Upgraded Engine Mounts ...

[elrao]

Hi guys

Been a while since I posted over here, as I am normally resident over on the TT Forum, however it was suggested that I ask my questions again over here as there seems to be more experience with Big Turbos and the related mods over here.

I had a big turbo conversion done on my TT earlier in the year and, only a few hundred miles on, the exhaust snapped

One of the welds broke clean through, it was the last weld in the de-cat section, right before the clamp on to my Magnex 'cat-back' exhaust. Obviously being the last weld, it is the weakest part of the exhaust when it comes to movement of the engine, as it is furthest from the point of rotation.

The custom pipe does have a flexi-joint, however this is where the cats 'should' be, not on the downpipe like you would normally see on big bore downpipe for a TT (I think the OEM downpipe also has a flexi on the downpipe?). Meaning it is also further down the rotational axis than if the flexi were on the downpipe, in turn meaning that any rotation of the engine is magnified by the time it reaches the flexi joint by compaisson.

The flexi is also now horizontal, where as I believe the normal ones are near vertical. Again this means that the flexi is working in a different way. Being vertical would mean the flexi is inline with the rotation of the engine, meaning it works by being 'squashed' and/or 'strecthed', by being mounted horizontally, then it works more like it is being 'twisted' or 'bent', i.e. raising one end of the flexi up and down along its axis.

You can just see the flexi here, and the brake in the exhaust:

What I was trying to say about flexi movement ...

Which way is best for a flexi to be mounted? In line with the rotational axis of the engine, or transversely?

Do you guys think i am giong to have continued problems if I just get the exhaust repaired (manufacturer are replacing it for free)?

They have recommended that I upgrade my engine mounts, to reduce the amount of movement and hence reduce the risk of it happening again, however I am reluctant to do this as I know lots of people running more power than me with stock engine mounts and no issues, they all have flexis on the downpipe, as close to the manifold as possible. Those people I have spoken to who have tried uprated engine mounts tend to give the same feedback about them causing excessive vibration through the car chasssis (the force has to go somewhere!!).

Thoughts, comments?!

Cheers

 

[pj1985]

All of the companies I know that do BT say you have to have uprated engine mounts for them to warranty the dp. Engine mounts wear and yours might be knackered. Flexi can help reduce the engine movement impact on the exhaust but only to an extent as they only have so much give in them. I dont think you really have any choice but to limit your engine movment to make sure this doesnt happen again as no matter what else you do you risk it.

 

[elrao]

Cheers. Uprated engine mounts were never mentioned or discussed when I got my quote or even when the work was being done. First I heard about needing them was after the exhaust had snapped

If I am going to uprate them, any recommendations on what mounts and where to get them from?

How long should it take to have them fitted?

 

[barnsley]

around 2 hours to fit i say which BT are you running

 

[elrao]

I have a JBS Twin Scroll conversion.

So two hours to fit isn't too bad, just need to find prices for the mounts themselves....and decide which mounts are man enough to do the job but aren't going to cause me to shake my teeth out.

 

[caney]

i've never run uprated engine mounts,never had an exhaust problem either.unless your engine mounts are completely shagged?why would it cause the weld to break so far down though?

 

[elrao]

Hi Steve!

Being the furthest weld away from the engine, then it is under the most strain when the engine moves, as it tries to move the furthest (being the furthest point (radially) away from the engine) but is then clamped into place by the cat-back section, so can't move (if that makes sense).

Where is the flexi on your downpipe Steve? Near the manifold? By halving the radial distance that the flexi is away from the point of roatation (the crank?) then you half the amount of movement it needs to absorb, everything downstream of the flexi should then not move.

 

[barnsley]

is it this one been looking for a kit for my motor and came across this
http://cgi.ebay.co.uk/TIG-ART-VAG-V...photoQQcmdZViewItemQQ_trksidZp1742.m153.l1262

seen the breaks in the same place befor jabba like the flexi to be right up next to the turbo soon as posible in the down pipe

 

[elrao]

Can't look at eBay from work, but Tig Art used to make the kits for JBS (AFAIK), but JBS now make their own inhouse. The twin scroll turbo is from an Evo too, so is probably the same thing.

Agree that the best place for the flexi is as close to the manifold as possible, not sure why they have not put it up there to be honest, would be more than twice as effective!

 

[jabba_luke]

We dont or never have used uprated engine mounts on any of our kits, and have not had a need to.

The position that the flexi is in the downpipe is critical to the downpipes life.

 

[ibizacupra]

luke... c'mon kiddo... you are digging a hole with shite advise like that, and it is not even true.. remember i have been a jabba customer and upratedf mounts were req'd to try to avoid breakages of downpipes etc, and jabba have advised customers to fit them when their manifold and downpipes snapped!



nothing wrong with the location of that flexi.. but if the whole system is stressed to fit, or the flexi is full expanded or collapsed then its not got much "flex" left in it.

stronger mounts are a very good option, as engine flex when haldex is coming in and out is extreme, and where the motors flexing the downpipes got to take up that slack.,,

 

[elrao]

Cheers Bill, any recommendation on which mounts to go for? One option are the vibratechnics ones, other the street density mounts from INA. Already have an uprated dog bone mount, just need engine & gearbox. 2 hours to fit has been confirmed, prices for the mounts are quite a bit different, INA are about 220, VT ones are about 100 more.

 

[ibizacupra]

INA's are the cheapest you will find. Vibratechnics are all new mounts including being different castings, not just harder rubber in OE castings, they are uk made, but more money.

Both will work for you.

 

[HTC]

I agree with Bill regarding flexi placement. Mine is horizontal. Has been used with standard and now INA mounts. Was fine with both.

Maybe it was just a weak weld???

 

[ibizacupra]

do the welds look like they are "coked" inside, carbon'd and crusty or smooth clean welds? (evidence of a poor weld without backpurge if they look cokey) If cokey then thats indication of that weld just being a weak one. does the joint "want" to go back together or is it stressed to go back into that position? again if its stressed then when it expands (a lot) when hot it may make the whole system fight against its fixed points.. (mounts, downpipe etc)

 

[elrao]

It is entirely possible that it was just a weak weld, but I don't want to take the chance by having it re-welded and then have it break again. It is a day trip to go up to Chesterfield to get these things fixed and a tank and a bit of fuel too. First time round then it is possible to blame it on the weld and hence JBS had no issues fixing it under warranty, however if it were to brake again then I think JBS would be fair in saying that it was due to the engine mounts and so I would most likely have to pay to have it repaired a second time.

Might as well get the engine mounts done while I am there! INA mounts are $315 + £115 to fit, for VT mounts I am being quoted £320 + £115 to fit.

I would prefer the softest mounts that are going to do the job, as my car is not a 'track' car and so I would like to retain as much of the comfort as possible, without excessive vibrations.

I assume I would need the same VT mounts as the MKIV golf? So this one:
http://www.vibra-technics.co.uk/parts/part-details.asp?id=415
and this one
http://www.vibra-technics.co.uk/parts/part-details.asp?id=417

Then it looks like I need to buy the rubber separately?

http://www.vibra-technics.co.uk/parts/part-details.asp?id=427

Is that correct, I would need all three (roughly matches the price quoted by JBS).

Has anyone tried both the INA ans the VT mounts?

 

[elrao]

do the welds look like they are "coked" inside, carbon'd and crusty or smooth clean welds? (evidence of a poor weld without backpurge if they look cokey) If cokey then thats indication of that weld just being a weak one. does the joint "want" to go back together or is it stressed to go back into that position? again if its stressed then when it expands (a lot) when hot it may make the whole system fight against its fixed points.. (mounts, downpipe etc)

I didn't look to be honest, I was at Marlin motorsport in Bletchley and they took it off and welded it back together for me (just patched up to get me home), so will never know about the weld now.

 

[ibizacupra]

excess engine movement can stress things if its flopping about a lot.. I remember seeing a few haldex'd 1.8t at awesomes RR when the haldex was coming in and out, and feck me the engine was leaping up and down like a b'stad!! it was shocking. mounts are well advised.

INA's are probably worth a go. I only have experience with vibratechnic, and they do couple more vibration thru to the cabin, but the car is so much "tighter" and gear change is sweet when done. They tend to settle down a bit after some miles on them.

regards
bill

 

[ibizacupra]

You can just see the flexi here, and the brake in the exhaust:

only other thing i would suggest, is to help take the weight of the exhaust, which is henging on the flexi/dp, is an aditional support hanger by thet first joint so the weight is supported, so the flexi is just catering for vibration and growth/shrinkage and not supporting the systems weight as well. Think about when cornering hard that inertia of the exhausts weight is going to load things up too and fro.. my ibiza exhaust has this additional front support to hold the systems weight so the flexi just has to cope with expansion/contraction and the minimal engine movement my race engine mounts allow.

 

[Willie]

It is entirely possible that it was just a weak weld, but I don't want to take the chance by having it re-welded and then have it break again. It is a day trip to go up to Chesterfield to get these things fixed and a tank and a bit of fuel too. First time round then it is possible to blame it on the weld and hence JBS had no issues fixing it under warranty, however if it were to brake again then I think JBS would be fair in saying that it was due to the engine mounts and so I would most likely have to pay to have it repaired a second time.

Might as well get the engine mounts done while I am there! INA mounts are $315 + £115 to fit, for VT mounts I am being quoted £320 + £115 to fit.

I would prefer the softest mounts that are going to do the job, as my car is not a 'track' car and so I would like to retain as much of the comfort as possible, without excessive vibrations.

I assume I would need the same VT mounts as the MKIV golf? So this one:
http://www.vibra-technics.co.uk/parts/part-details.asp?id=415
and this one
http://www.vibra-technics.co.uk/parts/part-details.asp?id=417

Then it looks like I need to buy the rubber separately?

http://www.vibra-technics.co.uk/parts/part-details.asp?id=427

Is that correct, I would need all three (roughly matches the price quoted by JBS).

Has anyone tried both the INA ans the VT mounts?

Hi mate

I have the Street density engine mounts with the track density DBM.
I would strongly suggest this set up.
I changed my Polyflex DBM for the Track density INA one and the difference in vibration was massive but handling exactly the same if not better.
Go for the INA ones you will not be dissapointed but the vibratech ones are supposed to be a bit OTT for a street car