engine mods questions
 

I am about to have my 3.2 out for a major overhaul and am thinking about if there is anything else I want to do while the engine is out or should i just stay stock.

Some thoughts;
- 964 cams
- Pistons and cylinders to 3.4L

What kind of performance gains am I going to get from either of these from a stock engine?
Is there anything else I should be considering while my engine is apart ?
By doing these are there issues with smog (i am in california) ?

Simple mods make some sense. If you are considering getting more extravagant I would think about selling your engine and starting with a nice 3.6 engine from a later car.

If it's just a street car there's a few mods but mostly just leave it a stock 3.2

The pocketbook is the limit if you want to hop it up.

Two questions: How much disposable income is available

How fast do you want to go

Assuming you were/are content with the performance of a 3.2, I would not go too crazy, it's easy to chew up thousand dollar bills with these builds.

You might be able to get away with 20/21 cams in Cali. There are a few who have. That wouldn’t set you back too much and would be easily reversible. In that same vein, you could also chip your car and delete your cat bw smog inspections but it’s illegal. Looking at some of the timing and fueling maps for stock 3.2s, they do look to be setup very lazily and so there’s great bang for your buck in those mods and all are reversible. Googling might get you an idea for HP gain and whether that scratches your itch.

If you want to go further, any of the air cooled diviner’s here can help you but you probably need to volunteer some more information on budget, use etc.

I would do the following:
Bore existing cylinders to 98mm and re-plate and add JE or CP 9:5 to 1 Pistons for single plug.
Update cams, 964 is only one option might talk with Performance developments and KnightRace about there updated offerings.
Custom chip from Steve Wong to match cam and new displacement.
Those would be the easy things.

john

I would ditch the Motronic AFM and go for Sal Carceller's MAF conversion.

http://forums.pelicanparts.com/911-engine-rebuilding-forum/871561-1985-3-4-build-using-maf-279-56-hp-237-63-rwhp.html

http://forums.pelicanparts.com/porsche-911-technical-forum/851912-my-87-3-4-maf-project.html

Sal also offers a chip and matched injectors.

http://forums.pelicanparts.com/porsche-911-technical-forum/888986-new-product-performance-chip-matched-injectors-3-2l-carrera.html

ultimately increased capacity improves total torque. Changing cams allows you to move torque up and down in the rpm space. Bigger cams may give you more power but in a place where you don't use it.

What are the plans for the car? how do you drive it?

Is MAF CARB legal for California? Since it is a very visible conversion it would not pass visual inspection if not approved.

john

Wow, thank you everyone for your suggestions. And sorry for the late reply.

@930cabman I don't have unlimited budget, but want to get return on investment.

@jpnovak your build looks awesome, but I don't think that would pass visual here in CA.

I think I'm going to go 98mm P/C and 964 cams for the midrange. I mostly drive twisty mountain roads and freeway so the mid-range will be nice.

I have been flip-flopping back and forth with going twin-plug or not. I'm not sold yet that there is enough return on investment to warrant it. Thoughts from everyone on that ?

What compression are the new 98mm pistons? Twin plugging may be unwarranted or completely necessary. You have to look at the whole picture, you can’t just pick and choose features and components individually and expect everything to work together.

I have a stock '87 3.2 with the 964 cams, custom Steve Wong chip and custom 1.62" SS heat exchangers and free flow 2-in 1-out muffler and my engine runs great. Street car and it pulls well to the limit. Now it is in my 914-6, so less weight than a 911. But I think I am around 240 HP.