I was wondering how fast (top speed) a stock or relatively stock LT4 powered Vette should go, and was it limited by gear or power? Mine is a convertible and I maxxed out at 160 in 5th and ran out of power. Does this sound right?

 

Per January 1996 issue of Car and Driver, the top speed of a Grand Sport is 168MPH @5800rpm in 5th gear.

Top speed in 6th is 140mph @3200rpm, top speed in 4th is 135mph @6300rpm.

I'd say 160 in ragtop compares pretty well to C&D's 168mph in a coupe.

Shouldn't ask, but where did you do this & how long(time/distance) did it take you to max out????

 

Depending on where you look, it can vary from 168 - 175; likley somewhere in between. Personally 162 for me ang still had plenty to go just ran out of clear road. Slowing to 80 felt like I was going 40 and the rotors were blued from the rapid heating...

 

133mph on the dyno.... in 4th gear :). I'd venture to say my car could go 180 - 185 :yesnod:

 

and just where on long island did you obtain that speed?
my LT4 has no pull in 5th, and would need an extremely long road to reach 150. I tried at pocono, and no way did I even see over 135.

 

I just looked to see what mine with 4.10 gears might do. Looks like I would run out of RPM's (6300) in 5th at 153.5mph. If I then shifted to 6th at 153mph/6300rpm my revs would drop to 4200 with loss of torque because of higher gear ratio, I quess it would bog and start slowing down??

So I'd guess with 4.10 gears the top speed would be reduced from from 158 to 153.

 

It doesn't take that long of a road, ask me how I know.

Your LT4 should be able to spin 6300 RPM's, if it's got the stock rear gear in it you should be able to pull 140 at that RPM. You shouldn't need much pull in 5th. Even my LT1 would pull pretty easy in 5th gear, it doesn't take long to grab 10 extra MPH until you get way on up there and the wind resistance starts taking it's toll.

How long is the straight at Pocono? Granted I know you have to slow down to make the turn, something you don't have to do on an interstate romp.

 

I was surprised to find that top speed is reached in 5th gear. At about 150 I shifted into 6th and with foot to the floor began decelerating. Shouldn't tell you where I did this as it wasn't legal, but I had about 3 miles to play around and probably maxxed out after 1 or 1 1/2 miles in 1 - 1 1/2 minutes. Thanks for the input.

 

Maybe you should have that thing checked out. You should pass 135 with ease.

 

Ive had mine (93 hotcam/headers LT1 6spd) up to 150 MPH, plenty to go just got scared since state troopers patrol that area regularly.

had a nice road though. Too bad I didnt get to see how fast it would go since I dont get those chances much.

 

I wish somebody would just pave a 5 mile stretch of road that you could use to figure out top speed. That should be plenty of room to get there and plenty of room to slow back down without killing your brakes.

 

:iagree: :iagree: :iagree: You should hit 150 with little trouble. I believe there is a forum member (bluewasp ?) who says he had his GS to 178. I've heard others at the corvette action center say 175+ too.

 

135 does seem low... you may have some issue there and may want to get that checked out. My LT-4 is nothing resembling stock other than exterior and suspension (i think the suspension is stock... but who knows). I got on my car here on a section of road and ran mine up to 145 before i chickened out and backed out of it... and the car was pulling awefully hard! 145 felt sooo smooth in the car! I can't wait until I get it back from the shop and can run more boost!!!!
I tried running my 95 5.0 mustang on up there in speed, but picked a bad road... 35mph zone which happens to be heavily patrolled by the po-lice and I'm just a booking along this open 3 lane (one each direction with a turning lane) in a section with no turn off roads... no cars... and a bridge to cross... so I'm backing down and I look up and I see a nice shiny crown vic headding my direction comming around a slight curve... sure enough blue lights then clicked on, and my my hand instinctively went into the motion of dropping back down a gear into 4th... by the time I decided to pull over a 1/4 mile or so down the street... and after he finally caught up and pulled in behind me I was praying he didn't get my top speed because when we passed I looked down and saw 128 on the speedo (which translates to 125 b/c my speedo is 3mph off). This fine officer walks up and asks if I know what he clocked me at... i had no clue and answered as such... he said 90... (sigh of relief on my part) :yesnod: and I think... well that's better than 125... then he gives me the whole thing about being able to take my license and that he could impound the car and what not (which i knew already full well). I then explained that I had just gotten the car back from the shop after having $7,500 in engine work done and so he says "do it in the country but not in the city... :nono: I've got a vette myself and I like to open it up every once and a while too, but you can't do that in the city in a 35 zone. :banghead: go figure! So after an 8 hour driving class... having the worst offense in the class, and paying higher insurance I came to the realization that you shouldn't try that in a 35 zone! Granted my best friend was pulled in his ferrari 308 dino gt4 doing 145 in a 45 and the cop let him go... but I'd guess that's a rare occasion!


[Modified by GS387LPE, 1:32 PM 9/12/2003]

 

there is nothing wrong with my car. It runs perfectly fine.
I have no idea how long the back straight is at pocono.
It pulls hard all the way to redline in 4th gear.
once you shift to 5th. it loses 2 miles and hour, then slowly starts climbing back up.

The amount of road you use to reach 150, must be twice as long as pocono, and I wont do that on the street or any public road. It's rather stupid... and I'm not 18 anymore. common sense prevails :smash:

 

:cheers: If I had the financial power to do such a thing I surely would. I say someone build it and they will come.

 

My car would get to 125 on the back stretch at Sebring. Acceleration in 5th is kind of funny- It seems to pull harder once you pass 135 vs 125. You just have to find a safe road and a stretch about 1.5-2 miles and start at 80. I have only been able to do this once (in 1 year since I got the car) over a wide 3 lane (ea direction) bridge at 4:30am. (actually going to a Buc's preseason opener party). There is no way i'd pass anyone at that speed, they will find a way to pull in front of you...

 

Does the ZR1 also reach it's top speed in 5th? If the LT4 does 168 @5800 rpm in 5th gear, I guess the 700 or so extra rpms combined with the extra power would reach the neighborhood of 180 mph. Or does it top out in 6th gear? I know that this isn't the ZR1 section, but I was wondering if LT5 power levels would propel my car to 180 with existing tranny & rear.

 

Yes it does. It has the same trans as the lt4 & lt1's.

 

One guy that has a LT1 in Germany says he hit 171mph with an automatic.
I think with a long enough stretch 170 can be done maybe more with an LT4...
I've done 268km with mine that's 161. I've done it a few times..i've tried shifting to 6th and i did feel a that the car wasn't increasing speed because i let off but i think if i had the space it would eventually climb up. I got the Z06 package with the 355s. I also tried a 6th gear climb surprising it didn't stop past 240km thats 144mph.

 

:lurk: