Greybeard ZR1

A lot of ZR1's are in bed for the winter, but down south we're getting some of your cold air, so it's time to head for the 1/4mi. at Moroso, West Palm Beach. Anybody else going?

I just got my rebuilt trans back in last week, and I'm hot to take another shot at the elevens. My car has all the usual bolt-ons, Drag Radials, 4.10's, "Forced Air" intake, Rippie (Camaro) flywheel. Headers, 3" exhaust, (no mufflers tonight), but otherwise stock 375hp. motor. Set up like this, with 22lbs. air in the DR's. it cut a best of 12.06@117- 1.74 60 ft.
This was on a muggy 75-77degF. night. With some dry air in the mid-fifties, I think I have a chance to dip into the elevens.

Just a couple of questions:

This is my fourth trans. in the ten years I've had the car, and I'm inclined to start "Granny Shifting" it to save the sycros. How much e.t. will I give up if I avoid full throttle banzai powershifts?
It was cool when the rice boys told me the car sounded wicked, and asked if it was an automatic, but i'm just sick of getting the gearbox re-built.

Also, I've always run 20-22lbs. in the DR's. Should i drop it further to get a better launch? How low have you gone? When do you reach a point of diminishing returns?

I'm not going to get into this engine for porting, or anything else until I can break the 12.00 barrier. Wish me luck! :seeya

Zrxmax

If you can get the same 1.74 60' time, the cooler air would probably get you to the 11s... but the shifting is going to be tricky... Don't know if your really gaining much holding the pedal down and power shifting anyway... Hard to say, but I lean towards saving the trans... it is just not worth the expense to me... I would rather lift just ever so briefly at the shift point... your skills will be tested... :D
Tell us what happens...
Good Luck!
Ted
Sun City, CA

DDSLT5

Good luck!! Hope you can do it - we're all behind ya - love to see a stock ZR-1 hit the 11s. :seeya

90 Corvette ZR-1

That would be impressive

White 68

Hey Greybeard ..What DR are you running ? I was at the strip a few weeks ago and ran 22lbs in my nittos ...Another buddy was running 16lbs in his Nittos on a C4 and had some really good 60ft times. Next time out I,m gonna drop mine down to 16-18lbs and do a good burn out . I was running 22lbs with just a short burst to clean my tires off no burnout . My 60ft times were just 1.9,s .
Back to your question my friend had no problems with 16lbs and was running in the 11,s

LoTu5

Good luck and hope you hit the 11's :steering:

xsmph

Bob, on my Z06 i noticed ZERO gains from power shifting (full throttle shifts) vs. speed shifting (lift throttle shifts). Both passes were made back to back at Bradenton and both times I shifted the same way and at the same rpm. Only difference was on the right foot (lifting vs. to the wood).
I'm with you on the trany. Powershifting feels good, and if feels like the car goes foward stronger upon engaging the gears, but I think it will not cost you any.
Best way is to do two passes back to back and find out for yourself.
Let me know how it works out!
Julio


[Modified by xsmph, 10:23 AM 12/19/2003]

GTB/ZR-1

Hey Bob, I'm heading out to Orlando Speedworld tonight, but I'm looking for MPH more tham I am ET.
I NEED to hit 125 MPH on motor tonight. I ran dscott's 125MPH car @ the SGC gathering, and we were dead-nuts even all the way to the rev limiter in 4th gear. So I'm really hoping it'll happen tonight. The weather will be in the low 50's(high 40's) w/ low humidity(hopefully!)
I'm going to try 16lbs on my BFGs as well to get a good launch. We'll see...

Good luck on the 11 second quest!!! :thumbs:

xsmph

Let me know how that Big Boy runs on cool weather. check this site out to calc. density Altitude.. http://www.csgnetwork.com/densaltcalc.html

it might get to -800 ft for tonight!.. Damn I wish I had my car!!!

Greybeard ZR1

Thanks for the feedback, guys. I'm going to drop the DR's down to 16-18lbs. and do a good 2nd. gear burnout.

I'll post the results, good or bad. :yesnod:

Now i've gotta get out there and get those sticky tires on!

GTB/ZR-1

The temp was good, although humidity was 71%.
On my second run I managed an 11.85 @ 123.5.
My 3rd(and last) run, I went for broke, and missed 2nd badly(twice!). It still turned a 12.20 @ 121.85--methinks that run woulda' been 11.70ish @ 124+ Oh well...
Howd'ya do Bob?

Greybeard ZR1

Well, it got down to low fifties, high forties in West Palm Beach. I got in 3 passes early, after which, it got so crowded that it took an hour for the last run.

First run, I left 25lbs. in the DR's. I left at 3Krpm, no power shifting. -1.95 60ft. -12.39@114.98

Next, I dropped the pressure to 18 lbs. left at 3K and bogged. - 2.10 60ft. -
12.68@113.78

3rd. run I pulled the air filter, and dropped pressure to 17lbs. left at 3K. - 1.99 60 ft.
12.32@116.03

4th run- Waited an hour (the strip was becoming very crowded), upped the launch to
3,500rpm - 1.89 60ft. and 12.17@116.36

The strip was then so crowded (150 cars in the sportsman lanes) that when a Comp car oiled the track, I went home.

Lessons:

I'm a little rusty, after not doing this for a year and a half.

Next time I won't go with 3/4 tank of questionable 93 octane fuel.

Cool temps make for more power, but may hurt traction.
( nobody seemed to be getting great 60ft. times. There were a few Corvettes there, a 2002 ZO6 with intake, and DR's. turning 12.70's, a 50th anniv. automatic turning high 13's, a stroker C5(lost in the crowd, didn't see him run), and a 2000 Viper coupe who was
running stock 335 Michelin Pilots.

BTW, I lined up with the Viper two times in a row, and spanked him good, both times. He got into it too hard and went up in smoke with 2.3-2.4 60ft.times. I think he got psyched by the uncapped LT5. Before we raced, there was a little crowd around the Viper. The consensus was, he was going to shame that old, stock, Vette. When I did a 7K burnout, we had everybody's attention, NOTHING sounds like an uncapped ZR1, NOTHING.... After we ran, the crowd was around the Z, and they wouldn't believe that "all it has is loud pipes". :yesnod: :lol: :lol:

Next: Line-Loc, lower the rear-end, only a 1/4 tank of 100 unleaded, and 4K launches.....pray for cold air.

Fuzzy Dice

:seeya George...good to see you last night...sorry to hear about your last run...I went up in smoke on mine :( ...with some seat time and a well prepped track your beast will scream... :thumbs:

White 68

Greybeard ..Have you ever dynoed your car with the 3inch exhaust uncapped ? I,d be interested on how much hp you pickup and also torque ...
speaking of line locks . how are you holding the car in the lights and keeping your rpm,s in check?..once staged I have trouble keeping my car from rolling through the lights as I bring the rpm,s up and watch the lights . A line lock would really help reaction times I bet...
Nice times with no motor work ... :thumbs:

LoTu5

Nice one Greybeard :hurray:

:seeya

CDNZR

Maybe next time Bob. We all pulling for you to get her into the 11's! IMHO, you may need to power shift your Z to get her into the 11's. :thumbs:
:cheers:

Redmanf1

He is probably doing the heel & toe thing. Also I imagine he is using the soft setting on the FX3 for weight transfer.

Greybeard ZR1

Yes, it's tough to keep the proper revs at the line while keeping the car from rolling. I just let the clutch out enough to keep the drivetrain from going slack, but not enough to roll the car through the lights. I think the line-loc will get me a tenth right there, and be more consistent too. Any opinions on that from those who've installed one?

I'm intent on milking the last tenth out of this setup that i'll try some more tricks if you've got them. Here's some that i've been too lazy to do so far:

Unhook the links to the front anti-sway bar, or remove it entirely ( for better weight transfer)

install FX3 shock controller with Drag chip, which I think softens the front shocks (for more lift), and keeps the rear stiff. (correct me if I'm wrong) Anybody got one of these for sale, cheap?

Lower the rear, with longer spring bolts.

Rippie Drag suspension brackets. I've never spoken with anyone that uses these, that could say how much they help, if at all. :confused:

Lightweight hood, lose those heavy pop-up headlights.

remove side mirrors, for a better CD.

Skinny tires up front. Is there a way to put radial skinnies on a ZR1 lookalike wheel with the proper offset? If not, what's the best radial combo that won't make it look too much like a dragster?

I'm tempted to go with a stickier tire, but then I'd be spending all my $$ on driveline parts.
There are some cars in the nines running BFG DR's, so I may stick with them.

BTW, the only time the car's been dynoed it pulled 328rwhp on a hot day, but with the headers on, and a Borla "2 3/4" setup. It's no magic motor, but I'll bet it pulls slightly more than a stock 405hp. ZR1 does, when the pipes are uncapped. I'm guessing 350rwhp.

I'm even thinking about dyno tuning the stocker. Making a race-only chip for 100 octane unleaded that dials out spark retard, optimizes everything for the open pipes, etc. I think there's more h.p. in the stocker. Has anyone ever done this?

I could even go with an automatic. The big 415's are starting to run them, why not a stocker?

Gee if all these little things really added up, you could get a "stock motor" ZR1 in the MID-elevens. Or lower!

BTW, some would say "why bother, when you can just port the plenum and injector housings, and get to the same numbers at the strip?" Well, i just love this motor, and nobody I know has left it alone and optimized the car around it. Just like the Super Stockers of the sixties, I think there needs to be a "benchmark" as to what you can do without hogging out the plenum, or putting different pistons or crank in. And I want to find out. Plus, I'm cheap. Plus, I'd like to put a little sign on the back that says, "You have just been spanked by a 'stock motor' Corvette" :lol:

I invite your suggestions.

GTB/ZR-1

HUH??? :confused: :confused: :confused:
You talkin' crazy man!!! :D
Experienced Roadracers/Autocrossers heel-toe when they need to downshift quickly when braking into a corner. I sure hope Bob wasn't using all 3 pedals simultaneously goin' down the track ;)

415LT5

The line loc helps with the heating of the tires. I wouldn't try using one at the line with a standard transmission. Too much going on there for me. I usually see them being used at the line with automatics. I think you have the right idea Greybeard. It just takes a hundred passses or so to get it down right. Plus heating the tires better will defenatly help with the 60 ft times.