[oldman]

Originally Posted by Norm Peterson

No, you still don't quite understand. Where the transmission issue is concerned, it's because the performance improvement is the result of taking the driver yet another step away from . . . doing his own driving.

I do understand, what you are not getting is the C8 is a step beyond the C7 and part of that is the "doing the own driving" can't shift fast enough period end of the story. It is a combination of mid-engine and the DCT that makes this ride a full second or more faster than a very similar engine in an SS.

I also don't think you have any understanding of the complexity of the mechanical linkage needed to put a manual shifter in front of an engine/transaxle combination. I do drive and sometimes race my bro's aftermarket turbo Boxster flat 6. My 23 year old Integra (direct linkage to the trans via rod) shifts a million times better than the Boxster. IMO if Porsche can't get the shifter to feel even OK after what 70 years or something. There is hope GM is going to get something even remotely better than terrible.

Originally Posted by Norm Peterson

I do like "rough around the edges", but that's a subtopic for another time and a different thread.

I knew you would, it was meant as a compliment.

Originally Posted by Norm Peterson

1.0x lateral g's is already kind of a yawn. That crude, horribly limited Mustang of mine can pull more than 1.2g. On true street tires.

Please Norm, now you are killing me. It took Ford what 30 years or something to copy the 3 link + Panhard rod from a Camaro?

All the while the SVT / Skunk Works / Shelby crowed could not figure out why the Mustang rear just flopped around on 4 cheap arms. For the one true living god, it always amazes me how Ford could even sell a V8 powered "performance car" and not bolt in a chinzy Panhard rod.

As we both know the problem with a live axle is not that it can't turn it was always that the ride sucked and the performance went to zero of irregular surfaces so nice try on the smooth track, don't try that on a road where cars go because we all know how skitish a tightly sprung live axle is.... Well at least Ford did bolt a Panhard rod back there. At least that is my assumption.

https://www.americanmuscle.com/every...hard-bars.html

https://www.maximummotorsports.com/t...p_panhard.aspx

So um glad your Mustang can do what a Camaro can do for MANY decades, given a decent set of tires, a stiff suspension, plenty of front end camber and a smooth road course... works like magic. Too bad as an ACTUAL car on the road it sucks, hence every OEM has gone to IRS.

But yea, I kind of like the Boss 302 (don't let it out) Heck if I won the loto and the oldlady would only buy one car it would be:
https://revologycars.com/car/1966-shelby-gt350/

And as a tribute to you I'd get it in M6

[Norm Peterson]

Originally Posted by oldman

I do understand, what you are not getting is the C8 is a step beyond the C7 and part of that is the "doing the own driving" can't shift fast enough period end of the story. It is a combination of mid-engine and the DCT that makes this ride a full second or more faster than a very similar engine in an SS.

A conventional 3-pedal MT would be able to shift fast enough for me. I've never been into abusively banging gears. But maybe I will run that sim.

I also don't think you have any understanding of the complexity of the mechanical linkage needed to put a manual shifter in front of an engine/transaxle combination. I do drive and sometimes race my bro's aftermarket turbo Boxster flat 6. My 23 year old Integra (direct linkage to the trans via rod) shifts a million times better than the Boxster. IMO if Porsche can't get the shifter to feel even OK after what 70 years or something. There is hope GM is going to get something even remotely better than terrible.

Wasn't it me who even brought the shift linkage issue up (in this thread)? Of course I have some understanding. I spent too many years doing the structural kind of engineering to not recognize that it would not be a simple task.

I knew you would, it was meant as a compliment.

Thanks.

Please Norm, now you are killing me. It took Ford what 30 years or something to copy the 3 link + Panhard rod from a Camaro?

Nice try, and not too far off. The 3rd and 4th gen Camaros used a torque arm with its PHB, which isn't the same thing. I'm not putting the F-bodies down by that, as they were miles ahead of the Fox-body in the handling department. Me, I've always wondered if Ford was listening in to a few stick-axle suspension discussions we were having over on Corner-Carvers back in the early 2000's time frame.


I don't want to run down this side topic any further here. Let me put the rest of my thoughts in a PM.


Norm

[oldman]

Omg, that is funny, Ford could not even copy the GM three link? Too funny, i’m still try to figure out any advantage to the short two pivot rear link at the top of the diff, the gm torque arm had a slight pivot at the front and held the diff at a perfect angle... dunno.
How is the insta-center calculated or anti-squat? Too complicated, I’ll have to breath and move on...

[6spdhyperblue]

What about taking a SS a10 mag-ride car and optioning 1le suspension (springs and sways wheelstires etc). Will this car be quicker around the track than a 1le 6spd?

I believe the ZL1 is quicker with the a10

[Norm Peterson]

Originally Posted by oldman

Omg, that is funny, Ford could not even copy the GM three link? Too funny, i’m still try to figure out any advantage to the short two pivot rear link at the top of the diff, the gm torque arm had a slight pivot at the front and held the diff at a perfect angle... dunno.
How is the insta-center calculated or anti-squat? Too complicated, I’ll have to breath and move on...

Among the various "simple" stick axle suspensions, the 'true' 3-link and the torque arm are probably the best two.

The nod for overall handling generally goes to the 3-link, if for no other reason than because the TA can become subject to brake hop (some F-body years were infamous for that). I'm thinking - guessing, really - that the length of a TA being physically limited while the side view distance from the axle to the virtual intersection point of the LCAs and a UCA is not has something to do with it. Maybe rigidly fixing the diff with respect to the TA inclination is a disadvantage.

Oddly enough, you'd start your TA geometry plot by assuming that a virtual 3rd link exists at the chassis end of the TA. This fictitious link will be perpendicular to a construction line drawn through the TA's chassis pivot and the axle center (this construction line will lie close to, but generally won't be coincident with, the TA's long axis).


Norm

[samurai]

Originally Posted by 6spdhyperblue

What about taking a SS a10 mag-ride car and optioning 1le suspension (springs and sways wheelstires etc). Will this car be quicker around the track than a 1le 6spd?

I believe the ZL1 is quicker with the a10

I remember the difference between ZL1 1LE AT and MT on the ring was about 2 seconds on an above 7 minute lap. So the AT may be easier to drive fast since the AT helps you downshift to the best gear before corners, but in the end the driver is much more important compared to how much MT vs AT matters on the track.

[Norm Peterson]

Here's a look at what the DCT gives you only from the "faster shifting" aspect. Same transmission gear ratios, same everything else except shift speed and weight. I used 0.10 seconds for the DCT shift time vs 0.45 or about 0.6 seconds for the MT depending on whether you have to dog-leg through the neutral gate on the way to the next gear, and I did add 25 lbs to the DCT car (it's probably a little more than that).



The comparative speed traces are probably about what you expect them to be (the DCT trace is in red and I'm not going to go back in and edit the legend). But the time difference probably isn't. It's there - I'm not arguing that - but there's not as much there as 350 to 500 millisecond differences per shift might lead you to expect.

You roll racers will appreciate that on a 60 - 120 blast the driver in that DCT-equipped car should expect to pull out about a 66 foot lead over his MT competition. Roughly four car lengths.


FWIW, the overall lap time improvement on either of NJMP's courses for the same car would probably fall in the 0.5 - 0.8 second range. I haven't tried to see whether a faster/more powerful car would benefit more than that or not as much, yet.


Norm

[ST1LE]

Originally Posted by 6spdhyperblue

What about taking a SS a10 mag-ride car and optioning 1le suspension (springs and sways wheelstires etc). Will this car be quicker around the track than a 1le 6spd?

I believe the ZL1 is quicker with the a10

I think the e-diff on the 1LE has a significant impact on its corner exit speed, but the a10 maybe makes up for that? it would be really close I bet but faster I doubt.

[undy]

Originally Posted by Norm Peterson

Here's a look at what the DCT gives you only from the "faster shifting" aspect. Same transmission gear ratios, same everything else except shift speed and weight. I used 0.10 seconds for the DCT shift time vs 0.45 or about 0.6 seconds for the MT depending on whether you have to dog-leg through the neutral gate on the way to the next gear, and I did add 25 lbs to the DCT car (it's probably a little more than that).



The comparative speed traces are probably about what you expect them to be (the DCT trace is in red and I'm not going to go back in and edit the legend). But the time difference probably isn't. It's there - I'm not arguing that - but there's not as much there as 350 to 500 millisecond differences per shift might lead you to expect.

You roll racers will appreciate that on a 60 - 120 blast the driver in that DCT-equipped car should expect to pull out about a 66 foot lead over his MT competition. Roughly four car lengths.


FWIW, the overall lap time improvement on either of NJMP's courses for the same car would probably fall in the 0.5 - 0.8 second range. I haven't tried to see whether a faster/more powerful car would benefit more than that or not as much, yet.


Norm

For what it's worth, DCT shift time for the C8 is 0.010 seconds, ten times faster than what you graphed.

[Norm Peterson]

Originally Posted by undy

For what it's worth, DCT shift time for the C8 is 0.010 seconds, ten times faster than what you graphed.

I'm only finding "under 0.1 seconds" for a DCT (Jalopnik and Motorauthority specifically for the C8, and Tremec as a general sanity check). Not "0.01 seconds".

If you can provide a reference for 0.01 seconds, I'll re-run the same sim with that or any other specific shift time you can find (only takes a couple of minutes including printscreening, cropping, uploading and what-not). Otherwise I may run 50 milliseconds (0.050 seconds).


Norm

[oldman]

Originally Posted by Norm Peterson

Among the various "simple" stick axle suspensions, the 'true' 3-link and the torque arm are probably the best two.

The nod for overall handling generally goes to the 3-link, if for no other reason than because the TA can become subject to brake hop (some F-body years were infamous for that). I'm thinking - guessing, really - that the length of a TA being physically limited while the side view distance from the axle to the virtual intersection point of the LCAs and a UCA is not has something to do with it. Maybe rigidly fixing the diff with respect to the TA inclination is a disadvantage.

Oddly enough, you'd start your TA geometry plot by assuming that a virtual 3rd link exists at the chassis end of the TA. This fictitious link will be perpendicular to a construction line drawn through the TA's chassis pivot and the axle center (this construction line will lie close to, but generally won't be coincident with, the TA's long axis).


Norm

The TA has a solid anti squat characteristic, while accelerating. I can see this advantage in reverse during braking. Since I more into accelerating, it is clear to me that I like the TA. I can see the 3 link is more of a neutral design..

[oldman]

Originally Posted by 6spdhyperblue

What about taking a SS a10 mag-ride car and optioning 1le suspension (springs and sways wheelstires etc). Will this car be quicker around the track than a 1le 6spd?

I believe the ZL1 is quicker with the a10

In the FWD world the dynamic torque vectoring diff and or brakes is a quantum leap forward. Fwiw a dssv shock imo is far better than a mag ride, and is the number one reason I did not order a mag ride. I would have ordered an ediff if it was a separate order item

[oldman]

Heck a 66 foot lead!!! That is blown into the weeds in a what 7 second knife fight? That high heeled admin is pulling away a car length a second while talking to her sister on the cel.

[Norm Peterson]

Originally Posted by oldman

Heck a 66 foot lead!!! That is blown into the weeds in a what 7 second knife fight? That high heeled admin is pulling away a car length a second while talking to her sister on the cel.

Thought that would get your attention (next go-round I'll post the lead/lag distance plot as well as the other two).

I'm entirely willing to let the numbers fall wherever they may. Anything after that is up to each individual (including me) to evaluate against what's important to him.


Norm