[carguy55]

Someone needs to try it and report back. I heard it cost $280

[Chris V]

Originally Posted by carguy55

Someone needs to try it and report back. I heard it cost $280

That’s what I paid for it today. Trying this weekend at DriveAutoX.

[Chris C 1SS 1LE]

Originally Posted by Chris V

That’s what I paid for it today. Trying this weekend at DriveAutoX.

.3 hours labor? That's point three...

[Boost Creep]

Originally Posted by Chris C 1SS 1LE

.3 hours labor? That's point three...

Maybe that dealer charges $933/hr?



You would think it would be about $40 for a 0.3hr reflash, not $280, it's like they are charging 2 hours or more.

[bishir]

We ran the calibration on my car this weekend... stock 1le with re71rs and Chris has the PDR data. Awaiting results... although preliminary looks like a slight improvement.

[5senna5]

It looks likes from the description that this is intended for Autocross where full disabling of all systems is done? The way I'm reading, it wont offer any calibration change to "Race" mode in "Track" PTM setting since all systems aren't fully disabled?

[waterman]

Interesting thread. Following.

[Chris V]

Originally Posted by 5senna5

It looks likes from the description that this is intended for Autocross where full disabling of all systems is done? The way I'm reading, it wont offer any calibration change to "Race" mode in "Track" PTM setting since all systems aren't fully disabled?

That is correct. You engage it by holding down the traction control long enough to engage both lights. Then you get faster coupling and decoupling.

I'm just waiting to make sure I've got the comments down right before I post the results. I'd say it's worthwhile, and for a few hundred bucks it'll make the car more than a few hundred bucks better. It turns in better and you can get on the power earlier.

[carguy55]

Some guys are road racing in Track -off -off mode so this may help them, but $280 worth?

[Chris V]

Originally Posted by carguy55

Some guys are road racing in Track -off -off mode so this may help them, but $280 worth?

How much is .2 seconds worth on a 49-second autocross course to you?

[S2K+1LE]

Definitely more than $280, you'd probably spend 10x that otherwise.

[carguy55]

Originally Posted by Chris V

How much is .2 seconds worth on a 49-second autocross course to you?

agree, which is why I specifically said road racing and not autocross

[Chris V]

Alright, so here's the scoop:

Take this away - the team at GM is awesome, and it's so cool that they're releasing stuff like this. They really care about the car, autocrossers, and it's amazing that they're giving us these options. I was getting messages from three separate people at GM before I had taken my third run asking for feedback.

On Saturday, we were at Optima's DriveAutoX in Peru, Indiana. It was a great, fun, laid-back event with gorgeous cars and some really fast drivers. I'd recommend going if you can make it - they have an event coming up at Gateway in August and Mineral Wells in October. The event was so cool, Brian Mason let us run a little testing while we were there.

Driver: Brian Peters - 8x SCCA National Champion and 1SS 1LE owner

Cars:

bishir 1LE - 1SS 1LE with 19x10.5 and 19x11 wheels and 305 square RE71Rs
Chris V 1LE - 1SS 1LE with 19x11 and 19 x 11.5 wheels, 305 square RE71Rs, Whipple, camber plates, 300 lb front springs, 1000 lb rear springs, DSC

Control run - Peters in Bishir's car: 49.719. This was disappointing to everyone who had a modified car, as FTD was in the 49.3 range on Saturday. FTD for the overall event got down to 49.0. The stock 1LE is really good.

Next we put the new diff calibration into Bishir's car: 49.533. Brian's comments on the diff calibration are as follows:

Originally Posted by Brian Peters

Decel and off throttle behavior is significantly improved, with a noticeable change in willingness to tuck with lifts.

Car had a much freer behavior in tighter turns and didn't experience any looseness or negative trade off on entry of the higher speed corners on course.

Corner exit was harder to gauge a benefit, but partly because in retrospect, I likely didn't push the OEM tune hard enough on baseline run. My experience driving 1LE's and even Corvettes has imparted an automatically delayed throttle foot, to avoid the cars stepping out early. Taking the run with the new tune, I was still somewhat reluctant to get greedy, however, it did feel that when it would lock, it would lock both wheels earlier and while this wouldn't necessarily end up keeping the rear behind, it would at least be more predictable and manageable. Overall, no-brainer net improvement over OEM tune, on that course, that day, that car.

As I shared earlier, I want the tune in my car.

I could see how the new tune might not help some drivers, especially on faster courses factory tune does a good job of trying to help with corner entry yaw control, which could be a big benefit in some situations.

We then added the DSC Sport box from my car to Bishir's car, Brian ran that. He ran a 49.6, but said he botched a turn and would have gone faster with another run. He didn't expect it to add compression to the front under braking and it messed up his first turn. Brian's thoughts on the topic:

Originally Posted by Brian Peters

So putting the DSC shock box on the otherwise stock 1le was interesting.

I think there's promise with the adjustability for sure (once users can wrap their heads around where the actual knobs are) my run was slightly slower due to a mistake in a braking zone, but the shocking thing was immediately feeling the springs steady state. I've been most critical of the compression tune in the factory mr setups and the inability to get decent rebound behavior without ending up with way too much compression. I.E. for both the 1le and Grand Sport, I've wanted a "Tour" level of compression with "Track" mode level of rebound. The DSC tune immediately fixed the compression complaint. Grip felt better and car was more responsive to small throttle changes mid corner on that particular course, that day, that car, I didn't notice any huge difference on rebound behavior between the tunes.

I didn't like some braking compensation algorithm DSC employed where it threw all kinds of shock up front under hard brake application. That said, I've seen enough of the software to know that can be fixed (in theory)

In my car, he went 49.6 both with and without the new diff calibration, but we were chasing what seemed like a feedback loop on corner exit that kept us from putting power down initially. We're looking into that, but we have a few working theories:

1. User Error - I forgot to re-zero the shocks when I put the new springs on, and they're lower than stock.
2. The eLSD uses a torque value calculated off the MAF, and my car is supercharged. We're looking into the torque tables to see if that's causing it to be wonky.
3. The car may be too low in the rear, causing it to be on the bumpstops too much.

This is what happens when you develop a new car and there's no knowledge out there. Once the car is sorted, it's going to be a rocket. This is why we test


TLDR: The stock car is great, the diff tune is noticeable, but may not be faster for some drivers. It's a great option. It's easy to test if you have a buddy with one and swap the module over (anyone at an event with me is welcome to try mine). Modifications take testing. DSC allows you to fix some of the bad behaviors of the car, and go faster still.

A great CAMC car would be a 1LE on 305s with camber, DSC, and Diff Cal, in my opinion. Those will gain you a lot more control over the car, without having to go crazy validating things like a blower tune and springs/ride height. I'm a little broken so I'm going further.

[JRL1LE]

Great feedback and data! Thanks Chris