Bee Jay

I've been fiddling with the fuel injection and ignition timing since I put this LT4 Hot Cam and RPM AIr Gap manifold in two months ago. I think I just about got everything dialed in so I lower the 295s to 30psi and I put $20 of Premium gas in the tank and head out toward the beach.
My first run I engine braked and launched at 2000rpm. The car just sat there forever spinning the 295/35-18s. I shifted at 6500rpm, and more tire spin. The car pulled really strong in second and third especially about 4000rpm. With a very bad launch I almost matched my best time with the old cam and intake. 13.06 seconds @ 114.4 mph. I was determined to get into the 12s today, so I turned around and did it again, this time into the wind. Tire spin again and a very late shift into second scrapped this run for sure, but it was a fairly decent 13.7 something. This early Holley Fuel Injection won't support redlines above 6500 rpm and it won't rev past. I didn't even bother to write this time it down. At least by now, the rear tires are warm. I turned around for run 3, again with the wind. I only power braked to 1500 rpm, barely above idle. But when I released the brake and buried the throttle, there was no tire spin. None, nada. I short shifted at 6000rpm this time trying to avoid the mistake of my second run, and again, no tire spin, no chirp. The car was hooking and moving, and again at 4000rpm it pulled like never before. In third gear the tach needle swung toward redline. The car is only good for about 140mph in 3rd, so I was reaching for the shifter. I never had to do that in the 1/4 mile before. But just before shifting the G-tech flashed and I backed down. I was hauling *** but I didn't know how much till I saw the numbers on the G-tech.
11.50 seconds at 135.8 mph. HOT DAMN! SHOOT! and Mother Fuddrucker.
I was shaking, so I drove the car home and put it in the garage. I don't smoke, but I need a cigarette. I need to go out again tomorow and see if it will do it again with no wind. I wanted in the 12 second club and jumped right into the 11 second club. I won't claim membership untill I repeat, this just seems too good to be true. But I trust my G-tech.
I love this car. I guess this cam works really good with the AFR 195s, the RPM Air Gap, and three inch Flowmasters. I was thinking of going to 3.7 gears in the rear end but I don't want to have to shift into overdrive in the quarter, so I think I'll stick with 3.55s..
Bee Jay

MIKE80

11s! Nice run! Let us know how you make out tomorrow

gkull

My $800 dollar Tom's posi unit finally expired. So after 20+ years of 4.11 I just bought 3.55 gears to go with my tko 600.

I could go about 135 -140mph before shifting into OD

Aggitated Monkey

Very nice Bee Jay. You have planned an work hard for it. Enjoy

chevymans 77

Sounds like you goter tuned in just right

did you run it with the old set up after removing the crash bar and stuff?

Bee Jay

Check it out:
http://forums.corvetteforum.com/c3-t...-114-6mph.html
Yep, I ran a 13.04 just before changing the cam and manifold. I just looked up some 1/4 times for some new cars. This is Z06 times. I don't believe I'm making 505hp, so I'm really skeptical about tomorow.
Bee Jay

Gordonm

Beejay, As much as I want to agree on your times something sounds amiss. For a trap speed of 134 mph you have to be making close to 600 flywheel HP. That is a huge jump in trap speed from where you are at. Even a trap speed of 125 mph requires 500+ HP and the extra 10 mph or so really ups the HP. The Gtechs are good but for real accurate measurements a trip to the strip will confirm everything. If you are truely at 130+ mph man that is just flying. There are some heavy hitters not running 130. Keep us posted.

Glensgages

as a general rule of thumb, a car that is well set-up & sorted-out, using all of it's available power & TQ to the ground from launch, will 'hook-factor' in the area of 1320-1330:
the 'hook-factor' has been used for many years in helping Stock & Super Stock/class drag-racers determine how efficient they are at making a perfect run, and is calculated by multiplying the ET by the MPH... these tells them if they are leaving ET on the table by running to-tall a gear ratio, or if traction is plauging them

ET shows how efficiently you are applying your power to the ground in 1320' via traction, gearing, suspension, and TQ-multiplication, while MPH is indicative of the power you are making at that particular time

the first run of 13.06 @ 114.4 equals 1494.xxx, while acknowledging tire-spin:
a 114 trap-speed is typical of a car that is properly geared & tire'd, running 11.50s

The last run mentioned, with traction, 11.5 @ 135.8, delivers a 'hook-factor' of 1561.xxx, a worse number



I assisted a friend with his back-halved, 3300-pound '83 Monte Carlo that ran 10.0's @ 130 MPH consistently (3 consecutive 2nd Place points finishes), powered by a 12.5:1 468 BBC, THM400 with an 8" spragless converter, 4.88:1 gears, and 33" x 15" slicks:
while it's possible the Monte could've gone quicker & faster, we concentrated for consistency instead, but it is doubtful that it could've run 135 MPH in 1320'

Data from a legitimate strip might prove me wrong (and the incremental times provided on an ET-slip would help you in further tuning & driving decisions), but I'm skeptical of those times & MPH:
I'm not-tryin' to burst your bubble, Bee Jay, as I am only offering what little I have gathered at the track

Bee Jay

Yep, I'm thinking it was a fluke or wind aided or something. I didn't want to turn the g-tech off and let it flash 11.50 and 135.8 all night. The car ran consistant 13.0s before the manifold and cam swap so maybe I can get it in the 12s for sure. It's raining today and my makeshift dragstrip is too well traveled by commuters and the Po Po on weekdays, so maybe next weekend I can get some good legitamate numbers. That run sure felt strong though. I'd be happy with a 12.99. Sorry to get you guys excited.
Bee Jay

Glensgages

no-reason to apologize, and because the car is obviously pulling 1300'-plus, you might be capable of 'working-around' running the car a full 1/4-mile ~
if you can convert your G-Tech distance to 660', an 1/8-mile, and work-on getting the car to run quickly in that distance, it should easily equate to 12's in the quarter-mile

8.30's @ 83 MPH, should do it (I go 8.20's @ 84, and run 12.80's @ 105), and those speeds might-not attract as much attention from the federales...

I believe my 330' time is 5.33x... get that car to consistently hook and run the first 300', and it'll produce stellar ET's for you



~ EDIT ~let me do some digging-around, and maybe I can find some of my old ET-slips & post that information here, so you'll have something to compare against

gkull

Yep, You need a date with your local drag strip. Which one is closest to you? How high of lateral "G"s has your g-tech recorded?

Bee Jay

So, is it possible that the 11.50 is good and the 135 is bogus? Hey, with 3.73 gears, what rpm are you turning at the end of a quarter. I'm trying to decide if 3.73 gears are for me and my 700R4.
Bee Jay

gkull

This only gives you the 3 & 4th gears Just plug in your tire numbers

http://700r4.com/speedoCalc/rpmcalc.shtml

Glensgages

that is possible, but unlikely, as you felt like the car hooked, and wasted no-time spinning it's tires:
a 135 MPH trap-speed is typical of a car running well-into the 9's, and for him to run 'just' 11.50's, he'd have to have spun big-time off the line, then run like a raped-ape to the stripe to reach 130+

I probably wasn't clear with my earlier post, as my '82 Corvette runs 14-flat @ 97, with a best of 13.93 @ 99+ in killer atmospheric conditions:
I shift @ 5000 RPM, and trap just before the shift-lite blinks in 3rd Gear with 3.73:1 gears & 700-R4

My 28,000 original-mile 1979 Z28 runs 12.80s @ 105 MPH (best-of 12.779 @ 109.72 MPH on a cool & dry day), but it is set-up to compete at the strip, with no provisions for street useage (8" converter, 4.10 gears, open-pipes, 28" slicks, etc), while using a streetable motor (10.3:1, iron-head, hydraulic flat-tappet cam, 5,800 RPM shift) in the 3,700-pound beast



it could probably go quicker & faster, but for durability, I don't buzz the snot out of it

After rummaging-around, I have found my old log-books from the 1992 NHRA Division One E.T. Bracket Finals (I haven't raced it since 1993):
my quickest run of that weekend was a 12.799 @ 104.07 MPH, just barely burping the throttle at the strip (I beat my opponent to the finish-line by .046-seconds... my records show that 41 minutes later, I ran 104.77 MPH, losing with a 12.815 ET)

Here are the incrementals from that run:

0060' - 1.808
0330' - 5.242
0660' - 8.140 @ 84.72 MPH
1000' - 10.653
1320' - 12.799 @ 104.07

Solid LT1

In my book only 1/4 mile claims are ones that can be backed up with a timeslip from a track (my best 12.28@117MPH.)

Stu's81

+1

Rebelrob

BJ, that's a tuff looking car. I like it.

Bee Jay

Not trying to get in your book, but G-tech and GPS technology is acceptable to me. How do you think all of the magazines road test? There is no local track for me to run to and test regularly. I will retest soon and find out what the car is capable of. Congrats on your 12.28@117. I hope to do as good someday.
Bee Jay

BKbroiler

11.50 at 135 mph? I believe thats what your meter told you but there is no way in the world that is accurate. Check any one of the HP to trap speed to weight calculators on the internet. Assuming your car weighs at least 3,400 with you in it, that works out to 650 to 700 hp based on the trap speed.
I think you mentioned in the past that your nearest track is 100 miles away. I know a number of people who drive that far to a track 20 times a year. Until you post some times slips from a sanctioned track with numbers like that, plenty of us here will be very skeptical.

Bee Jay

Thanks Rebelrob.
Bee Jay