Ticking all the emotional checkboxes with an engine rebuild

[francisluu]

Hello Steve (and everyone else)!

I'm really happy to have discovered this forum! I've got a lot of frankly novice questions and didn't want to waste anyone's time through more official business channels

A bit of context — I'm a fairly recent 993 owner, picked up a great-condition car about half a year ago up here in the Seattle area. My first 911 is of the 991 generation and I was worried to be missing out on all of the character of the air-cooled models. Suffice it to say, I'm smiling a whole lot more driving my 993 than my 991 (even though the 991 is video game-fast — mine is a Turbo S).

I've had some work done on the 993 — Bilstein PSS10s, re-geared transmission with an 8:33 ring and pinion and an Albins 3.00 first gear (read: *super*-short but so much fun), exhaust, seats, steering, wheels/tires, shifter. Really happy with it so far! Touching the engine is something I want to do in a couple of years and I'll admit that my criteria is more based around the emotion of it rather than optimum performance for a street car that sees occasional track time.

Here are the checkboxes I'd want to tick if I were to venture down the path of creating a more emotional experience with the engine (besides shelling over the enormous funds that this apparently takes, haha):

– High rev limit. Understandably, our engines don't make much power past a certain point, but the ability to safely rev high has always captivated me. Seems like a GT3 crank and other bits are key to allowing this safely?
– Mechanical "wailing" sound in the upper rev range. The Singer engines have this characteristic and it's reminicent also of the 991.1 GT3 between 8200 RPM — 9000 RPM. Chris Harris' video on the Singer Porsche while he's on the track and inside the car best shows off this sound.
– Still streetable. Lumpy-ish idle is fine if that means it can breathe okay at the upper rev range.
– GT3 intake plenum + maybe ITBs? There's something beautiful about this setup, and it seems like this also helps with it breathing at the top end?
– 3.8L or 3.9L. I'd like to see a general power increase but the other bits do it for me more than just getting the most power.

Obviously a weird, backwards approach to an engine rebuild. I'd love to get thoughts on what components contribute to what effect. Let's say that, well, budget is up there for now haha.

[Steve]

[francisluu]

Thanks for the warm welcome, Steve!

For picking your brain on this matter, let's use a window of $30k — $40k as a budget range to get a sense of what's possible.

Also, I wasn't aware of the point you made about passing smog emissions testing. Is it possible to control power output through software for passing these tests but still have some of the componentry that would otherwise disqualify the car? Also not quite sure if we're pushing ethical and/or legal boundaries here...

[francisluu]

Oh I forgot to mention — my 993 is a MY1995, so OBD-I I believe? Does that mean that OBD-II compliance won't be an issue?

[Steve]

[francisluu]

It looks like I may have to wait until 2020 when my 993 becomes 25 years old and is exempt from emissions testing to really pursue the engine build I want. It sounds like trying to reliably raise the rev limit with the bottom end, intake, cams and software isn't as feasible with the emissions restrictions?

Unless, 996 GT3 engine swap?! Haha.

[Steve]

[mradovan]

Steve,

I am interested in knowing if it is possible to improve performance on a 1996 993 by JUST switch to RS cams. The engine in question will be going into an older car which is smog exempt. I also have a 95 DME and harness for the car which I will adapt for use on the 1996 engine so I can have a reprogrammed chip made for the engine. Exhaust will retain the stock heat exchanges with a custom muffler and no cat. I also will retain the hydraulic cams. What, if anything, can be gained by just switch to RS cams.

[Steve]