C6 Preview. . .Anybody Know When??? NM

**Joe L.** · March 31, 2003, 02:42 PM

Re: C6 Preview. . .Anybody Know When???

Jack----

Likely the 2005 model year or, possibly 2006. For the first time in a long while, the C6 will share a platform with another car. That car will be the new Cadillac XLR Roadster which will begin production at Bowling Green mid-2003 and go on sale as a 2004 model soon thereafter. The XLR Roadster will be powered by a 4.6L Northstar and will be the first use of the Northstar in a rear wheel drive application. The XLR will be built on a dedicated assembly line at Bowling Green.

The C6 Corvette will share the XLR's platform. So, when the XLR finally arrives in showrooms, we'll be able to see a "preview" of the C5 platform (suspension and chassis). It won't be exactly the same as the C6, but it will be the same design/architecture.

The C6 will use a new small block V-8. It won't be the "dual cam in-block" set-up that was discussed, though. It will be OHV, however, and not overhead cam.

Some folks think that it's a degradation for the Corvette to share a platform with another car "for the first time". However, it's not really the first time. The C1 chassis was, basically, 53-54 Chevrolet. The C2 and C3 front end chassis was, basically, 1963 Chevrolet. So, it's NOT the first time. It's a departure from C4 and C5 which did not share a chassis with any other car, though.

**Clem Z.** · March 31, 2003, 03:20 PM

Re: C6 Preview. . .Anybody Know When???

detroit auto show jan 04

**Mike M.** · March 31, 2003, 04:42 PM

Re: C6 Preview. . .Anybody Know When???

Joe: the C-1 front suspension was first used by chevy on their 49 chevy pass cars and was used till the end of 54 production on the full size chevys regards, mike

**Tom H.** · March 31, 2003, 05:55 PM

Re: C6 Preview. . .Anybody Know When???

How long and what parts from the 63 Chev were used in the C2 Corvette?

**Mike M.** · March 31, 2003, 07:38 PM

Re: C6 Preview. . .Anybody Know When???

clem do you think they will name the C-6 non roadsters "coupe de Ville"? Hope they don't use the sombrero(sp?) hubcaps and put a compartment for golf clubs on board per the late 20's caddy & LaSalles . regards, mike

**Clem Z.** · March 31, 2003, 09:13 PM

Re: C6 Preview. . .Anybody Know When???

i want to see the caddy to see if it does have a aluminum frame.

**Joe L.** · March 31, 2003, 10:58 PM

Re: C6 Preview. . .Anybody Know When???

Tom-----

Pretty much the whole front suspension was the same. In fact, I think that the a-arms are identical. Obviously, different springs, sway bars, etc. were used to "tune" the front suspension to Corvette requirements. But, the basic design was the same as 63 Chevrolets. Since the Corvette chassis remained essentially the same through 1982, the front suspension on an 82 Corvette has its roots in a 1963 Impala/Biscayne.

**Tom H.** · April 1, 2003, 07:43 AM

Re: C6 Preview. . .Anybody Know When???

Thanks! Funny how much many of us don't know about Corvette origins!

**Mike Yager** · April 1, 2003, 09:48 AM

Re: C6 Preview. . .Anybody Know When???

Joe:

I thought I remember reading that the '63 Corvair shared the same basic rear suspension design as the '63 Corvette. Do you know if that is true?

Also, I remember reading that the change to the Corvette design rear suspension cured the roll-over tendency of the Corvair, which made Ralp Nader famous. However, the damage to the car's reputation was already done and the Corvair never recovered, although it stayed in production I think through the '69 model year.

I believe the VW Bug had the same roll-over tendencies as the early Corvair as it had a similar design. However, Nader went after GM as it was a much bigger fish and the VW Bug was too popular with Nader's followers and the "counter-culture" crowd.

**John H.** · April 1, 2003, 11:37 AM

Re: C6 Preview. . .Anybody Know When???

"I thought I remember reading that the '63 Corvair shared the same basic rear suspension design as the '63 Corvette. Do you know if that is true? "

The original Corvair rear suspension (1960-64) was a "Swing Axle" design like the VW (and the Mercedes 300SL), where the axles pivoted at joints at the diff, but were solid at the wheels, so the wheels described an arc as they moved through their travel. The Corvair design changed in 1965 to be similar to the '63-up Corvette, with trailing arms and half-shafts jointed at both ends and camber strut rods so the wheel's camber angle remained essentially constant as it moved up and down.

**Duke W.** · April 1, 2003, 12:30 PM

Re: C6 Preview. . .Anybody Know When???

GM has announced that the C6 will be officially shown at next year's Detroit Auto Show, which will be in early January. It will be billed at a 2005 model and retail deliveries should commence May/June.

I've been tracking the rumors/intelligence and the following points are essetially guaranteed.

1. Fixed headlights.

2. About 1" more wheelbase (same as the XLR spec which has been published) and slightly shorter overall length.

3. Slighly lighter - up to 125 pounds (one EPA weight class)

4.. A "richer" looking interior.

5. "Heritage" exterior syling features with less visual bulk at the rear

6. Magnetic shocks will probably be standard, but will have different software algorithims depending on the model or suspension option.

As stated, the C6 and XLR will share the "platform", which is the same basic architecture as the C5, but most of the parts will be NEW. Although photos taken of the XLR undercarriage at this year's Detroit show don't show any obvious changes relative to the C5, my expectation is the the platform is a completely new design with mostly new parts, not just a "stretched" version of the existing C5 platform.

G2 on engines has been much tougher to sort out, but here's what I think the deal will be.

1. Base engine will be 6.0L with torque and HP ratings at or near 400.

2. The "high performance model" (likely to still be carry the "Z06" moniker) will be available as a 2006 model, and it will have the "twin cam" engine - two inblock cams to enable independently variable inlet and/or exhaust cam phasing. This engine will be 392 CID (6.4L) and will carry torque and HP ratings around 450. Recent rumors of 500 HP have surfaced, and though the twin-cam engine may be capable of this output, for marketing reasons GM will save this for future upgrades. GM's Displacement on Demand (DoD) system that will debut on some '04 truck engines does not seem to be part of the new Corvette engine program, at least in the first couple of years, but if it is eventually added, Corvettes should achieve 30-35 MPG EPA highway fuel economy ratings.

I expect the June car mags will have detailed write-ups on the XLR based on the long lead press review, which has probably already gone down or may be occuring as we speak. The details on the XLR chassis and suspension architecture will apply directly to the Corvette, and hopefully the mags will report the percentage of new parts for the XLR/C6 platform relative to the C5.

Don't try to project ANY C6 performance numbers from XLR data. The XLR has a completely different "chassis tune" (springs, bars, shocks, wheels and tires). The Northstar engine has much less torque and power, and the XLR will be much heavier at about 3600 pounds, but the suspension GEOMETRY will be the same. I also expect the brake system to be identical with the possible exception of brake pad material.

Platform sharing is the way GM is contolling costs, even on high end cars. The new Saab 9-3, Saturn Ion, and upcoming new Cavalier all share the same Delta platform and Ecotec engine, but the average driver would never be able to guess this is the case after back to back comparison drives. Platform sharing doesn't mean the "badge enginnering" of yore.

Duke

**Clem Z.** · April 1, 2003, 12:45 PM

Re: C6 Preview. . .Anybody Know When???

did any one check to see if the caddy has a all aluminum frame to get the 125 weight savings?

**Duke W.** · April 1, 2003, 02:38 PM

Re: C6 Preview. . .Anybody Know When???

Caddy press info to date clearly states that the XLR side rails are STEEL!

I believe the modest C6 weight reduction will be the result many detail design refinements If you read All Corvettes are Red, you know that Dave Hill is hell on weight and is constantly on his engineers to cough up weight reductions.

If you look at the evolution of most make/model designs over the last ten to fifteen years the vast majority have gained a lot of weight. For exmaple my '88 MBZ 190E six-cylinder is 2900 pounds. The current C-class equivalent peaked at 3400 pounds a few years ago, but is now down to about 3300 with the substitution of an aluminum block V-6 for an iron block I-6, but that's still a 14 percent increase!

I expect next generation of Z06 could actually come in with a curb weight of about 3050 - about the same as my forty year old SWC. This is a very commendable accomplishment when you consider how much more "stuff" is in a modern car.

Duke

**Jack H.** · April 1, 2003, 11:28 PM

Thanks Duke, For Providing This Seemingly . . .

esoteric information. You ar obviously still "hooked up" with the General.
Jack

C6 Preview. . .Anybody Know When??? NM