It's also possible the driver could have made a slight error at various parts of the track. You cannot directly compare results at various parts of the track unless the cars are racing almost nose to tail in the hands or professional drivers over a number of laps.

I'm basically saying, you cannot make a definitive assessment based on just a hot lap alone (or three).

 

Are those figures correct? They seem all over the shop to me?

Sector 2 - Climbing Esses

Camaro has higher entry and exit speeds yet the avg speed is way less?

Sector 5 - Hog Pen

The Mustang has a much lower min speed yet a much higher entry and exit speed?

 

Yep. Walking slowly, but walking nonetheless.

 

At 100 mph... 0.1 secs equates to one car length!

 

The track layout, for reference:



And the stats for the section:
Interesting:
The Camaro lost 14.8 mph through this section (86.2 - 71.4), and the Mustang only lost 6.9 mph (75.0 - 68.1), but the Camaro's entry, minimum, and exit speeds were all higher.

 

I agree except for a technical point. Increased front bar stiffness will increase understeer, as would decreased rear bar stiffness. To dial out understeer you need more rear bar or less front bar (or more rear spring or less front spring). As far as ride comfort, there isn't much problem with increasing the bar diameter if the wheels on both sides hit a bump at the same time, but since you have removed some of the independence of the suspension and increased effective spring rate, there is some penalty when wheels are going over uneven pavement.

Not really going to argue there.

Definitely.

 

Not necessarily. Yes, in general increasing the stiffness at a given end should lead to a loss of grip but there are cases where this is not the case.

If the car is soft enough, turning into a corner will result in a loss of of contact patch at the front due to camber loss in roll. This is especially true of a strut car which really doesn't gain any camber under compression. In this case a larger front bar will actually return a net gain in grip because the improved contact patch gives much more grip than the stiffer bar takes away.

FWIW even the SLA 4th gens are the same way with any kind of "normal" spring rate. I have 600 lb springs on the front of my car (stock is ~292) yet the car still needs a 35mm front bar (stock 30mm) AND a 21mm rear (stock 19mm) with 150lb springs to be fast (ie. not push).

The CMC RR guys can't legally run a front bar larger than 32mm and therefore it is not uncommon to see them run 1000lb springs to get the front roll stiffness they need to be fast.

It's all about the contact patch.

 

Haha. You are correct HAZ-Matt, I let my own current car tunning (fixing an oversteer condition) pop into my head when I wrote that part. And I do think the penalty would be small with what we know of how compliant the current suspension is.

This has got me thinking, do we know what size front and rear bars the CTS-V runs compared to the Camaro? How about spring rates? To me, this should give team Camaro a great starting point of what flat out WORKS and WORKS WELL on this chassis. Especially since the cars have similar weight and balance (the CTS-V of course being heavier).

How can we have a CTS-V running circles aroun things and being praised for its handling as "world class" and a lighter Camaro on the same chassis being called a "pig that wouln't turn"????? I feel like I am living on Mars or something. Something like this just shouldn't happen. As a Mechanical Engineer myself, it is unexcusable.

Do better next year team Camaro. Do better.

 

But if you went to a 25mm bar on the rear, the rear would respond faster and you would likely experience oversteer. If you dropped your front bar down to 30mm you might experience the same thing. However, as you said, this is likely because you have stiff enough springs to maintain a good contact patch.

I do see what you are saying about contact patch, which opens up the question: Is the Camaro overcoming the front tires due to a loss of contact patch or is the rear simply not responding fast enough? Or some of both?

I think I would be tempted to start with a larger rear bar and go from there.

 

The 25mm is just too much. The rear becomes too "loose" when driven hard. It's all you can do to hang onto the car when the bar comes in. It does have a place on these cars though and is / can be used when the rear roll center is dropped with a Watts or relocated panhard. (the lower roll center makes the springs and bars "appear" softer to the car)

As an aside...... I had a 30mm front on the car (stock size remember). I had more front stick with a 32mm bar. Then I had MUCH more front stick with a 35mm. You can absolutely get to a point where the front bar is too big. However, unlike at the rear, there doesn't really appear to be that option available in the aftermarket for these cars. Also, don't forget that if you really have to increase the spring rate a lot to compensate for a small bar, you'll eventually get to the point where the car loses grip over bumps. Somewhat less of a problem for most RR guys, but still.

I've read the books, asked questions and played around with this a lot. Over the years I've had four different front bars, four different front springs and three different front shocks on the car. At the rear I've had two different bars, two different springs and four different shocks. I've also experimented a bunch with alignment settings and endlink bushing hardnesses (yes, really). Ultimately I wound up where pretty much everybody else (including the guys that win) has their cars. The platform has been pretty well sorted out over the years. Seems like it's only the small things that change now as tires develop, new parts become available, etc.


Car tweaking rule of thumb for racers:

Always first start working on the end of the car that is causing the problem.
When you run out of adjustment options at that end, then you can work on the other end.

 

Hah now we have successfully hijacked this to a 4th gen thread.

I was aware of the camber control benefits. My car isn't fast but it has a 35mm bar in the front and 22mm in the rear

 

Sammy hollow bar, right? About the same stiffness as my solid GM 21mm. We have basically the same bar setup.

I'll try to refrain from any further hijacking.

 

Don't forget, the following thread is a great resource for rollbar information...

https://www.camaroz28.com/forums/sho...=705723&page=5

 

I think you missed my point (and it may be that I wasn't clear....)

You plan for two versions -- one for the mainstream -- and one (a track package) for the guy or gal what wants to take it to the track........

.........and then the world comes apart -- and something's gotta give.

There was simply no time to go back and 'redo' the suspension..........

The opera ain't over..........

 

That actually explains allot.....