MrLexse

Okay, assuming you're not going to have anything cu$tom ground and want to stick with "what's out there", what are the camshaft options for boosted/non-boosted applications on a 5.0 litre engine? I've been told running GT intake cams with GTS exhaust cams is a hot option, but I'm not even sure an obtainable set of GT intake cams is still "out there". I've read that 32 valve 86.5 intake cams are very similar, and I know Devek had some aftermarket cams available some time ago. I'm not sure what the status of those is at this point, either. What could go into a basically stock 5.0 (or 5.4) litre boosted motor that makes sen$e?

atb

I've got a set of GTS exhaust cams if you're looking.

You're on your own for the GT/32vS intakes.

SwayBar

NA, the GTS exhaust cam is the worst by far of the Porsche 32v camshafts.

That is true; the exhausts are identical, and the intake on the 85/86 opens 8 degrees later than the GT although both have the same duration. The 85/86 intake would be more boost-friendly from a detonation deterrent stand point since it will bleed off more cylinder pressure versus the GT intake. In this regard however, the GTS intake is the best by far.

85/86 cams are the easiest to get a hold of, but requires machining of the driver-side exhaust cam to make the front journal fit into the S4+ head (..requires a machinist), as well as hacking off the ends of all four cams (..easy to do).

MrLexse

I may have gotton it backwards then. The GTS intake cams with GT or 85/86 exhaust cams (machined to fit the S4 head) are the combination I was referring to. Does anyone actually run this combination (or something close to it) on a boosted engine?

mark kibort

no, the GTS cams are better than the S4, but still pretty far behind the GT or 85 cams, as far as lift goes as well.
I have a modified set of 85 cams that are still in service today since being modified by Elgin Cams for that exhaust cam on the driver side. (and the ends hacked off)

Mk

SwayBar

That is true regarding lift, however, on a 4v head, duration has much greater impact than lift. So in that regard, the GTS intake is the best.

As far as mix and matching different cams, I do not know if that is possible as far as indexing goes since the workshop manual states that the SE and GT cams are interchangable, but makes no mention of that for any other cams.

Kevin in Atlanta

I have cams leftover from my euro/5.0 hybrid project lying around.