jec993

I got a B&B exhaust system for my 96 993 coupe and I noticed that the stock cans have a heat shield attached to them while the B&B’s don’t. Do the B&B’s need a heat shield? Is there going to be a heat problem (melted bumper?) by running the B&B’s with no heat shield? Or is everything going to be ok…

You can see the difference between the two in this picture:


Thanks for your info
-jim

os993

Hi Jim,

Don't worry about this. Most aftermarket mufflers omit the heat shield and no problems seen. My Fabspeed mufflers don't have these, and no problems whatsoever.

Enjoy the B&B's!

jec993

Whew! Glad to know it's ok.
This was the first DIY I've done on the car and i was a little nervous about it...

thanks!
-jim

Randall G.

Hi Jim,

As I recall, the heat shields are there to keep the heads/valves from getting cooked too much. The shield is on the inboard side, towards the engine, right?

Assuming I'm correct, I would be a little concerned, though I'm sure B&B feels it's okay to omit the shields ....

Hank Cohn

Jim:

I wouldn't worry about it at all, but if you wanted to be sure go to almost any auto parts store and buy some header tape. I think you need a hose or wire clamp to affix it to the pipe, but it is used on headers and other very hot surfaces. I don't think this is necessary, however.

Hank

Randall G.

.... And, I should add that I'm far from an expert on the effects of running sans heat shield. Still, unless someone corrects me, I do believe Porsche installed the heat shields to protect the heads/valves. Suppose the question would then be: is this a case of over-engineering, or something that's really worthwhile to maintain? I personally don't know the answer ....

Joe@Fabspeed

Randal.....the heat shields on stock 993 mufflers have nothing atall to do with protecting heads or valves of the engine.

They are as useless overengineering and disposable as the 993/964 engine undertrays.....dont even think twice toss out these parts. There is so much heatshielding under and around the stock 993 exhaust systems the sheilds at the mufflers is useless and annoying and usually falls off due to rust & corrosion at some point.

tom_993

Has anyone ever heard of rust and corrosion problems on a 993? These parts are made of high quality steel. They’ve got corrosion proofing on them. They’re made to last. They’ll last 10 years easily, even in bad climates, and will probably last a lot longer than that.

Randall G.

Looking at the below photo of a 993 engine, one can see a relatively large gap between the engine and the heat shields in question. So, it appears the heat shields would offer little benefit to the engine (yes, you can say I'm changing my tune ). If they're not there to protect the engine, then what? I dunno'.

Now, in the lower picture of a 964 engine, the cat. runs right up against the valve cover. It's easy to see the benefit of the heat shield on the cat. in this case.

jec993

Thanks everybody! I appreciate your help.

-jim

McCulla

My 02p. I have had the B&B for about 8500 mi. on my 96 C4S with no heat shields and no damage to my bumper. I only street drive, but occasionally do long hiway drives (summer, high temp.) with no damage. Hope it helps. Live the system, BTW!!

McCulla

Excuse me, LOVE the system! (in other words, I really like the B&B set up)

Kevin

One of the reasons for the heat shields it to help protect the hydraulic bumper shocks. And to keep the heat from radiating to the frame rails.

Joe@Fabspeed

the heat shields are totally unnecessary.........TOM 993 you live in Los Angeles...land of beautiful tall california blondes and NO WINTER or SALT....on the East Coast daily driven 993 cars see plenty of salt in wintertime and those heatsheilds rust up and fail as they are galvanized thin guage steel.
Also under no race or all out raceengines have we seen bumpers get affected from the lack of heat shields. So acftermarket mufflers without heatsheilds are 150% good to go!

Kevin

RS Clubsport;

The heat shield around the inlet part of the mufflers do nothing to shield the heat from the bumper cover. You have other shields that are in place that will do that. Will you agree that the cat is operating in excess of 1200 degrees, those shields overlap the muffler clamps and cat, they are designed to protect the rear bumper shocks. People should replace them if they are corroded and missing. Why wait till you have been rear ended to find out if your rear absorbers have failed leading to more structural damage to the frame rails.