kalikazam

The 73 RS is of course the crown jewel but the motor platform in the 74 carrera's is said to be the "same motor". The US motors were weaker than the Euro motors for emissions reasons I think. As the owner of a 74 Carrera Targa I am interested to understand what exactly was different on the US motors vs the Euro motors? and can the US motor be turned into the Euro motors in a specific way? If it was an emissions issue I am thinking it would be an easy fix to get the motor performing like the 200+ HP 73RS/74 Euro 2.7??

Speedster911

Your US 74 came from the factory with CIS producing 175 HP. a 73 carrera had MFI and produced 210 HP.

Easy to get a US 2.7 to the higher hp without sacrificing reliability.

I invite you to join PCAs 73-77 Cattera FB group https://www.facebook.com/groups/4323378721033917

rstarga

The US Carrera had a CIS motor identical to the 911S. The euro motor was MFI 2.7 identical to the 73 RS. It would cost a bundle to convert.

kalikazam

Sorry deleted Facebook or I would have joined.

What are your top 3 easy changes?

Speedster911

Replace CIS with , Webers, PMOs or some type of more aggressive fuel delivery. Your fuel economy will go down but you will get a slightly more responsive motor and a few more HP once setup correctly. is is assuming you don't have some state inspection that would disallow this. Add a short shift kit or aftermarket shift kit. No increase in HP but makes a 915 a bit crisper. Look at your suspension , if it hasn't been refreshed in years, you would be surprised what a difference it makes , again no HP gain but will allow you to use what you have more efficiently and provide a better drive experience..

Another " easy" way to modify your car is to lose weight. M&K muffler eliminates approx 12 lbs and may make your engine exhale a bit better = a few HP, fiberglass front/ rear bumpers, eliminate back seats etc. Really depends on what you want with your car.

Don't listen to the 2.7 doomsayers - I have 3 cars with 2.7 and they are all great.

if its true HP you are after, not an " easy" upgrade - but build 2.8 or 2.9 motor. easy to get in the 225 -275 Hp range with a build

rstarga

Even the US Carreras have gone up in value quite a bit. Instead of modifying your current matching numbers engine, put in a nice 3.0 or 3.2 engine and put yours on the shelf.
You can modify the replacement to your hearts delight without affecting the future value of your car, it will be cheaper too.