some perspective needed on 73 3.6 swap.

[ezraman]

I am on final approach to a 3.6 install in my 73 911t. for those who have done this and have driven this car for a while what should I expect and also what should I consider doing in addition to the engine mechanics? I am planning on a first year low mileage 89 964 with a mid eighties 915. I am considering a shop in California called performance motion in riverside. My car had a wide body steel conversion on it when I pick it up and I have chosen not to try and put it back to its original condition. Other than new bilstiens and spacers for 18 inch turbo twist rims and tires the suspension is stock. As a daily driver I have heard many stories about this conversion, how the noise levels can be with different types of exhaust systems and also that the power to weight ratio can be a bit much. With power in mind what are we talking about in terms of comparable newer cars on the road today? Will it feel safe or will it need alot of additional mod's in order to compensate for the 3.6? My goal is to have a unique week end driver with as modern engine mechanic as I can afford when I am finished with the engine I expect to be about 12,000.00 into the conversion with another 5,000.00 in a solid 73 911t with steel wide body flares and C2 fiberglass bumpers. I will prob. do a little more with the interior but first I want to get the car up and running. I plan to keep this car for peace of mind as my drug of choice.

Thanks for your thought's.

This site has been so helpful in so many ways that I can not express the joy in knowing that I am not alone.


Richard

[DW SD]

I have a '71 with a 3.6. I upgraded suspension and brakes. It depends upon the condition of your suspension. Adding a few 100+ lbs to the rear of the car with a 915 and 3.6 might warrant making sure your suspension is ready. Even the 84 to 89 cars had larger rear torsion bars.

It is comforting to stomp on the large turbo brakes and know they will slow things down in a hurry. Will early brakes do this? Yes! But for how many cycles in a row? That is a question mark. It is unlikely you can put too much heat into the stock brakes on the street.

I might expect you to spend more than $12k if a mechanic does the conversion? And you add appropriate cooling while also adding a 915 into the budget?

All that said, I wonder if you might be better off selling the early car and buying a nice 964, since you are wanting to reproduce that look anyways? From there, you could strip out some weight and have a very nice, modern car with effective AC. Might not be bad out in Riverside?

Yes, the noise levels are loud. For a more direct perspective, if you want, you can drive out to Encinitas and I'd give you a ride in mine.

Doug

[TRE Cup]

Doug- he already should have a 915 in his car, being a 73, BUT if its tired it won't last long anyway with a 3.6 torque monster coupled to it.

That being said, what Doug is saying re: a already done C2 makes financial sense if you can purchase one already done Otherwise you can get it converted , then work on other parts of the car bit by bit. This will be an expensive journey

[DW SD]

Dave,
His initial message said he would add a mid-eighties 915. I assume that is out of pocket cost against the $12k budget?

Bottom line, Dave is absolutely right, it will be "an expensive journey". Budget at least $25k to $40k by the time it is all said and done, if done by a shop. Or sell and buy a nice 964 or 993 or 930 Turbo or do the work yourself and save some $ in labor.

+ $ for suspension refreshing ~ $1500 to $3000
+ $ for adding proper oil cooling ~ $2500 installed (lines, cooler, thermostat, misc fittings, etc)
+ $2k for late 915 trans.

Also a first - year 964 engine could have issues, if it hasn't been updated (head gaskets).

If you want, itemize the budget and ask folks to add missing line items. This will get you closer. Dave has all of the answers and expertise. His shop (TRE) would do an amazing job, especially a project of this magnitude.

Doug

[jpl500]

Richard,

I have an 80 targa with a 3.6 and I think you should prepare yourself to have a rocket located 3 feet behind your seat. I've only had mine for 100 miles so I cannot offer anything substantial other than saying I think you'll like it. Good luck and I want to see pix when it's done.

best

pat