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Expands 25mm when hot! !
Posted: Thu Feb 22, 2007 1:23 pm
by RSVI
Cars in Audi and one of the jobs was to adjust the Milltek exhaust.
Spoke to them this morning and they've said they're not able to do it because they're worried it wont fit properly and they don't want the responsibility. This i can understand.
Went into Milltek's site and was reading their fitting instructions and came across this
Make sure that there is adequate clearance around the system, remembering that this system will expand by around 25mm when hot.
25mm! ! that's 1 inch!
Where do you suppose that is? Diameter or length?
Anyone know someone that would refit the exhaust for me in the south?
Preferably someone you've used. (kwikfit is not an option

)
Thanks
Posted: Thu Feb 22, 2007 1:38 pm
by Rich_C
Can't help with the fitting but the RS6 Milltek certainly expands in lenght by an inch or so after some spirited driving ... I have visions of being pulled over by a copper with a tape measure!!!
Rich.
RE: Expands 25mm when hot! !
Posted: Thu Feb 22, 2007 1:39 pm
by david7m
I think its length! (which mine would grow an inch ....)
My standard S3 exhaust gets an 'erection' when hot. I'll try to get some photos of when cold VS hot.
Dave
Posted: Thu Feb 22, 2007 1:40 pm
by RSVI
Rich_C wrote:I have visions of being pulled over by a copper with a tape measure!!!
Rich.
Does this mean there's a "max overhang allowance" for the exhaust tips?
Amazing, never knew an exhaust would grow an inch in length. Well you learn something new each day! !
Re: RE: Expands 25mm when hot! !
Posted: Thu Feb 22, 2007 1:45 pm
by RSVI
david7m wrote:I think its length! (which mine would grow an inch ....)
My standard S3 exhaust gets an 'erection' when hot. I'll try to get some photos of when cold VS hot.
Dave
lol, as for your erections and wanting another 1"! ! !
You crease me up with some of your posts, keep it up (excuse the pun

)
Posted: Thu Feb 22, 2007 1:49 pm
by Rich_C
I don't below the exhaust can stick out further than the end of the rear bumper but nobody seems to bother with the Nova brigade so I wouldn't worry about it.
What I meant was (in the voice of a traffic policeman "... Ah yes Sir you exhaust has expanded by 18.2mm which equates to 30 minutes at 90 miles an hour - that'll be 6 points then ...". Who needs fancy laser camera's when a £3.99 tape measure from B&Q will keep her Majesties finest gainfully employed.
Rich.
Posted: Thu Feb 22, 2007 3:10 pm
by RSVI
LOL

Posted: Thu Feb 22, 2007 4:01 pm
by david7m
Here is a thread I created back in 2003 about my new exhaust expanding
Dave
Posted: Thu Feb 22, 2007 7:04 pm
by Daveperc
This looks about right. Petrol engine exhause can easily run up to 800 Celsius. Cooefficient of linear expansion for stainless is 13-16/1,000,000 m/mK so on a 2.5 m run that would give of the order of 25mm expansion allowing for a thermal gradient along the pipe etc.
Mind you, on the other aspect of this thread, I'm sorry for you guys if you can only grow an inch when "hot"!! Not that I run at 800C that often you understand!
Dave
Posted: Thu Feb 22, 2007 8:06 pm
by david7m
Daveperc wrote:
Mind you, on the other aspect of this thread, I'm sorry for you guys if you can only grow an inch when "hot"!! Not that I run at 800C that often you understand!
Dave
Thats additional diameter Dave, not length
Dave
Posted: Thu Feb 22, 2007 8:15 pm
by shineydave
too much info !!!!!!!!!!!!!!!!!!!!!!!!!!
pmsl
Milltek erection!!!!!!!
Posted: Thu Feb 22, 2007 9:12 pm
by quattrosteph
It does a lot on mine as well when very hot, after an excinting ride down the lane.....
Yeah stainlees steel does expande when hot, nothing to worry about. It's so why a good fitting is important, a bad fitting can make a very noisy exhaust.....
RE: Milltek erection!!!!!!!
Posted: Thu Feb 22, 2007 9:40 pm
by derdle
You're down in Surrey....could QST at Haywards heath fit it for you?
(PS sad bast*rd fact..the SR71 "Blackbird" spy plane and Concorde grow by about 6 inches in flight)
I don't believe I was sad enough to type that. G*d I must get out more.
RE: Milltek erection!!!!!!!
Posted: Thu Feb 22, 2007 10:38 pm
by RSVI
lol....too many posts to reply to
I heard about Concorde extending 6" or so when in flight.
Going on what Daveperc posted (confused the hell out of me) shouldn't Concorde shrink as up at that height it's a bit bloody cold.
Things normally get smaller when it's cold, don't they boys
Don't really want to know David7m

RE: Milltek erection!!!!!!!
Posted: Thu Feb 22, 2007 11:37 pm
by derdle
It may be very cold up there, but at 1400mph the friction on the skin is so high that it heats the plane up. Must be worse on the SR71 cos it'd black although made of titanium. In fact the SR71 leaks fuel out of its tanks when stood on the ground. Sorry guys...I will try to get out.