Strut tower braces

[zedevan]

I'm looking into what strut tower braces to purchase and after looking though the american based sites was wondering what similar things were availible here. I'm interested in a triangular type one as my bonnet often pops up going over uneven roads or bumps, so would like to try to prevent all the flex.

 

 

i know that http://www.len-brennan.com.au/ sells some, and from the pics of his car he must sell a triangulated front one, does anyone know about the back?

 

 

i'd b interested in something like this for the back to stop the beam just bending when compressed, does anyone know of a place preferably in melbourne that sells them? I'm going to ask len about his rear brace and the pricing of them both, is anyone here using them?

 

also since mine is a 76 260z i assume i cannot purchase a 240z rear strut brace, but the front ones are the same? would 280z braces fit or are they different again?

 

this is an interesting link regarding braces from what i've read so far http://www.pistonheads.com/gassing/topic.asp?t=195399&f=135&h=0

[zedevan]

i just tried emailing him at sales@len-brennan.com.au and it was sent back to me, does anyone know another way of getting in contact with him?

[sco_aus]

I got my ones from www.technotoytuning.com . I beleive they do triangle ones. These guys sell some parts for Zeds that are hard to get. I litterally just received some roll centre adjusters in the mail, no more bump steer.

[Toecutter]

Hi Evan,

 

Adjust the closing mechanism, (latch), on your bonnet, it should'nt open that easily. The 240 and early 260 2 seater rear strutt towers are the same but the later 260 ones are taller from memory.

[zedevan]

it doesn't pop open that easily or often, but either way you can tell the car is flexing! if it starts happening more often i might adjust it.

 

thanks for the link to www.technotoytuning.com, i assume they are based in america? how much was postage of the items you've gotten so far? is it hard to install bump spacers?

 

the pdk front brace looks very interesting

[sco_aus]

I think from memory I paid $350AUD all up for front and rear strut braces, not sure if they are making both or the triangle ones anymore, but it wouldnt hurt to email them. The bump steer spacer post cost was $7 and its extremely easy to install, but thery only make them for the front. Its just a case of unbolting the bottom of the strut, insert and rebolt.

[zedevan]

sweet, thanks for the info! i think my car has the 280z body, but then nate told me it didn't at one of the cruises? but then i had to get the 240z struts modified to work, so basically i'm confused as to which type i'd order, i guess they can give me the length of it and i could measure the distance between the rear struts?

[gav240z]

Hi Evan,

I'll PM you Len Brennan's Mobile number, if that doesn't work I'll send you his home number after checking with him that it's ok.

 

I think Len doesn excellent work and perhaps over engineer's in many instances. His Roll Cage is a work of art, I know who I'd ask to build my cage if I get one .

 

What year is your 260z Evan? I think it was a 75 from memory and would more than likely be more like a 240z body style than the later 260z style.

[240ZR]

I've gone to the trouble of making my own strut braces using 6mm alloy plate & a tig welder for the end plates & the standard alloy bar that Whiteline use on their various types along with their hardware (eye bolts etc). I've since found a machinist that can machine the ends out of billet for $85 each at a minumum of 10 peices.

The 3rd pic is of one all ready done that only needs a final touch for the finished product.

These are pretty simple to make with all the available material from Whiteline. The only other thing you'll need is a tap to thread the ends of the bar.

If anyone is interested let me know so I can put the order through.

 

Nick.

 

 

 

[zedevan]

why did u decide to go down that path? i assume they are adjustable by all the threads on it

 

technotoytunings ones are (US?)$119 each and postage is $30 if ur happy to wait over a month, or $60 for under 2 weeks, but they dont have any triangular ones currently

 

 

i haven't called len yet, i've been busy and lazy

[Scando]

A friend of mine is making a front strut brace up for me at the moment.

 

I've had heaps of people tell me that they make the car heaps different to drive and that I "have to get one." The only thing is that nobody can tell me me how it actually effects the cars handling. All anybody can tell me is that "it makes it better."

 

I'd be interested to find out how it changed the handling from anybody who has put one on their car.

[PZG302]

My racer has a front strut brace across the towers only. It improves the handling by "tightening" the shell and providing another link between the suspension points to keep them aligned. I have also seam welded the front of the car through out the engine bay to tighten up the chassis.

 

The rear strut brace is part of the cage, with a bar going from one rear mount to the other just above where they mount to the strut towers.

 

The front of the Z's have a very long chassis rail, and these will move up and down indepently of each other under load, ie heavy cornering. What the strut brace, and seam welding if you have this as well, will do is limit this movement of the rails keeping the location of your suspension mounts closer to where they should be. It's this stopping of the suspension points that aren'r supposed to move from moving that improves the handling as the chassis is not flopping about.

 

This is a fairly simple explanation and hopefully one that makes sense. There are a few others on this forum that would be able to give a more in depth explanation if needed.

 

Matt

[Zeddophile]

Just to add to what PZG302 said, it basically reduces twist in the body, or more specifically the point where the body is attached to the suspension - the end result is a better tyre contact onto the road, less dynamic change in all your alignment angles, and improved feedback and feel from the chassis.

[PZG302]

Also, further to the above, I don't tie the brace back to the firewall to keep good access to the motor.

 

We only have to undo two bolts to remove the brace and then have acces to the motor injection and manifolds if needed in a hurry at an event.

 

My motor has had a nasty habit of spitting off rockers when buzzed above 7200. We seem to get a nice collection of spare lash pads at rebuild time :lol:

[Scando]

I should have explained myself better sorry.

 

What I'm trying to find out is how the car handles differently with a strut brace. For example, did it give you more bight on turn in, better stability, less/more understeer/oversteer, etc?

 

Thanks

[Zeddophile]

all of what you said. Because the tyre contact patch is more consistant and slightly larger (due to the alignment angles changing less under load), you should see less understeer and less tendency to oversteer, along with better predictability/controllability during oversteer. Not sure about bite on turn in, would depend on how hard you flicked it in - but in a quick flick of the wheels, I'd say that it should bite better yes. Should also get better traction under acceleration out of corners, I'd imagine.

 

It will handle more like they did out of the factory, as over the years bodyshells fatigue and can flex more and more - this is why serious competition cars are generally at least partially seam welded, and are backed up with a rollcage braced to most of the suspension points.

 

A strut brace is a budget answer to seam welding - not quite as effective, but definitely an improvement. Generally nothing is modified to fit a strut brace (except for the more fancy ones maybe!), so put one or both on, and see if you like it - if not, pull them off, return to standard, and sell them on. Or if you know someone with a zed with them fitted, ask them if you can borrow the braces for half an hour or so, and try them out!

[Scando]

Thanks Zeddophile, that's what I wanted to know.

 

Sounds like it should be exactly what my car needs. I run a welded diff so I struggle with understeer on turn in and oversteer on exit. Hopefully the front strut brace should find me some time on the track then I already have a cage in the car so the harness bar has the same effect as a rear strut brace. The cage made a massive difference to the car, I droped a second and a half off my lap times at our local track after I had it put in!

 

Thanks again for your help

[Zeddophile]

i think you'd probably gain a lot more by switching to a limited slip diff over a welded centre, in terms of circuit times!

[PZG302]

Gotta agree with Zeddophile about the locker, I run one but have the car set up to my liking for turn in and powerdown and they arfe a lot chepaer than LSD centres :lol: . I have been able to set mine up to handle pretty neutral, though it will still step out on cold tyres or with a bit too much right foot :lol: and can be a pig to turn in when tyre are cold also.

 

I definately wouldn't recommend a locker on a street car, I've seen too many go bang and the nasty stop after it, plus I'm pretty sure constable plod would rake a dim view of a locker....

[Scando]

I'd love to put an LSD in it but the expense of an long nose R200 is too much for me to justify at the moment. I only use the car as a circuit car, it's not registered so road legality isn't an issue.

 

The handling is far from horrible but just needs fine tuning and I'm hoping I can keep improving it without the expense of an LSD. I plan on running more castor to attempt to eliminate the understeer. Probably the hardest thing with the handling at the moment is getting the power down. I have to be very tentative as it comes onto boost on the exits or it kicks the back out big time! When I bought the car it had a standard front sway bar and a 22mm rear (probably to get it to turn in with the welded diff) I've now gone ot a 18mm rear and this helped it off the corners but it still needs improving.

 

PZG302, I'd be interested to hear what you've done to your car to make it handle with the locker?

[PZG302]

I'd love to put an LSD in it but the expense of an long nose R200 is too much for me to justify at the moment. I only use the car as a circuit car, it's not registered so road legality isn't an issue.

 

The handling is far from horrible but just needs fine tuning and I'm hoping I can keep improving it without the expense of an LSD. I plan on running more castor to attempt to eliminate the understeer. Probably the hardest thing with the handling at the moment is getting the power down. I have to be very tentative as it comes onto boost on the exits or it kicks the back out big time! When I bought the car it had a standard front sway bar and a 22mm rear (probably to get it to turn in with the welded diff) I've now gone ot a 18mm rear and this helped it off the corners but it still needs improving.

 

PZG302, I'd be interested to hear what you've done to your car to make it handle with the locker?

Good to see it's not on the road with the locker....I see a few cars on the road with them and wince when I see it.

 

To help with the locker, have done it for the same reason you have, cost, we have played with the suspension a fair bit, but have found it not to be a real issue for us. I don't have a lot of power, about 150 rwhp, based on a Dyno Dynamics shootout reading of 143.1 hp with a prior to swapping the points dizzy to electronic and tidying up the fuel tune and some timing issues.

 

I also have the luxury of a selection of 3.7, never really used, 4.1 and 4.8 diffs for different tracks. We generally use the 4.1 for pretty much every where, but the 4.8 for wakefield, Amaroo before it shut and hillclimbs.

 

The suspension was set up initially with the lockers in mind and also my driving style.

 

Basically the car sits about 2\\" lower all round, achieved by dropping the spring seats on the strut towers, makes wheel selection an issue at times, espacially with the 18's I run. This gives us full length of travel for springs and struts making for a stiff ride but not on the bump stops. We use pretty mucha standard spring length and rates around 420lb/inch front, though could go higher to maybe 460 and slightly lighter in the rear.

 

Can't tell you what size sway bar at the front, though 25mm sounds familiar. We don't run a bar at the rear, I like the bum to move around and it helps with power down out of corners and weight transfer with a little roll.

 

For the wheel alignment on the front we go as much neg camber as we can, at the moment about 2.75 deg and plenty of castor, does make steering around the pits heavy :lol: , but fine at speed.

 

Toe depends on what we are running and from memory is not a lot, but can't tell you off hand as the car is 900km away in Sydney.

 

The rear alignment is pretty much standard.

 

One we haven't done is go overboard with nolathane bushes everywhere. We still use a fair bit of rubber where you want some compliance.

 

The car is set up to what I like and I find it very easy to drive, feels neutral with good turn in and no nasty suprises powering out of corners, unless the slicks are cold :shock:

 

Hope this helps you in the quest for faster times.

Matt

[Scando]

Thanks Matt

 

That's excellent info.

 

The front suspension arm mounting points have been moved on my car so it has plenty of -ve camber on the front, but I'm not to sure on the actual degrees. Rear has pretty much no camber but I think I'll be lowering it a bit (has adjustable ride height) so that sould give a little -ve rear camber at the same time. I think I'll definatly try some more castor to get rid of the understeer from the locked diff, it sounds like it works well on your car.

 

As I said, my biggest problem is keeping it straight and getting the power down off turns. The class i run we have to run semi slicks and I don't have flares or anything so I only run 15X7's. The car runs an L28 with a T04 on it so it's a fairly fine line between getting on the throttle early enough to eliminate lag, but not to early or the car's sideways and frying the tyres. I'll have to try it with no rear swaybar next time I'm at the track to see if that helps.

 

Thanks again for your help,

 

Shane

[PZG302]

Shane,

 

For hillclimbs and wet weather running I use 215/60/15 Toyo Proxes on 15X7 challangers. The setup works well with them also, but can fry tyres with the power :lol: if not careful.

 

How were the mounts moved and how far? You have to be pretty careful with the mount points can induce all sorts of nasties like bump steer. The more usual route that I know of is to lengthen lower control arms to get some more track and -ve camber. A bit of fabrication is needed but easier to get the desired results as you haven't moved the locating points.

 

Lowering the rear won't really give you more negative camber if you are adjusting height by lowering the spring seats as the movement is along the axis of the strut keeping everything pretty much relative to each other still in terms of the mounting points. Again the better way is to lengthen the control arms. And if you getting that type of work done you also then set up the rear toe as well, and try to build in some anti dive anti squat with the locations.

 

The other thing to watch is lowing one end too far in relation to the other. Mine is dropped pretty equal all round.

 

Hope this helps some more. I would recommend you get some books on suspension design to learn more. When I start reading them my head hurts as I watch plenty of aircraft going overhead :shock: :lol: But there are some good books that explain everything pretty well, just need to go to specialist motoring book shop.

[Scando]

The holes for the lower control arms have been re-drilled further out on the cross member, I haven't measured how far but it looks like a bit over an inch.

 

I've just received noltec bushes to put through pretty much the whole car and I got the ones for the rear suspension arms that enable you to adjust camber and toe so I'll be able to get the -ve camber that way if I choose.

 

What class do you run your car in?

[PZG302]

My car ran Marque Sports, now production Sports Cars as a 2B sports car.

 

Since the big dollar cars came into the category, the Robnells and Porches I haven't had too many runs, just enough to keep the licence, also work gets in the way of racing :x .

 

I will be looking at running the MGCC NSW 4 event series for sports and touring cars, probably won't be able to get involved until later next year with work and home life at the moment.