stingraygene

just read where they were saying aluminize in/out is better than ss due to less heat through floor and that ss can expand up too 1.5" from front to rear causing rattles from the close tolerances? Is this really true? got me wondering now if I really should order ss since car is going to have only 1000 miles per year. but suspect the condensation is the real killer of systems and that is ss advantage?

naramlee

maybe a full sized diesel truck with a mega tune on the turbos

for stainless to expand that much, you would need the whole system heated to 1200* from tip to tip over a 10' span... not happening in our cars

calculator we use for figuring metal expansion: https://www.utausa.com/metalconverter.html


main problem with stainless is using cheaper grade and poor weld quality, the thermal contraction over the lifespan constantly puts pressure on bad welds and will quickly crack them if the system is improperly welded

a true stainless system has to be purge welded if you use any form of welding... just gas on the weld side is NOT going to hold for long, the whole pipe your welding has to have a flow of inert gas over the backside of the weld to prevent "sugaring" of the weld: iron oxide, chrome oxide, nickel oxide resulting from exposure to oxygen while at elevated temperature.

7T1vette

The difference in expansion rate between SS vs. regular steel (the 'aluminized' pipes are steel with aluminum coating) is negligible. The aluminum coating on the regular steel pipes has more chance of falling off due to expansion rate differences...and that doesn't happen either.

SS is just damn hard to work with, weld, bend, etc. And it might be 'stainless' in normal environments, but an exhaust system is anything but 'normal'.

If you are building a high-end custom show car, maybe you go with stainless tubing (most go with chrome). But for driven cars, aluminized pipes are the way to go.

leadfoot4

I agree, but it sounds like the OP is looking at aftermarket, "off the shelf", pre-bent systems....

LT1M21Vette

Make sure the pipes are mandrel bent.

Richard454

Hey Gene-

I saw in another thread where you were pondering sidepipes or not.

Ended up making my sidepipes- I have an electric cut-out to go from obnoxious to quiet. I used the factory covers ( fiberglass chromed) and wrapped them with heat shield to minimize heat.

Used stainless 304- mandrel bent pieces- and had my buddy weld them up . It was a LOT of work- pain to work with- eats up drill bits and expensive!!!

If you are not worried about performance you can buy aftermarket not so loud mufflers and run the factory covers- Be able to talk in the car -not burn you leg and look great!!!

Priya

I bought an aluminized exhaust system just because it was cheaper and I probably only drive my car 600 miles a year (when its on the road) and its garaged all the time and not winter driven so I'm sure the aluminized exhaust will last my lifetime.