Wrench Monkey

I did some searches and found some info... my question is this,

If someone wanted to build a 2V 951 and mod everything, ported head, intake, cam, exhaust, tune, turbo, internals, race gas, SOME WHAT steetable ect ect how much power could you make (ball park)?

I have seen a bunch of 500hp cars out there but most are pump gas cars and look like they still have some left in them.

Thanks.

944obscene

Special Tool, I think still holds the record for one of the highest powered 951's and he's still running a 2.5 IIRC. Think he laid down 602 on the dyno.

Wrench Monkey

WOW!

dillon410021

I think 500 hp is about as good as you will get for it to be reliable. Yet people like special tool made over 600 hp.

Wrench Monkey

As long as I can take it to church and hit some local Saturday cruise in's and am not breaking every night I am happy.


My last car was an 83 Z/28 with a BBC on nitrous making about 800hp and was so loud that it gave you a head ache and I loved it. My father has an 81 931 and he pretty much said it was nuts haha.

dillon410021

if you are planning on making power, the 3.0L is the way to go. Also, you need to decide if your want a SOHC 8 valve or a dohc 16 valve head

Wrench Monkey

From what I am seeing putting a 16V head on a 2V motor is not really worth it. If I rememebr right the Turbo S has the 3.0????

A DOHC 16V turbo motor would be cool but the headaches.... haha.

95ONE

3.0 liters blocks are more stout.. what you should start with.

Lorax

Even the most mild 16v head outflows the big dollar 8v heads.

Wrench Monkey

So buy a DOHC 3.0 motor and put some work into it and swap the turbo parts over? I figured they would flow a lot more..... just looking at any 2V head compared to a 4V head would tell someone that.

Most of my brains is with the 931 stuff so I am still trying to learn all the engine combo's....

944obscene

2.5, 2.7, 2.8, 3.0, 3.1, 3.2

dillon410021

It is power vs. reliability. It is hard to have both at a high hp level

Wrench Monkey

Reliability to me is not breaking after a quick Saturday cruise.... If I am lucky I put 100-200 miles a year on my fun stuff haha..

Tom M'Guinn

All 944 turbo's were 2.5 liter motors, including the S versions.

At the risk of over-simplifying, there were two basic blocks for the 944/968 series, and two basic cranks.

The original n/a and turbo blocks had 100mm bores with an open top design.

Starting in 89, Porsche came out with a new block with 104mm bores. The cylinders are attached to each other in these blocks and the water jackets are shallower, making the cylinders less likely to move and cause head gasket leaks. Later versions of these blocks had piston squirters, which are nice to have. Compare pictures below to see how the 100mm blocks have separate cylinders, whereas the cylinders in the 104mm blocks are connected.

The original n/a and turbo crank had a stoke of 78.9mm, where as the later cranks had a stroke of 88mm. All 944 turbo's had 100mm bores and 78.9mm stroke, for 2479cc total.

With the right pistons, the bores and cranks can be mixed and matched to make the following:

100mm x 78.9mm = 2479cc (e.g., original 944 and turbo)
100mm x 88mm = 2765cc (e.g., Andial 944 turbo stroker)
104mm x 78.9mm = 2681cc (e.g., 1989 944 "2.7" motor)
104mm x 88mm = 2990cc (e.g., 944S2, 968)

Aftermarket builders can sleeve these motors also, with 106mm bores (or bigger), which can get you up to 3106cc with an 88mm crank. There are also a few "stroked" cranks out there beyond 88mm, for really big motors...

d993

Exactly, so less boost is required to get more power.
Turbo sizing is also important, and make sure it's a good reliable turbo, not some cheap knock-off like some that are sold as 944T upgrade kits which fail after a few hundred miles.