Strut Brace question

[chrism964]

I have recently fitted a strut brace to my 1990 c4.

My question is what way should I tension the strut bar?
Do I make it longer (and therefore push the strut tops away from each other)? Or
Do I make it shorter (and therefore pull the strut tops together)?

I'm guessing it has a lot to do with the way the forces act on the struts when they are subjected to a load (in a corner).

It's probably not too important for me anyway as my wife says I drive like Morgan Freeman in 'Driving Miss Daisy'!

Thank you for any replies.

 

[Steve Brookes]

I simply set mine neutral i.e. I just tightened it firmly by hand. I've always been lead to believe the brace is there to stop the struts flexing at the top. If you adjust it so that it is pulling the struts in or pushing them out, you're messing with the geometry that has been set up on the front suspension.

Even with it set to neutral I immediately experienced a better turn in so they certainly work IMO.

 

[chrism964]

Thank you for the reply.

I guess my question is not specific enough. The slack may be taken up by making the strut bar longer or shorter. Even if it is only hand tight.

In making yours Neutral did you take up the slack by making the bar longer or shorter? And does it matter?

 

[Dave Wilkinson]

Chris,

I think the point that Steve was making is that it's important that the strut brace is adjusted - whether it be longer or shorter - to be a snug fit between the towers. You should not use the adjustment on the strut brace to attempt to move the strut towers at all - just use the adjustment to make it snug, and only finger tight.

The clue is in it's name - it merely supports what is there. The aim is to prevent, as much as possible, the strut towers deforming under load. By bracing them against each other the tendency to move is greatly reduced.

Once the brackets are mounted on the towers all that remains is to adjust the bar to fit - end of story.

Regards

Dave

 

[chrism964]

Thank you for the reply Dave.

I understand the principles of the brace. It is there to prevent the strut towers from flexing either outwards or inwards under load and thus distorting/altering the geometry of the front wheels (mainly the camber). In doing so it also reduces body roll.

I'm probably thinking about this too much. I was just wondering whether the predominant tendency of the strut towers was to flex outwards or inwards when loaded. It would therefore make sense to 'take up the slack' with the bar (even if hand tight) by doing the opposite of the predominant movement. I suspect as the bar is rigid the effect either way is negligible anyway.

I was not planning on using a torque wrench and lever bar to make the strut bar to pull/push the strut towers in or out (I suspect the forces required would be fairly ridiculous anyway.)

Thanks everyone.

 

[polar964]

Chris,
What make of strut brace have you fitted? and for what reasons did you choose that particular make?

 

[chrism964]

Paul,

I chose on price. I had done some research but figured the principles are pretty much the same for all of them. There are some that claim to cut down on the flexing of the rubber top mounts too but I guess this is of dubious benefit in a mostly road going car and that monoball top mounts would be a better route to go down if I wanted to do this.
I managed to get one of these for £55.

http://www.advancedcarproducts.com/proddetail.asp?prod=Strut_P964

May just be expensive bolt on tat i.e. more show than go (only time and testing will tell) but it looks pretty and the standard of workmanship is good. It's also light!
We'll see. I don't think I actually do very much of the type of driving required for it to give me any benefit. It may end up back on e-bay.

 

[Steve Brookes]

Hi Chris,

Yes I see my description was a bit vague. I put mine and adjusted it so that it was easy to bolt the metal plates to the top mounts. At the same time I ensured there was equal thread on either side of the brace. I then tightened it by hand to take up the slack and then tightened the lock nuts. This means that the brace is pulling the mounts inwards rather than pushing them out (if you tightened it the other way). This seemed the logical thing to do to me, I hadn't even thought of the alternative way of tightening a brace 'outwards' until you mentioned it.

Yours looks the same as mine but you paid half the price I did!

 

[chrism964]

Cheers Steve.

As I said before, I think I have gone way too cerebral with the whole thing but I have scanned the interweb(!) and found that the general consensus is that strut towers flex outwards underload.
I guess the brace prevents this whichever way it is tightened (it being solid) but I will take up the slack by shortening it. I suppose I could do some very unscientific testing by driving my favourite road with the bar tightened one way and then the other using the 'seat of my pants-o-meter'.

On another note, my bar seems to foul on, what I think is, the fuel tank sender unit (the black box with Porsche VDO) written on it. Did you just jiggle yours a bit to help it to fit without pressing on it too much? I am considering relocating it (the black box) as it appears to be held in place by a jubilee clip.

Chris.

 

[Steve Brookes]

As you can see from the pic above, the brace is very close to the sender unit but does not foul it and I didn't have to move it at all. However I did notice that if I had tried to fit the brace by turning it through 180 degrees so that the brackets faced the other way (i.e. you wouldn't be able to see the nuts in the pic above), then the sender was in the way.

 

[chrism964]

Thank you Steve,

My bar presses down on the box whichever way the mounts sit. Probably a bit of poor design. I may try pushing (a gentler term for bending) the mounts back but I think that resiting the unit someway is probably best.....

 

[polar964]

Hi Chris,
May seam a daft question, but did you purchase yours from the supplier you gave in your link, as the price appears to be £87+p&p and not £55 as you had indicated.

 

[chrism964]

It was purchased new from Ebay but from that supplier. I think they were having a stock clearance as the auction was for 5 in total. I was surprised that the price remained so low.
£55 all in. []

 

[polar964]

Nice one. I 'll take a look on ebay! cheers

 

[mr pg]

I got one of those too a few months ago, and paid forty odd quid! Bargain. Mine doesn't foul the sender either. I did mine hand tight, and then tweaked with a spanner to tighten. Makes a difference to Targa, as you'd expect.

 

[Ian964]

I had the same brace in my C2, and like you found it fouled the sender whichever way round it was. I ended up by relocating the sender, initially with duct tape to the front of the fuel tank, then by making a bracket that just moved it forward but still using the normal mounting point.