IanM

My mechanic completely rebuilt my engine a few months back, and I currently have about 3000 miles on the rebuild. Everything is working great, but I have a few questions. I had a wide-fire ring head gasket installed, but when I asked my mechanic if he thought I should go with upgraded head studs (like Raceware), he didn't see the point in it. He's a very experienced mechanic, so I trust him, but everyone's talking about Garrity and Raceware studs, what's the deal? Why aren't the stock one's good enough? Should I have insisted on new upgraded studs? I'm running my manual boost controller at 17psi, and haven't had any problems yet.

During the rebuild, I had a valve job done. I asked my mechanic if he thought it would be worthwhile having my head ported and polished. Again, he told me not to bother, and didn't figure the gains would really be worth it. I've got an HR Stage 2 turbo, MAF, etc, so I'm pushing a lot more flow through the system. How much hp gain are people really finding with ported and polished heads?

Flight 951

I had a Wide Fire Ring installed a few weeks ago on my mildly modified 89 951. My mechanic didn't see the benefit in using aftermarket studs either. (I asked too.) He ordered a head install kit from the dealer. He mentioned that he has seen a number of aftermarket studs break when/if taking the head off later. 17psi seems pretty tame when compared to some of the race cars out there. Your set up sounds good to me.

I don't have any experience with porting and polishing a 951 head, but I can't imagine the difference would be much more than a tenth of a second or two from 0-60. I wouldn't worry about it since the job is all done now.

keith

i don't suppose the P&P makes too much difference if you are PUSHING the air in, as opposed to sucking it...?

IanM

Keith,

That's what I figure too. I've heard several times that flow optimization is most important on a normally aspirated car, and not so important with forced induction. Thanks for the comments, it makes me feel better.

'86turbo

I disagree. I believe that a p/p setup will yield significant gains. Why would flow optimization on a turbo be any less of a concern. I would think smoother, LESS RESTRICTIVE, more uniform ports would be much more beneficial. Flow rates of a turbocharged car are considerably more than on an n/a which imho would have more to gain if drag is decreased and turbulence is increased. In other words greater flow rate+ better volumetric efficiancy= more power better burn. And in addition to a tuned intake, exhaust, and throttle body, I think you sceptics would be quite impressed.

Brian
86 951 on the operating table