6Speeder

I've dyno'd all my past cars (many times) but this will be the first of my 1,300-mile stock 2023 Z06. This will be on a Dynojet chassis dynamometer using SAE correction factors. I will try and monitor HP, TQ (natch), A/F, timing, and KR. Anything else?
Questions: What gear since none are 1:1? Third (1.22:1) or fourth (.88:1)? Any "GOTCHAS" to know with this platform?
I will post results of this, my baseline, prior to any modifications. Any others care to show their results?

BearZ06

Gear may depend on the top speed the dyno can handle.

newchevyman

Thanks for the reminder that of the eight gears we have to choose from five of them are overdrive.

My '17 ZL1 had 10 years and three were overdrive. Time for a swap.

AzDave47

... and what would you propose to swap too?

newchevyman

10L90 ftw!

thrilled

I plan on doing Dino when will be able to do a tune. Can on the stingray. The Z06 still locked. Have been hearing around 610 hp at the wheel.

AzDave47

Are you sure that will fit in the C8 transaxle and mate up with everything and be controlled with required different software? You know the DCT in the C8&Z is a transaxle not a transmission mated to a separate rear end like the C6 and C7 Corvettes were?

Joefab

Fabspeed Motorsport has a Dynojet 4 wheel unit as many of the mid 1996+ to current new cars freak out if you dyno rear wheels only. Yes they are work-around but many late model Porsche, McLaren, Lamborghini and other cars have wheel sensors and satellite /software live communication that in 2 rear mode the cars go into limp mode or reduced power “safety mode”. The hardest car to Dyno is the Acura NSX Twin Turbo hybrids .

The C8 Z06 should be dynoed in 5th gear which is almost 1:1 ratio. 4th is approx 1.31:1 and will give artificially higher power #s. At Fabspeed in 5th gear Z06 cars are trapping 190-192 miles per hour. Make sure you install redundant cross strap ratchet tie downs ………..it’s the fastest speeds we have encountered bar a 1400hp GT2 RS. The C8Z06 is a beast and rocks!

newchevyman

I was being facetious but the 10 speed gearing would be nice. We've all heard enough complaining about the C8 gearing.

Is this due to a multiplier or? These cars obviously top out in 5th gear but it's listed as a .65 versus .88 for 4th gear. I'd imagine a hub dyno would be safest bet at those speeds.

6Speeder

Yes, fourth is closer to 1:1 than fifth. We ran the car in both, with similar results and did most runs in fourth due to our fear of those wheel speeds at 190+ MPH. I have personally seen a wheel weight fly off a different car at 120MPH on this dyno. NOT PRETTY!

My results: 590 SAE RWHP/412 SAE RWTQ. This is the same percentage loss through the drivetrain as my manual transmission C7 Z, and I can't see the DCT being any more efficient (in gear) than a pure manual transmission/diff car.
A couple highlights before I go over the data: This engine LOVES timing! At higher rpm's (6,000+) she was pulling 35 degrees of timing with no KR. She also runs really cool. We had to turn the fans off to get any temp (175 f) into the motor. The A/F after the cats was 12.8 to 13.0 (direct injection!)
Also interesting: We ran in fourth gear, from 2,000 rpm to redline, and even though (from the data on HPTuners) I requested full throttle at 2,000 rpm the engine was commanded to only 50% and ramped up to full by 3,800 rpm. Is that the breakin till 1500 miles that limits low end torque?

robob

LMR(Late Model Racecraft) is getting low 600s I believe. Any idea why your's is low?

Inferior fuel?

Sincerely,
Robert

BearZ06

As you know, no two dyno's are the same which in IMO likely explains the difference.

Z0HS1CK

LMR also claims 60 or so rwhp increase from their stage 1 package so idk.

newchevyman

Not according to dyno racers.

JMB

on brand x dyno this is true...on a Dynojet, nothing could be further from the truth! Dynojet guarantees power repeatability to within 2%!

Case in point, my NA SBE LS7 Monte Carlo SS laid down 704 RWHP in WA State on a Dynojet....I moved to Phoenix, re-dynoed the car at CPR in Tempe on their Dynojet and it put down 698 even though it was running ~1 point richer A/F than in WA State. I then re-dynoed on my new personal Dynojet in Phoenix (actually Laveen), still running rich again, and laid down 695! Three different dynos, three different weather conditions but all SAE corrected! All runs monitored for same engine temps, full timing and no KR, case closed!

JABCAT

Seems most stock dyno results appear to be within that 2% range (590's - 60x). Only one vendor claims their stock Z06 was in the 640s...

6Speeder

I don't believe my numbers are low, I don't know LMR's conditions, fuel, or procedures. My Z has steel brakes and forged wheels, would the CCB's and carbon fiber wheels make that difference? We made no "glory" runs, it's all on 91 octane (best available here), tire pressures normal, temps cool to normal, back to back runs, all as I would run on the street. And again, on the same dyno, my C7 Z06 M7 had the same percentage loss through the drivetrain, so I have no reason to doubt these numbers. Mine was the first C8 on this dyno, I'll rerun it after 1500 miles to see if the lazy low rpm throttle response is better, and with my first mod. Two of my friends have C8Z's, I'll try and get them to dyno on the same dynojet.

robob

Yeah, maybe, but I am wondering if there is something appreciably different in their test methods

:-)

AzDave47

LMR, I think, and most of the East Coast tuners use Standard correction which bumps up their numbers versus SAE.

JMB

Amen...for some reason they try to convince people that Std is OK when it really isn't!