The true measure of any project, no matter how well planned, is to put it to the test. That’s especially true with hot rods and custom cars; there’s never been one built that didn’t require some alterations after the shakedown run. You just gotta drive ’em to find the flaws—and you can quote us on that.
Suspension travel is essential...
Suspension travel is essential for ride quality, so while Bret Voelkel and his team built a new rear coilover using one of their 13-inch bodies, we adjusted the upper mount upward to allow for more compression distance.
In the last issue we brought the tale of Project X’s first real road trip since it’s rebirth via PHR teaming up with GM Performance Parts and their Skunkworks division. Most of X’s prior outings had been short jaunts and often at modest speeds through town and traffic. Joining up with the AMSOIL/STREET RODDER magazine Road Tour allowed us to spend long periods of time behind the wheel at freeway speeds and on many less-than-ideal back roads. That’s where you can start finding all the little stuff that will go mostly unnoticed otherwise.
All seemed fine at first when we got up to speed on the freeway, though the ride was a bit overly firm. We really weren’t concerned about the harshness until several dozen miles into the trip when we ran across the first large break in the asphalt and received an unsettling surprise. We’d describe it this way: The front felt like it transmitted the shock of the bump directly from the tire to the steering wheel with very little dampening, kind of like a go-kart. The rear was a bit more troubling. A significant bump resulted in a jarring impact with the rearend jerking to the left. Needless to say, we slowed down and watched the road cautiously. Luckily, our first leg of the 700-mile road trip was short and mostly on slow Indiana back roads.
Up front, X is basically a...
Up front, X is basically a C6 Corvette since the full cradle and suspension have been grafted into the frame. With the suspension at full droop, it’s hard to tell that there were issues, but the odd wear on the inside edge of the front tire is a clue.
Fortuitously, our last stop of the day was at RideTech in Jasper, Indiana. After a great tour around the shop and a generous barbecue dinner, the rest of the Road Tourians departed. We hung around bench racing with RideTech’s Bret Voelkel about various projects and mentioned X’s ill ride quality. Since he’d shut down the shop for the day and had no plans, Voelkel insisted that we pull X in and get it up on their lift for a look. It’s a good thing we listened. Here’s how it went down …
We had a similar issue in...
We had a similar issue in the front; the shock body was once again too long to allow significant travel when compressed into its installed height, but that didn’t really matter since the 400-lb/in spring was in full bind with essentially � inch (at best) of travel available.
While X has been in the air...
While X has been in the air on our two-post lifts a couple times, RideTech’s four-poster represented the first time we’d taken a look underneath while the suspension was at normal ride height. What we discovered immediately explained the ride quality.
Unfortunately, Voelkel didn’t...
Unfortunately, Voelkel didn’t have his scales on hand for us to weigh X exactly, but he was able to run some numbers using previous experience and the amount of compression exhibited by the 250-lb/in springs to determine an excellent starting point. The RideTech spec’d Hyperco springs are 375 lb/in and mounted on one of RideTech’s new non-adjustable mono-tube coilovers.
Here was another issue we...
Here was another issue we discovered with X at ride height: Even if the coilovers had any travel, there was only about � inch before the axle hit the bumpstops. Even trimming didn’t do the job (they were longer than pictured!), so Voelkel installed some of RideTech’s shortest stops (foreground) to allow the coilovers to do their job.
Voelkel stepped up the spring...
Voelkel stepped up the spring rate considerably to 550-lb/in RideTech/Hyperco (left) springs rather than the 400s (right). The larger diameter wire on the RideTech springs allows for more distance between coils and therefore more available compression during suspension travel.
The problem was actually compound;...
The problem was actually compound; at 14 inches eyelet-to-eyelet free height, the coilover bodies themselves were too long for the 11-inch installed height, and the 250-lb/in spring was insufficient for X’s heft and was nearly in full coil bind. There was roughly 1 inch of travel available.
With the new RideTech equipment,...
With the new RideTech equipment, we ended up with the same low ride height, but 3 inches of possible travel, and far more appropriate spring rates and valving to handle X’s massive rear wheels when a bump puts them in motion.
Creating X’s front coilovers...
Creating X’s front coilovers was much trickier than the rear, and required a custom-built 3.5-inch body as well as a custom spacer for the spring. Thankfully, RideTech’s shop is fully equipped with fabrication and machining equipment and guys who know how to chuck up a hunk of aluminum and whittle out spacers in short order.
Here’s how that slick spacer...
Here’s how that slick spacer created the new front coilover assembly for X. There were two reasons for this creative solution: A 550-lb/in spring of ideal length wasn’t available, and this arrangement worked nicely to create more control arm clearance at full droop for the larger diameter spring. The result is a custom part specific to X that fits perfectly. Problem solving is hot rodding!
We had no fitment issues on...
We had no fitment issues on the control arm side even with the adjusting collar on the coilover set to the bottom of the threads. We’ve even got room for adjustment if the need arises.
The bottom endlink is the...
The bottom endlink is the one removed from X; the top is the �-inch longer custom one created from RideTech parts to fine-tune the sway bar’s orientation.
Fishing the whole assembly...
Fishing the whole assembly with the spacer up through the control arms was a little tight, but luckily nothing else had to be removed.
The new coilover package actually...
The new coilover package actually dropped X’s nose roughly an inch while still giving us almost 3 inches of suspension travel. The height drop did necessitate modification to the sway bar endlinks, though.
That simple fix put the bar...
That simple fix put the bar back in proper relation after the slight lowering. Now we’ll actually get to see how well it functions since the suspension is able to move.
Here you can see what we meant...
Here you can see what we meant by control arm clearance. During normal driving circumstances we’ll never extend the coilovers this far (hopefully!), but this arrangement will prevent any spring and control arm contact issues when lifting X on a two-post lift that allows the suspension to droop.
These are the rodders from...
These are the rodders from RideTech who made our late-night suspension swap possible. We should mention that it was about 1 a.m. by this time. The RideTech crew wasn’t about to cut corners or let X leave their shop with a Band-Aid. Thanks to these guys the rest of the road trip was smooth sailing—literally.
Check out the video of us testing Project X the next day on what had to be the roughest road in Indiana on PHR’s new YouTube channel: YouTube.com/PopularHotRodding!