Stainless v Mild Steel Exhausts

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Mon Feb 23, 2015 7:51 pm

I have a question that I would like to ask if I may, as I'm looking to get a new pipe this spring.
Will there be, or is there any measurable difference in performance terms, when mounted on the same 2 stroke motor, two of the same exhausts design, one made of stainless steel & the other made of mild steel, for arguments sake take something like a Jl or Franspeed 3.
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nastro azzurro
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Mon Feb 23, 2015 8:08 pm

Don't know about differences in performance, but if you're away with your scooter, stuck in the middle of nowhere with an exhaust that needs welding, I know which one is going to be easier to get repaired........

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Mon Feb 23, 2015 8:15 pm

..........and which one will crack and snap more easily!
Scootering since 1968.

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Mon Feb 23, 2015 9:24 pm

My car has the same stainless exhaust that it left the factory with 15 years ago.
Did you have to do that?

B-Race Tuning
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Mon Feb 23, 2015 9:27 pm

...and from testing, I'd err on the side of mild steel from an engine reliability point of view. It may need removing once a year for a wire brush and paint up, but at least it'll last a year. And a car / 4T exhaust cannot be compared as different environment. S

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Mon Feb 23, 2015 9:34 pm

mild steel everytime. the stainless exhausts ive had , (ive got a stainless JL on me vespa) crack for fun. never seen one that didn't, the stainless Devtours for lammys are good pipes, but need welding every year. my JL has been welded 3 times , 20 quid a time, so sounds cheap...but then a 300 quid exhaust is now a 400 quid exhaust with the chew on of taking it to get welded etc. If it was mild steel I could MIG it up in the shed. performance wise? the mild steel one I had on the P221, and I don't see a difference between mild steel VS stainless, its just the chew on of them splitting for an expensive bit of kit, so I would get the plain steel one everytime.

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Mon Feb 23, 2015 9:44 pm

I've heard that stainless exhaust's hold more of the heat than those made of mild steel,hence more chance of a heat seize.I have no proof of this,its just something that I have been told and I'm sure someone with more knowledge of the two metals will be able to say wether this is true or not.

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Mon Feb 23, 2015 9:53 pm

Speaking from my own personal experience, about 7 year ago my good mate fitted a brand new Sip JL stainless pipe to my mallossi T5, which has been thrashed to many a rally since and I've got to say it's been the best fitting reliable pipe I've had.
Maybe I've been one of the lucky ones.

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Mon Feb 23, 2015 9:57 pm

I've ran a ss taffy copy on my SX TS1 plenty miles no problems. Never seen a welder. Got a ms one chromed on my GP again no problems again no welding.
built a T'S for a mate and used a ss taffy copy - no problems.
performance wise can't say there's any noticeable difference
Both pipes have had the mountings altered to my spec.
Had a SS JL/SIP performer on p2 for years - was welded in the first 1000 miles - so I remounted it and no problem for many miles - to be honest I wasn't happy with the original mounting and should have modified it from start.
same pipe on my mates T5 again no problems

I would have used stainless again on my S2 but a ms one came along very cheap and it was chromed very reasonable (whole thing was £160)

can only speak as I have found.

I have never heat seized a bike as a result of using a stainless exhaust. When I switched from a ms one to ss on the SX the jetting has remained the same and done miles on the ss exhaust. I would question other things causing seizures before a stainless pipe.


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Mon Feb 23, 2015 10:02 pm

It's my very good friend shaunmc's T5 172 i was referring to in my post.

SS in my experience have given no issues on vespa and lambretta.

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