I'm pickin' up bad vibrations - dogbone mount

[ChoonDoode]

so an update on the hybrid lower mount for you all. IT'S GETTING TAKEN OUT!!!!!!!

 

I've driven with it now for approximately 5 months and done about 6000 miles with it fitted and I can sum up with the following;

 

Pros

The car, I feel, does handle better with it in. It doesn't feel as 'understeery' when pushed hard.

 

Acceleration does feel more precise. That may because there isn't anymore squishiness in the mount.

 

Cons

The cabin vibration is the problem. Full stop. End of. 

 

Initially on lockdown and with limited driving because of WFH as well, it didn't really annoy me. Now things have sort of returned back to normal, I'm doing a normal ish commute (can sometimes be 100 miles) and I'm experiencing it properly in day to day driving. Trying to drive as normal as possible, the vibrations get on my nerves. I try not to drive paranoid about being ultra eco, but even just going along a 30mph road in 4th, the engine is happy to be there, but the vibrations coming through mean I'm putting it into 3rd to get it revving out of the 'vibration range'. Whilst I appreciate it's only the car's advice, but the majority of the time if you try to drive in the recommended gear, it's going to be an uncomfortable journey. There's a bit of road by where I play footy and why it's 20, god only knows, but it's a copper's area of choice, so 20 gets stuck to rigidly. I've driven along this stretch in the past in 4th, like the car has expressed it is happy to do. It's a 2nd gear road at the moment.

 

It is also a hindrance when you're driving along the motorway in one of the 50mph zones. The engine isn't being laboured driving in 6th gear at that speed in that gear, but if there is a slight incline in the road, you are shaken to bits by the vibration.

 

Sitting at idle when the stop start doesn't kick in (regen or air con related) you sit there shaking.

 

I've my service due next month and I'm going to get the mount taken out and it put back to standard. It is a once bitten, twice shy affair. Whilst the mount provides the performance side, the NVH aspect outweighs it most certainly. I hope this will serve as a 'take heed' post for those considering changing your bushes. I appreciate there are different options and I've gone down the extreme end of the scale, but I feel it's best leaving well alone.

[MarkyG82]

Thats a shame.  I really do like the benefits it offers and dont get anywhere near the issues you describe.  The raised NVH goes as soon as the gas pedal is hit.  The only time I have noticed it is when coasting in eco mode on the dsg.

 

You have tried it and chosen what is right for you.  Better than not trying it at all IMO.

[ChoonDoode]

24 minutes ago, MarkyG82 said:

Thats a shame.  I really do like the benefits it offers and dont get anywhere near the issues you describe.  The raised NVH goes as soon as the gas pedal is hit.  The only time I have noticed it is when coasting in eco mode on the dsg.

 

You have tried it and chosen what is right for you.  Better than not trying it at all IMO.

 

That's it, I've tried it, the result isn't as hoped, but hey ho.

 

The result may very well have been different just getting an insert, but I don't want to try anymore.

[elmo230]

On 19/04/2020 at 21:52, tunedude said:

Now this is your stereotypical case of 'the devil makes work for ideal hands'........ and it appears to have gone sideways.

 

After a while of thinking to do it, I've finally fitted an aftermarket dogbone mount bush; a Powerflex Front Lower Engine Mount Hybrid Bush (Large) PFF85-833BLK to be precise. I chose the black series just to get the 'best' I suppose, but I don't know if that's the root of the problem with it being more track orientated. Unless I've fitted it incorrectly and or bought the wrong one, it's vibrating like a right beepity beep.

 

When you have the car idling, there's a little bit of an additional hum, but I was expecting that. The main issue appears when you go to move away and when the revs are between 1 and 1.5k, there is an almighty vibration which goes through the whole car. I drove the car up my close and the vibrations go away completely when you're over 1.75k. I've had the car back on the ramps to make sure I've not done a schoolboy error and forgotten to tighten it all up, but everything is as tight as it's recommended (I don't want to tighten it any more in case I break something)

 

Now I had to go to work this morning (slightly knobbled car or not) and I was able to check it going through the gears properly, even up the motorway. Once your moving, it's fine. As is accelerating (which actually feels better). But go into the above rev range and it's god awful.

 

I understand the rubber mounts are deliberately designed to get rid of any harshness, but deary me, if this is what a poly bush feels like, I've well and truly made a mistake fitting this. I'm at a bit of a loss because I had to 'chop' the old one out.

 

Help. Advise. Please 😢

 

Only read to about the second page, so someone might have mentioned it already. Did you replace the bolt when fitting the bushing? It's a stretch bolt, so a new one is required. Probably wouldn't have the effect you're mentioning - just something to consider. 

[ChoonDoode]

1 hour ago, elmo230 said:

 

Only read to about the second page, so someone might have mentioned it already. Did you replace the bolt when fitting the bushing? It's a stretch bolt, so a new one is required. Probably wouldn't have the effect you're mentioning - just something to consider. 

 

yeah swapped that both times. Only a few quid

[ChoonDoode]

My car went in for it's service yesterday and, as said previously, it's had the OEM bush put back in. They replaced both the top and the bottom bush, but only charged the labour for the bottom.

 

It was amazing to get back into the car after I picked it up and the tranquillity within the cabin is uncanny. I've always been aware the poly bush amplified the engine noise, but it is amazing how much the OEM rubber bushes dampened the interior NHV. On the return the car was going into stop start and I was finding myself double checking the rev counter the engine had restarted.

 

I'm glad I experienced the poly bush as I would say it did make 'going for a blast' that bit more enjoyable. HOWEVER........ I'm glad I've refitted the OEM bush because with the temperature dropping, I've already had a few instances at the lights when the car hasn't cut out, leaving me sat getting shook to bits.

 

If I still used a van and the car wasn't my daily, I may having considered keeping the poly bush in.

 

So that's my experience using a hybrid lower dogbone mount bush on a VRS tdi. YMMV using one yourself or using a basic insert.

[MarkyG82]

It's great to get different view points on these mods. Having recently turned stop/start back on I can vouch for the comfort sitting at lights with the engine off.

I'll be removing the insert prior to parting in the car so it'll be interesting to see how it feels lowered but no insert. 

[KikiB]

I  have registered on briskoda to reply into this topic... Test subject VW Passat B8 2.0 tdi & Powerflex Red Dog Bone insert...

1. I am angry at Powerflex. Why? They sell this red insert with instructions that we should change original stretch bolt to new one!? Ok! Great! Just Great! Why don't you offer mentioned bolt with your Dogbone insert set? Why I have to spend additional time(finding, ordering, driving etc.) to get one screw? Ok I've bought OEM bolt so lets go next...

2. Don't start unscrewing mentioned dogbone stretch bolt before you have pushed red insert into voids! Once when you've pushed the insert(silicone spray, silicone grease) you can start loosening the bolt(not easy, lot of force here)

3. I was aware that NVH will occur; but boy! This is teeth rattling on the idle so I used VCDS to raise idle speed on 950 rpm's to smooth up things a bit... Now I saw at leat 5 posts on google various web sites claiming that NVH will dissapear after 1000 miles of break in period time?! 

4. After 2000 miles this insert acts same as the first day... So for me that really proves that Powerflex has high quality product that does not require break in period to settle down! But not for everyone!

5. I would not recommend this in a daily driving car... Better car starts without wheel hop, crisper gear changes are worthless when you have terrible Noise, Vibration and Harshness or NVH at idle! Especially if you live in a Town or City...

 

I wonder weather Powerflex engineers test their product after designin it? Make us something that will work equal way as yor red dogbone insert but without NVH!

 

[J.R.]

There is a reason why void bushes were invented and adopted.

 

There is a reason why rubber to metal "Silentbloc" bushes were invented and adopted.

 

There is a reason why after more than 100 years they are still used on every new vehicle on every articulating suspension joint.

 

Using polybushes on a road car is like stepping back 100 years, more in fact because the solid bushings back then had lubrication nipples.

Edited 26 March, 2023 by J.R.

[Schtum]

I had a red Powerflex insert fitted to my Mk5 Golf GT Sport 170 TDI which was remapped to c. 210 bhp.  It lasted 3 days before it was removed again.  It was awful, particularly when reversing.  My wife drove it and said, "You've ruined your car!"

 

Much more successful was the anti-lift kit which I had fitted at the same time.  That kept the front end down under hard acceleration and reduced the understeer. 

[ChoonDoode]

yeah, once you were moving it was fine and the vibrations blended into the normal driving ones. Come to a stop or drive slowly and it was unbearable. It was 'fine' to a point when I first installed it because of lockdown and I was only using the car every so often. Once it was lifted and I was back using the car more regularly, it was time to get rid.

 

One of the worst things I've ever done to any of my cars

[KikiB]

On 26/03/2023 at 23:50, J.R. said:

There is a reason why void bushes were invented and adopted.

 

Yes... I agree now... Poly has advantage while driving the car but "IDLE" kills that good driving

On 26/03/2023 at 23:58, Schtum said:

Much more successful was the anti-lift kit which I had fitted at the same time. 

I am all into Ears now... What is anti-lift kit and where I can order one? 

 

On 27/03/2023 at 20:18, tunedude said:

One of the worst things I've ever done to any of my cars

 

We must be realistic here. It has some benefits like better launch starts by elimination of wheel hop, crisper gear shifting wit MT transmission cars, car feels more solid while driving but man! Idle is OMG 👎 

[J.R.]

How does removing the voids from the dogbone bushes allegedly improve handling?

[KikiB]

3 hours ago, J.R. said:

How does removing the voids from the dogbone bushes allegedly improve handling?

PU inserts fills the voids from dogbone bushes and side effect of that is reducement of engine movement which is better explained on this  034 Motorspor video:

 

But imho PU insert works in even more extreme way than 034 with probably even less movement than on this video.

So PU and 034 significantly eliminate Drivetrain slop or drivetrain movement and bushing deflection because they are filling large voids that are made for NVH reduction. 
As a positive side effect you(we) will certainly have better starts or launch than the same car without it plus improved gear shifting feeling (you can really feel it no joke here) so at same time also improves car stability(downshifting before hard turn definitely noticeable) because whole car is significantly firmer.

But negative side effect is only one but big as a house and that is NVH at idle... Now if someone can live with it and often drives in "lap timer discover media mode" simple dogbone insert will certainly improve his lap-time. 

 

What can help(it helped me) is raising idle speed on 950 rpm's but I am still not satisfied...

 

So If someone found the way how to get rid of NVH with installed dogbone insert or similar dogbone stuff please put your findings here. 

[Schtum]

6 hours ago, KikiB said:

 

I am all into Ears now... What is anti-lift kit and where I can order one? 

 

 

The is the one I fitted to my Mk5 Golf.  https://www.awesomegti.com/shop-by-car/audi/a3-8p/whiteline-anti-lift-kit-golf-mk5-mk6/

 

However, as far as I can see, there's nothing available for MQB platform cars as yet.    

 

This link which doesn't open is listed on Google as offering:

 

Control Arm Lower-Inner Rear Anti Lift Bush Kit ... Anti Lift & Caster Increase. ... Sport Spring & Damper Kit -MQB Platform AWD: Golf 7 R.

£109.50.     https://www.vag-performance.co.uk/product/control-arm-lower-inner-rear-anti-lift-bush-kit/

[KikiB]

Anti lift kit would be set of bushes for lower control arm. Something like this: https://www.kmsmotorsport.com/index.php?route=product/product&product_id=2703

 

Well this is something to consider if you are making a track car same as mentioned "sport" dogbone bushes/inserts. 

 

Anyway for comfort driving just don't put any inserts on your car. Check your OEM dogebone bushes and if they are broken(cracked and rubber usually) just order new set of 2(upper and lower)... It will be hell to replace just bushes but it is only proper thing for comfort driving I'am afraid :(