Strut Brace?

[craigturbo2]

I was toying with the idea of a Strut Brace, but was wondering if there was any benifit using it for mainly road use.We are very lucky as allot of the roads in the area are drivers roads hense the question(lots of nice fast twisties).

Craig

[domster]

In isolation, they normally just increase understeer on the limit (or in the wet for normal road use).

There may be benefits if you revise the geometry, upgrade other suspension components etc. Maybe consider going the whole hog when the snow has gone (I doubt a strut brace will be beneficial on wet or icy roads).

[craigturbo2]

I dont really use my car in the wet dry use only,what i did not say was the springs and shocks have been upgraded thanks for your response.
Craig

[domster]

It could be worth getting one then. You could consider a harness bar to stiffen the back as well, although this will get in the way of rear passenger access. The most important thing will be getting the geometry set up/4 wheel alignment. This will be about 150 GBP at a good independent with the right equipment.

Geometry mods on their own may have more effect than adding bits. A small adjustment to camber/toe in etc can make big differences to handling.

The second thing to do is book yourself on a North Weald car limits day with Andrew Walsh, for about the cost of a trackday (no track insurance needed tho').

It is the best money spent on making your car handle. In my case, I was causing half the handling problems (terminal understeer to snap oversteer) myself, then buying bits to fix them! Andrew shows how you can reduce understeer etc. using your driving technique. This is also a handling upgrade that you can take from one car to another

I guarantee you will go quicker from A to B spending money with Andrew and driving a standard T2 than modding it to the hilt and having no training.

Of course, you may be an ex-rally or racing driver, in which case you probably don't need training, so ignore me.

Plus strut braces do look good when you pop the bonnet.

[Melv]

domster said:

In isolation, they normally just increase understeer on the limit (or in the wet for normal road use).

You're talking b0ll0cks as usual, Dom.....

Mel

>> Edited by Melv on Wednesday 23 February 18:41

[Butzi]

Melv said:

domster said: In isolation, they normally just increase understeer on the limit (or in the wet for normal road use). You're talking b0ll0cks as usual, Dom..... Mel >> Edited by Melv on Wednesday 23 February 18:41

Someone please enlight me. I thought if you stiffen the front, you reduce oversteer and increase understeer, right? But then when I asked about strut brace a while ago, I was told ti doesn't do anything other than help maintainning the geometry/set up. ????

[tony.t]

Butzi said:

But then when I asked about strut brace a while ago, I was told ti doesn't do anything other than help maintainning the geometry/set up. ????

That's what I thought as well and in maintaining geometry it actually reduced understeer.
Perhaps it's the extra weight up front that causes the increased understeer.
I'm not entirely sure strut braces do much at all with rubber top mounts.

[clubsport]

Being just an average driver I have to admit I only find the benefit of a strutbrace on the limit,or I think i do??,,assuming you have the car set up properly the car should handle nuetrally the strutbrace is incorporated in this set up.
It is good to hear from the real drivers on here who are able to extract the full benefit at road speeds from a 1" diameter ali/ carbon bar across the suspension top mounts...respect

[Butzi]

tony.t said:

I'm not entirely sure strut braces do much at all with rubber top mounts.

That's why I waited til I changed my rubber mounts to Monoballs before I installed the strut brace, otherwise you just end up transferring all the slacks onto the rubber, at least that's what I was told anyway.
I'll see if I can tell the difference this yr on the track with the Monoball/RS wishbone/strutbrace set up.
Anybody gonna be in Bedford on G. Fri?

>> Edited by Butzi on Wednesday 23 February 22:14

[domster]

Melv said:

domster said: In isolation, they normally just increase understeer on the limit (or in the wet for normal road use). You're talking b0ll0cks as usual, Dom..... Mel

So are you going to enlighten us then Merkin Man? For once I speak from experience: I tested the effects of a strut brace on an E36 M3 Evo at Goodwood with Peter Gethin, the ex F1 winning driver. It was a dedicated test - clear circuit - to see whether a strut brace did any good in isolation to other suspension mods on a sportscar (albeit an M3 not a 911). With the strut brace on, it understeered more on the limit. With it unbolted, the chassis was twisting more but the engineers had allowed for this and the geometry was actually better positioned on the limit. Peter found more grip and more neutral handling. Thus you had a bizarre situation where grip was actually higher without the brace. In theory the brace would allow a greater tyre contact patch and increase grip. In reality, it fecked up the factory geometry settings and decreased it. So shave that off your yak and wear it Plus isn't it a generally accepted rule that stiffening the front increases understeer, stiffening the back increases oversteer?

I must admit that I may have been hard pushed to tell the difference between strut brace on/off at the limit, but an F1 driver at the helm normally helps with these observations

[shadowninja]

I was under the impression that it would increase understeer but everyone I've heard says it improves handling. And surely buying some bolt-on bit from Halfwits must improve the car, right?

Anyway, I remember once hearing about some TVR racing team recommending softening the rear of a Cerbera to make it less oversteery... 2 + 2 = 4 etc.

[burzel]

There is some interesting reply’s to this one. I might be able to throw a little light on this one.
On early 911, 89 and back, the inner wings flex more, by fitting the bar, you get the extra support from the unloaded turret. The American weltmeister bar sits over the top rubber bushes and also stops this moving. There for keeping the geometry close to how it’s been set stood still! It may effect over or under steer, when the car is working hard. Quick fix’s of both are normally dialled in our out on the roll bars. Once you know how the car is behaving on the limit, you can then make adjustments to the set up to suit you and the car.

Our early 911 rs ,has the weltmeister one, and before now, we have tightened this up as a quick fix to increase camber for the circuits rather than hill climbs.( This pulls the top of the strut turrets in),This will then alter the grip of the front end by putting more rubber on the road, in the corners, where the limit is normaly found! So then normally reducing under steer with the extra grip found.
The later cars have a better chassis and less flex, the bars fitted to these cars don’t do a lot as a road car, unless you have plastic outer wings. As the steel outer wings help stiffen/support the inner wing.
This all changes if you put grippy track or slick tyres on again.
I have just fitted a strutt brace to my gt2 racecar, because i have plastic/carbon outer wings and soft compound 265 x18 front slicks, with tremendous front end grip. This did alter the car through fast corners, as i was able to put more camber on the front,
-3.5%.
Just to say every car is different, and you may well get a opposite effect to another person or car. How fast is your limit to some one else’s,a faster man may get more under steer, and a slower person no under steer at all. A good balanced driver may drive the car completely neutral .Its a big bag of worms, chassis & geometry mods, ask the opinions of 2 real experts, and you will probably get 2 different answers

[domster]

Cheers for the post, Paul.

I am still a little confused why stiffening the suspension at the front/rear tends to cause corresponding under/oversteer (as an extremely general rule).

In theory, stiffening the suspension limits roll and keeps the car flat to the ground, increasing the tyre contact area. But in practice people sometimes stiffen the rear suspension if they want it the back to be a bit livelier and oversteer more... just thinking about this is making my head hurt.

Is it true that the first rule of suspension set up is that there are no rules?

And to think there are things like rising rates and bump steer to consider. Aaaaagghhhhhh

[speedlimit]

I have had two 3.2's lowered and a weltmeister strut brace fitted and in both cases found the turn in to be much improved. In fact the improvement was so good with the first car that when I bought the second car I had it done within 4 weeks of acquisition. I understand that this is not in isolation but my experience leads me to recommend it.

[tony.t]

domster said:

I am still a little confused why stiffening the suspension at the front/rear tends to cause corresponding under/oversteer (as an extremely general rule). In theory, stiffening the suspension limits roll and keeps the car flat to the ground, increasing the tyre contact area. But in practice people sometimes stiffen the rear suspension if they want it the back to be a bit livelier and oversteer more... just thinking about this is making my head hurt.

I don't think that fitting a strut brace stiffens up the spring rates at the front and as such won't affect the understeer/oversteer balance in the same way as a anti roll bar would since this does effectively alter spring rates.
The stut brace stiffens the chassis not the spring rates, and it's this stiffening of the chassis that allows constant geometry under load.

[domster]

The problem is that a flexible chassis compromises the stiffness setting off the dampers. Although the dampers don't move much on a mega-stiff setting, the chassis does. So they act like softer dampers.

Or am I hopelessly misguided?

I have an engineer stiffening my Ultima chassis at the moment who knows about such things and is doing his best to educate me (and probably failing miserably!).

Cheers
D

[tony.t]

domster said:

The problem is that a flexible chassis compromises the stiffness setting off the dampers. Although the dampers don't move much on a mega-stiff setting, the chassis does. So they act like softer dampers.

I don't know at what level of stiffness the chassis flex starts acting as the spring rate or what type of load is required but I wouldn't have thought it would be problem for road spring/damper rates with rubber top mounts, road tyres and a normal driver. A committed driver running slicks on track with 1000lb springs is a different matter.

[domster]

Yeah, you are right Tony. My conversation was in the context of a chassis running fully-rose jointed suspension.

Despite all this, I still maintain that 200 GBP spent with Andrew at North Weald is better than 200 GBP on a shiny strut brace.

[Buster44]

tony.t said:

I don't think that fitting a strut brace stiffens up the spring rates at the front and as such won't affect the understeer/oversteer balance in the same way as a anti roll bar would since this does effectively alter spring rates. The stut brace stiffens the chassis not the spring rates, and it's this stiffening of the chassis that allows constant geometry under load.

[Melv]

Thankyou Tony t.

Dom, I think you're confusing the effects of a strut brace with the action of running stiff or loose anti-rollbars.....

You know old chap, a little knowledge is a dangerous thing........

Sorry, got to rush, I can hear another yak hair delivery arriving in the yard.....

Mel