jaybird81

Well I finally have my 81 running good. I've done all the improvments to it that I am going to do for a while. I put a stock non computer controled carb on, an HEI distributor w/ a recurve kit a K&N air filter, true duals with flowmasters (no cats, but still has the manifolds), I tok off the AIR pump, and put in a cooler thermostat. Without the carb it's like a stock L48 vette. It's an auto with the stock 2.73 gears with posi. I have 60 series tires on it and thats about it. I am thinking of taking a few runs with it at the local track. Just to have fun. I know its not a fast car but I took my dads 6 speed c5 to the track last time and because i"m not good with a stick I turned a mid 16. So if I am going to turn a mid 16 in a vette it might as well be my own. My question is what are your stock L48's running (or any stock C3). also any ideas of what mine might run. Also in a few years I am thinking of putting a 3.55 or 3.73 gears in and 202 heads. It's my belief that those two mods along with what I allready have done would really bring it to life, am I right?

Marc80

I took my 80 out to tthe track before I did a complete rebuild with a higher performance motor. My best time was 15.02. You should have seen the motor. It was black like a bbq. The suspension needed to be rebuilt, the breaks, the wheel bearings, shocks, u joints ...on and on. Now, restored, I am getting 280 HP at the rear wheels and it really moves. I am curious to run it again. I think the old motor was getting about 190 hp flywheel ...probably about 150 hp to the ground. I hope I could run about a mid 13 now.
I would expect you would also run a 15, topping out around 95. The biggest gain in power seems to be from the cam/head combo.


PS:(355 cid w/headers and 3.07 gear)

Have fun.

Yeller81

My Stock 81 runs the 1/4 in 16.448 , 83.86 MPH
This car is Stock with 83,000 Miles on it . Just to give you an idea.

:steering:


[Modified by Yeller81, 8:52 AM 10/21/2003]

tabbruzz

See my sig below.....My 79 is stock except for the mods listed....

Glensgages

jaybird81:
I took my bone-stock, then 18,000-mile '82 to the strip last year a few times, during THE hottest part of July/August.
Deep-staging (for quicker Reaction Times, which results in slower ETs), I recorded ETs from 15.90 to 16.10, all @ 86 MPH.
(even with just 200HP {advertised}, and 2.87 gears, it had a hard time 'hooking' the BFG TA Radial 255s; I think the 3.06:1 1st gear was the reason)
I also saw a guy there, in an '80/'81 (?) 4-gear, bone-stock, 40,000 mile car, running 15.20s; forget the MPH.....
I recently swapped the 2.87s to 3.73s; stay tuned for hard-core MPG/ET results.....

pingdashf

Bone stock '74 L48's best time is 15.02. That's as fast as I can get her without mods so I'm not taking her back to the track until I get some mods done. I would think with your setup you'd be in the mid 14's, but that depends on so many things you really wont know until you put her on the track.

Glensgages

Guys, I've posted this info before, and will do-so again. Maybe it'll benefit somebody (sorry if you've read it before) ...
I bought my '79 Z28 25 years ago, this Friday (24 Oct '03). It had the 'LM-1' 350/4-bbl (2-bolt block, 'standard' rods, cast crank, cast pistons, etc.), THM350, 3.42:1 non-posi rear-end, and 225R70/15 UNIROYALS.
When the warranty expired, we added the following to the 'stock' short-block:

650 dbl-pump Holley; Chevy dual-plane intake (327/365 HP from mid-'60s Vette); 64cc/1.940"-1.500" valve heads with nothing but a valve job; hydraulic cam (.450"/.450", 288*/288*, 224*/224* @ .050" lift); 'on-sale' headers (BlackJacks?); the Y-pipe/cat/Y-pipe 'got lost' and was replaced by 'straight-pipes; a B&M shift-kit; and slapper/traction bars.

I never ran the car 'before'; road-n-track tests of the day 'boasted' of 16-flats/16.40s @ 84, and mine CERTAINLY wasn't much better.

(in fact, two high-school buddies bought new Z28s; one a '78/4-speed, the other an '80/auto. The '78 ran 15.80s {with OEM 3.73s}; the '80 ran low 16s)

The 64cc heads raised the CR from 8.2:1 to approx 9:1; instead of 'nosing-over' @ 4800 RPM, the 'new' cam pulled to 6000 RPM, but I shifted @ 5500 (#1- I was 'scared' of the cast pistons causing 'oil-pan-failure', and #2- the 3.42s were too 'tall' for 6000 shifts). The shift-kit 'chirped' the tires going into 2nd gear, and it idled @ 800 RPM.
(in fact, WITHOUT the cat, I passed a few Pa. Emmission Tests in the early/mid '80s, by leaning-out the mixture screws)

On the Uniroyals, with open-headers, and running SUNOCO94, AMOCO Gold, or Hi-Test GULF, it ran effortless 14.40s @ 97 MPH, no matter how hot & muggy it got.
I swapped the 3.42/open rear to a posi/4.11 after a few years; it then ran 14-teens, with no MPH increase (looking back now, 4.56s woulda been ****, but...)
I ran that motor like that for 9 years, until we put the current 12.80 @ 106 MPH set-up in it...
The point here, is to show just 'what' can be done to a 'stock' bottom-end, and 'how-fast' you can go without taxing it, too...

Feel free to ask questions :thumbs:

Corvette_fetish

Wow, your times are a little better than mine, and we have some of the same mods. I actually have an '85 L98 transplanted into my '79 (- the TPI). I too have 3.55s, headers, the '85s dual exhaust, holley carb, TH400 ... My first run was a 15.8. After that I started manually shifting and ran consistent 14.8 1/4 miles.

flood

I have a stock 75 w/4 speed.

my best so far at 4500 ft above sea level is a 15.8 @94mph

I think at sea level I could cut a 15 flat , maybe better :confused:

tabbruzz

Yeah, my 79 seems to run pretty good. I will run it again this Sat for the corvette challenge at E-town. I do think in the much colder weather that she will run very low 14s....

Corvette_fetish

Good luck this Saturday! I too am looking forward to cooler weather to help my car's performance. I'd like to see low 14s too! Unfortunately I'm in Phoenix and were STILL having 102 degree + weather here. :mad


[Modified by Corvette_fetish, 11:23 AM 10/22/2003]