LT4 LT4 Fastest Convertible built through 1996

[benchrgw]

I've been around the Corvette hobby since buying my first in 1976, a L82 4 spd 1974, since then have had 12 different Vettes including some fairly rare ones including a 365 horse '64 Coupe with factory a/c - should have kept that one.

At any rate in researching my '96 Collector Editon Convertible with LT4 I can't find any convertible up to '96 that came close to its performance numbers since the ZR1 was never offered in a convertible - Some of the 427's got close but none seemed to post actual 0-60, 0-100 and 1/4 mile times in stock trim that the LT4 is capable of running and needless to say handling of the early Big Blocks was not good - old technology and way too nose heavy.

So does that make it officially the Fastest Production Corvette Convertible Built to that
point? Your thoughts? :confused

 

[Evolution1980]

I'd put some money down on a '69 L71 to run the LT4...

What is your criteria for "fastest" Corvette? 1/4 mi? 0-60? Top speed? Something else?

 

[C-4 Now]

LT-4's are great but better not try to outrun B2K convertible 1987-1991

 

[benchrgw]

I should have been specific - B2K - Callaway Twins were not a GM production although available as a dealer special order - I meant to limit to production rather than tuners such as Callaway or Ligenfelter - Granted stupidly fast cars but at $33,000 option on a $32445 base hardly a production option. But you're right I don't want to run one. - You lucky dog

Evolution - on top speed LT4 would win just on aero-dynamics (C3's above 130MPH get pretty scary) but most Car & Driver / Motor Trend etc tests then to now seem to show LT4 a few ticks faster even in the quarter mile - of course tires back then stunk so who knows.

 

[Evolution1980]

...but at $33,000 option on a $32445 base hardly a production option

Evolution - C3's above 130MPH get pretty scary.

Well, the L88 option was the cost of the car. And I think the ZR1 option was also the cost of the base. (It also wasn't exactly factory as the engines were produced by Mercruiser.)

As for C3's...Don't know about the older ones, but I'm completely comfortable in mine at 150mph. 'Course, I have my aligned for straight line top speed. I think the LT4 was good for over 150, no?

 

[DRTH VTR]

'Dre, yours is nowhere near stock. I suspect that there were few stock C3's that would go 150MPH. I have read that the front wheels get pretty light at high speed, as well.

 

[*89x2*]

I should have been specific - B2K - Callaway Twins were not a GM production although available as a dealer special order - I meant to limit to production rather than tuners such as Callaway or Ligenfelter - Granted stupidly fast cars but at $33,000 option on a $32445 base hardly a production option. But you're right I don't want to run one. - You lucky dog .

Facts are facts, RPO B2K (Callaway Twin Turbo) was a factory option, no other outside company has ever been contracted to make an engine for Corvettes and hold an RPO before, or since.

Enjoy!

http://www.corvetteactioncenter.com/forums/forumdisplay.php?f=134

 

[benchrgw]

Evo - Actually if we knew then what we know now we'd own a bunch of L88's 1969 L88 Option was $1032 and only $947 in 1967 which if you had one today you could probably name your price to right collector - Car and Driver showed dead stock LT4 at 168 top speed in 5th gear - 6th overdrive was actually slower.
ZR1 never went in a convertible - but was installed in coupes in Bowling Green despite engine being built by Mercruiser as you said. Last yr for ZR1 '95 list price was $31258 so not quite double the coupes base price

 

[benchrgw]

89x2 - RPO - ZR1 built by Mercury Marine under contract to GM and was actually line installed at Bowling Green - B2K as I recall was subassembled at BG and then shipped to Callaway where they worked their magic. Right - wrong ??

 

[*89x2*]

You are right w/ the ZR1 engine being built in OK by Mercury marine however, it was a GM design and was done under contract w/ the Lotus partnership as well.

close, but not the same.

 

[benchrgw]

DRTH - yeah if you read the history on the C3 body development the chin spoiler had to get bigger and bigger to keep nose on the ground and horsepower requirement for 100 mph from being more than the C2 it was to replace - dang thing wanted to become a wing. Chin spoiler also helped push more air through an engine compartment that didn't cool all that well.

 

[benchrgw]

89X2 Rumor has it they are playing with a Turbo C6.5 or whatever - showroom 600+ horse - I can hear my insurance man laughing already

 

[*89x2*]

89X2 Rumor has it they are playing with a Turbo C6.5 or whatever - showroom 600+ horse - I can hear my insurance man laughing already

Amen to MORE POWER!

Also, WELCOME to the

 

[benchrgw]

Thanks - great site for we Corvette addicted types. Thank goodness spring finally arrived.

 

[Evolution1980]

'Dre, yours is nowhere near stock. I suspect that there were few stock C3's that would go 150MPH. I have read that the front wheels get pretty light at high speed, as well.

Never said it was...
I was just making reference to the notorious C3 front-end lift at high speeds. Which yes, was very unsettling before I had the rack & pinion put in and an alignment done. At 120 the front would feel very light and want to wander around. That coupled with a worn steering box was a bit unnerving. But after the Steeroids and an alignment, it was awesome!

I don't think any factory C3 beyond the '69 hi-perf 427's would be able to challenge the LT4. If we kept everything "as is" for the model year, I'd say only the L88 or ZL1 might challenge it in the 1/4 mile. But running on 7-8"(?) bias ply tires wasn't exactly the best thing for nailing down a 1/4 mile sprint. :L

 

[6 Shooter]

benchrgw - Welcome to the

LT4's were/are Sweet Corvettes...
​

Later . . . . . .
6 Shooter

 

[Toms007]

Never said it was...
If we kept everything "as is" for the model year, I'd say only the L88 or ZL1 might challenge it in the 1/4 mile. But running on 7-8"(?) bias ply tires wasn't exactly the best thing for nailing down a 1/4 mile sprint. :L

That was going to be my comment. I think that if you could get the power to the ground the L72 would be hard to beat.

 

[C-4 Now]

I still remember 1st new LT4 I drove! I was thinking this thing feels way stronger than just 30HP more than a LT1. And thats from a guy who has owned many Vettes including a 67 427-435 and 68 L-88 and a few well modded small block Vettes! I can't imagine many being disappointed with these cars!

 

[nuck]

I think an LT4 would hand it to an L71 car unless the older car had slicks. I remember one of the car mags ran a stock early C5 against a restored 427-435 and the big block got destroyed, even with modern rubber(N50-15s?). Nose heavy and peakier engine in a heavier car with worse aerodynamics. If you believe, as many do, that the LT4 is the equal of the early C5, at least in a straight line, then the results should be similar. The C5 was running 13.1-13.2 and the C3 was 13.5-13.6.
A strong LT4 can run under 13.0 seconds, and I think the discussions of horsepower in Stan Adelman's comments in the 1996 performance review in the Tech Center are accurate.
Now if you put some 335 30 18s on the older car maybe the results would be somewhat different but I think the bottom line is the 435hp car was more like a 350-375hp car, and the 330hp LT4 was under rated.
Just bench racing of course but the road tests I recall on the old solid lifter big blocks were mid 13 second results. I know of one LT4 coupe that ran a 12.8. I doubt a ragtop could match that but should be within a couple of tenths.

 

[4CAM LT5]

I really enjoy mine...for every type of driving, regardless of the numbers. The LT4 is just one sweet motor, coupled to the ZF six-speed.