I don't want you to have any surprises at your first event.

Have you picked your racing number from the list yet? We need to get you a set of 944-spec decals, too, including series sponsors.

If you can, make the POC event at Streets of Willow on the 6th and 7th of Nov. We'll take a good look at your car and make sure you're ready for the NASA event at Willow Springs on Nov. 13-14.

Racing License yet? Race school is coming up too. http://www.Driving Concepts.com

Let us know how we can help.

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