hey! well i finally got my dream car! its a 81 c3... iv done a lot of research on it and im ready to make a thread about it now... i know the 81 dont have as much power as the other years, and they need to be upgraded...
well mine has a edelbrock intake, manifold, 4b carb, cams, ignition, headers, and dual exhaust....
i read on a thread on here that with all those mods that the car should scream, and get it sideways! my car runs really good but it just seems like it should have alot more power then it does...
im thinking that since it has all these upgrades maybe its just not dialed in right....
ill try to describe how it runs.... when i start it up for the first time of the day or when its cool, i have to give it a little throttle to keep it from dying, but after its been running for around 15 seconds it will idle... when its at full operating temp, from a dead stop, smash the gas to the floor it wont break the tires loose but it churps when it shifts into 2nd.. it dont miss a beat and pulls really hard but after reading some post on here it seems like it should be leaving 2 black stripes on the pavement...
as i said, the car looks, runs, drives and handles great! but im sure im not getting its full capabilities out of the engine...
when i checked the plugs, they seemed to be good, but they are auto lite and look kinda cheap.. would seem to cancel the ignition upgrade if using cheap plugs...

any ideas? thanks for any help or interest...-Trevon-

 

ttt..

 

I also have an 81 and though not modified as yours is, I have had dual exhaust on it, and I have done ignition upgrades.

The car puts out 190hp stock. With your mods I am guessing that you are maybe at around 250hp. There's not much more you can do, asidew from changing the rear gears, without going into the engine. I could be dead wrong, but I can see you not really breaking the tires, and I can't see how anyone with these mods can get their car sideways.

I think someone down the line was doing a little exaggerating. That being said, with what you have done your car will be more enjoyable to drive had than a stock 81

 

get that ignition kit that this guy on here is selling f/ $40.00 and that would get the car more straight than it is, unless you already have the ignition dialed in.

 

How does a spark plug look "cheap"?

There's nothing wrong with Autolite plugs.

It probably runs as good as it's going to with the stock heads.

 

The storyteller's cars may lay stripe if they powerbrake it down the street otherwise usually tall tales...or really old and hard tires.

 

The heads and compression ratio is going to really limit what you're going to get out of that engine. To get the most out of what you've got, I'd start with the tune. Where's your timing set? Both inital and advance. What kind of advance are you running, vacuum, mechanical or both? How is the advance set up? How's the carb tuned? What carb is it? What cam is in this engine? That could have an impact on how you'd want to run the timing and carb set up.

Once you get the tune straighted out, you should know you're likely running a 2.72 rear end gear. It's gonna take a ton of HP to get that car sideways from a dead stop on a dry road, 250hp won't even come close. If you haven't changed the trans, it's a TH350C so changing the rear gear will have a price at highway speeds. Also, with the mods you've made I'd bet the lockup feature has been bypassed in the trans to, further impacting highway driving.

 

With out knowing specifically what those mods are .... and if you've still got original heads and bottom end ... it difficult to say what the motor is capable of .... as stated, doing what you can with what you do have is the best you can do at this point. Cold start issues can be resolved with some carb adjustments .... the plugs you have are okey ... ((not my choice)) but they do a good job. make certain all your wiring is good as well ....
congrats on getting your C3 .... they are way fun to drive .....

 

Ummmmmmmmmmmm Don't forget Spinning tires loses races. These cars were designed to squat and get and that equals more traction.

 

Learned that the hard way years and years ago. I had a 69 Chevelle SS 396, that I'd done a lot of work on. It was an 11 sec street car (after I learned how to drive it!!). I was at the local drag strip, and they lined me up with a girl in a stock 76 powder blue Mustang. Lights came down, I side steeped the clutch and tires started spinning and smoking, hit second and more of the same. By then I was looking at tail lights! I finally started moving and almost caught her, but didn't. Got back to the pits and my buddy said, wow, you really smoked those tires.....and got beat by a girl in a stock powder blue Mustang.... That week I went to school....

 

Welcome to Corvette ownership! If you like wrenching and learning you've come to the right place.You should get your carb setup first,float level,choke,idle mixture.Email Lars for his timing paper at v8fastcars@msn.com he may also have a paper to setup your carb.When you have carb and timing setup and your still not happy with the power. You will most likely need some better flowing heads and a cam to work with those new heads.Then you will find your gearing is not optimum for the engine upgrades and a change in rear gears are needed.Then you will discover the RPMs are to high on the hiway and want an OD trans...Ask me how I know this...... been there and done all of it,Vette is a blast to drive now...Good Luck and Aloha's

 

The lower the gears the higher the Muscle car feel/fun factor. Back in the day everybody had to have 4.11s. Lot of 300hp cars back then and 4.11s made for great fun at the stop lights. Of course everybody had their air shocks maxed out to keep the fenders out of the 50s so they weren't going to be traveling far anyway. As was mentioned before, your going to need mondo HP(seriously maybe even 400 range) to get the feel your looking for when your routing the power through 2.72s. My parts runner is a '90 TA with a 230hp 305 and 3.42 gears and it is fun to drive. Nothing to brag about but it does have a good stoplight feel and will smoke the rubber even with the posi, and it's not rapped up to terribly tight at highway speeds in 4th. Go for the gears. They are relatively inexpensive compare to building 400+hp, and even if you did, you'd likely buy the gears later anyway.

 

If you want to burn rubber, change the torque converter to something around 2,800 to 3,000 stall speed. It's easier and cheaper than changing the rear ratio. But, you should do that too.

 

You didn't mention whats inside the Motor, or even if its got the stock Motor in it. I'd start doing some investigating in that dept. Check serial numbers, Block casting Numbers, Cylinder Head Numbers and learn more about what you have. As the Car sounds like it runs OK now there probably isn't a screw or spark plug that is going to wake it up. A set of Aftermarket Heads will probably wake up what You all ready have in the Motor dept more than anything along with the corect Cam. But before You do this I would consider a 4 speed trans, were are assuming this is a Auto trans car. A 4 speed trans will give you a lower first gear for a bigger smokey burn out.

 

just for info i did up a car once with 425hp,3000 stall,th350 yada yada...i drove it with the stock 2.72 gears (just for a giggle)until i got the 3.73 gears put in week later and it chirped at best from memory , thats about it.it felt like the car was running on solar power. Once the nice rear gears went in i could powerskid from corner to corner