When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
C3 to C4 was the biggest jump in my opinion. The C4 introduced the platform which can still be recognized in the C7 chassis. That's pretty significant.
The C5 was a big improvement but it was just that. An improvement. And 12 years down the road of course improvements are expected to be significant.
C3 to C4 was the biggest jump in my opinion. The C4 introduced the platform which can still be recognized in the C7 chassis. That's pretty significant.
The C5 was a big improvement but it was just that. An improvement. And 12 years down the road of course improvements are expected to be significant.
I don't disagree about the C3>C4 jump being the biggest leap. But there is literally nothing in the C5-C7 platforms that is recognizable from a C4. Not a single part from a C4 interchanges. The suspensions - especially the rear suspensions - are completely different. The transmission is moved to the rear in the C5. Other than having unibody frames (like literally every other car in 1997), their engines ahead of the driver, using a double-A-arm front suspension, and using fiberglass monoleaf springs, there are no similarities at all.
BTW, one massive upgrade from the C3 to C4 that we kind of glossed over is that move from body-on-frame construction with frame rails to a unibody design. That's a pretty massive update. And even though the C4 was more flexible than we'd like, it did pave the way for much stiffer unibodies in the C5/6/7.
I don't disagree about the C3>C4 jump being the biggest leap. But there is literally nothing in the C5-C7 platforms that is recognizable from a C4. Not a single part from a C4 interchanges. The suspensions - especially the rear suspensions - are completely different. The transmission is moved to the rear in the C5. Other than having unibody frames (like literally every other car in 1997), their engines ahead of the driver, using a double-A-arm front suspension, and using fiberglass monoleaf springs, there are no similarities at all.
BTW, one massive upgrade from the C3 to C4 that we kind of glossed over is that move from body-on-frame construction with frame rails to a unibody design. That's a pretty massive update. And even though the C4 was more flexible than we'd like, it did pave the way for much stiffer unibodies in the C5/6/7.
Didn't gm call the C4 frame a uniframe because it wasn't quite a full unibody or am I remembering wrong?
C3 to C4 was the biggest jump in my opinion. The C4 introduced the platform which can still be recognized in the C7 chassis.
Originally Posted by MatthewMiller
But there is literally nothing in the C5-C7 platforms that is recognizable from a C4.
I Dis-
The basic architecture that was laid out for the C4, is most certainly "recognizable" in the C7.
Look at the C2/3 architecture/design/philosophy:
Now look at the C4. See anything at all, that is similar? No...those platforms could have come from different companies.
Now the C7. While there are profound improvements....I see the lineage; Unit structure with similar shapes, gussets, cross members and dimensions, "free standing" drive train, I see the architecture/design/philosophy that was created w/the C4. This architecture/design/philosophy didn't exist before the C4, from any auto maker, but it still exists today, in the C7....
The basic architecture that was laid out for the C4, is most certainly "recognizable" in the C7.
Look at the C2/3 architecture/design/philosophy:
Now look at the C4. See anything at all, that is similar? No...those platforms could have come from different companies.
Now the C7. While there are profound improvements....I see the lineage; Unit structure with similar shapes, gussets, cross members and dimensions, "free standing" drive train, I see the architecture/design/philosophy that was created w/the C4. This architecture/design/philosophy didn't exist before the C4, from any auto maker, but it still exists today, in the C7....
I agree with you. That's the most radical structure change in the history of the car, maybe until we see the C8.
The other thing for me is the huge leap an L98 was over the earlier motors. GM was just starting to make heads and tails of what could be done with fuel injection and more modern engine controls. TBI is a kludge, basically a carburetor by another means. The next step, the LT1 with the Optispark showed what could be done when you really REALLY knew where the pistons were in relation to the valves and how you could play with the timing and injector firing.
The only real argument for any other generation I see is C4 ---> C5, with the LS.
C8 looks to blow all that right out of the water though. Fearless prediction: don't be shocked when electric motors show up at the front wheels on the C8.
I agree with you. That's the most radical structure change in the history of the car, maybe until we see the C8.
The other thing for me is the huge leap an L98 was over the earlier motors. GM was just starting to make heads and tails of what could be done with fuel injection and more modern engine controls. TBI is a kludge, basically a carburetor by another means. The next step, the LT1 with the Optispark showed what could be done when you really REALLY knew where the pistons were in relation to the valves and how you could play with the timing and injector firing.
The only real argument for any other generation I see is C4 ---> C5, with the LS.
C8 looks to blow all that right out of the water though. Fearless prediction: don't be shocked when electric motors show up at the front wheels on the C8.
I just don't see the base car having electric motors. Z06 and up? Hell yea it's a possibility.
As for the LS architecture, it was an improvement in every respect (well technically a downgrade from the LT-5 but that's an entirely different animal honestly) except for the trigger... iirc something about square wave timing vs sine wave and one being able to be tweaked better or something? I don't remember exactly what it was but the one became more popular because it was easier to work with but there were better benefits with the other one... I could also be remembering wrong.
...except for the trigger... iirc something about square wave timing vs sine wave and one being able to be tweaked better or something? I don't remember exactly what it was but the one became more popular because it was easier to work with but there were better benefits with the other one... I could also be remembering wrong.
You are right; The Timing trigger in the LT1 had 360* of crankshaft resolution, the LS1 only had 24 points of resolution.
Unfortunately...we all know that the 360* system didn't turn out to be impressively reliable.
The basic architecture that was laid out for the C4, is most certainly "recognizable" in the C7.
Look at the C2/3 architecture/design/philosophy:
Now look at the C4. See anything at all, that is similar? No...those platforms could have come from different companies.
Now the C7. While there are profound improvements....I see the lineage; Unit structure with similar shapes, gussets, cross members and dimensions, "free standing" drive train, I see the architecture/design/philosophy that was created w/the C4. This architecture/design/philosophy didn't exist before the C4, from any auto maker, but it still exists today, in the C7....
Fair point. I tend not to think of the C4+ architecture as a "free-standing drivetrain." Really the only thing that ties it all together as a single unit is the C-beam, which is not really a frame member at all - it's just a very effective pinion snubber. I still tend to think of it as a front and rear subframe with the engine and clutch (and transmission in the C4) up front, and the rear suspension and transaxle (or just diff in the C4) out back. I'm not sure how unique it is from other sports cars in that context. But visually speaking, there's a huge line of demarcation within the Corvette lineage that clearly separates the C4-up from the body-on-frame architecture of the previous generations.
Really the only thing that ties it all together as a single unit is the C-beam, which is not really a frame member at all - it's just a very effective pinion snubber.
And X-member eliminator -which is part of the C4/5/6/7 philosophy.
I totally agree with you that the C beam is not a frame member at all and I've made that exact point on this forum, in the past. I didn't mean to imply that is was part of the frame, but rather that it was a philosophy in design that set a new paradigm that is recognizable, today. The Torque tube does the same job and is also not a frame member at all. The C4 was originally designed with a TT, but vibration/noise lead them to remove stiffness and rigidity from the tq tube to drive the frequencies down out of the audible range. What we got was the relatively flimsy (in most directions) C-beam instead of the torque tube that came later, with more engineering time and refinement (and the movement of the trans). By "freestanding" drive train, I meant this:
...which you can't do with a typical front engine/RWD car that has x-members, and is architecturally and philosophically very similar and paving the way to this:
Anyway, point was, it was a radical change and a huge step toward where we are today with the current C7's general architecture.
Makes one wonder if you could add a left side to the C-beam or adapt a Torque tube to the C4.
I can't see a good reason to do that. It's only function is to resist upward/downward motion of the transmission tailshaft and the pinion of the diff. That's the one direction in which the C-beam is very stiff. It does excactly what it needs to do. I would guess that the needs for multi-way stiffness are a little higher for the transaxle cars, which is why they went to the torque tube?
And X-member eliminator -which is part of the C4/5/6/7 philosophy.
I totally agree with you that the C beam is not a frame member at all and I've made that exact point on this forum, in the past. I didn't mean to imply that is was part of the frame, but rather that it was a philosophy in design that set a new paradigm that is recognizable, today. The Torque tube does the same job and is also not a frame member at all. The C4 was originally designed with a TT, but vibration/noise lead them to remove stiffness and rigidity from the tq tube to drive the frequencies down out of the audible range. What we got was the relatively flimsy (in most directions) C-beam instead of the torque tube that came later, with more engineering time and refinement (and the movement of the trans). By "freestanding" drive train, I meant this:
...which you can't do with a typical front engine/RWD car that has x-members, and is architecturally and philosophically very similar and paving the way to this:
Anyway, point was, it was a radical change and a huge step toward where we are today with the current C7's general architecture.
I would guess that the needs for multi-way stiffness are a little higher for the transaxle cars, which is why they went to the torque tube?
That is a good question. IDK why there is actually a need for a TT. You could support the "transaxle" just the same as the diff is supported, on the C4; with widely spaced torsional mounts (batwing) and a C-beam. The advantages to the Tq tube that I can see are:
*You can run a NON, U-jointed driveshaft
*All of your engine tq is resolved through the TT; there is no reaction tq in the diff. The only reaction tq from the entire drive train would then be opposite wheel acceleration. Not sure the benefit other than no reaction tq through the frame...but the frame is more than capable of handling that...
* Possibly better packaging with the narrower diff mounts?
* Supports the clutch disk precisely
I'm sure it weighs more than the C-beam/joints and aluminum shaft.
That is a good question. IDK why there is actually a need for a TT. You could support the "transaxle" just the same as the diff is supported, on the C4; with widely spaced torsional mounts (batwing) and a C-beam. The advantages to the Tq tube that I can see are:
*You can run a NON, U-jointed driveshaft
*All of your engine tq is resolved through the TT; there is no reaction tq in the diff. The only reaction tq from the entire drive train would then be opposite wheel acceleration. Not sure the benefit other than no reaction tq through the frame...but the frame is more than capable of handling that...
* Possibly better packaging with the narrower diff mounts?
* Supports the clutch disk precisely
I'm sure it weighs more than the C-beam/joints and aluminum shaft.
I was thinking about not needing U-joints after I posted that. That's a nice advantage. But I bet you're on target if they used narrower diff mounts. I'm sure that's easier to package.
07-12-2019, 04:21 PM
