Update: a number of you have been arriving to this page after searching Google for tips on “Porsche 911 CIS Modifications”. While we have done some work to our ’73 911T with CIS, we are by no means experts. However, we wanted to point you to a book that might help you in your research. How to Rebuild and Modify Porsche 911 Engines 1965-1989. Written by Wayne Dempsey of Pelican Parts, this book provides a very thorough overview of Porsche engines, how to rebuild them and what you can do to modify them. We hope it is helpful. Now, on with the article.
A new reader contacted us the other day looking for suggestions on how to modify his ’77 911s. In his own words he would like the Porsche:
“to look like a ’77, but have the ability to hang with a modern ‘vette or anything else that might take it for granted.”
As the pictures below show, the car is in nice cosmetic condition (we love the Minerva Blue exterior) and currently runs well. The owner is looking for suggestions that will give him the best bang for the buck while meeting his stated goal(s).
Personally, we’re not huge fans of modified Porsches (we’re purists by nature) but have no problem with what others want to do to their own cars.
Manufacturer’s Specs for a 1977 Porsche 911s
The 2.7 liter, normally aspirated, motor produced 157 hp and a top speed north of 130 mph. Curves were carved using a combination of MacPherson struts, shocks and anti-sway bars while stopping power was applied via vented disk brakes. Outside of the common problem of “pulled” cylinder head studs known to plague these magnesium blocked cars the ’77 was a great car for the time and one that still represents a good bargain today.
Before getting into possible mods, let’s start with some basic information regarding the car itself:
- Engine Displacement and Type: (all 50 States) – Type/911/85; 2687 cc (163.9 cid) SOHC, Bosch K-Jetronic fuel injection (CIS), air pump, thermal reactors, EGR
- Maximum HP: 157 SAE net @5800 RPM
- Maximum Torque: 168 ft-lb @ 4000 RPM
- Weight: 2470 lbs + 90 with Targa
- 0-60 mph: 7.5 seconds (factory)
- Max Speed: 134 mph (factor) subtract 1.2 seconds Sportmatic
- Brakes: Vented disk brakes. Power assisted w/M590 Comfort package and Sportmatic
- Steering: ZF rack-and-pinion
- Suspension Front: MacPherson struts with telescoping shock absorbers, wishbones, torsion bars, antisway bar. Optional softer Bilstein shocks in M590 Comfort Package
- Suspension Rear: telescoping shock absorbers, two-piece trailing arms, transverse torsion bars, antisway bar, Optional softer Bilstein shocks in M590 Comfort Package
- Transmission: 915/61 4-speed
Suggested Mods
Normal suggestions for most modification generally include:
- increased hp (possible motor swap)
- improved suspension
- transmission upgrade
- new wheels and tires (handling of the normally aspirated ’77s can be greatly improved by increasing to the 16″ tires that came standard on the Turbo/930)
- improved braking (a lot of people forget that when you increase hp you need to increase your stopping power too)
- interior and exterior cosmetics including paint, seats and electronics
The owner of this car is looking for specific suggestions from other early 911 owners. Have any of you modified your cars? If so, what have you done? Are there things you’ve done that you now wish you hadn’t? Conversely, are there things you didn’t do you wish you had included? Let us know by commenting below or using the contact page to get in touch with us.
[Tech Spec Source: Randy Leffingwell’s Porsche 911 Buyer’s Guide]
View Comments (18)
The 1977 Porsche 911 might be one of the least sought after 911 models due to documented engine issues. As such, I wouldn't hesitate to modify the car accordingly to meet the goal. I agree, we're talking at least a huge motor swap, and potentially forced induction to achieve that goal. It would be cool to keep the exterior as stock as possible to keep the car's potential in sleeper status!
dc
Lighten the car as much as you can stand, interior bits, spare tire, etc. Put on a fiberglass ducktail or flat decklid. Those turbo tails are heavy.
Swap in a good used 3.2 unit. Add a free flow exhaust. This will be the best bang for the buck option. But figure on at least $8k total.
Swap in new rotors and pads. With the car being lighter you won't have to go too big reds or anything.
Can't give specifics but lower it. Heavier torsion bars. Bilstien shocks.
Good suggestions so far. I just received an email from another reader who asked a great question.
What's the budget? Caleb, care to weigh in on that???
ok, so as of now ive got around $5k. by next summer ill have an upwards of around $10k. i was thinking of a motor swap for those that r suggesting it. any ideas on which would be sufficient? i had my heart set on a 3.6, but i think a 3.2 or a 3.4 would be good enough...
3.0 is the easiest,as you go up add into the fray ECU,MODULES ETC,HIGHER THE LITRE MORE THE WORK, A 3.0 IS A CLOSE TO A PLUG N PLAY AS THERE IS,THE 3.6 GETS THE HP ON.
and i have already began to lighten the car. since i first got it, i have striped the car of about 200 lbs. if anyone has a great way of lightening the car, dont hesitate to tell me. thnx!
Caleb, I thought the Porsche in question was yours! I love the color. Whatever you do, don't change that! :)
I was the one who asked about budget... If I only had 5k to spend and the car was already reliable - I would lighten the car, go through the entire suspension (I am currently running Moton Club Sports on my 993 - thinking Smart Racing Products or Elephant Racing would have you covered) and upgrade to better brakes. I would not worry about horsepower until these two items were addressed...
have you had the car on the track yet? -IMO the best upgrade you can make regarding performance is seat time on the track.
For 10/12k you can get a really sweet stand-alone ignition/fuel injection - convert to twin-plug and you'll have a monster. -nothing wrong with 2.7 if built correctly. -Used 3.6's are very expensive... -ask me how I know! =)
i have had it on the track a couple of times. the one problem i did face is the shifting times. if i could reduce shifting by half the time it now takes, that would be amazing! suspension is one area i was looking at as well.
btw, could u elaborate more on the stand-alone ignition/fuel injection? im curious to know more about this. and what do u think of new cams?
http://www.wevo.com will stop all your shift issues.
Regarding your question about cams: Remember that the engine is a "system" and needs to be upgraded as such - the right cams will need to matched with fuel system, exhaust, and possibly and head work... Here is a great place to start: Bruce-Anderson's Porsche 911 Performance Handbook
One thing I learned while building my 993 is that you can't just start bolting things on these cars and expect great results... I like to form a plan, save up, and replace a group of components all at once.
I know the stand-alone my buddy uses on 300HP 2.7 is a Tec3 system... I'll find out where he bought the system and post...
Good Luck and welcome to the slippery slope!