78 911 SC questions

[jbrubaker001]

Long time fan and new owner of 78 911 SC - fully stock

- want to upgrade to SSI - can you make the large flange SSI from 81SC work on the 78?
- what is the best weight/power muffler upgrade to fit the SSI?

Thanks for all help.

[tonythetarga]

I think you mean thick flange vs thin flange. You have to change studs at a minimum and that is easier said than done in some (most) circumstances as they have a tendancy to break off instead of unscrew. They ARE removable nonetheless. I am not an SC guy, but the other thing to check is whether the stock exhaust has a fitted insert into the exhaust port or it is a flush fit. If it is a flush fit, you should just need new exhaust gaskets. If the SSI's have that lip to insert and the stock ones do not have it, they may have to be ground down before mating with the head.

[FinallyGotOne]

I am curious, are you eliminating the heater then? I hear Stainless Steel Headers end up eliminating the interior heater.
Just curious.
by the way there have been a lof of research with the muffler. Look on you tube and there are some sound clips, and on here there are some performance stats.

[sc_rufctr]

SSI's are almost bullet proof. They have been the standard "upgrade" for a long time.

More recently people have been using 993 exhausts on earlier cars with great results but you have to turn the exhaust flanges.

This pic is from our hosts site. As you can see they do have heater boxes.
Some P car owners have cut off the heater boxes in the quest for lightness.
The weight saving is significant at about 8kg total... (16-17 pounds)



One of the best Mufflers for SSI's is the "Monty" IMO... Nice deep sound and Australian made.

[snbush67]

Originally Posted by jbrubaker001

Long time fan and new owner of 78 911 SC - fully stock

- want to upgrade to SSI - can you make the large flange SSI from 81SC work on the 78?
- what is the best weight/power muffler upgrade to fit the SSI?

Thanks for all help.

Unless you all ready have the thick flange SSI's, find some thin flange they will probably be a bit cheaper and you will save about two years of your life upside down under your car with cutting oil and chunks of metal streaming into your eyes.
You will also benefit by not experiencing an 8 inch bruise on your shoulder from applying constant pressure of 30 lb force to the drill, probably save about 6 trips to sears and about 300 dollars in titanium carbide diamond tip drill bits, another 200 in a mounting jig.

Saying all that do whatever it takes to avoid breaking an exhaust stud when you go to remove the old muffler or you will be drilling it out anyways, but is is better to just replace one or two studs than to try to replace them all, that is why it would be better to just get the thin flange ssi's.

Then again, doing the smart thing isn't all-ways part of the man-code, thats why I am writing this from experience ( caveman tool time grunt ).

Good Luck,

Shane