PDK Fabrication strut braces install

[ezzzzzzz]

I just finished the installation of both front and rear strut braces from PDK Fabrication. Overall, I am satisfied with the end results. I'd like to point out a few observations and stumbling blocks. The quality of the product is good enough although I'd rather have chromoly over mild steel. If it had been so the cost would surely have be more substantial. As with any car as old as ours there is bound to be twist and turns accounting for misalignments. Mine was no exception. I chose to perform the install out of sync with the online instructions. I also want to note that the online instructions show the install in a bare engine bay. I had to do this with a complete drivetrain, all wiring and wheelwell-mounted parts. Tight working conditions come to mind!

First, I loosely bolted on the front strut brackets. Then the cross brace was fitted in place using the supplied 7/16" socket head bolt. A nut is also provided and instructions state to use a screwdriver inside the down tube to hold this nut to tighten. That's because the tube diameter won't allow for a socket. That was ridiculous so I purchased threaded rod couplers to use instead. These extend about 1/2" outside the tube so a proper wrench can be used. The rear triangular pieces were fitted up only to find the passenger side left a gap of about 1/8" from the strut brace. I ignored it and continued on. The hood bump stops were removed and the braces pulled into position. I used a small C-clamp to hold this tight. I suitable drill was used to drill through the captured nut using it a guide. A tap was used to cut threads into the brace using the captured nut as a guide. The hood stop was reinstalled and the C-clamp removed. The next step was to drill down through the cowl lip into the brace and fit with a supplied nut and bolt. I chose a different option. The inner brace leg was clamped and drilled through into the firewall with a 1/4" bit. The braces were removed and the firewall hole opened up to install nutserts. Once done, the braces were reinstalled.

The down tubes were next on the list. I jacked up the frontend and placed jackstands under the framerails behind the tires. The anti-sway bar links were disconnected from the LCA's as were the frame brackets (this isn't mentioned but it will become readily apparent that it is required). I drilled out the fixed frame nuts to 1/2" as directed. There is a spot-welded bracket on the passengerside framerail topside where the down tube brace fits. The instructions say to beat this flat. I chose to drill out the spot-welds and remove it correctly. The fuel feed and return lines also needed to be reshaped to clear the down tube. The down tubes were loosely fitted and the brace holes marked. These were drilled out to 5/16". The supplied crush tubes and lower support plates were cleaned and painted (they come as bare metal). The crush tubes were tapped into the frame rails. The anti-sway bar, brackets, and plates were installed with the supplied 5/16" bolts. At this point I'd like to state that this proved to be a PITA! I was working alone and stuff just didn't want to line up. The holes from top to bottom were misaligned. I managed to get everything bolted up despite the difficulties. If you undertake this then be sure to find a second set of hands to assist if only to hold the anti-sway bar in place! It would have been a big help! After all the efforts I was able to snug all the bits up tight using a hex bit, extension, ratchet, and wrench....yippee! The strut braces were finally tighten down.

Next came the rear brace. It was much easier. Again, the strut brackets were loosely installed and the cross brace fitted. The lower legs were drilled from either side and the chips vacuumed up. The supplied bolts/nuts were installed and everything tightened down.

I cleaned up my mess and took the Z for a brisk spin. The local interstate seemed the logical choice with several exit and entry route banking left and right. We all like to think that time and money invested proves positive. I tried to remain objective. There are several ramps that I've taken in the past at comfortable limits with a bit of tire squeal. These same ramps seem to be much more pliable...truly and with no tire squeal although I pushed the car much harder. The car did hold tighter to the road without the harsh banging on expansions joints as felt in the past. Even the straight aways felt smoother. I believe the suspension is actually working harder instead of the car being twisted and bounced around. Of course, I must admit the bracketing does look formidable and very functional. If you're looking to stiffen up your car I believe this is a viable solution for the budget-minded.

[buZy]

Great write up and tips on the install. Thanks!

[Armand]

Nice write up. My rear strut bar had some triangular pieces welded onto the points where the upper and lower bars meet. I wonder why your's doesn't have them?

[ezzzzzzz]

Good question about the gussets. I don't know. Maybe they were trying to rush the kits out and shortchanged me. I'm not real happy with the spray can finish. It will probably get pulled out for blasting and powder coating in the near future. At that time I'll likely add more gusseting too.

[cygnusx1]

I doubt those gussets add any significant structural value in this application...I would enquire though, just because they look cool. Nice article.

 

Armand, do you thik that bar is strong enough to use for your harness? Curious.

[buZy]

I doubt those gussets add any significant structural value in this application...I would enquire though, just because they look cool. Nice article.

 

Armand, do you thik that bar is strong enough to use for your harness? Curious.

 

If it had more structure front to rear it would stand a better chance.

[ezzzzzzz]

It might bend in a severe impact but it isn't likely going to break. If it does you're probably heading to the morgue anyhow. I won't worry about the gussets for now. As stated, it does add some bling but probably little else.

[EvilC]

I would believe it is to serve in a bending moment for the rear strut bar but in a twisting/bending movement does it really do anything....I think no. This may be the reason why it was removed from the "later production" bars. From the pic, it looks like it is just on the surface of the bar and not welded to the inner surface like it should/could. I guess I am thinking of pop sticks in an A formation. If twisted, the A for would hold up more than a V shap. If our Z's never really experience the full twisting force required to break the A shape, then the V shap would be fine.

 

Hope I make some sense...I am rushing to type this before the boss walks by again..lol

[dr_hunt]

IMO the gussets are more bling than anything and in no way will keep those rods from failing. IMO if they bend then your car is totalled anyway.

[Dan Juday]

PDK's web site photo of the rear bar shows even more substantial gussets than Armand has on his bar.

 

Thanks for the write-up ezzzzzz. I'll be buying this brace as well. I bought the Top End bars but I'm not going to be able to use the front bar.

[Wedge]

Wonder how those bars fit with engine swaps like the RB ?

[Armand]

cygnus, I think they are plenty strong to hold my harness. The way it is attached is pretty damn strong and the actual structure of the bar itself is put together well. I think the worst thing that can happen is that it will bend slightly. I don't think PDK would say that it can be used as something as important and serious as a harness bar if it wasn't capable of doing so. I would imagine a pretty big lawsuit if it were to fail during an accident.

[JMortensen]

I agree. I'm thinking that the strut tops are the thickest metal in the whole unibody. These bars bolt straight to the strut top, so you're basically relying on the tube itself. So long as the tube thickness is reasonable that bar should be plenty sturdy. I've installed "harness bars" in 911's that were not nearly as robust as this thing is, and they were specifically sold for the job of attaching harnesses.

 

I don't think I'd attach my harnesses to a bar with small rod ends like the MSA bar or anything like that, because then the rod end is the most likely potential failure point, but in my opinion this one should be fine.

[dr_hunt]

What I'm trying to say is that there is plastic and elastic deformation. Jon picked up on that. The gussets are for elastic deformation control, ie. it goes back to original shape after stress, but has nothing to do with the strength of the bars except where they join. Makes it less likely to bend at the joint. If you get those bars under enough stress you will get plastic deformation, your screwed gussets or no gussets cause it'll bend right next to the gusset.

[NZeder]

Wonder how those bars fit with engine swaps like the RB ?

Anybody know the answer to that question?

[EMWHYR0HEN]

Anybody know the answer to that question?

 

 

It really depends what mounts you use. Regardless, it's going to be a tight fit.

[=Enigma=]

Sorry to bring up an old thread, but does anyone know why the PDK Fabrication strut bars are "unavailable until further notice" according to their website? I sent an e-mail to Mark at PDK and I'm awaiting a response. If it turns out that these will no longer be mfg, I just might take this on as my first welding project.