tube80z

The problem with this when you adjust your ARB or turn the car you also change the motion ratio. I also don't know if the ARB would act as a filter for some of the frequencies the damper would normally see.

Morgan Smith, who has the red Z with the large IMSA flares was running 550 lbs/in springs on his Z and using the 15 inch GY FA tires and the bushing died after a season. He was complaining the car was inconsistent and when he took the strut off I shook it and it rattled. The top busing was toast.

You'd be in revalve territory or very close. Just as an FYI try searching for "used race shocks" on ebay (https://www.ebay.com/sch/i.html?_odkw=penske+shock&_osacat=107057&_from=R40&_trksid=p2045573.m570.l1313&_nkw=used+racing+shock&_sacat=107057&LH_TitleDesc=1) You can get a few that aren't in the best of shape for 30 to 40 dollars and you can decide if this will work for you. I bought some Penske 7300 adjustable shocks with base valves, two extra sets of pistons, VDP pistons, and a s-load of valving shims for $1400. I bought new coilover tubes from Alls

Unfortunately when I saw it I wasn't smart enough to know what I was looking at. A friend explained it later and they called it a Preston strut at the time. When I asked what the hell that was I was told Don Preston (maybe faulty memory) got fed up at IMSA and used coilovers that were mounted to the lower control arm and then hooked to the strut tower but used an old strut as the normal top suspension element. This was all to do with rules that said you couldn't do this or that. I can't remember if this was a 200SX Datsun or an RX-7. Both had a live rear axle. I think I was around 15 at

I know this has been the prevailing wisdom but it makes no sense. When it's wet the weight of your car and the suspension don't change. That's primarily what the shocks work with. While it's true the grip is lower it's the same as saying I need to valve my shocks for 50 MPH or I need valving for 100 MPH. I can anecdotally share I tried softening everything on the wet and ended up going back to my normal rebound and compression on the DA shocks I was using. I did remove the rear ARB and soften the front ARB but that was it. Left springs alone. I also suggest running your nor

In XP suspension is free. That means you could use an old strut and stay that way and add a rocker and use real coil overs. You won't get the advantage of an SLA but you wouldn't have to pay tons extra just because you have struts. This would be more like your ARB project as far as work goes.

There are two versions of these spacer/steering arm out there. The old version has too much of a pocket in the steering arm and can break if you use them on track days and autoxs. The other problem is they are flat. So any spacers under them aim for the wheel. A friend tried these and they wouldn't work when we went for enough of a spacer to lower bump steer. Personally this is one item I don't think I'd use aluminum for. One other general item I'd add around the spacers is to weld it to the steering arm and then use thin spacers to finish of the bumpsteer. This is stiffer th

Hi Clark the rod end works better in most cases. If you have a roller bearing it can still bind when the arm flexes in the middle. A common problem people run into is they install collars to hold the ARB in place but when it bends these hit the inner ARM mounts and cause bind. Give it 1/8 to 3/16 space and the binding stops. The rod ends are also great on older cars that may not be as stiff as a tubeframe chassis. I stole the idea from a Riley & Scott trans-am car but have seen it all over the place. The Realtime racing Acuras that raced in IMSA used this method as did a lot of older

The one thing that hasn't yet been mentioned I'd like to point out is get a bolt long enough so only the shank is against the bushes. If you buy a bolt that fits it will most likely have threads in one of the bush ends. I don't think I'd recommend notching for the spindle pin as this will add a failure point and this system doesn't have the fail safe the stock system has. If you do decide to notch the bolt make sure to paint of put some corrosion inhibitor on it. cary

What fuel pressure you are using? Webbers generally don't need much more than 1.5 to 2 PSI. These carbs need regulators if you're system is higher than that. When I used these on my old race car I would get flooding at anything over 2 PSI of fuel pressure. Sometimes on the street 2 PSI was too much.

Derek, Any chance you know the weight of the complete TL70 and/or the CD009? I'm looking at options for building a street card. thanks, cary

I'd also recommend torrington bearings under the spring seats (top and bottom). Those will help front and rear as the suspension moves through it's range and they will allow the spring to rotate torsionally as it's compressed extended. I'm also not sure why there isn't more of a spacer on your camber plate to top hot that moves the load to the bearing. That's the silver bit Jon mentions. If you still end up needing more camber than you can get from all the adjustments it's possible to slightly bend the strut tube (i.e. crash damage) or pull the strut towers slightly closer together (assumi

I'd only use metal of similar thickness to the frame rail, which I cannot remember off the top of my head. I can check today if needed as I have my race car cut up for a number of mods. You're spot on to why I'm doing all this. It isn't so much for stiffness, although that may benefit too. It's really protecting the passenger compartment from a wheel coming back in via this normally weak area. The main benefit I'm looking for is to add more crushable structure to this part of the car. I never gave much thought to any of this until I saw how badly the Falcon deformed

I don't think you need to go that large. I'd use the same tube as you would for a strut bar for the purely torsion stressed members unless you already have the material. It will just weigh a little more in the end. I think you have a couple options. You can do it in tube similar to what you have or was used on BJHines car. The other is to make a larger torsion box out of sheet in similar thickness as the rest of the car. Look at the convertible torque box mod for Ford mid-to-late 60s Mustangs and Falcons. They have a very similar unibody design to the Z. In those

I love the level of work you're doing. The crash comment is one I've thought a lot about too. About 20+ years ago (vague) I witnessed the aftermath of a Ford Falcon leaving the road at not much speed and hit a tree. This was well below normal racing speeds (hillclimb event) as the road was wet. The driver suffered a broken leg, pelvis, and now walks with a limp. Why I bring this up is that the underside of a Ford Falcon is very similar to the Z cars. His car had a good cage and a racing seat. How he got hurt was the car rolled off the door bars when he went sideways into the tree and fl