Watching the California desert sun set over two of the most special cars we've ever tested, it hits us just how lucky we are. We're lucky because, as enthusiasts, we're experiencing great times. Not long ago the cars in our market were nothing more than tarted up econoboxes and the idea of manufacturers building one-off hot rods was laughable. Today, plenty of manufacturers are giving time and money to building such specialty vehicles.
These factory hot rods push the performance envelopes of the manufacturer's chosen platform, motivate the gearheads in the engineering department who are usually stuck designing cupholders, and shout to the world, "We get it. Speed is cool. Buy our stuff." Yes, it's a good time to like cars.
Today, the sun is setting over Dodge's SRT-4 Extreme Lightweight and the Lexus IS 430 built by Rod Millen Specialty Vehicles-two of the coolest factory hot rods we've ever experienced. Both offer unique insight into what can happen to a car's performance when a manufacturer like Dodge or a specialty shop like Millen's sinks effort into going quickly.
And since going quickly is exactly what we like most at Sport Compact Car, we ran these two machines through our usual round of instrumented tests. Then we took them both to the Streets of Willow Springs road course, where they were substantially flogged. Naturally, we included a stock version of each car for comparison. Enjoy.
SRT-4 Extreme LightweightMopar doesn't screw around. Whether it's designing upgrades for Dodge's latest lineup of hot rods or custom-building one-off track machines, these guys know how to go fast. The most recent example of this overpowered nonsense is the SRT-4 Extreme Lightweight-the quickest and fastest front-wheel-drive car we've ever tested.
Settle down. It doesn't run a 10. Or even an 11-second quarter mile. It runs a 12.5-second e.t. at 119.2 mph. And, yes, that's very, very fast. Porsche Turbo territory. Corvette Z06 territory. And, yes, Viper territory. But it doesn't tell the whole story. The whole story is that the Lightweight has a power-to-weight ratio of 6.7 lb/hp, pulls over 1.0g on our skidpad, splits our slalom at an impressive 74.9 mph and stops from 60 mph in 109 feet. By the numbers, this is hands down the most impressive front-drive car we've ever tested. And it's American.
In all fairness, we can't very well compare this car with 'Vettes and Vipers. It has no interior, it has no side glass in the front windows, and half of its body is made from carbon fiber. But it is a Neon. So pointing out it's as quick as the mighty V10 snake seems appropriate. For comparison, it ran 1.5 seconds quicker in the quarter mile than a stock SRT-4 we tested the same day. It also pulled .14g more on the skidpad and zipped through our 700-foot slalom 2.9 mph quicker. And from 80 mph it stopped 12 feet shorter than its stock brethren. Serious improvements.
Again, you won't catch us commuting in the Extreme Lightweight. With one Recaro racing seat, a harness and a roll cage as the only interior amenities, it's clear this car was built to impress in only one arena. And in that arena, it's staggeringly quick. On the Streets of Willow road course it had the exact same effect on our attitude about front-wheel drive as it did on its own front tires-devastation.
This much power has no place driving the front wheels of anything on a road course. Was it impressive? Absolutely. Was it fast? Unquestionably. Was it balanced and predictable? Well, not really. But it was one hell of a lot of fun. Turn the Lightweight into a corner and it responds instantly-just like you'd expect of a car with this much rubber and significant spring rates.
Trouble is, when you get into the gas at corner exit, the Lightweight cooks both its front tires so severely it refuses to change direction at the next corner. It's entertaining and terrifying all at once, really. The only hope is to balance the throttle against the brakes with your left foot at corner exit to quell the Lightweight's instant boost response and keep power delivery to the front wheels in check. Luckily, there's a set of gigantic Stoptech brakes up front to handle the task.
Keep this brake/throttle tug of war up in the 100-degree heat of the California desert for very long and the Lightweight turns itself into a hugely destructive mass of thermal and kinetic energy, But still, it's a hugely entertaining mass of energy.
Not so surprisingly, driving the Lightweight is a lot of work. Both feet are constantly busy with the pedals, your arms are fighting against 383 lb-ft of torque fed through the Quaife limited-slip differential and your neck is balancing your head against the loads created by sticky Michelins and massive power. The only saving grace is there's not much shifting required to keep the beast on boil, as the Lightweight produces a minimum of 360 lb-ft of torque between 3000 and 5000 rpm. Still, its lap time of 1:30:35 was more than 6 seconds quicker than the stock SRT could manage and was by far the quickest of the day.
When it comes to driving there's really no similarity to the stock SRT-4. The Lightweight is in its own freakishly overpowered world. The stock SRT-4 is soft, quick and relatively civilized. The brakes on the stock SRT-4 are the first component to suffer on the track. Within a few laps, the pedal softens and the rear wheels begin to hop under heavy braking. The Stoptechs on the front of the Lightweight work flawlessly, producing consistent pedal feel stop after stop.
The Lightweight has impressive ride quality for a car this hard-core, but that's where the civility ends. It's brutally fast, smells of race fuel and feels like a submarine inside. And we really mean brutally fast. It recorded among the quickest zero-to-100 times we've ever seen at 9.6 seconds-beaten only by all-wheel-drive cars.
It's this straight-line acceleration where the Lightweight really shines. Obviously, it has difficulty putting power down off the line, but once it's hooked up we can't think of anything that crushed us into the seat with such authority. It took BFGoodrich drag radials to produce the 12.5-second quarter-mile time we mentioned earlier. They were used in conjunction with the dial-a-boost set to the second setting, which is designed for use with drag radials and limits boost in first gear.
Amazingly, all that power comes from a stock SRT-4 engine and cooling system fitted with Mopar's Stage 3R upgrade and utilizing the Stage 2 turbo toys. The only other engine mod is the side-exit 2.5-inch exhaust. That's it. Get yourself a Stage 3R, some 100-octane fuel and make 369 hp to the wheels. Don't expect the rest of the Lightweight to be so easy to duplicate.
A big part of the speed here is courtesy of the unobtainable Mopar diet. A small crew of fabricators and engineers were responsible for finishing this car for the SEMA show in 2003 and had plenty of DaimlerChrysler resources at their disposal. O.E. levels of refinement are obvious in the quality of the final product. The doors, for example, look exactly like the stock doors inside and out-until you try to shut one and it doesn't have enough momentum to compress the seal and engage the lock mechanism. Body panels of this weight and quality are rare in the aftermarket.
The hood, doors, rear fascia and diffuser were all made of hand-laid and vacuum-bagged carbon fiber in the DaimlerChrysler plastics shop. So were the front fascia and splitter, which include brake duct cutouts. The decklid was hand-laid and bagged, then cooked in the autoclave at Multimatic, Inc.
The rear glass is from 3/16-inch polycarbonate also from the DaimlerChrysler plastics shop. Literally everything is gone from the interior including the seats, carpet, trim, wiring, airbags and sound deadening. In total, the weight saving is 405 pounds, shaving the total weight down to 2,495 pounds, according to DaimlerChrysler.
The suspension is all Mopar and parts-bin Dodge. Mopar Stage 3 coil-overs with 260 lb/in. springs in the front and 170 lb/in. springs in the rear suspend the Lightweight. The front anti-roll bar is a 26mm solid bar from a PT Cruiser Convertible and the rear bar is a 19mm solid bar from an export-market Neon. Michelin Pilot Sport Cup R compound tires sized 225/45ZR-17 are mounted on 17x8-inch SSR Competition wheels, and the whole mess is brought to a stop by 12.9-inch Stoptech rotors and four-piston calipers.
So what's the coolest thing about the quickest front-drive car we've ever tested? It wasn't the crazy power. It wasn't the impressive numbers. And it wasn't even the the carbon body panels. Driving the Lightweight on the street made it impressive. We made the trip from our Orange County office over the Angeles Crest Highway about 100 miles to Willow Springs Raceway without one driveability glitch.
The fact that a car can be this focused and still be driven normally is amazing. In fact, there's no reason this car couldn't have all the comforts of a real car re-installed and be driven daily. It's that good.
Lexus is 430Every enthusiast understands the truth in the saying "always get the bigger engine." If you're a real car geek, there's never any question about which way to go when it comes time to make that decision. But that isn't the case with the Lexus IS 300. There is no bigger engine.
Yet.Lexus is careful not to admit the production possibility of a small V8-powered sedan that has obvious crosshairs on cars like the Audi S4 and BMW M3. But the simple fact is Lexus wouldn't commission a car like the IS 430 if there wasn't someone thinking about its production potential in the U.S. market. The job of marrying the IS 300 chassis, GS 430 engine and Toyota Supra transmission, clutch and rear end, fell in the hands of Rod Millen Specialty Vehicles. Millen and his company have a longstanding relationship with Toyota and are known for their ability to create outrageous show cars as well as capable racecars. And it shows in the IS 430.
Romp the throttle and the IS emits a throaty rumble that initially seems out of place coming from a Japanese sedan. Its sound is low and smooth-American in tone but Japanese in frequency. Completely unique. It's visually striking as well. Chip Foose Design and Chris Guinn coated the IS 430 in a spectacular red and black paint scheme that complements its distinctly Japanese shape. Eighteen-inch SSR wheels and huge Michelin Pilot Sport Cup tires completely fill the fenders. Bottom-line first impression? One mean IS.
But looks and sounds are second to performance. It's on the street and on the track that the IS 430 would make its strongest impressions, particularly when measured against the O.E. levels of refinement found in the IS 300 we brought along for comparison.
With 4.3-liters of overhead cam muscle motivating roughly 3,200 pounds of sedan, the IS 430 makes some stomp on the street. Light into the throttle from a standstill and you'll quickly make friends with the good folks at Michelin as you leave a 265mm-wide footprint for 30 or 40 feet. It certainly doesn't lack power. Trouble is, the electronic throttle carried over from the GS 430 was calibrated to work with an automatic transmission and combines with a rather unintuitive clutch engagement to make the car hard to get moving smoothly.
High revs and a sloppy clutch dump are actually the easiest ways to get the car rolling, which is fine if you're editor Oldham. His whole world revolves around the burnout. But if you live in a neighborhood infested with home owner's association Nazis, burnouts aren't your first priority. We executed careful footwork when necessary.
Still, it's not a slow machine. Once you've got your head around the throttle, clutch and power delivery of a big motor in a small car, you can focus on the chassis. Suspended by Tein Flex coil-overs we expected a harsh ride. But with 16-way adjustability there was a large range of ride quality available. Achieving a comfortable street ride was easy, but damping, particularly in the rear, always seemed a bit hard to control.
We had fun in the IS 430 on the street. It sounds awesome, is comfortable and reasonably quick, does huge burnouts on demand and has the best stereo we heard in any car. Admittedly, our ears are better trained to hear detonation under high boost than to evaluate Mozart's Fifth through the 720-watt Mark Levinson 20-speaker system in the IS 430, but it sounded good to us. Really good. Good enough that we actually sat in the car for the sole purpose of listening to music, which is saying something since everyone around here knows cars are for powerslides.
On the track, our impressions about the IS 430 were concreted. The monster sedan rewarded wheelspin in the quarter mile, producing better times with lots of slippage. We thought it would run in the 13s, but the staggering out-of-the-hole power was slightly deceiving as the IS 430 didn't meet expectations on the high end. Best it could manage was a 14.0-second time at 100.1 mph. Still, that's 1.3 seconds better than the stock IS 300 we tested. Sixty miles per hour came and went in 5.1 seconds, 2.2 seconds better than stock.
Handling numbers were very impressive, as expected with such sticky rubber. Around the skidpad the IS 430 yanked our eyeballs out at .98g, which is light-years beyond the IS 300's .85g. More impressive was the IS 430's slalom speed. It navigated the cones at a frightening 75.3 mph-the second highest number we've ever recorded and 7.6 mph quicker than the IS 300.
It also stopped well with massive Brembo rotors and calipers at all four corners. Sixty to zero came in 104 feet, 11 feet better than the very respectable distance laid down by the IS 300 (115 ft.).
Instrumented numbers are only a small measure of a very big picture when it comes to evaluating a car, which is why driving it back to back on the track with its stock counterpart was educational. It's no secret the IS 300 isn't the fastest sedan in the world. But it is a well-mannered, textbook-handling car when it comes to front-engine, rear-drive machinery. All the standard formulas apply here-more throttle, more oversteer. These characteristics make it obvious when fundamentals are altered in a car's handling, like in the case of the IS 430.
Make no mistake about it, the IS 430 is quick around a track. But "quick" and "confidence inspiring" are very different things. We found the IS 430's steering to be weird. It produced uninspiring turn-in and mid-corner feedback, perhaps a product of the modified scrub-radius from the wide SSR wheels. Dynamically it was also a bit shaky. Around Turn One at Streets, the IS 430 went into a frightening pitch/yaw dance. Any high-speed, high-load corner produced an ass oscillation that would make Shakira proud. This kept us from completely committing to any turn on the street or the track.
Still, it cranked out lap times 6.3 seconds quicker than the IS 300, which is a lifetime on a track this short. Even with the handling issues, power and cornering speed were a huge improvement over the standard IS 300, which translated to a big difference in lap time.
Building a car with this many factory parts isn't as straightforward as it might seem. Even with heavy use of Toyota's factory parts bin, Millen's crew had to produce many custom solutions to the various problems this scenario presented. The biggest of those, according to fabricator Adam Dupre at Rod Millen Specialty Vehicles, was the electronic interface between the GS 430 engine and IS 300 chassis. RMSV built a custom controller to mediate between the stock GS 430 engine controller and the rest of the IS 300 wiring. Of particular concern was the dash instrumentation, which had to be made to work with eight cylinders instead of six.
Other concerns were more physical. Making the 4.3-liter engine fit functionally in the IS 300 chassis wasn't easy. The first order of business was fabricating custom tubular stainless-steel headers to facilitate the exhaust exiting safely and efficiently. Dupre says there's probably a small performance gain from the headers but they were designed primarily to allow the engine to fit into the space available.
Bolting the 1UZ-FE to the six-speed Getrag from a Supra required more custom work. Millen's crew measured the back of the block and CAD-modeled an adaptor to bolt to the modified transmission bell housing. The clutch, rear end and limited-slip differential are all products of the late Supra turbo as well.
The fuel system modifications weren't as complex. The IS 430 retains the stock IS 300 tank, but uses the 430's pump and sender with several custom lines between the body and the engine.
In all, the IS 430 is an impressive product of factory, aftermarket and custom parts and know-how. Making any mongrel machine-factory-backed or not-isn't easy, and Millen has made clear efforts to make the IS 430 an awesome performer. And he has, for the most part, found success. Plus, it does awesome burnouts.
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