2.7 s engine upgrades

[slater]

What are the best or most worthwhile performance upgrades for a 75 911S 2.7 motor? First thing I plan on is new exhaust, any recommendations? Thanks

[khyden]

I did some planning and discussed with other Porsche guys, due to same problem, i.e 2.7 and mooooore power and torque. My decision was to sell the 2.7 for best offer and get a 3.2. The 2.7 is out the car and sold. A decent 3.2 is on the way.

Kris

[Adam]

Unless your 2.7 has been fortified with the standard mods (like ditching the thermal reactors, new headstuds/timecerts and 11-blade fan) you'll really need to attend to these before you start trying to squeeze more power out of a standard/original 2.7.

I know Wayne prefers case-savers to timecerts (he hates timecerts), but if the engine is being rebuilt at some stage, either are better than the standard 27 year old motor's studs. I'd also look at getting rid of the standard magnesium valve covers (upper and lower) if they're leaking. They will warp with age and the only way to cure the problem is to go for the aluminium covers from a 930. While you're under there, throw on a set of stainless steel HeetSheets. I can personally vouch for them.

I chose to leave the exhaust/heat exchangers on my car stock. I have the Euro model, so I don't have the thermal reactors and I have a pre-muffler instead of a cat. I simply fitted a 3" single-in, single-out Monty, which does tend to breathe better than the standard unit. It sounds pretty damned good, too. They seem pricey in the USA though. I paid less than US$350 for a new one, direct from Monty himself. He is the Australian manufacturer.

Other than that, I'd check the state of your injectors. If they're the original squirters, then they've had 27 years of cruddy fuel pumped through them and they'll likely need a very thorough clean, which I'm told is not always successful. My mechanic fitted a new set for only US$25-30 a pop. Made a huge difference to the grunt of my car and I thought mine was pretty quick beforehand. Then get the car properly tuned by someone who has an exhaust gas analyser. You'll be amazed at the difference. Mine is very lively now. Good Luck!

[911_Dude]

Here's some of the things I've done to my 2.7. I'm very happy with it.
- Headers, stock muffler. Want to get a high perf muff, but dont want the noise.
- Webbers. The throttle response and sound is awsome.
- Cams. I changed to the older "solex" grind, which is a good mid range cam. My goal is a peppy street car and I dont like to scream down the street at 6000 rpm.
- I shaved the heads 2.25 mm. I cant really say if it has made any difference and may not be worth the trouble. I guess it has to have increased compression, but....
- Electronic ignition. I hate adjusting points.
- All the basics: 11-blade fan, turbo valve covers, time certs, oil fed tensioners.
I went from a tired old leaking 2.7 to a total rebuild with all these mods at once. So that was really nice in some respects, but I didnt really get a chance to see the incremental improvement that some of these mods would have shown.

[slater]

thanks for all the info! you guys have been very helpful. -k