Do later-style Carrera axles fit on SC?

[beepbeep]

Simple question...do late (85 to 89) axles fit on SC lengthwise?

I know that CV's are bigger, but we will change flanges on both sides.

Pleeeease... :-)

[dean]

Yes, I just installed 88 azles into my SC to go with the G50

[beepbeep]

Dean: thank you thank you thank you!

Just two additional little questions:

1. Did you change stubs (splined things that go into wheels on one side and are bolted to outer CV's on other) to 88-type too? (You probably had to, as later axles have 108mm CV's compared to old 100mm CV's)

2. Is G50 flange-to-flange width same as 915 width? These axles are going to be bolted on 930 transmission (it's exactly as wide as 915) so it's important...


Thanx one more time!

[dean]

You are welcome

1. Yes, I changed the stub. The hub is the same from SC's to late Carreras. So I used the complete axle. The Carrera axles come with the hub stub attached.

2. I don't know if the width is the same. I assume they are the same. The axles work perfectly with the G50.

[beepbeep]

Gracias!

[Mike Kast]

why wouldn't you use an SC axle?

[beepbeep]

Originally posted by Mike Kast
why wouldn't you use an SC axle?

Beacuse we are going to have heaps of torque and 100mm CV SC axles are weaker than 108mm Carrera axles...

[Mike Kast]

Have you ever heard of the SC axles failing because the couldn't handle the torque? The extra mass is also extra weight. I'm going to change out my axles sooner than later, that's why I'm asking. I'd like to do what is best. I'm not convinced that bigger is better. My SC is still a 3.0 though. The only reason I'm changing the axles is to change the CV's and the boots. The axles are fine. Enlighten me!

[kellzey]

How much torque are you going to be running?!?

The SC axles can handle most anything unless you're putting a 400HP beast in your car!

[Mike Kast]

thanks Karl, That was my line of thinking exactly. But I have no real information to go by. So why did the engineers make them larger on the Carrera anyway? Was there ever a problem with the SC's axles being too small? There must be a line where the torque gets too great. Is the line between 3.0 and 3.2? would the CV's last longer? I don't see why the boot would. Seems like once the boot goes you may as well change the axle. Unless you catch it before the grease is lost.

[beepbeep]

It's not axles themselves but CV's that are spinky. You never heard of failing axle on a SC you say?

Here are some broken shafts on Pelicanhead cars, from the top of my head:



Car Is Dead....please help

Dangit, disaster strikes.

My name is KC Moore, and I have a problem...

There are many more, those just popped up first on search. They all sheared their CV's with pretty non-torquey SC engine. 930's have much bigger CV's with their 400Nm and we are gunning for at least 500Nm... so i don't believe that SC shafts are indestructible? (Note that big peak torque doesn't equal big power)

We need brand new axles anyway (and when i say axles i mean both CV's, axle between and hubs). Why not replace them with bigger Carrera items that are cheaper, already assembled/grease-filled. They have one-piece outer CV's (no bolts) so increased weight is probably negated by absence of bolts, and no bolts means you cannot break them off either.

So answer is: Carrera axles are indeed better. Question isn't whether we can use them (we already decided that we will if they fit).

Blown has them in his SC so I know they fit in the hubs but don't know if G50 diff is as wide as 915/930 one....that's the main question: Do they fit lenghtwise on 930 tranny with OEM 930 flanges?


Cheers!

[914timo]

Beepbeep, you sure have interesting project !!! Good luck with it !!

But, if you have those SC axles there apart, could you measure how long they are ?? And, I mean from one end to the other. That would be very interesting information and I would like to compare it to the length of 914 axles.

[beepbeep]

Timo:
Original SC axles are removed, cleaned and re-packed with grease, to be sold to someone who needs them better.

We'll measure them and i'll post results tonight!

Cheers!

[Mike Kast]

They all sheared their CV's with anemic SC engine

The CV joints failed, not the axles. I'm thinking I have offended you because of your anemic remark. That wasn't my intention at all. Is what your saying that the Carrera CV joints do not fail as often as the SC's. I'm assuming most CV failure is caused by grease loss, Broken boots.
I don't mean to be the pelican pest, I'm just looking for some real evidence before I assume bigger is better.

[beepbeep]

Originally posted by Mike Kast
The CV joints failed, not the axles. I'm thinking I have offended you because of your anemic remark. That wasn't my intention at all. Is what your saying that the Carrera CV joints do not fail as often as the SC's. I'm assuming most CV failure is caused by grease loss, Broken boots.
I don't mean to be the pelican pest, I'm just looking for some real evidence before I assume bigger is better.

No offense taken!

It's just that rest of car is kinda overdimensioned, so it would be a pity to go with same shafts that get broken with OEM N/A engine that has lower torque figures.

On the other hand, it's torque at the wheels that breaks the cammel's back, so N/A engines are also capable of inducing high torque loading during 1:st gear burnout.

Anyway, my line of thinking is that Porsche probably had a reason for enlargning CV's on Turbo and later Carreras. Also, it's my mistake to use term "axle" when it's in-fact CV's that crack.

Now what i really never heard of is 930 shredding it's CV's... I think that main reasons for that not happening are:

1. Turbo lag
2. Veeeery long 1:st gear
3. Much bigger CV's

They simply cannot do same sort of 1:st gear burnout as they cannot produce enough ummmphhh in 1:st gear due to lag and long gearing.

Anyway, what go with anything less than the best? :-) Besides, Carrera-axles are cheap, come in one piece and are really easy to install...extra torque-rating is a bonus!

Take care!

/Goran

P.S. Yes, SC engines (edit) very strong and powerfull! :-P

[Superman]

Now I can see why you're calling SC engines 'anemic.' You're planning to put a big whopping 2.3L Saab engine in it. You'll probably need titanium body panel bolts too, otherwise that massive torque is likely to rip the fenders right off the car.

Seriously, I've heard of the need to upgrade CV joints when power is increased, just not on Porsches. Nevertheless, if you think your axle assemblies need replacing anyway, and if Carrera units are cheaper and more sturdy, then your plan makes some sense.

You might also want to check out the Cool Collar and K&N air filters. Oops. Wait a minute. You won't need your oil tank at all with this engine "upgrade."

[beepbeep]

Hehehe... Superman, check this out:

It's a dyno of exactly same engine-type as ours, with it's original T25 Garrett, non-ported heads, race catalyst and chip:



Take a look at torque curve. That's 450Nm which is "a tad more" than 237Nm that original SC mill has. Now our plan is to replace turbo with GT40, port the heads and run around 1.7 bar of boost with very straight exhaust. See where i'm coming from? Yes it's 2.3 liter...but it's 21:st century, for god's sake! It has 16-valve heads, direct ignition, knock-control, it's turbocharged...

Now back to the topic: is there anybody with loose G50 gearbox that can measure diff-width or loose Carrera axles that can be measured? ... or is this all tabu beacuse engine isn't aircooled?

/Goran

P.S.
What's with cool-collar and K&N filters remark? Did i ever said anything good about using them? Check out the archives ...

[beepbeep]

Originally posted by 914timo
Beepbeep, you sure have interesting project !!! Good luck with it !!

But, if you have those SC axles there apart, could you measure how long they are ?? And, I mean from one end to the other. That would be very interesting information and I would like to compare it to the length of 914 axles.

SC axle length is between 470 and 500 mm, CV flange-to-flange (they are telescoping somewhat to allow wheel-movement)

[Mike Kast]

I still have my original axle CV set up on my anemic SC. Its lasted 230,000 miles and 25 years. If I changed them to carrera axle CV set up would they last until 2032 instead of 2028? It doesn't seem relevant for my pitiful, ugly, slow, stock, little 911
good luck with your really really fast car!

[914timo]

Many thanks Beepbeep !!!

That was not exactly the information I asked. I would like to know the exact length of the axle. But, I do understand you have assembled the CVs + axles and you can not measure those any more.

Sorry to see everybody dont understand your project. I dont know your reasons why you have chosen the Saab engine, but I do understand that our american friends dont see that Saabs are as common here as Chevys are in US. I think you can compare the Saab conversion very well to all american Chevy SB + 911 conversions. The Saab conversion is the european way to do the same thing. So, if you dont like Chevy conversions, I believe you hate Saab conversions too. I just dont understand why.....