Hey Guys,

My C6 Z-51 m6 seemed much quicker than my C7 Z-51 m7. Is it poor recall, gearing , traction control system ie.. more computer nannies. I feel my C7 is much faster but my C6 was much quicker.
I live in a rural area so there are many farm roads I can go to with nothing but fields on both sides for miles. I have played with it in track mode with traction control off and am lucky to get 2nd and 3rd gear chirps. I would have thought with the HP of these cars it would boil the tires without a sweat but I guess they are geared for top end.

On the heels of this if I change the throttle body will that eliminate the hesitation from idle to help bottom end performance.

I will close by saying I Love my C7 but was curious what others had to say that have owned both.

 

Gearing def makes a difference, even though my current c7 has more hp than my old c6z, the c6 did seem snappier off the line

 

‘It’s bizarre, google says C7 is faster but past forum members say it’s the fact that the power is felt more in the C6 . Something to ponder C7 more hp but weighs more🤔

 

My c6z was at 497 whp, my c7 is at 533 whp. 6 vs 7 speed means you can rev out the c6 gears more. I loved my c6z, sold for wrong reason (damn girls).... c7 is a better driver car with way better technology

 

‘Maybe a Supercharger would help the skinny pedal 😁😁😁

 

Tbh....after torque tube rebuild, it's not out of the question

 

I thought the same thing until I took my C7 to the track , my C6 LS3 with factor run craps , TC still on because of bad Trac prep would run consistant 12.5 in the quarter mile . Our track was not at sea level and our DA is always terrible . I was able to get it to a 12.1 with a tune and headers . That's pretty fast for what's really just a street car and it felt fast

When I got my C7 , I thought it was slower , till i ran it at the same track . Out of the gate , with TC on and factory run craps popped a 1.7 60 footer and consistent 12.0 runs , it ran a best of 11.7 .

I can only atribute this to the fact that the C7 was so much more refined in every way is the reason it did not "feel" fast

I have since fixed that with the addition of a supercharger 😀

Dave

 

What SC did you install and who installed it for you.

 

Procharger , I did the install and had it remote tuned
Best move I have ever done , no regrets !
Dave

 

C6 and C7 Z51 cars with manual transmissions have the exact same gearing (except obviously 7th gear) in the transmission and the differential.

 

Thanks for the input , I would have again just by driving both bet money the C6 was geared more aggressively.

‘I haven’t put mine in Track/race mode and tried to burn out using launch control but will say this , my C6 at ~45mph throw in 2nd or 3rd side step clutch and spin the tires for a short distance (meaning not just a chirp). My C7 I have taken TC off and had to hammer it pretty good just to chirp 2nd and 3rd.

I guess this is similar to comparing my 400 hp 68 Z-28 to a 425hp C6. The 68 you better know how to drive to get it all on the ground compared to the C6 felt fast but it was just point it in the right direction, then the stock C7 you could be on a hands free call while making a run because of its manners.

 

Well put , that's exactly how I feel about it

Dave

 

Then either the car has other issues and/or it would help greatly for you to learn about the various modes. This is particularly true if you have Magnetic Ride Control shocks and therefore have Performance Traction Management (PTM). It's quite easy to spin the tires in a C7. There are plenty of YouTube videos of guys wanting to show off with the car leaving their parking lot shows. They put it in Track / Race ('cause they're cool), and then proceed to stuff it into a wall or a curb or another car since they've never used that mode before and frankly can't drive.

I had a student this weekend at an BMW HPDE who had no idea about the various PTM sub-modes. It was quite eye-opening (and rewarding) for him.

 

I appreciate the input , it’s greatly received 👍. I am sure the car doesn’t have issues and it’s a 3LT that has MRC and PTM so I will check some more videos on you tube.

 

This guy does a great job explaining the modes

 

c6 is a few hundred pounds lighter than c7. the c6z especially is way lighter than a c7. the lack of response one feels in the pedal is 100% tuning related.

 

He is a little off in his descriptions.

In track mode, there are basically 4 functions you are working with:
Stability Control (dead band varies with setting with a larger dead band giving driver ability to move car around)
Traction Control
Throttle Dampening slows the opening and closing of the throttle to avoid sudden changes that may disturb the balance of the car
Performance Traction Management (PTM) A combination of varying suspension settings, eLSD activation and torque limiting based on available tire grip as determined by tire slippage and tire temperature.

I will only talk about Sport 1, Sport 2 and Race Modes.
In Sport 1 you will get the following:
Throttle Dampening
Stability Control (like a Competition Mode version)
PTM

In Sport 2 you will get the following:
Throttle Dampening
PTM

In Race you will get the following:
PTM

You can hear when PTM activates when you are driving off a corner. As you increase throttle and the rear tires start to slide sideways (lose grip) PTM will use spark control to limit torque to the rear wheels this is heard as a blatting (maybe misfire type of sound) coming from the exhaust. As the tires start to regain grip the engine is permitted to deliver more torque and the eLSD determines how it is proportioned to the rear tires. Unlike TC you don't get a throttle bog that lasts for a second or two when PTM activates.it really does increase torque delivery to let the car accelerate faster as grip increases. Although the OM says to go wide open after passing the apex of a turn I don't recommend it since PTM sometimes doesn't limit torque sufficiently to keep the rear from kicking out as you are unwinding the steering. When instructing students that have never experienced PTM action I usually have them place the car in Track/Wet Mode so they can hear and feel the system working. After a lap or two I have them move the setting to Sport 1.

Launch Control is available in Track Mode but I consider it a variation of PTM as it essentially acts the same way just from a dead stop and in a straight line Vs at speed exiting a turn's apex. When running an autocross that had cars starting on a down slope I found that launch control was activating on the start line as I hit the throttle and let out the clutch. I had to hold my right foot on the brake while waiting for the start signal and as soon as I got the signal I moved my right foot from the brake and used the throttle to take the rpm above 2000 rpm, let the clutch out and nail the throttle. As the car moved through the start beam I could hear the exhaust blatting and feel the rear wheels stuttering as they spun/slowed/spun until the tires gripped.

Bill

 

Tire chirping isn't an indicator of performance, but poor traction. If you'd like to make the C7 light up the rears in almost any gear, then install some really bad tires. Alternatively you could do poor alignment to induce more traction loss on the rear.

 

https://www.edmunds.com/car-reviews/...rack-test.html

 

"Feel" isn't a good indicator of one car being faster than another. Use an actual performance timer like dragy to know. Older cars will tend to feel faster because they're lighter, have less advanced suspension, and likely aren't as well put together.