brassplyer

Please indicate year, engine, auto or manual, differential ratio and anything else you think is pertinent. I'm wondering what realistic performance can be expected from pre factory detune era and post factory detune era C3's. Also wondering how much performance difference between auto and manual. Ideally looking for numbers of stock Vettes but any that aren't wildly modded are okay - maybe an aftermarket ignition, upgraded carb.

You can indicate 0 - 60 as well but times at a track presumably are going to be more precise, not subject to inaccuracies of stopwatch use combined with questionable accuracy of a given speedo.

Thanks.

An added caveat after seeing some responses - I'm talking about running with modern tires.

gkull

The word of stock takes most drag race type people out. Not many stock people do anything, but take their cars to shows and then their are NCRS people that are into pure vettes. But for many years I went to the Sacramento All Corvette drag races on a sea level NHRA track and it is amazing how slow 427/390 hp and the 327/350 ci inch vettes are. It takes some mods to get a 355 ci to be a consistent sub 13.00 machine with a modded TH350.

Most people are a little more serious that actually try to compete and are willing to tear things up This forum has some nice cars!

brassplyer

What do you consider "slow"?

I see a number of ostensibly stock C2 and C3 Vettes on Youtube running 13's and 12's on street tires but I don't know how stock they really are. Wondering what results people on here have gotten.

I see one '69 427 L88 supposedly factory stock running 11.49 with only a so-so reaction time but that's apparently a super-rare example. I'm thinking about more run of the mill BB cars.

Big Block Dave

Although not purely stock, my 1974 Ls4 4 speed went 13.44 @104 on firestone radials.

There were two modifications at the time. Msd distributor set to 38 total, and hooker sidepipes headers.

Otherwise, the car had a stock cast iron intake, qjet, m20, and 3.55s. I bought the car completely stock with neglected engine bay, so highly doubt anyone stuffed in a cam or any sneaky headwork.

Today the ls4 resides on an engine stand.

BKbroiler

My car looks completely stock outside, but has a 383, reworked TH350 with 3,000 stall and 3.73 gears. It has gone 12.15 at 110.

jb78L-82

What's your guess on Gross HP and RWHP for that 383 with that outstanding time? You didn't do that time with those BFG Radial TA's? I would be shocked if you did.......

BKbroiler

I use drag radials at the track, M/T ET Streets now, BFG Drag Radials originally. A few years ago, just for laughs, I made a few passes with my regular BFG Radial TA street tires. My best time was a 12.80 on one run but it was very erratic.

gkull

Slow is anything over about 13.50 seconds. We successfully banded all cars over 13.50 from competing on divisional bracket race days. things got so out of hand with people showing up in the family station wagons and pickups that Saturday races starting at 5 pm couldn't even get to the final bracket rounds till 2 AM Sunday. Nobody wants to see one wheel burn outs and broken down junk cars.

If somebody is posting videos of their drag racing it means that they are a little bit serious and it is not going to be a stock C-3 vette

ajrothm

Ben Lurkin

My 1972 LS5 with bias ply tires, M21 transmission and 3.08 rear would run 14.0 at 98 MPH.

jb78L-82

Most of the BB manual trans C3's would do low 14's back in the day with the autos in the mid 14's including the 427's as well. The tires at that time simply had poor traction and were not wide enough to put the power down, coupled with GROSS HP ratings which are very misleading (thus the switch to NET HP ratings in 1972) since they do not represent usable HP in the car. The pre 1972 Gross HP ratings are an easy 12-15% less in real world NET HP. On a great day with a tail wind a 70 LT-1, 70 454, or 69 427 might break high 13's, if you are lucky.

A 435 GROSS HP 427 is actually around 375 NET HP which equates to even less RWHP...the numbers are inflated, coupled with extremely poor tires, results in poor 1/4 mile ET's back in the day. Most modern updated engined 355/383 with decent compression/great aluminum heads and a high lift roller cam would crush any of the aforementioned BB/SBC stock C3's. Forget the modern C5/C6/C7's...my 10 C6Z06, totally stock, I've seen run on stock treaded street tires 11.2 sec in the 1/4, 0-60 MPH 3.5 seconds...its almost ridiculous.............LOL

The 69 L46 and 70 LT1 are the only SBC C3's with fairly stout GROSS HP and 350/370 GROSS HP, respectively. These 2 only could achieve around low 14's in the 1/4 mile. The 71+ LT--1 is really nothing special beyond the later L-82's with 9:1 compression and 330 GROSS HP...the same LT-1 in 1972 rated as NET HP had only 255 net HP......74 L-82 is rated at 250 Net HP as well..there you go!

leigh1322

My stock 70 LT-1 ran 14.0s at 102-104.
Thats in a Z28, with headers, all else stock 3550 lbs.Fresh, rebuilt, blue-printed, super-tuned carb/distr, but all stock motor.
4:11 with a M21 or 3:55 with a M20, ran both ways, same 3 gear ratios, same track time.
That was before the 30-30 cam, all that did was make the MPH jump to 104-106.
60 series BFG street tires. Lousy 60 ft. like 2.5?? Rookie driver.

bazza77

this was me in my L68 4 speed not long after I got it on the road . Absolute rookie driver , mid 14,s at around 100 mph in the 1/4.

Barry's70LT1

'70 LT-1, with open headers and 750 DP Holley, otherwise all stock. Best 13.02 @ 110.30
'71 - '72 timeframe ( No 60' times)
Goodyear Polyglass, 60 series
Muncie M21, 3:70 rear
Weight at track scales 3,342 lbs.
Sea level track.

427Hotrod

It was possible to get the big blocks and hot LT-1's in the 13's without too much trouble. Bumping timing and driving well. A good four speed guy could do well. With any sort of traction like 7" slicks you could go 12's.

A 427/425 C2 could do low 12's or high 11's with some 4.56's in the rear. An L-88 with slicks, gears/headers could go 11's all day.

But as mentioned...DEAD STOCK made for some slow stuff.

Also remember when comparing.....back then the 1/4 mile trap speed was calculated by the time it took to travel the traps that were placed 66' before AND after the finish line. Today...speed is calculated in just the 66' trap BEFORE the line...there isn't a trap after the finish line. That means the trap speeds back then were higher than what you would see today in the same car.

JIM

brassplyer

The gross/net issue aside, I've always heard manufacturers often understated (i.e. lied about) true factory horsepower numbers for insurance purposes.

jb78L-82

The conservative HP ratings generally occurred in very limited cases involving the BB engine ratings such as the L88 427, maybe some of the late 60's 427/435+ Gross HP ratings, and the LS6 454/450+ Gross HP engines, for insurance purposes. This issue was not wide spread, especially not effecting the SBC motors, but really only the top Gross HP BB's. Either way the numbers were inflated just being a GROSS HP rating and the 0-60 MPH times and especially the 1/4 miles times confirm the distortion. The NET HP/TQ ratings post 1971 (staring in 1972) are definitely more indicative of the engines' actual useable HP/TQ and the speed trap times reflect those more accurate numbers........

jb78L-82

Not surprised with that time with open headers and a 750 Holley DP! Those 2 changes alone could be worth 40-50 Gross HP since the stock exhaust was choking that 370 gross HP LT-1 which would put that engine at 410-420 Gross HP with significantly less weight than the BB C3's......

george2066

slow is a 1977 l48

brassplyer

Okay, not too far off my personal notion which has always been that 13.anything is the start of "fast" territory.

Lol. Years ago someone at our local strip was famous for winning several run-what-ya-brung nights with a bone stock old Volkswagen hatchback because their times were so dead-on consistent.