Clint's 944

I have a few questions about the conversion before I dive in. I have a complete 3.0 engine with all accessories and computers/ harness from my parted S2. I also have my 951 with everything on there. I'm debating on whether I can get this done quickly so I can drive my car again, or just put it on the back burner and buy a shortblock for my 951.

1. Will the S2 headers match to the 951 crossover or will a new crossover pipe have to be fabbed?
2. Do I have to do a 3" downpipe or could it wait until a later date?
3. Should I get a k26/8 or a k27/8? Anyone have one?
4. Should I use the S2 computers or the 951's?
5. Can I use the clutch disc from the 951 on the S2 engine?
6. Can I use just a piggyback or do I have to have a custom chip with the piggyback?
7. Where can I get the intakes cut/welded together? I can't find anyone local that I would trust to do it right.
8. If I change the connecting rods, will I have to install new rings?

Thanks!
~Clint

Jeremy Himsel

Based on your questions, put it on the back burner. You have a lot of reading to do and a lot of money to spend of you don't want to do it again in a few months.

Clint's 944

I have done alot of reading, this is why I have the questions....

Looking back through the archives, I've seen alot of different configurations and alot of conflicting information, sometimes in the same post. Just trying to get the latest and the greatest for doing it on a budget!

Thanks though...
~Clint

MPD47

1. Call Tim, see #7, maybe he'll cut you a deal on headers if you get both. (And a 3" downpipe to boot, oh wait, see #2)
2. You can never flow to much for a turbo application. Get a 3"
3. Get a Vitesse Turbo, it's bolt on.
4. Get Tec3R from Chris White
5. 3L turbo......? Yes, you'll need a new clutch.
6. See #4
7. Get a SpeedForceRacing intake (see #2, and #1)
8. Use custom rods, use new rings, and while you're at it, get the proper pistons.

Or if you dont feel like spending $15-20k

Get a used 951 long block from lart and swap it in.

Clint's 944

OK, nevermind then....

m73m95

Ok, I might not be reading this right....

I would very much like to put a 968 3.0 in my NA. I've heard its not to difficult. Only thing you need to make up is a new air box tube. Everything else is pretty bolt up. Bell housing, clutch, exhaust....it all bolts up....... Or am I seriously mistaken???

(I know about the DME......I'm just talkin about the engine itself)

333pg333

What you're asking is not just a matter of dropping a different engine into your car as you are finding out. Don't take the advice given here as a put down or snub. There is a lot of info in here to find, and also emailing people can sometimes help. If you want to try a cheaper type conversion try searching under Markus's threads. Just to inform you this motor isn't working anymore so perhaps 'cheap' and 3.0L turbo don't mix. If you want something cheaper and powerful search under Blown944's threads. Sid's car isn't a 3.0L but it's plenty powerful and he's done it on a fraction of the costs that most of us have spent.

Chris White

Hmmm....are you sure? The wiring for the 968 is seriously different than the 944 series. Even the A/C system is different - its controlled by the DME in the 968 and not in the 944s.
THE bolt in part of the operation is not too difficult – but the wiring up part is a major change.
Another example – the 944s use a 12v signal to the DME as the key on signal, the 968 uses a ground signal….and they both use the same wire location!
Plan on spending a lot of time with the wiring diagram…..!

gt37vgt

you kill joys
1 you can mod the crossover to suit
2 a 3" is really worth it if your tight just start with the front half.
and for the rest bide your time and slowly gather bits from in the classifieds and on ebay .
as for tuning stand alone is pretty cost effective these days but has it own challenges .
#7 i feel your pain its super expensive in the US it seems I expect to have a custom manifold with twin injectors made for half the cost here in OZ.


And don't rule out a super charger

fortysixandtwo

1. Will the S2 headers match to the 951 crossover or will a new crossover pipe have to be fab'd?
No they do not bolt together. But you can cut the flanges off of 951 headers and weld them to the S2 headers. This will need to be done with the turbo and head installed to get everything lined up. Then tack weld the flanges in place, remove and do the final welding.
2. Do I have to do a 3" down pipe or could it wait until a later date?
Factory down pipe will work just fine. Those who tell you otherwise, like spending other people’s money. There will be a performance increase with the 3" but it's a bolt on item that can be done later, along with the rest of the exhaust.
3. Should I get a k26/8 or a k27/8? Anyone have one?
I don't have either but, with the engines displacement, the K27/8 would be the better choice of the two.
4. Should I use the S2 computers or the 951's?
I don't know too much about the S2 computer. Look at it this way, the 951 DME/KLR computers were created to work with a turbo engine, the S2 computer was not.
5. Can I use the clutch disc from the 951 on the S2 engine?
Yup. Use all the 951 clutch stuff: bell housing, flywheel, clutch, starter, etc.... It will all bolt to the S2 block and be the correct length for the torque tube. (I'm not totally sure if the length is an issue for the S2, but it definitely is for with a 968 setup.)
I assume you're no planning on using a used clutch, so get a good one to handle the torque.
6. Can I use just a piggyback or do I have to have a custom chip with the piggyback?
In my opinion, piggybacks are wack. However in this case, I don't think many chip burners have enough experience with turbo 3 liter 16 valve engines. You might be better off being able to tweak what they provide.
7. Where can I get the intakes cut/welded together? I can't find anyone local that I would trust to do it right.
Yellow pages, find a welding shop that can tig cast aluminum with a little oil soaked in. This is where it gets a little tricky. Like the exhaust this will need to be mocked up on an assembled engine. Unless you want to make a custom length throttle cable (not too hard) the throttle body needs to stay with a few millimeters of the original location. This will require taking X,Y, Z measurements of the original location from a point on the car's chassis. You also need to make the decision of whether you are going to graft the 951 and S2 manifolds (easiest) or make a plenum from scratch and use the S2 runners. If you're handy with a saw and a grinder, you can do the fitting yourself and have the two pieces welded together. If going this route, you will need to talk to a welder first, to see what they need for a chamfer and what sort of gaps are allowable.
8. If I change the connecting rods, will I have to install new rings?
If you want an engine that doesn't have issues with blow by, you would replace rings and hone anytime the pistons are removed from the bores.

This really isn't that big of a project if you are either A: comfortable making a lot of the parts yourself and have the means to do so or B: have deep pockets and pay someone else to do most/ all of the work.

From a fabrication standpoint, you only have to deal with the intake and exhaust manifolds. Both pose the same issue with needing to be mocked and fitted to an assembled engine. The exhaust will need to be done with the engine on a stand and the intake is better done after the engine is installed. At least the exhaust is the easier of the two and might give you the confidence needed to do the intake. You might have noticed the logistical problem here. Car is in the garage (your garage) and you need parts tack welded with them in place. Hopefully you can find a welder that can come to you, and yes it will be multiple visits.

Now the big $$$ part. The engine bottom end and maybe the top too. Unless you're keeping the boost really low, the stock bottom end of the S2 is not going to hold up. Once parts start to be taken apart the cost snowballs. If you pull the engine totally apart, you're basically looking at the cost of a full rebuild. You will come to the point where you've totaled the amount your about to spend (this is never a good idea and don't recommend it) and realize that the cost of forged low compression pistons and better rods are not that much compared to the total cash outlay and the value they add at this point. Especially considering that they're the foundation of everything else your about to do.
The head can be used as is, just have it refreshed. If you want, getting everything ceramic coated would be a good idea, but that’s more icing on the cake than anything else.
The reason I'm a little more willing to spend your money on the short block is because the costs of changing anything after the fact are quite large (gasket sets, machine work, and assembly). Plus if one of these parts fail and take out the block and crank after spending as much money and time as you just did, well that's enough to swear someone off of these cars for good.

Darwantae951

you really make it sound easy...

FRporscheman

The S2 computer will not run a car with a 951 flywheel. And the KLR is a nice thing to have.

The mechanic at my local Porsche dismantler told me the S2 driveshaft is a different length than the 944. I don't believe him at all, but I would at least double check to be sure.

Have you considered an 8v build? I'm not necessarily recommending it, just asking. If you liked building models as a child, you will like the 16v build. If you preferred legos, you will like the 8v build.

sm

Off topic -

Chris, can you explain how the a/c system on the 944 interacts with the DME? Does the idle speed pick up when the a/c is on?

If I have the a/c on, my RPMs drop like a rock when shifting and I'd like to fix that. The revs drop to about ~200 rpm or so and it feels like the a/c compressor is causing major drag on the motor.

TurboTim

[QUOTE=fortysixandtwo;5577195]1. Will the S2 headers match to the 951 crossover or will a new crossover pipe have to be fab'd?
No they do not bolt together. But you can cut the flanges off of 951 headers and weld them to the S2 headers. This will need to be done with the turbo and head installed to get everything lined up. Then tack weld the flanges in place, remove and do the final welding.




Welding inconel should only be done by a professional unless you want a failure almost immdeiately.



2. Do I have to do a 3" down pipe or could it wait until a later date?
Factory down pipe will work just fine. Those who tell you otherwise, like spending other people’s money. There will be a performance increase with the 3" but it's a bolt on item that can be done later, along with the rest of the exhaust.




Actually,to install the 3" downpipe requires the removal of the turbo which is a big job so it might be in your best interest to do it at the same time as your turbo install.You will save alot of ime doing it then,instead of later.


3. Should I get a k26/8 or a k27/8? Anyone have one?
I don't have either but, with the engines displacement, the K27/8 would be the better choice of the two.
4. Should I use the S2 computers or the 951's?
I don't know too much about the S2 computer. Look at it this way, the 951 DME/KLR computers were created to work with a turbo engine, the S2 computer was not.



The problem with trying to use the 951 computer on the S2 or 968 is the crank triggering.If you want to keep it simple use the S2 or 968 computer and use a piggyback or at least a custom chip to map your feul and timing.



5. Can I use the clutch disc from the 951 on the S2 engine?
Yup. Use all the 951 clutch stuff: bell housing, flywheel, clutch, starter, etc.... It will all bolt to the S2 block and be the correct length for the torque tube. (I'm not totally sure if the length is an issue for the S2, but it definitely is for with a 968 setup.)
I assume you're no planning on using a used clutch, so get a good one to handle the torque.
6. Can I use just a piggyback or do I have to have a custom chip with the piggyback?
In my opinion, piggybacks are wack. However in this case, I don't think many chip burners have enough experience with turbo 3 liter 16 valve engines. You might be better off being able to tweak what they provide.



Piggybacks are not wack.They do a great job and controlling fuel,timing or both.However,it is not as great as stand alone but for the cost,the piggybacks are hard to beat.

Just thought I would add my 2 cents since we have done this kind of conversion before.

fortysixandtwo

No problem, its always better to have the most information possible when making a descision.

Thanks for adding stuff about the 968 & S2 computers, I use a Tec-III so I never had to investigate this option. I still like the idea of using the 951 flywheel and associated parts which would also make using the 951 computers and harness possible.