IwishIhadAvette

http://autoweek.com/cat_content.mv?p..._code=06210908

If Dave Hill succeeds, auto enthusiasts won't confuse Cadillac's two-passenger XLR roadster with a Chevrolet Corvette.

While the 2004 XLR and the redesigned 2005 Corvette will share a platform and other structural components, the cars will be engineered for buyers with different expectations, said Hill, vehicle line executive for the two cars.

For the first time since 1955, the Corvette will share a platform with another nameplate, giving Hill a daunting challenge. He must deliver a cutting-edge sports car for Corvette buyers while developing high-performance luxury for Cadillac's audience.

Both cars will be produced at the Bowling Green, Ky., assembly plant, home of the Corvette. The XLR goes on sale in May or June of 2003, while sales of the redesigned Corvette are slated for fall 2004.

Hill said that the XLR will be targeted at sporty luxury vehicles produced by Jaguar, Lexus and Mercedes-Benz. It will offer "more sophistication in the powertrain and refinement in quietness" than the Corvette. For example, the XLR will feature a retractable hardtop that will reduce interior noise, while the Corvette convertible will keep its soft top.

But Hill said that Corvette enthusiasts will not be shortchanged because the Cadillac and redesigned Corvette will share the same architecture.

"Most of the welded metal, underbody, the structural systems will be identical," Hill said. "Under the belt line they are the same, but everything that the customer sees is going to be different."

For example, the suspension structure and hard points will be identical. But the components will be tuned to create a distinct personality for each car. Hard points are unchangeable connecting areas for a vehicle's major components.

But the "Corvette is still going to be America's performance icon," Hill said.

"A Corvette has a different set of competitors, a different expectation in refinement, a different expectation in terms of quietness," he said.

The XLR will be powered by General Motors' 4.6-liter Northstar V-8, its first appearance in a rear-wheel-drive vehicle. It is expected to generate up to 375 hp. The 2005 Corvette's engine is expected to be based on GM's 5.7-liter V-8. The 2003 Corvette Z06 engine produces 405 hp.

The XLR will use an upgraded version of the five-speed automatic transmission offered in the six-cylinder Cadillac CTS sedan. The XLR's transmission, which is designed to handle a higher amount of torque, is produced by GM in Strasbourg, France. A version of the transmission is sold to BMW for the 5 series. A manual transmission is not expected for the XLR.

SWCDuke

The basic structure/chassis requirements for a sports car or luxury two-seater are the same - a stiff structure and no-compromise suspension architecture and geometry, so the same state-of -the-art platform is a natural for both the XLR and C6.

Each will have unique tires and suspension "tuning" in terms of bushings, springs, anti-roll bars, and shocks, to create the ride and handling expected by each market segment. The XLR will have every luxury feature in the book, and, of course, completely different exterior body panels and interior, so it will be at least 500 pounds heavier than the Corvette, and with an engine that has considerably less torque across the entire rev range, it will not have acceleration performance in the same league as the Corvette, but it should be "sufficient" to compete with the targeted Lexus and Mercedes two-seat luxocruisers.

I wish GM all the success in the world with the XLR because the Corvette's future will be tied to it. Two profitable cars from the same platform will provide the financial incentive for GM to continue with updates and redesigns to keep the cars state-of-the-art.

The article mentions that this is the first Corvette to share a platfrom since '55. That's not correct; '54 was the last year. All C1s were built on a shortened '53 full sized car frame and used its front and rear suspensions, steering, and brakes. The '55 Chevy had a new body, frame, front suspension, and steering, but Corvette continued to use the '53 components until the new Sting Ray was introduced in 1963. The Sting Ray got a unique frame and rear suspension. The steering and front suspension were off-the-shelf Chevrolet passenger car and were basically updated '55 parts, but on the Corvette they were mounted differently to provide more sports car like suspension geometry.

The '63 Corvette base brake package was also right off the full sized passenger car, which featured new, wider 2.5 inch front drums.

Duke

Scissors

"Most of the welded metal, underbody, the structural systems will be identical," Hill said. "Under the belt line they are the same, but everything that the customer sees is going to be different."

I have to call :bs on this one. The thing that the customer sees most, the dash board, looks just like a C5's dash but with edges added.

SWCDuke

The door pillar/windshield frame substructure is assembled off line and the IP with instrument binnicle is installed on this substructure prior to the entire assembly being installed on the chassis as it moves down the line. This makes assembly much easier.

The XLR's instument binnicle looks very much like a Corvette - nothing wrong with that - but the rest of the IP/dashboard doesn't. It would be quite possible for the XLR to have a different door pillar/windshield substructure with a different windshield, or the same structure with the same windshield and different IP/instrumet binnicles. There's a lot of flexibility when it comes to trim parts on identical structures as evidenced by the body panels.

The XLR will also need some kind of substructure in the rear that will have to be more substantial than the soft-top Corvette in order to handle the XLRs heavy hardtop and retracting mechanism.

The fact that the XLR has a conventional looking analog instrument cluster is encouraging. I feared that they might go back to some electronic dash abomination like in the eighties, but apparently not. Modern race cars may have electronic instrument clusters nowadays, but there are some sports car traditions that shouldn' change, and a complete set of conventional analog instruments is one of them IMO.

Duke

Senna1994

Duke, I read your posts and am constantly amazed at your knowledge on Engineering and what we can expect, I just wanted to let you know I think you and Jinx are exceptional writers. I always enjoy what you have to say because you really understand the concepts black and white.

SWCDuke

Thanks for the compliment!

I started my career as a production engineer at Pontiac and went on to engineering positions in the aerospace industry (structures and propulsion systems) before getting into CAE/CAD/CAM sales and marketing where I got a lot more exposure to engineering and manufacturing in almost every imaginable industry; so I probably have more than average insight into the issues that surround the design and manufacture of complex products.

I also follow the fortunes of the Corvette quite closely from published (and unpublished) sources including technical papers from SAE, so I probably have a good handle on what is going on for an "outsider".

Many appear to read a lot more into published reports in the popular automotive press than is reasonable. I understand everyone's enthusiasm, but sometimes I need to try and bring everyone back to earth.

I'm particularly interested in the C6 as I have a space for one next to my Split Window Coupe, but I'll have to wait and see how it turns out. So far, I see nothing that might disappoint me, except for "demand" pricing when it first becomes available, but I'm a patient guy and can wait until there are reasonable deals available. Besides, I like to buy cars that are seasoned with a least a year of production, which is usually what it takes to route out most the the significant design and manufacturing problems.

Duke

Senna1994

Great to hear it Duke, do you by chance live close to King's Harbor? Also have you ever been to Corvette Mikes? He is a buddy of mine and before the C5 was introduced at the L.A. auto show, Jim Schefter (R.I.P) brought over a Pilot Red C5 for us to drive and see. I used to Live in Redondo and have been a Corvette nut since my Father bought a 69 427 Tri Power Convertible. Anyway nice to chat with you.

SWCDuke

I live in the north end of RB a few miles north of the King Harbor. I'm actually closer to "downtown" Hermosa Beach and Manhattan Beach than I am to the harbor.

I've never been to Corvette Mike's establishment, but I've talked to him at NCRS events.

Duke

95 Saleen S351

"The fact that the XLR has a conventional looking analog instrument cluster is encouraging. I feared that they might go back to some electronic dash abomination like in the eighties, but apparently not. Modern race cars may have electronic instrument clusters nowadays, but there are some sports car traditions that shouldn' change, and a complete set of conventional analog instruments is one of them IMO."

I couldn't disagree more. I hate analog guages..they are hard to read and require the driver to take their eyes off the road...which is dangerous. Electronic instrumentation allows the driver to view the speed clearly without removing their eyes from the road...of course with HUD..I guess they can make both of us happy. :) I still would prefer a digital speedometer. I loved the original C4 dash. That orange crap they came out with in the second gen interior...well that is another story.

Wilson6t7

I like both analog and the digital dash from the first gen C4 interior. Howabout a compermise{sp?}, we get the analog gauges, traditional Corvette, and like in the early C4 a little area with digital numbers like in the digital dashes. That would be :cool: IMO

Jinx

I find that I can read analog guages more quickly and more accurately because my brain can more readily see differences in the angle of the needle (and know what that angle means) than see, process, and decode a low-res blocky number.

.Jinx

SWCDuke

Agreed! Also, our brains subconsciously compute the first temporal derivative so we have an idea of the rate of change of the measured quantity. When you catch a glance of the tach and see it passing 5K revs you also understand the rate of change and have a good idea when it's going to hit 6500. Flashing numbers don't allow that brain function to work.

Duke

Senna1994

Anyone here seen the Ferrari Enzo Dash and Steering Wheel. Like an F1 Car it starts blinking at 500 RPM increments past I believe 5,500 RPMs on the top Rim of the Steering Wheel and once it hits Red ready to shift. Of course that car comes with an F1 transmission (6 spd, no torque converter, no auto shift mode). I think the C5 Dash is perfect and those who want Digital can have that on the HUD. :jester

Saving 4 C6

very good point.

e3pres

True dat.

potent45acp

I don't know about my brains first temporal derivative but i have been driving by an analog tach long before rev limiters or BullS... digital gages. Never blown one up due to inability to read over rev on the tach.

Weasel

And I also don't have a problem,looking straight out my windshield and seeing the numbers. And I don't have a problem letting rich Caddy owners pay for the cost of developing my love object.
Nobody here gets confused about the Thunderbird,or the Lincoln L.S,or the Jaguar "S" type. Nobody..But they ALSO are the same underneath. They are even different kinds of people. The T-Bird Kind isn't the same as the Lincoln kind. N' nobody is like Jag people. They don't even like each other! :yesnod:

John Row

If the Northstar fits between the frame rail then, wow, look at all the extra room there will be for headers, turbos, superchargers, etc. It's a wide heavy engine compared to the LS1/6.