Project SRT-4 is fun to drive. Not goofy fun like a fat girl on a moped; rather, the little Mopar is fun like its automotive brethren, the muscle cars of yesteryear. It boils automotive good times down to the most basic form: Cheap, smoky burnouts.
After the installation of Mopar Stage One engine hardware in part one (SCC, January '04), Project SRT-4 made some serious numbers: 240 hp and 260 lb-ft of torque. With this kind of power on hand, the car would leave stripes on command. More impressive is its ability to make WRX owners cower in fear. At anything above 10 mph, the Neon gone wrong will show its taillights to any stock WRX and even give EVO drivers something to think about in a straight line. What the car lacked, however, is the ability to do this on any road that isn't perfectly straight.
In stock form, the SRT-4's handling is impressive. Even lacking a limited-slip differential, the car's balance and composure at the limit is better than expected. Add power and the equation changes. Even with larger Nitto NeoGen rubber, which we added in the last installment, the chassis wasn't able to deal with the added power. This month, we'll address this issue on all fronts with different tires, springs, dampers and a rear anti-roll bar.
Mopar coil-overs/Ground Control camber plates
Mopar's coil-overs for the SRT-4, which are built by KW suspensions, are a smart choice for several reasons. First, Mopar engineers dedicated to working on the Neon platform calibrate them to work with the Neon chassis. Secondly, the level of detail we've come to expect from Mopar upgrades is present in their design. This means features like shortened strut rods for near-stock travel at lower ride heights, matched spring and damper rates and O.E.-level quality are built in. Other cool details include factory-style mounting points for the brake lines and ABS sensor wires--seemingly obvious features which are frustratingly often absent.
Mopar offers three different suspension packages depending on your needs and budget. Stage One is a spring upgrade only. Stage Two is a full threaded-body coil-over which allows height adjustment from zero to 30mm lower than factory ride height and has non-adjustable dampers. Stage Three adds adjustable rebound damping via a hex bolt on top of the strut from 20 percent under to 50 percent over Stage Two settings. Both kits include powdercoated springs, anodized aluminum spring collars and a locking ring to keep the car from being lowered too much.
Shortly after our car arrived, a Stage Three coil-over kit showed up from Mopar. We knew before installing the struts that aggressive camber would be required to make the SRT-4 handle like a real sports car. In stock form, the SRT-4 has 0* front camber and no provision for adjustment. The Mopar coil-overs try to solve this problem with a slotted hole on the strut mounting ears. In theory, this allows you to tilt the hub/brake/wheel assembly inward when you assemble the suspension, giving you instant, free camber. In practice, though, it's nearly impossible to get exactly the camber you want with this system. Manually pushing the wheel to exactly the position you want, to 0.1* precision, and simultaneously tightening this impossible to reach bolt, all without blocking the alignment rack's lasers... well, that's what we call difficult.
To make matters worse, tilting the hub relative to the strut puts the top of the tire closer to the strut, which limits how wide a tire you can use. With our 225/45ZR-17s, we wouldn't have room for any meaningful camber.
Ground Control Suspension Systems in Shingle Springs, Calif. provided the solution. By pulling the tire as far away from the strut as possible and then tilting the whole strut/hub/wheel assembly from the top, you get both better tire clearance, and a much easier alignment job. Ground Control's camber plates are CNC machined aluminum and utilize a Torrington bearing (fancy name for a big, flat roller bearing) on the upper spring perch. This bearing supports the weight of the car and saves wear on the camber plate's spherical bearing. Most camber plates put the car's weight on the spherical bearing. The downside is that the Torrington bearing requires periodic cleaning and lubrication.
Assembling the camber plates and front struts requires removing the locking collars on the front struts. Using the stock upper mounts requires compressing the springs slightly in order to thread on the top nut--a job most easily performed with two people and an impact wrench. However, since the camber plate assembly is slightly taller than the stock top mount, the lower spring perch must be moved lower on the body to install the camber plates. This can't be done with two people. It's easier to drill out the stopper bolt and unscrew the locking collar, which allows the spring perch to be lowered enough that the top nut can be threaded on. Then the spring perch can be raised back to an appropriate height using the included spanner wrench.
When removing the stock upright bolts, we noticed the last inch of shaft before the bolt head was splined like the back of a wheel stud. This makes them a hammer-tight fit in the upright. It also means if you try to turn the bolt with a wrench, you'll screw up the splines. Turn the nut. When putting it all back together with our camber plates in place, we pulled the wheel and upright as far away as possible from the strut body before tightening the whole assembly to provide maximum tire clearance.
Removal of the stock struts and installation of the coil-overs and camber plates was relatively easy. The Mopar parts come with installation and adjustment instructions in case you've never done it before. The only real problem we ran into was the need to remove the rear brake calipers in order to remove the rear struts from the uprights. Once the brake caliper is off, removing the rear struts was easily accomplished with a medium length 3/8-drive extension and a mallet. With the brake caliper removed and the nut loose, but still in place, use the extension and a mallet to drive the bolt out past the splines. Do this with the nut in place to keep from damaging the threads. From there, you should be able to remove them by hand.
Fine-tuning a car's handling through roll stiffness is a good way to adjust to your specific handling needs. We prefer rear-biased handling and usually opt for the stiffest rear anti-roll bar we can find. The Progress Group had bars ready for the SRT-4 about the time this project was coming together so we installed its rear bar. We plan to install a Progess front bar as well, but will hold off until we've installed the Quaife limited-slip differential, because increasing the front roll stiffness by using a stiffer bar could cause the inside front wheel to unweight enough under hard cornering to cause uncontrollable wheelspin. That is to say more uncontrollable wheelspin than we already have. The Quaife comes stock in all '04 SRT-4s and is now available through Mopar. We'll install both a Progress front bar, an even stiffer adjustable Progress rear bar, and the limited slip in a future installment.
The non-adjustable Progress rear bar is 22 mm in diameter vs. the stock bar's 17 mm diameter. Installation is straightforward using the stock mounting points. Progress uses polyurethane bushings in place of the stock rubber bushings to mount the bar to the body and replaces the stock end links with equivalent pieces of its own design.
All 2004 SRT-4s will come with the latest version of BFGoodrich's g-Force KDW tires sized 205/50-17. Our wider wheels allowed us to fit wider-than-stock rubber and since we've had good experience with the g-Force line it makes sense to try the car on the same tire. It was an easy choice then to fit the updated KDW in 225/45-17. This tire is designed for both wet and dry conditions, with large tread blocks at the sidewall and significant void area on its face.
The final step before testing was to set the car up with more aggressive camber settings. This was easy with the camber plates allowing us to set camber to 2.5 degrees negative in the front. Rear camber was set to 1.0 degrees negative. Front and rear toe were set to zero.
These changes did improve project SRT-4's handling. After several damping adjustments, we learned that the car performed pretty much the same throughout the range of adjustment.
On the skidpad, Project SRT-4 pulled 0.91g, up from 0.85g. Through the slalom, the improvements were equally marginal. In stock form, the last SRT-4 we tested slithered through at 69.1 mph. Project SRT-4 broke the gates 1.3 mph faster at 70.4 mph. The real changes, however, aren't easily measured in our instrumented tests. Project SRT-4 is now a much more serious driving tool. With real turn in and the ability to seriously rotate off the throttle, it's no longer a contest in howling tires and understeer at every on ramp.
Perhaps the best part about our updates this month is that they come with very little compromise. It's clear that the Mopar engineers are accustomed to building parts that must meet O.E. noise, vibration and harshness requirements. Near stock ride quality is maintained, in the softer settings, and we've experienced no durability or interference problems. Project SRT-4 is like the stock car on speed. Fun. Lots of it.
Still, we think it can be much better now that we know where to direct our attention. Despite our best efforts to avoid it, project SRT-4 spins its inside front tire at hard corner exits. Obviously, the addition of a limited slip will eliminate this problem and add some control. The car is also showing handling woes we suspect are a product of its soft stock bushings, like lots of undamped rebound under hard braking or cornering and massive wheel hop under acceleration. Stiffer polyurethane bushings are in its future. Hopefully, these combined changes will further improve the numbers and feel.
Next time we'll install and test Stoptech brakes and further down the road we'll show you how to build the side exit exhaust you can see in this month's lead shot using Magnaflow parts.
Howell Automotive carbon-fiber hood
The 1970 AAR Cuda had a flat black hood. Project SRT-4 has a flat black hood. Black is cool. Carbon fiber is cool. Howell Automotive sells a black, carbon-fiber hood for the SRT-4. Howell Automotive is cool.
Seriously, we love carbon fiber. It's strong, light and looks bitchin' regardless of its finish. Even though the stuff looks great without paint, we turned to Santini Paint and Body in Westminster, Calif. to turn up the cool. As nice as the hood is when delivered, it was just too shiny, so Santini used 800 grip wet sandpaper to prep the surface then applied a coat of clear adhesive sealer and a coat of urethane clear with a flattening agent to take away the sheen. The results speak for themselves.
The Howell hood weighs 15 lbs. That's 13 lbs less than the stock steel hood. However, with those 13 lbs. go some of the stock hood's cool features. The stock hood scoop is ducted to blow cool air over the back of the engine, specifically, over the turbo helping keep it cool when the car is moving. The Howell hood lacks this ducting so we assume the flow through the scoop isn't as effective in doing this job. We've seen no ill effects, but it makes us wonder nonetheless.
There's some work required to make the hood fit and function. If you want windshield sprayers, you'll have to drill holes in the Howell hood and move the plumbing. There's a space for the hood prop rod, which also requires drilling, but there are several places to prop the hood up without a hole. The hood scoop also needs to be cut out so the insert from the stock hood can go in. The hood can be yours for $399.