Polybush exhaust rubbers, worthwhile?

Stormster

Stormster

Stormster

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What are the main benefit of these? Do they cause loads of vibration in the car?

My car is a Fiesta ST.

I wanna buy new rubbers because as expected my local powerflow made a dogs dinner of my new exhaust :o - they only needed to make me a centre section as I'd bought a Piper backbox - at first it was catching on the underside heatshields and resonating against the cars body and banging about if you got any wheelspin.

I had to go back and he has tweaked it, cut it down a smidge on the centre pipe so no more catching/resonating BUT:

1) When the exhaust cools down/goes cold, it rises up and pretty much touches the lower valance on my back bumper. When it warms up it drops a bit away from the valance.

2) It's now sitting crap anyway, its actually pointing in ever so slightly to the middle of the car! If anything you'd expect it to point a little towards the drivers side rear corner of the car.

3) He refused to change the rubbers (even offering him a new one which came with my Piper backbox which luckily he's not modified in any way) and the exhaust can wobble about a lot, if you get wheel hop pulling off quickly from junctions in the wet with a bit of wheelspin it still bangs under the car because it's so wobbly!

So, what are the benefits of poly exhaust rubbers? Or will OEM new ones do the job better? A mechanic friend is going to try and rehang it better when I get new ones. I'm not wasting my petrol or time off going back to the powerflow dealer.

Thanks :)
 
Coincidently there was a thread today on ClioSport all about this.

If you find it eats new OEM rubbers you could go for something a bit stiffer, but don't put on anything completely solid. Going solid can snap the brackets off the backbox as the exhaust has to be allowed to move. Even if your system has got a flexi joint at the front (designed to allow the engine to move and the exhaust to stay still), there's still a bit of movement needed in the exhaust.


Plus also with solid mounts the exhaust vibrates the boot floor and will make it horrible to drive due to noise.
 
Thanks for the reply, my cars also got a miltek 60mm flexi pipe. The rubbers on there currently are the original ones, cars a 58 plate and done 45k so new OEM ones may be beneficial.

That reno exhaust moves a lot on the vid!
 
The engine mounts must be very soft on the Clio to cause the amount of "in and out" movement on the exhaust.

Polyurethane exhaust rubbers are an utter waste of money, they don't do anything any better than the rubber ones and they don't last either.
 
Westyfield2 said:
Coincidently there was a thread today on ClioSport all about this.

If you find it eats new OEM rubbers you could go for something a bit stiffer, but don't put on anything completely solid. Going solid can snap the brackets off the backbox as the exhaust has to be allowed to move. Even if your system has got a flexi joint at the front (designed to allow the engine to move and the exhaust to stay still), there's still a bit of movement needed in the exhaust.


Plus also with solid mounts the exhaust vibrates the boot floor and will make it horrible to drive due to noise.
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Your gear changes are awful.
 
I have them on ITR
I had them on my EG Civic
RECOMMEND them
Stops exhaust hitting stuff on speed bumps. And Stops Bumper from melting :P
Like 20f mod but 3 years down the road and they are like new. If i remember i got 3 on my car.
Get those ones
$(KGrHqR,!pIE8VbQtv7QBPWhE-fnEw~~60_35.JPG

You can tweak mounting on custom exhaust with those and they are like extra 2f a pop.
 
I spent the first year with my GTR melting the rear bumper, tried new hangers and everything but nothing solved it. Finally solved it though when I fitted the silenced decat - only reason it was touching the bumper was because of the cheap decat someone had fitted with warped flanges.
 
Poly hangars help a lot, on the fiesta st they srandatd ones are really soft and the exhaust wobbles all over the place. When I had my fiesta st at one point it had a miltek flexi and mountune cat back (with bigger tailpipe than standard), after a while it melted my rear valance a bit. Eventually went for poly mounts and also polybushed the rear engine 'dogbone' mount, this reduced engine movement considerably, tightening up the gear shift but also ensuring the exhaust didnt flap about so much. Do that and put a poly rear mount on the last part of the exhaust and you should be fine.
 
It's tricky, as said exhausts need to be able to move quite a bit, if everything is poly bushed, engine gearbox suspension etc, then fair enough but, if one happens to deteriorate for whatever reason, it's gonna snap something.

If your exhaust is hitting the body work, it's a very poorly fitted exhaust.
 
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It's a bit bigger diameter so it seems from reading about quickly today it's not unheard of for them to catch the underside if you get a bit of wheel hop.

Still annoying and I'm disappointed at the centre pipe I had made.

The rubber posted above with alternate holes seems a clever idea, where can I get one of those?

Will, did you get any extra vibrations in the cabin with poly dogbone mount? The rubber has started to split on my dogbone mount so I need a new one anyway soon.
 
Stormster said:
Will, did you get any extra vibrations in the cabin with poly dogbone mount? The rubber has started to split on my dogbone mount so I need a new one anyway soon.
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Its a bit more vibey but it settles down after a week or so. Worth it for the improvement to the gearshift in my view, and it seemed to reduce wheel hop a little. Helping to keep your exhaust still is a bonus.
 
The centre pipe I asked them to make is a bodge (two bits welded together as he cant bend one long piece of steel twice!) and also the fitting is poor, the rounded out piece on the tailpipe catches the valance as he's cut a bit off the centre pipe to stop it catching the heatshields in turn making the backbox go up higher and close to the valance.

Not wasting my time going back lol. Gonna order standard rubbers and just a single poly one for the rear, as per the red one above with extra holes, to try and sit the backbox better :)
 
Stormster said:
The centre pipe I asked them to make is a bodge (two bits welded together as he cant bend one long piece of steel twice!) and also the fitting is poor, the rounded out piece on the tailpipe catches the valance as he's cut a bit off the centre pipe to stop it catching the heatshields in turn making the backbox go up higher and close to the valance.

Not wasting my time going back lol. Gonna order standard rubbers and just a single poly one for the rear, as per the red one above with extra holes, to try and sit the backbox better :)
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Think Unique exhausts in Stafford are meant to be good if you wanted to get somewhere else to fix it. They are a powerflow place but meant to be pretty good, more skilled than your average place when it comes to fabrication.
 
Yeah unique exhausts are the best around here definitely. Only problem is getting booked in quickly, busy bloke! Also he shuts up shop most summers to go welding on oil rigs, must get paid a bomb.

As said though, it's a case of finding a good franchise thats all, I wanted it on quickly and didn't pay much but just a bit of hassle getting it right, soon be sorted :)
 
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