RaveDisc

Hi everybody,

I am wondering how good can it be to install a turbo to a 964 C4, since it's a 3.6L (and not 3.3L like most of the 964 turbo versions that used the old turbocharged engine of the 930).
What kind of performance could you expect by getting a turbo, intercoolers, bigger fuel pump, etc. ?

The car is quiet fast, I drove it until 260kph and it wasn't under full throttle.
Here's the kit I already have (although not everything is installed yet : I only have the lightweight flywheel, additionnal exhaust and air intake, no chip, MAF...). And it also has bilstein suspensions that makes the car feel very stable under any conditions.

http://shop.fvd.de/de/en/Porsche-0/9...964-89-94.html







Regards and merry christmas !
C-24

psiegel

Installing a turbo can be great but its like that old saying, the whole (finished system) is greater then the sum of the parts. For instance the cone filter that is shown in your kit is probably not sufficient to meet the needs of a turbo system. Injectors, fuel pump, divider network, compression, wastgate and new mapping also need to come together to form a complete system. There are a number of great tuners out there that can put it together to accomplish your goals. But yes, you can end up with a really good car, depending of course of what your definition of good is. Do you want longevity, maximum power, good gas mileage? How important is low end torque? Information like this will help your tuner design and build a car that will meet your definition and expectations.
Good luck

tjr

IMO, if you want a 964 turbo, sell yours and buy one - it will be cheaper than any conversion and will hold its value better.

Good luck with whatever you decide.

rob964.c4

i am also getting some info about ading a turbo on an 964.c4.

and i already have spoken to psiegel.

i found a compagny in germany www.t-t-p.de , i am waiting for their reply.


robert

RaveDisc

Tjr,

You'll notice that in my initial post the idea is to have a 3.6L turbo, not a 3.3. I read somewhere that only 1'600 (more or less) 3.6 turbos 964 were made, and that's why I think it's very interesting to upgrade mine. It's even more interesting because of the all wheel drive engineering, IMO.

Anyway, about the costs... it's nothing like paying a well maintained 964 3.6 turbo. For the turbo and intercooler I can probably manage to find both for less than 3-4k$, those parts are the 'core' of the modification. The rest is less expensive, the only thing I need to find is a good tuner.

Geoffrey

From my experience (100+ turbos), it will be more expensive to build a proper 3.6 turbo engine out of your C4 than it would be to find a 93/94 3.6 Turbo. It would be a cool car for sure.

aussie993gt-faux

not as easy as a snail and cooler..compression of engine must also be changed then theres the tuning + little bits that add up like fuel deliver/intake/exhaust.

i didnt do what u want to but am in process of upgrading 911 into something its not. im too far gone to stop now but i suggest u stop before u start. if u want a 965 buy one or if u got $$ and want a unique car go for it!

my 2c

JJJMCD

The turbo parts aren't the expensive part; it's the labor and other things involved in getting it all to work properly, which requires specialized expertise. As Aussie noted, you'll need to swap out your pistons for lower compression ones, which means that you'll be doing essentially a full top-end rebuild ($5-10k) on your engine because, while you're in there, you'll likely find worn valve guides, etc. You can probably find a factory 3.6 Turbo engine for $12-18k and sell your 3.6 engine for ~$8k or so. Swapping in a complete, working Turbo engine will be much cheaper than rebuilding your existing engine, adding the turbo parts, and paying for the diagnostics to make it all work. Best of luck.

psiegel

ok, there are a few good reasons why it can makes sense to convert a 964 C4 to Turbo.
1. if you want a 964/965 C4 turbo you have to make it since Porsche didn't make (for public anyway) a 4 wheel drive turbo until the 993.

2. Flip around what JJMCD said and come at it in the opposite direction. All of our cars are getting older and at some point will need at least a top end rebuild if not the whole engine. At that point the decision is, do I dump my 964 for next to nothing and by something else or do I go for the rebuild. If you decided to keep the car you that may be a good time to modify for a turbo in the process.

3. Look in the classifieds in this site. A turbo that you know nothing about will cost $65,000 give or take.
If you own you C4 outright and need to have the engine rebuilt due to age, than think about the cost of the Turbo to be: Cost of rebuild $5,000 to $8,000 plus cost of Turbo modifications add another $12,000 to $15,000. So, in this case what is the cost of the turbo since you have to spend the money for the engine rebuild anyway? About 12 to 15 thousand.

4. So yes you can have a 964 C4 turbo for a total cost of about $35,000 less then buying a used 993 and its still your car, one that you know everything about already. That in itself has some benefits. Another way to look at this is, if you sold your 964, lets say you got $25,000, added the $22,000 (that you would need to put into the 964 to have a rebuilt engine and turbo), you would still need to come up with another $10,000 to $20,000 min depending on the cost of the used 993 turbo.

5. Value of a modified 964 C4. How much value is it really. How much value is a 15 to 20 year old 964, sure some that are of very low miles and in pristine condition certainly can have a very high value. But for most of ours that are every day drivers, the value will be higher then if we don't rebuild the engine. Yes less ten a 965 and less then a 993 Turbo.

6. Fun - most important for those who want to keep their 964, who have already spent a lot of $$ upgrading or keeping it up, who want a C4 with a Turbo. Its really fun, while still a great everyday driver the 964 C4 turbo can hold its own with any car in any road condition. Best of all it still looks like a 964.

But if you are going to do this, as everyone here has said, have really competent people pull it all together.

One last comment about the C4 turbo. Every day, I drive the car to work, it's like being on a mini vacation.

These are just my thoughts and as Dennis Miller said, "I could be wrong."

RaveDisc

Thanks for the advices.

The idea of swapping the engine with a 3.6 turbo engine sounds good.
Where is it possible to find such an engine ?

I have to try the kit from fvd.de first...
Is it possible to tune the car above 300hp without turbocharging it ?

In Switzerland I don't see any 3.6 turbo, the only turbo versions are the 3.3liters 320hp. So even if I wanted I couldn't buy one.

RaveDisc

Psiegel, nice post. I agree.
Do you have a 3.6 turbo ?

38D

A 964 rebuild is more like 13-15k.

I suspect the modifications will add up to way more than 15k.

1) Suspension: with the added weight of the turbo engine, you'll need different spring in the rear. Then the shock should be revalved to match the springs.

2) Trans: No idea on what power levels the C4 trans can handle, but I suspect that something will need to be upgraded.

3) Electronics: since the C4 system is different, it will take quite a bit of wiring. Might as well upgrade to motec instead.

4) Brakes: you now own a turbo, don't you want turbo sized brakes? Add in big reds all around.

I've upgraded cars before, and it never pays. You will end up with a unique car, but you'll definitely spen time (and money) sorting out the car. Btw, mechanics love people that do these kinds of projects.

psiegel

Depending on what you want as an end result will determine how far and how much $$ you end up spending. In my case it is for a daily drive and not a track car.

1. My C4 was at 145,000 miles so I was at the point of needing a top end at least. Local Porsche dealership had quoted $6,500. I then obtained a price of about $23,000 for the complete turbo modifications including of course the engine rebuild so the numbers are actual.
2, Suspension - I had already, like a number of others on this site changed out to a more aggressive/ performance suspension system. I my case, I had opted for 965 ROW coils and HD Bilsteins. Although after removal of the primary I would think the weight differential is small, I do agree that more power demands a better suspension but does not need to be a dramatic change.
3. I am not an expert by any means but the C4 transmission has held up in my case perfectly since the modification. As I understand, stock can handle double the horse power. The clutch/pressure plate should be changed out to one that can handle the upgrades. Most tuners will/should include this with the package.
4.Electronics- In my case there was a bit of harness work but that related only to the installation of the the 993 MAF. Otherwise depending on the tuner, little change is needed except for the mapping of course.
5.Brakes- I would have loved to changed to bigger brakes but because I run 16s in the winter, larger brakes were not possible. I think if you were tracking the upgraded 964, that would make a difference, but for everyday driving the stock C4 brakes are great. I have yet to have a fading problem. In reality, how much do I ever drive above say 90 MPH and need to stop immediately. Not often and no more then I would or did when my C4 was an NA.
6. Yes the car does end up to be custom and that is where trust and faith come to be important with a good tuner, like some of the folks we have on this site. If the work is done by someone who has done this over and over you should not have many if any problems.

I hope this helps, again this is just from personal experience on the customer side.

Peter

Turbohead

RaveDisc,
Why don't you just buy mine ... already done for you no hassles with lots of mods.? Set up for track and street legal.
427 rwhp and 486 flbs of torque @ .9bar

Pm me
Elliot

Colin 90 C2

Rob,
I have most of the TTP turbo kit. It was originally installed in a 993. If you need any info, I can provide you with what I have gathered so far.
Colin