hardhattg

steadily heading for the 10s Amazing !!!!

C5 CU

Ranger ... good stuff! ... appears the .2 to .3 penalty from clutch/TM is still in play (?) my ole C5Z had 4.6 - 330', 7.1-2 660' and 11.1-2 1320'.. appears to me something other than traction is affecting the C6Z 60' and 330' time....

Ranger

In yesterday's conditions I would have run faster on DRs. On the stock tires, I was getting some spin on the 1-2 and 2-3 that DRs would have attenuated. I was making the 2-3 shift before the 330', that puts two shifts in the 60'-330' incremental.

And, of course, the LS7 clutch pales in relative capacity to the stock LS6 clutch. The LS7 clutch will not reliably accept a launch rpm above 3800 and I've settled on a max of 3500 on DRs. That limits the 60' unless considerable finesse is applied to the throttle squeeze.

With that as background, a C6Z with a stock tune (unchanged ECU/PCM) pays a Torque Management toll that pulls power on the launch and the 1-2, 2-3 shifts. Have done some conceptual work with dgdoc figuring out ways to measure and display visually the effect of TM. We are still working on that and hope to collect some data at track rentals in Oct and Nov.

With the track officials more vigilant, it's hard to get more than 2-3 passes without getting the boot. That leaves no opportunity to test right now, because I need to focus on running some numbers before the season end.

Ranger

outnumbered

I'd really like to see you work on his car then get some results.

Rangers will see high 10's in stock form.



Dan

Adrenaline Junky

Spectacular performance on a stock platform.

C5 Frank

Great runs Ranger!!! The air up there must be something! Down here in the FL heat we cant break 97 in the 1/8 or 124 traps in stock trim!! Congrats

Yaroslav

Ranger,interesting what time could you make on my car

dgdoc

Ranger:

Looks like people almost "expect" to see you hit 10's. Taking another .25 seconds off is really going to be tough -- especially on stock tires. But, there are more things to explore....

However, if you do manage to get into the 10's in stock form, GM and the car magazines might come calling.

Now, wouldn't that be great for your upcoming DVD....

GARY2004Z06

Congratulation Ranger. Your success inspires us all.

robz

Nice going as usual John. I actually think the narrower tires might yield better times but hard to say. I'm hoping to see if the mt et street radials makes any difference. The 17" rim should help if it fits. If you run 11.0 with 3/4 tank of fuel we may have to have u take pass with 1/4 tank.

VNAMVET

You are on 18's..........using front 04 Z06 wheels?.....with what DR's.......?

Ranger

Hey VNAMVET, the passes in post #1 were on the stock tires.

When I run drag radials, they are BFG 345.30.18 mounted on CCW Corsair Race wheels in 12" width.

I am not convinced this is the best combo. Believe I'll get about 40 passes on these tires before they gone (now at 28). So few folks at stock/near-stock power levels are running DRs that the range of opinions is pretty narrow. Plus the ET difference between stock tires and DRs is pretty thin, around a tenth, far less than on C5Zs.

I'd enjoy the opportunity to do a same day comparo of BFG 315.35.17 DRs and MT ET Street Radials. Not sure the LS7 clutch would be up to that.

Ranger

pDz

i thought of you and your new PR this weekend when i read the new Corvette Quarterly with the 2007 C6 specs. GM's official spec for the Z06 is 11.7seconds --somehow i thought it was a faster time than that. in any case, you're killing it, Ranger.

KNanthrup

Ranger,
Congrats on the runs. I noticed you hauled the DR's along with you to the track... had you planned on running them after a certain number of passes on the stock tires? Also, did they kick you out after three passes or was it just so crowded that you only got three passes in?

And in the grander scheme of things, do you plan on eventually making small modifications to your car to see what times it will bring? eg. I know that you are having an issue with both the TM and the stock clutch. Is it in the plans to eventually disable TM and do an aftermarket clutch to see what comes of it? Combine that with DR's and I would imagine you would have solid 10's with only the weakest points of the stock Z taken out. Then go with some minor bolt on power adders such as tune, lid, headers and my guess would be mid- 10's would be feasible.

Ranger

Hi KNanthrup,

I hauled the DRs to Cecil in case traction, after all the rain the previous three days, was too weak for the stock tires. Having spent 10 consecutive passes on technique experiments, I was itching to apply the lessons-learned to a couple max passes.

Once racing began, I quizzed several drivers returning to the pits on how their 60' compared to normal. They affirmed traction was quite good. So I decided to run the stock tires, in an effort to lower my PR (11.31 at 300' DA).

On race days at Cecil, you get two time-runs plus rounds in the brackets. But lacking a rollcage, I got two passes (11.24 and 11.26) and then a warning to dial no lower than 11.50 in round 1.

As for mods, I have no plan to change anything. My focus remains to mod the driver rather than the car and try in the process to explain to owners how to improve their own acceleration in the car.

Ranger

Dr.Ron

Nice driving John!
Looking forward to meeting & racing with you in November at the Atco rental.
Some people may be wondering if you're waiting to start down on the throttle until AFTER the clutch is fully out, or do you start AS you're releasing the clutch (or have it partly released)?
Ron

Ranger

Hi Ron, I try to hold the lanch rpm, then make a fast clutch release, and then, and only then, begin the throttle squeeze. I did that well the first two passes (11.24 and 11.26), and got aggressive with the throttle before the clutch was fully out on the third pass, thereby glazing the finicky LS7 clutch. My launch rpms were 3100-3200, the sweet spot for heat stock tires in those conditions.

See you in Nov at Atco.

Ranger

phantasms

Ranger,

I'm bringing down BFG 315.35.17 DRs on ZR1 rims with a crazy offset. I just tried the rims on the car last week and they fit....barely. The new BFG's should be arriving today. You're more than welcome to try them out Friday.

-Gene

Ranger

Great, Gene. I plan to find a spot on the fence left side of the track, between the 60' and 330'. Red C6Z. I'll have a racing jack, breaker bar and torque wrench. New Sanyo HD1A camcorder and tripod. Should be a great day. Weather looks fine. See you there.

Ranger

Ranger

Edited Post #1, to include a jpg of my 11.24 and 11.26 timeslips.

Ranger