176 replies to this topic

[hairy]

zinc : aluminium = good corrosion resistance 

[Raptor]

Ok sounds Good. Bit 45Nm is a bit low for M12!?  

 

it is what the manual says..

[Raptor]

 

Ok sounds Good. Bit 45Nm is a bit low for M12!?  

 

it is what the manual says..

 

 

correction - the vx manual is incorrect - according to Lotus these should be 86NM..

[Aerodynamic]

Very strange you should have an M10 nut to M12 screws. Could explaine the low torque spec maybe.

http://www.speedster...rame/index.html 2 SCREW,SOCKET HD.,M12 X 60, SUBFRAME TO CHASSIS 4 9197986 48 00 986 3 NUT,HEX.,SELF LOCKING,M12, SUBFRAME TO CHASSIS 2 9197989 48 00 989 4 NUT,HEX.,M10,SUBFRAME TO CHASSIS 2 9198086 48 01 086 5 WASHER,12 X 23.5,SUBFRAME TO CHASSIS 6 9198226 48 01 226

[Spitfire Engineering]

How much are the shims from Lotus?

How thick are they?

I assume the folds are just to aid fitting? 

 

If both mounting areas are completely flat and the shim more than 2mm thick I cannot see why you could not use a high grade stainless version.

 

[ditonics]

How much are the shims from Lotus? How thick are they? I assume the folds are just to aid fitting?    If both mounting areas are completely flat and the shim more than 2mm thick I cannot see why you could not use a high grade stainless version.  

Your next product maybe? To stop the dreaded corrosion worms could it be made of a non ferrous material?

[Spitfire Engineering]

 

How much are the shims from Lotus? How thick are they? I assume the folds are just to aid fitting?    If both mounting areas are completely flat and the shim more than 2mm thick I cannot see why you could not use a high grade stainless version.  

Your next product maybe? To stop the dreaded corrosion worms could it be made of a non ferrous material?

 

 

Possibly ....

 

To stop the dreaded corrosion worms could it be made of a non ferrous material? = a high grade stainless version       

 

Anyone have one handy?

 

 

[Wolfstone]

Talking to Vocky and Joe yesterday their view is that probably every VX needs these sorting now. And they mean NOW. Edit.....not that that means you can charge a fortune for them Gaz.

Edited by Wolfstone, 01 April 2017 - 09:43 AM.

[ditonics]

I was thinking more along the lines of an industrial nylon, should of said non metallic. It is after all only ever under compression and shouldn't see any sheer or tension.

[Raptor]

they are something like £15 each from Lotus but there appears to be a supply problem for over a year. I would agree it is a problem that all cars will suffer from but splitting the subframe off is not a quick job and I'd hate to think what a garage would charge for this.  

 

I'm glad I'm doing mine now whilst my suspension and engine/gearbox are out.

[vocky]

 

 

How much are the shims from Lotus? How thick are they? I assume the folds are just to aid fitting?    If both mounting areas are completely flat and the shim more than 2mm thick I cannot see why you could not use a high grade stainless version.  

Your next product maybe? To stop the dreaded corrosion worms could it be made of a non ferrous material?

 

 

Possibly ....

 

To stop the dreaded corrosion worms could it be made of a non ferrous material? = a high grade stainless version       

 

Anyone have one handy?

 

 

 

 

it would be a great idea to make some, these do need doing as a preventitive measure - the sooner the better    

[Aerodynamic]

Is no one else here worried that duralack reduces the friction between the surfaces?

[Spitfire Engineering]

Is no one else here worried that duralack reduces the friction between the surfaces?

 

Well it sets as it dries so would act more of an anti-slip agent.

 

 

Original anyone??

[vocky]

I binned my originals when they were replaced with new Lotus items, I never realised they would become so difficult to purchase

[fezzasus]

 

 

How much are the shims from Lotus? How thick are they? I assume the folds are just to aid fitting?    If both mounting areas are completely flat and the shim more than 2mm thick I cannot see why you could not use a high grade stainless version.  

Your next product maybe? To stop the dreaded corrosion worms could it be made of a non ferrous material?

 

 

Possibly ....

 

To stop the dreaded corrosion worms could it be made of a non ferrous material? = a high grade stainless version       

 

Anyone have one handy?

 

 

 

 

High grade stainless certainly wouldn't stop corrosion. It would encourage it when pressed against the chassis. I see no reason why the same mild steel plates with a zinc epoxy coating can't be remade. It's not that the plates degrade, it's that the plate traps salt and moisture

[Exmantaa]

 

 

Possibly ....

 

To stop the dreaded corrosion worms could it be made of a non ferrous material? = a high grade stainless version       

 

Anyone have one handy?

 

 

 

 

High grade stainless certainly wouldn't stop corrosion. It would encourage it when pressed against the chassis. I see no reason why the same mild steel plates with a zinc epoxy coating can't be remade. It's not that the plates degrade, it's that the plate traps salt and moisture

 

 

Was thinking the same; stainless steel there would be a bad idea for pitting corrosion on the alu chassis...

Simple zinc plated metal shims, fitted with duralac to prevent moisture seeping in should do the job me think.  

[Spitfire Engineering]

 

 

 

How much are the shims from Lotus? How thick are they? I assume the folds are just to aid fitting?    If both mounting areas are completely flat and the shim more than 2mm thick I cannot see why you could not use a high grade stainless version.  

Your next product maybe? To stop the dreaded corrosion worms could it be made of a non ferrous material?

 

 

Possibly ....

 

To stop the dreaded corrosion worms could it be made of a non ferrous material? = a high grade stainless version       

 

Anyone have one handy?

 

 

 

 

High grade stainless certainly wouldn't stop corrosion. It would encourage it when pressed against the chassis. I see no reason why the same mild steel plates with a zinc epoxy coating can't be remade. It's not that the plates degrade, it's that the plate traps salt and moisture

 

 

Well ignoring the very small exposed surface area of the Stainless (cathodic by comparison) compared to the relatively massive surface area of both of the other two, all three components are separated electrically by Duralac or similar.

 

Plenty of options, 430 active SS, you can Cad plate the stainless (seemed to work on the 747 OK) or use a nice steel and zinc/passivate/clear laq.

Cannot see any issues.

 

Why are the plates bent??

 

[fezzasus]

Wouldn't compare 747 metal pairing to the VX. 747 has a much more proactive maintenance and no exposure to salt.

 

I also wouldn't rely on coating as the clamping force of very rough surfaces will likely penetrate any coating.

 

Ultimately, you're trying to design a problem away that doesn't exist. The corrosion resistance of the spacers is not the issue (and only exist to create a barrier between the subframe and chassis), they are only replaced as they are a cheap item to replace and often deform as the aluminium chassis builds up aluminium oxide at the chassis-spacer interface. Just spec a like-for-like part

[Arno]

Is no one else here worried that duralack reduces the friction between the surfaces?

 

As Duralac is designed from the start to be a jointing compound I suspect it's desgined not to influence this by much.

 

Also the joint has to be fitted/tightened when the Duralac is still tacky/soft and not dry so any excess will be squeezed out of the joint and only a thin film remains:

 

http://www.llewellyn...ads/duralac.pdf

 

It will then dry/harden completely afterwards.

 

Bye, Arno.

[Spitfire Engineering]

Wouldn't compare 747 metal pairing to the VX. 747 has a much more proactive maintenance and no exposure to salt.

 

I also wouldn't rely on coating as the clamping force of very rough surfaces will likely penetrate any coating.

 

Ultimately, you're trying to design a problem away that doesn't exist. The corrosion resistance of the spacers is not the issue (and only exist to create a barrier between the subframe and chassis), they are only replaced as they are a cheap item to replace and often deform as the aluminium chassis builds up aluminium oxide at the chassis-spacer interface. Just spec a like-for-like part

 

True though the principal is the same, to get as many of the components as close to each other as possible in the Galvanic table either by base material or plating though both is a superior solution. If you are going to have to plate the steel option anyway then it is no different to plate a stainless version.

400 series active stainless is almost identical to steel with the advantage of not decaying itself.

Always worth looking at improving the OE if possible, most OE material decisions were heavily based on cost.

If the material cost is going to be £60p for steel and £1.20 for 400 SS then it would be a no brainer as in the total production costs this would be negligable.

Might be worth a little research on the latest compounds as there is probably something more suited with superior capabilities available today.

Some of the latest off shore use compound technology lasts for years.

 

If you can design the problem out altogether why wouldn't you try?

 

Anyone know why the plate is bent?