Hey guys I want to track my 1981 c3.

I’m 18 and this has been my first car for almost a year now.

I love driving it but am comfortably finding its limits nowadays and want to get alot faster.

I’ve done some basic weight reduction stuff but here’s my question:

What are the best bang-for-your-buck performance mods you can do under $1k?

 

best bang for buck performance is NOS, a 125 shot kit, installed yourself, easily less than $700
Track as in drag strip? Or autocross?
NOS is great for drag strips, not very useful for autocross.

not sure what state you live in, but if you’re allowed to delete the catalytic converter, that’s an easy hp boost

 

Yes for more autocross/track so NOS probably wouldn’t be the best idea… i’ll take a look at performance exhaust though!

 

Springs and shocks. If you had a bit more in your budget you could go with coil overs, fully adjustable. Front coil overs will bolt right in, but in the rear I think new trailing arms are a must. I got the offset rear trailing arms for more tire clearance.

 

Headers, true duals. Dont waste mmoney on expensive "corvette" cat backs, go to any muffler shop have them bend up what you need
Vette systems dont have complex bends short system. To pay 1k or more for 2 lousy pipes is a joke.
If you plan on modding the engine headers will enhance other mods. You can always do a roller tip 1.6 rocker and better springs, good opp to put fresh valve stem seals on it. Cheap mod and works.
If its gonna stay bone stock forever you still benefit from long tubes just not that much. If it stayed stock and manifolds stayed or shorty headers showed up so be it.
Cant imagine an 18 yr old wanting an old stock smogger engine if hes tracking it. Actually smart for reliability but who uses common sense with hot rods.

 

All cars should have headers.

 

Think its cool, at your age you are really finding limits. Will make you a more defensive and safer driver.
Most getting their license ought to be made to take some kind of course that teaches people the laws of physics lol.

 

This is easy with under $1k, ah nothing. you need more money.

But to make any C3 corvette track ready. Here is the order of importance.

SAFETY #1

1. BRAKES / Calipers / Rotors , make sure the calipers can take the heat without failing. Stock calipers may last 1-2 seasons before calipers fail / leak. Get high friction performance / race pads.
2. Make sure the suspension is 100% solid, all control arm bushings / tie rods / joints.
3. Factory Steering hoses wont last long, Replace all if aged more than 6 years
4. Change diff fluid

Ok so none of this will make the car faster / lap times but your car won't brake on the first day.

Then 3 things affect lap times Track experience , ah Track experience and then HP & TIRES.
HP requires BRAKES , BRAKES , suspension , tires.

So start with tires and lastly add HP.

eg going from factory street tires to PS4 performance tires removed 8 seconds / going from PS4 performance to track tires another 4 seconds. Changing motor from factory to 383 removed 10 seconds, transmission from auto to 6 speed removed 3 seconds.

You will have fun driving a C3 at the track as a factory car, once you have some experience with the car, the car will tell you the next step. Usually Maintenance stuff and tires.

Tires usually give you the best bang for you bucks. Try to find the widest wheels / RIMS you can get. My 78 without any mods mounted 275 40R 18 tires on 18x9.5 wheels with 4.75 Backspacing.

 

As someone who's been illegally road-racing for decades, i follow the same plan, every time. Gets me LOVING my car, and having fun, quickly, and for little cash.

Assuming you're starting with a half-decent platform (ie: C3 or other factory performance car), and assuming that everything stock already works the way its supposed to (brakes, suspension, etc.). I cant think ov a better 'cheap' platform to start with than a C3. ANY C3. Thats the beauty ov Corvettes... the worst one you could possibly buy is still a sub-3500lb car, thats low, wide, aerodynamic, simple, with IRS, performance geometry, and 12" discs on all fours. hell, they came with 8" rims. You could spend $5000 upgrading a nice A-body, or Mopar, or Mustang snd still not have all that. Anyways, that covered, this is what i do:

1, Rollers. The WIDEST wheels and tires i can jam in there. On these cars that means 265/50's up front and 295/50's out back, and thats without thinking. With a more intimate relationship with your tape measure, and the willpower to ignore the local tire 'expert', you can go even wider on these cars. This is important. You can spend $30000 on a hotrod chassis, with NASA-level suspension and 16" brakes, plus the LS7... and still the ONLY thing in contact with the road is TIRES. Personally, i tend to go with used tires. I know all the local shops, and what they have. A used 275/40/17 Direzza will outperform a brand new BFG Radial TA ANY day... for the same price, or less. On the FG Corvettes though, watch the date ov manufacture, you dont want to go too old. Used Corvette C5 or 6 rims are plentiful, and sometimes cheap. A $200 set ov quality hub-adapters will bolt them on, and set them exactly where you like them, looks-wise. I see used C5 and 6 Corvette tires CHEAP all the time. Rich guys are always upgrading...

2, Exhaust. Even if you have the absolute lowest C3 on the performance totem pole, like a L48 automatic 77, you can see 30+HP from a good full exhaust. Manifolds are ALL junk. Stock Corvette systems after 1974 are absolutely offensive. They make baby Jesus cry. Even the far better early systems came with awful mufflers, and no crossover. Get the best longtube headers you can afford, with collectors that actually look like they can flow air, and run a 2.5" mandrel true dual system out the back. Use a good X-pipe, and put it as close to the crossmember as you dare. Buy GOOD flowing mufflers (Borlas, Magnaflows, Spintechs, etc.). The lamer, stocker your engine, the less you'll get out ov this, but if you've got something making any steam, a good full system can easily jack you another 50HP over a stock system, and well more if you're still running that utterly asinine, post-74 cat/single exhaust system. Better yet, it'll LOOK better. BEST yet... the sound will put a big stupid grin on your face... one that you will wear every time you fire the thing up. And at full song...???

Make sure you tune the hell out ov the thing past this step. Factory tunes can be utterly horrific, and thats IF its still in tune.

3, Weight. You already mentioned this, but its my experience... and i'm a wizard mind you... that 90% ov people that do weight reduction do the bare, uninspired minimum, and say they're done. Now, for a lot ov guys, especially in here, they dont need a 2800lb car to win races... People here have MONEY. Some suspension, brakes, rollers, and an LS swap and they're giving the autocross guys fits. But YOU... sound like me... probably far too broke to be playing with expensive cars. Now, that doesn't mean you dont get to play (as much as some people insist just this...) but it does mean you'll have to get crafty. Rollers can be sorta cheap, if you go used. Exhaust costs money, but weight-reduction... well, that starts at free, goes a decent way at free, and then starts costing little money, long before you're into the aluminum block/carbon fiber level. Think ov it like this... these cars started out around 3050lbs in 1968. They fattened up to about 3500lbs in 77, mostly with government mandates and luxury. But then a magical thing happened... and this NEVER happens in cars... after 77 they started to get lighter again, and by 1981, they were almost back at the starting 1868 weight. Further, EVERYTHING they did, from 68, to 81, is interchangeable. Even better, the vast majority ov those lighter weight parts come on the far less than desirable years... that means, CHEAP (or free). Mix and match. You could easily build a 2800lb car, without gutting the interior or hauling out the holesaw, or without other silly **** like lexan windows or 4" front tires. 2800lbs is less than a Gen 6 Honda Civic SI. Thats less than an s2000. Thats a few hundred more pounds than the legendary AC Cobra. Even a stock, smogged-out L48 would be fast in a 2800lb car... Even better yet... most sub 3000lb cars are small. Small means small bodies, that means small wheelwells. If you get there, you'll be doing it in a car that'll swallow up a 12" tire on all fours... and stop them with a 12" disc brake. Thats BEFORE you upgrade that stuff. There are many threads here on weight reduction. None ov them are completely comprehensive (i'm gonna rectify that someday), but there are some good ones.


A typically modified old 350 with swap meet parts should make at least 300 net HP with that killer exhaust system. A 350 Vortec drop-in with cam and intake a lot more. Combine that with full C3 wheelwells, a good working stock suspension/brake system, and a sub-3000lb car and you should be having fun. Yeah, thats all a bit more than $1000, but if you're savvy, you could do each ov these steps for around that, the third for less. It'll look cool, sound cool, run as well as a stock C4, maybe even C5 depending on your skills. After this? THEN you start spending money... suspension upgrades, engine, transmission, gears...

I'm a Mopar guy. Challengers and Cudas are my game, but i am sold on these cars. No one else makes anything close.

 

A $1000 budget will get you started, but soon you'll need another $1k, and another, and another....

If you're considering autox or track days, then start with start by making sure that it's safe - check bushings, ball joints, bearings, and leaks.
After that, you can turn toward performance with better brake pads, adjustable shocks, and sticky tires. Me suggestions for starting off are Hawk HPS or HPS 5.0 pads, Viking double adjustable shocks, and 18x9.5" wheels with 200 treadwear 265 or 275/35R18 tires. There are a lot of choices for tires, like the Bridgestone RE-71RS, the Falken RT660, the Kumho V730 (not 720), the Yokohama A052, and the Nankang CRS or CR1, just to name a few. The choice of 200TW tires could have its own thread because there are so many choices right now, each with their own strengths.

Next after that, I'd look at springs, a 1 1/8" front sway bar, and SPC adjustable upper control arms. Maybe consider a Borgeson steering box for more responsive steering and few leaks.
After that you can add horsepower and change rear gearing for better drive off the corners.

Along the way, be sure to get plenty of seat time, preferably with an instructor that you relate well to. Seat time is great, but if you keep making the same mistakes, you're not going to get faster.

Good luck out there, and have fun.
-Chris

NMCA West Auto-X 2020

 

I like this response best so far. Too many guys go right for the power adders.
Spend your money on the car prep basics and track time with an instructor to find out if you really want to get into it before you start seriously modding your car.

 

Cliff notes?

 

I've got both a 73 and a 76 that have been campaigned in autocrosses for quite a few years. Both cars are very similarly prepared. I've won a NCCC Indiana region championship in both cars.

Both cars are setup for running in NCCC class 2 D. In that class small suspension mods, updating/backdating on motor parts, headers, and wheel/tire changes are allowed.
Both cars Front: 1 1/8" sway bar, 550lb springs, KYB gas adjust shocks.
73 Rear: 420lb VBP fiberglass spring, KYB gas adjust shocks, 1/2" sway bar
76 Rear: 360lb VBP fiberglass spring, KYB gas adjust shocks, 3/4" sway bar

Both have hooker side pipes, '71 heads, aluminum '80 L-82 intake and the longer spring bolts in the rear. I've run anything from a 15x8 to a 18x9.5 on the cars using adapters. Here you can see the 76 with both 18x9.5 C5 wheels and 16x9.5 C4 wheels.

As far as car mods go, tires will make the biggest difference in handling and lap times. Shocks, springs and sway bars will make the second biggest. But above all else, your driving will be the biggest difference. More experience and learning the car and learning good driving habits will create faster lap times. When I started racing at 16yo, I was Definity not fast. It too quite a few years before I was in the hunt for class wins. Learning from my dad and other corvette racing friends and keep pushing myself is what got me there. Don't judge your self too harshly against other people. Race against yourself and keep improving. Eventually if you keep improving, you will end up with the faster guys.




This is the 73 on power going through a fast left-hand turn so that is why there is so much gap on the left front.

 

Those ARE the clif notes!