Stainless Exhaust Question

[renson 0]

I have also posted in the which exhaust thread but didn't think many people would look in there.

 

My problem is that i have just got a powerflow exhaust fitted and tbh i hate it. Its far too loud for my liking but it was a case of needed something straight away. Anyway have noticed that the joint between the cat and 1st box has started to blow when its cold so was going to re-do the joint but looked on the net first and found this..

 

It is worth noting that stainless steel gets hotter quicker than mild steel and also expands noticeably when hot. This means that after a bit of use stainless exhaust joints work loose so when cold the exhaust clatters and rattles. It is only once warm that the metal expands and the joints tighten that everything quietens down. This is particularly common on VWs as the sections tend to be joined with compression clamps rather than bolted unions.

 

I found this on another site so before i drop the exhaust and re-do the joint is this true and would i be wasting my time? This is what has happened to mine, Done a 100+ miles and now it rattles/blows slighty form the joint when cold but is fine once it is warm.

[colinstubbs 0]

I'd just get it tightened again.

[ryan_16v 0]

I have a powerflow exhaust on my valver, its the same for me when its cold it sounds tinny / small blow from down pipe to 1st box joint.

Then it warms up its fine, not that loud (3 boxes) but a nice deep hum.

[Toad 0]

My magnex does this too. But I do keep battering it getting in and out of my garage, and my parent's farm...

[Kevin Bacon 5]

My problem is that i have just got a powerflow exhaust fitted and tbh i hate it. Its far too loud for my liking but it was a case of needed something straight away. Anyway have noticed that the joint between the cat and 1st box has started to blow when its cold so was going to re-do the joint but looked on the net first and found this..

 

Does it drone quite loudly when hot? Quite a common issue with stainless systems using 'straight through' silencers unfortunately. Some are quieter than others though. Had exactly the same issue with my Milltek.

 

As for leaking etc when cold, shouldn't happen if the clamps are A) good quality and B) done up tightly enough.

[g0ldf1ng3r 14]

I have also posted in the which exhaust thread but didn't think many people would look in there.

 

My problem is that i have just got a powerflow exhaust fitted and tbh i hate it. Its far too loud for my liking but it was a case of needed something straight away. Anyway have noticed that the joint between the cat and 1st box has started to blow when its cold so was going to re-do the joint but looked on the net first and found this..

 

It is worth noting that stainless steel gets hotter quicker than mild steel and also expands noticeably when hot. This means that after a bit of use stainless exhaust joints work loose so when cold the exhaust clatters and rattles. It is only once warm that the metal expands and the joints tighten that everything quietens down. This is particularly common on VWs as the sections tend to be joined with compression clamps rather than bolted unions.

 

I found this on another site so before i drop the exhaust and re-do the joint is this true and would i be wasting my time? This is what has happened to mine, Done a 100+ miles and now it rattles/blows slighty form the joint when cold but is fine once it is warm.

 

i had a full powerflow system on my old valver C but never had any issues at all with it - id take it back to where you got it fitted & get them to take a look :)

[renson 0]

Just popped it in and got it all tightened up now. Seems much better but think in a week or 2 going to modify it myself to fit how i want it. Seems ok but is still too loud for my liking even with with the 3 boxes.

 

Does it drone quite loudly when hot? Quite a common issue with stainless systems using 'straight through' silencers unfortunately. Some are quieter than others though. Had exactly the same issue with my Milltek.

 

I do have a magnex(sp?) backbox which i think i am going to modify and try too. That is quite a bit larger than the powerflow box so may silence it more. Exhaust didn't cost much so it's just a case of getting it how i want.

 

My magnex does this too. But I do keep battering it getting in and out of my garage, and my parent's farm...

 

Thats why i have put this one on, it sits much higher because the middle 'suitcase' is smaller. I live in the sticks and on a spirited drive i hit it and ripped a hole in that and it also broke the welds where the pipe goes into the backbox. I'm sure the loud sound of the exhaust is fine but not for me. TBH i liked the original exhaust and had this powerflow already so it had to go on as i needed the car ASAP. I think at 26 i must be getting old before my time as i liked how quiet the original exhaust was before i broke it.

[Jim Bowen 1]

just had a magnex fitted and not many miles later its blowing from the join, the garage said something about your not meant to use the putty/paste stuff on stainless system, but i told them to use it if needed.

 

they have it back at the moment to fix it, and straighten exhaust.

 

had no problems with my last stainless system and that had a similar connection, wasn't on a corrado though

[renson 0]

had no problems with my last stainless system and that had a similar connection, wasn't on a corrado though

 

There is my problem right there!

[colinstubbs 0]

There is my problem right there!

 

:lol: :lol:

[Spr711 0]

while were on the subject, im looking at getting a stainless system fitted this month. Anyone got brand reccomendations?

what sort of prices do you guys pay?

[renson 0]

Look Here, There is loads on that already. Read through it and you will soon get an idea

[Brooksie 0]

try longlife exhaust m8 they are custom made an lifetime garentee too, i used them on all my previous cars an i have one on my vr6 now, plus if you sell the car the garentee can be transfered so very good if a friend is having it least they hav no worries for a while

[pete_griff 0]

as Kev said, as long as you have decent clamps and they are done up tight enough, you shouldn't have any issues.

also i don't see why you can't use exhaust paste on a stainless sytem - stupid suggestion IMO! (not aimed at you 3CM - but the garage who told you that)

 

also, be aware that if you're fitting a magnex backbox, while they are very nice, they won't allow you to fit an uprated rear ARB without taking a hammer etc to the side of the backbox as they foul on eachother if left as stock. that's obviously only applicable though if you have/are going to fit an uprated rear ARB :)

[Kevin Bacon 5]

also i don't see why you can't use exhaust paste on a stainless sytem - stupid suggestion IMO! (not aimed at you 3CM - but the garage who told you that)

 

I know!! It's ridiculous the utter crap some garages spout to their customers.

 

also, be aware that if you're fitting a magnex backbox, while they are very nice, they won't allow you to fit an uprated rear ARB without taking a hammer etc to the side of the backbox as they foul on eachother if left as stock. that's obviously only applicable though if you have/are going to fit an uprated rear ARB :)

 

Yep, I've done that a few times :D Applies to the SuperSprint back box aswell as that's a hefty beast!

[Toad 0]

as Kev said, as long as you have decent clamps and they are done up tight enough, you shouldn't have any issues.

also i don't see why you can't use exhaust paste on a stainless sytem - stupid suggestion IMO! (not aimed at you 3CM - but the garage who told you that)

 

also, be aware that if you're fitting a magnex backbox, while they are very nice, they won't allow you to fit an uprated rear ARB without taking a hammer etc to the side of the backbox as they foul on eachother if left as stock. that's obviously only applicable though if you have/are going to fit an uprated rear ARB :)

 

That probably explains the occasionally knocking from the back end of my VR. :lol:

[davidwort 0]

also i don't see why you can't use exhaust paste on a stainless sytem - stupid suggestion IMO! (not aimed at you 3CM - but the garage who told you that)

 

I know!! It's ridiculous the utter crap some garages spout to their customers.

 

I can see why someone might say that, although a system should seal perfectly well without any paste (and makes things a darn sight easier if you want to remove, reuse parts) some stainless systems do seem to expand and contract a large amount which I'd have thought doesn't mix well with liberally appled paste.

But then if paste has been applied to seal an exhaust that has an underlying fitment problem, how long is it going to seal for anyway?

[mikkijayne 0]

My exhaust place uses high temp silicone on stainless systems for exactly this reason. They say the silicone can flex as the system expands and contracts.

 

I was skeptical to say the least, assuming it would just go up in smoke as soon as the system got hot, but its been fine for 6 months. As others have said, it's quite tinny and rattly from cold but soon quietens down to a nice hum. This is a Magnex system (I think from a mk3 Golf) on a 16V.

[pete_griff 0]

also i don't see why you can't use exhaust paste on a stainless sytem - stupid suggestion IMO! (not aimed at you 3CM - but the garage who told you that)

 

I know!! It's ridiculous the utter crap some garages spout to their customers.

 

I can see why someone might say that, although a system should seal perfectly well without any paste (and makes things a darn sight easier if you want to remove, reuse parts) some stainless systems do seem to expand and contract a large amount which I'd have thought doesn't mix well with liberally appled paste.

But then if paste has been applied to seal an exhaust that has an underlying fitment problem, how long is it going to seal for anyway?

 

most of the aftermarket systems i've seen, while of decent quality wouldn't seal up without any paste/silicone in my experience. you would have to do the clamps up very tight for it to seal - as you say with expansion/contraction the joint would soon leak (in my experience anyway).

if you've done the joint up "reasonably" tight, then it shouldn't move at all and the paste/sealer will just fill the tiny little nooks that wouldn't seal from just the clamp on it's own. haven't you seen the tiny little black streaks that appear on a joint without any paste on where the gas escapes....

 

 

 

 

i've also seen that high-temp silicone sealer you're on about MikkiJayne - its surprisingly good stuff isn't it. can you just buy it from any old motor factors?

[farrantino 0]

Sorry to bring an old thread up,

but my valver has a decat straight through middle box, with no suitcase and a rear silnecer,

the problem i have is that when the engine and exhaust are nice and hot i get a pop a little flame on deacceleration,

could it be the exhaust or something else,

also when i slow down and change down a gear it pops as it builds up the revs

 

Cheers