944Na/turbo camshaft housing?

ae1969 · 07-31-2002, 10:07 PM

So.... the early NA has the same camshaft as the turbo.....where as the late NA has a different camshaft.........

What is the major difference.... who has a few camshafts lying around???

I have a turbo head, and I am slapping on an NA camshaft housing (don't ask why)..........

so what would be the major difference in the camshafts if the early NA has the same(similar) as the turbo....and the late NA has a different one............

do they mean the late NA as the 2.7L ????

somewhat perplexed???

bogomili · 07-31-2002, 11:39 PM

The Porsche part # for the pre 85 944 (early) cam and the turbo cam is the same # : 944.105.155.05. The late cam is 944.105.155.09

Now does anyone know what the difference between the two are?

97XRAY · 97XRAY's Garage

I have a spare NA camshaft, but haven't ever seen the turbo, so I can't comment.
Nonetheless, I could take pics if someone wanted to see it and compare to their own pics of a turbo camshaft.

I love my camshaft, it's a little heavy for a softball bat, but far prettier!

robm-951 · 08-01-2002, 06:09 AM

The later cam (09) has a little more exhaust duration. Many run this cam on a turbo with good results. The attached picture is from the factory manual.

Rob

97XRAY · 97XRAY's Garage

So, what is the second column?
Is that the Euro Spec, or Turbo, or what?

My camshaft is a Euro

slevy951 · 08-01-2002, 07:50 AM

My wrench accidently(or maybe not) put an N/A cam on his girlfriends 951 after a motor rebuild. The car now has gobs of low end. Turbo spools much quicker. Lag is all but gone. But top end is gone also. Car runs out of breath at about 5600.....

ae1969 · 08-01-2002, 09:27 AM

first column is 82-early 85

the middle column is late 85 to 88

the last is the 2.7 L

So the differences are only in the exhaust opening and closing?

Does anyone have the specs on the turbo? to compare....

bogomili · 08-01-2002, 02:25 PM

Both the early 944 ('83 to '85.5) and the Turbo camshaft are the same cam.

Perhaps that was unclear. . .

marksportcts · marksportcts's Garage

SCott, don't most 951 start running out of breath around there? I thing most do especially with higher than stock boost levels. It may be that the K26 can't hold boost/flow at that higher rpm when modified. It is no longer efficient considering it is also 16 year old technology. See if your wrench put in a larger turbo and what happens.

ae1969 · 08-01-2002, 03:04 PM

bogomoli..... sorry it is clear ...

If the specs on the 83 and 86 (late are the same).... why are we using different cams? Assuming everything else is the same?

ae1969 · 04:34 PM

OOOOOPPPSSS! wrong post.

951carter · 08-01-2002, 08:45 PM

the specs on early and late are not the same.....the late cars have 8 more hp. there are other differences besides the cam though. don't anyone go getting your hopes up though, putting a late cam on an early car does not make any appreciable difference.

ae1969 · 11:05 PM

951 carter....

Not really asking about the 8 hp? in the later NA'S (88-89)

I am talking about the 83'NA with the (supposedly the same cam specs as the turbo cam) that has the same performance specs as an 86'NA ? my 86 has the 07 code?

same horsepower and torque with a different cam code..

I am just trying to satisfy my curiosity how the engineers had a certain cam spec in 83, and found it necessary to reintroduce those same specs into the 86 turbo while changing the cam specs in the 86 NA?

One of the parts listed as making the turbo what it is ....was the unique cam, as depicted in a couple of their advertisements of the 86 turbo?

slevy951 · 08-02-2002, 05:21 AM

Quote:

Originally posted by marksportcts
SCott, don't most 951 start running out of breath around there? I thing most do especially with higher than stock boost levels. It may be that the K26 can't hold boost/flow at that higher rpm when modified. It is no longer efficient considering it is also 16 year old technology. See if your wrench put in a larger turbo and what happens.

Well, this car runs out sooner than mine. Mine pulls nicely to 6500. But this car definely has better low end.

951carter · 08-02-2002, 10:31 AM

hmmmmmmmm..........maybe they just changed it in the n/a so they could say that the turbo had a different camshaft =)
I do remember the ads you speak of, i am sure that i have some of them around here somewhere.

marksportcts · marksportcts's Garage

IRCC alot of the 951 guys were talking about how their cars will boost up 18psi and drop off to 15-16psi at redline and it was always the turbocharger no longer being able to flow.

Also the 924 and the 931 apparently use the same cams.

robm-951 · 08-02-2002, 02:58 PM

Quote:

Originally posted by slevy951
My wrench accidently(or maybe not) put an N/A cam on his girlfriends 951 after a motor rebuild. The car now has gobs of low end. Turbo spools much quicker. Lag is all but gone. But top end is gone also. Car runs out of breath at about 5600.....

You might want to go and check the cam timing. Advancing the cam 1 tooth might cause this, but the extra 8 degrees of exhaust duration present in the later n/a cam shouldn't . As for the boost dropoff at high rpm's, this is normal for the k26/6 cars. If the boost is dropping off below ~10-12 psi, you might have a problem elsewhere.

Rob