engine and drivetrain Question -- IE exhaust hanger

[Dicks]

I love my stainless IE exhaust system. Do others that use this system also use a front hanger? I'm talking about the horizontal hanger from the stock system that goes from the transmission. Right now I don't have the IE system locked up there, and occasionally I get a little knocking. Wondering if a front mount would help. Thanx

[eurotrash]

You should always use one. The support makes the system one with the motor and trans assembly, so they move as a unit. Otherwise you are transferring undue stress to the manifold/header at the mounting flange as the motor rotates under acceleration. As well as general stresses from vibration. You can imagine the 'prying' action as the motor rotates against the rear muffler hangers.

[williamggruff]

You'll have to modify your stock exhaust hanger a bit to accommodate the slightly larger IE exhaust. I ground out the metal hanger to open it a bit, ovalized the holes through which the exhaust U-bolt passes, and bought an appropriately sized U-bolt. Quick and easy.

[wegweiser]

I just installed my IE stainless system last week. Haven't yet put the bracket on from the transmission, but it's on my "MUST DO" list for next week. I may end up making one from scratch (among the perks of working at a shop with stainless sheet steel in abundance).

It took me a little adjusting here and there, but I managed to get mine just right and thus avoiding the "clankclankclank" every time the car starts or shuts off. get those clamps REALLLL tight, too but ONLY after you have it perfect. Stainless doesn't like to bend or clamp down....so those beefy clamps are required.

Modifying your existing bracket should work.

[OriginalOwner]

From a mechanical engineering load analysis viewpoint ...... if that restraint at the tranmission is not installed, the bolts holding exhaust manifold-to-head resist all the induced loading due to exhaust system motion. Those loads can be very high due to the weight of the exhaust system moving around. That connection (manifold to head) becomes a "hard point" and all loads and loadings are resisted there by only the bolts.

As noted above in a previous post, that mount/restraint tends to prevent the header/flange from moving differentially to the engine. One wants to prevent those differential motions which thus ensures those bolts only hold (i.e., fasten) the exhaust manifold to the head and are not subjected to other loading conditions which may increase bolt stress beyond the yield point. In particular, a side-to-side swaying of the exhaust system will induce rotational loadings onto the bolts, and these loads can be surprisingly large.

That mount/restraint will prevent/restrict such induced rotational loads. And will also help resist the fore-and-aft motion of the exhaust system. That loading causes shear loading on the bolts.

Cheers,

Carl

[wegweiser]

Perfectly stated, Carl!

[OriginalOwner]

ha, 4 years of engineering school ..... but can I balance my checkbook ??

Cheers,

Carl

[eurotrash]

Also the culprit of manifold to down pipe gasket failures, cracked manifolds, and cracked header tubes.