Camaro hunting

[kevm14]

That was for the 90s Northstar...

[Adam]

That was for the 90s Northstar...

I see that now. Need to read all the words next time.

Post hijacked?

[bill25]

Looks like I am not the only person to notice the bucking:

https://www.camaro5.com/forums/showthre ... ght=manual

Also, Hill assist disengages as soon as the throttle is touched so if you have the clutch out a little like you would on a hill before taking off the brake, and touch the gas, the car basically gets dropped on the clutch meaning you need to rev a little quick, or stall immediately. Now that I know how this works, maybe I need to ignore hill assist altogether and give some gas while on the brake, and maybe this will disengage hill assist more gracefully?

Overall, relatively steep hills are still really difficult in this car.

[kevm14]

I am sure my CTS-V has at least as much driveline lash, probably more. It does not surge/buck at low speeds, like creeping in 1st with the clutch engaged. The lash may make things jerkier or more apparent but the surge itself is in the engine calibration I believe. Unless it is something like a dirty MAF.

[bill25]

Just for clarification, it doesn't buck with the clutch engaged/semi-engaged, it is pretty smooth until you come off the clutch, and are driving at low speed, then it starts to buck if you aren't on the gas. That is why I was saying it is hard to go slow, because you need to be on the gas for smooth operation at parking lot speeds. Otherwise you would be riding the clutch which I was told is bad.

[kevm14]

Engaged = foot off the pedal

[bill25]

Posting this clutch stuff for future reference.
https://www.camaro5.com/forums/showthre ... ill+assist

[kevm14]

I'm saying it does surge when the clutch is engaged (i.e. foot off clutch, in gear).

And by the way that is the kind of thing that would typically happen with a big cam. I remember taming that kind of surge was a process in cammed LT1s (and involved both ignition timing work, and fuel control work), but those PCMs were also far less sophisticated. So with a stock cam and a very modern ECM, I am not understanding the LS3 surging.

[bill25]

Interesting comments from camaro5 about the HSA (Hill Start Assist, or in my case, Hill Stall Assist)
https://www.camaro5.com/forums/showthre ... st&page=10

As an experiment I will go to the same store/inclined parking tonight and try a couple different things to see what happens...I will report my findings later tonight!

I will try 3 things once I see HSA is activated

1) Step on the gas and release the clutch at the same time
2) Step on the gas without releasing the clutch
3) Start to release the clutch without stepping on the gas.

Results:

Originally Posted by Dropspeed
1) Step on the gas and release the clutch at the same time
I tried this 3 times and did feel the car hold me in place but it seemed to release as soon as I wanted it too/expected it to in order to move forward. (could this be after the 2 seconds window??? maybe, but it was not odd)

2) Step on the gas without releasing the clutch
Nothing happened, HSA stayed engaged until the 2 seconds was up and then car rolled back (because I didn't release the clutch)

3) Start to release the clutch without stepping on the gas.
I released the clutch slow, car stalled without moving

So... 3) is what I do all the time, hill or not. This is why I am stalling.


More info though:

I went through all of these frustrations as well, sent nasty notes to GM, etc. Having said that it CAN be made to work if you understand:

1. The system engages based on the last brake pressure used. So if you come to a fast stop or mash the brake pedal for any reason it will maintain that pressure and you WILL stall.

2. The "remembered" brake pressure can be reset by putting the trans in neutral, releasing clutch, reengaging clutch while using just enough brake pressure to hold the car.

So, get in the habit of stop - neutral - reduce brake pressure - put back in gear.

Now I can live with it but it should be DRIVER optional.

WTF with number 1!!!!! and really? I am going to do the procedure for number 2 every time? This is ridiculous that if you stop hard, with a car that has really good brakes that they stay on just as hard and you have to power through that.

[bill25]

1 may not be true...
https://www.camaro5.com/forums/showthre ... st&page=15

One thing i did learn about the system is that works differently than others have reported. It dosn't hold the brake pressure that you stopped the car with, instead it looks at the incline of the hill and calculates the brake pressure needed to hold the car and uses that. Based on that, if the zero calibration is off, it would be using the wrong pressure.