[pbSS]

Originally Posted by Sweet Emotion

Watch this video which confirms GM knew what they were doing engineering 1LEs.

The owner of this vehicle put lowering springs which essentially made it worse...

We have no idea what springs he put on, and what his dampers are and how he set them up.

With that said, you guys do realize there's a LOT of people running track days with lowering springs, right? And guys running fast laps without hindrance. I understand there's this "omg the car is so perfect don't touch it", but sometimes we can get too caught up in the details. If you're a 10/10 Randy Probst type driver trying to break records, maaaaaybe they can negatively affect your times, but at that point you're likely looking to go coilovers and do other major mods (I thought these cars were so perfect why mod them??).

[PowerDemon]

Originally Posted by Dardecor

I agree with your philosophy and all of my track instructors have said the same. The best mod is driver mod . The lowering springs would really be for cosmetics, but I wouldn't want to take away from the performance too much.

The only mod I'm considering for the track is SPL Toe Rods for the eccentric lockout + camber and a rear cradle lockout (i experience a decent amount of wheel hop). Thoughts?

I did both on my ZL1 and it’s great so far. The cradle lockout kit makes a HUGE difference. It makes the car feel like it actually has 650 horsepower haha. So much more direct than stock. With the SPL links I think they improved straight line stability, but there was not as much a difference. That said they were more to keep the alignment consistent than an up front performance change.

FWIW my car is also lowered on BMR springs. No issues with some spirited driving on the street, but no track time. I did the mag ride recalibration and got it aligned to track specs as well.

[Dardecor]

Originally Posted by PowerDemon

I did both on my ZL1 and it’s great so far. The cradle lockout kit makes a HUGE difference. It makes the car feel like it actually has 650 horsepower haha. So much more direct than stock. With the SPL links I think they improved straight line stability, but there was not as much a difference. That said they were more to keep the alignment consistent than an up front performance change.

FWIW my car is also lowered on BMR springs. No issues with some spirited driving on the street, but no track time. I did the mag ride recalibration and got it aligned to track specs as well.

How many track days did your alignment last without aftermarket toe rods? I’m only doing 2-5 a year for budget reasons. SPL Toe Rods costs another track day and I’m wondering if it’s even needed as a casual track days person

[Stephen12ZL1]

I ran Eibach pro springs in my '17 ZL1 for a few years and can confirm they work fine for road course use. Compared to a stock ZL1 mag ride car, my car felt more composed. During transitions it felt like you didn't have to wait for the weight to transfer. The biggest difference was felt in the rear of the car but still not huge. You will definitely not hurt the handling performance. The springs are only minimally different in height...maybe 1/2-3/4 of an inch. I ran the cradle lockout kit from BMR also. Stock swaybars and everything else.

[PowerDemon]

Originally Posted by Dardecor

How many track days did your alignment last without aftermarket toe rods? I’m only doing 2-5 a year for budget reasons. SPL Toe Rods costs another track day and I’m wondering if it’s even needed as a casual track days person

Sorry I haven’t done any track days with the car yet.