I'm a newbie and have many questions.

ok i just got a 95 corvette 6 speed convertible. with only 33,000 miles.. the car runs ok but it seems to have a miss.
the exaust is not flowing as smooth as it should and my top speed is 146 MPH @ about 5000rpm in 5th and a little lower in RPM in 6th. does this sound rite to you guys?
is it a governor or am i incorrect to assume that based on all the articles i have read that the 95 corvette is supposed to be able to go almost 170MPH in 6th bone stock?

i know since its a convertable i probably won't see 170 but should i not be able to hit at least 160?
I just bearly beat a 2001/2002 BMW M3 the other day. imagine my suprize to see him not far behind me governd at about the same speed.

BTW I'm new to this forum so please excuse my ignorance if this post ends up in the wrong place.

 

1st off...convertibles' top speeds are much lower than a coupe because they are much more unaerodynamic. Top speeds of LT1 vettes aren't 170, more like 160, and that's the coupe version. You won't be able to get your top speed in 6th gear, it's too high of a gear. Even Vipers run their top speeds in 5th gear. So..145 at 5000 rpm sounds about right if you were driving into a wind. I bet if you were going with the wind you could have gotten to 155 at around 5200 rpm. Max power of LT1s are about 5200 rpm. But wind drag at that speed is a HUGE factor. So in a convertible, driving against the wind, that 145 mph sounds about right.

 

Another thing, don't get a big head and try to race an LS1 Camaro or Trans Am (1998 and newer). You will get spanked. LT1s just aren't as fast as LS1s. You might hang around till around 70 mpg, then the LS1 will pull you hard. If you get intake, headers, pulley, and bigger exhaust pipes, you'll be beating stock LS1s cause you are lighter. And 2001-02 M3s have a good engine, they are quick, so don't be surprised that your stock LT1 vette barely pulled one, they run 13s in the 1/4 mile.

 

thats weird i have read Stock LT1 corvettes beat stock LS1 F bodies on tracks due to handling and weight. i know 160MPH is not its top because if you read between the lines you will notice they say it can do "over" 160MPH and others that tell you it hits 170. it’s been documented at 170 in 6th for the coupe too often for me to beleave that 146 is the norm.
Just the fact that the car held 146 in 6th is proof of that. Something was holding me back otherwise i would have lost speed.
And I can assure you its was not wind. **** even my 95 Mustang GT convertible can do 146! Granted it will be smoking aftawards. 

However your f body stock is governed to 163. Witch I would speculate to be about the same as my top end. I’m sure you could get me to about 115 in stock form before my weight factor and Aerodynamics kicks in if all goes well for you .but I already got a 2000 LS1 TA.-"it’s my fathers". We only raced to 130 when I started pulling away from him & by the time I had two cars on him he just gave me a honk to let me know I had it. so the 146MPH top end was not revealed to me on that run.

BTW I do have some exhaust mods acording to a local corvette shop such as wider pipes, strate pipes and the resonators have been removed.
So I’m not buying this 146 BS its got to be my fuel pump, that mysterious miss, Somebody put in a bad chip, a governor or Worse.

somethings wrong I’m just not hitting any ware near my documented redline of 5600rpm +/- 1000rpm but rather just 5000rpm
Even the L98 could do 150/153MPH so their is no reason I should not see at least 150
Unless something is wrong.

And as far as the M3 goes in all honesty I really kicked his butt I spaced him by about 6 cars. when i hit 5th and had a semi comfortable lead Before I realized that I could not reach my redline in 5th. my car was choking up on me.
& felt as if I had a miss. Or gas was being cut off from the engine. as for the BMW i really cant give him but so much credit for allowing me to pull on him that hard.

 

LT1 vettes have gone over 170 MPH top speed in 6 spd. one of the later issues has a 96 6-spd redlineing at 172 MPH in 5th and a 95 formula(not even the fastest LT1) automatic doing like 163 or 165mph on radar, cant remember which one though. Dont worry about it being a bad chip. Your year is a MAF setup, not Speed Density. The last year that you could put a "chip" into an LT1's computer was 1993. Change your fuel filter, run some injector cleaner, carbon build up remover, and change your plugs. If the car only has 33,00 miles then it most likely wasnt driven often and prolly needs a simple tune-up(a car thats rarely driven is almost as bad as a car that is driven too much). If the problem still persist, check the injectors, check for a spark going to all cylinders, and check for possible clogged cat(s) depending on the aftermarket setup you have. Good luck, and congrats on owning a kicka$$ vehicle

 

thanks for the advice & congrats gangly.
that sounds more like it..
ill try all of that.

 

Yeah, modded LT1 corvettes will beat a stock LS1. I thought yours was all stock. And yeah, coupes have hit 170, but I don't see a convertible doing it. You're right you could probably see 160 though. Another thing, speedometers aren't very accurate at high speeds. Some get wayyyy off. So that 145 may have been a little faster if you actually put a radar on it. But if your car is crapping out at 5000 rpm, then yeah something is wrong.

 

A stock F-Body LS1 will pull a stock Corvette LT1 every time... but as for this quote:

you can go to the link in my sig and check out my car