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hey guys im wondering what is the easiest way to get some good power out of a 78. im not looking to do anything crazy im already planning to dosidepipes but what else should i do. i dont want to get super invasive with a cam and heads in the long run i might. but how can i make the most power easy.
l82 i believe do you reccomend an upgrade of a carb and dist? and how do i change the gearing?
not new but optimized for power not smog.
orig Q-jet can be worked/rebuilt
orig distrib can be "re-curved"
for power.
re-curv has to do with spark advance to eng rpm.
many threads here and a master member with 'how to" step by step proceedures. @lars
l82 i believe do you reccomend an upgrade of a carb and dist? and how do i change the gearing?
For the distributior id recommend getting any of the $10 eBay kits that come with 3 different sets of springs, running one medium and light spring, then throw the rest of the kit out. Lubricate and clean the internals and replace the cap and rotor if you haven’t already. Use a dial back timing light to verify you’re getting 36 degrees of total advance with vacuum advance unplugged at around 2,800 to 3,000 RPM. You’ll have to get a new vacuum advance canister so you don’t over advance your timing at cruise speeds.
As for the carb that’s a whole can of worms. Knowing what you have in the first step. I’m assuming you have the factory quadrajet, which will work wonderfully if set up correctly with other modifications. Post a couple of pictures with the air cleaner removed.
The first step in changing your rear gearing is finding out what you have in the first place. With the car jacked up in the air, remove the cover underneath the rear differential. On the bottom you should find a two letter code followed by some numbers. Those letters tell you what gearing you should have, assuming it’s original to the car.
Combined with a good exhaust, the car will feel entirely different, but don’t expect crazy horsepower. With an L82 you have a great foundation. Combined with some better cylinder heads and a more aggressive cam all the other improvements would be felt even more.
Good luck!
Last edited by Piersonpie; Jan 16, 2024 at 10:55 PM.
This thread may help you. Side pipes not for power but cool.
if it is an L82 than you already have ideal distributor. You should confirm this.time it like the thread below..
also see what gears you have now..auto ? Manual? You may already have the gears you want.
pics? Original carb? Have it rebuilt by member Lars here mentioned.
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
you need to be more specific as to where you want power
cheap off the line power is torque
for cheap torque you want to get your distributor set so you are all in by 3000 rpm, you want a lower rear gear, you want a lower first gear in your transmission so either a newer 5 speed with a low first gear or an M20 or turbo350, get a good breathing dual plane intake that fits under your hood and headers with 2.5 to 3 inch exhaust and good mufflers.
more money but cheap is a turbo setup which will give you upper end HP as well. Much better than a blower as it doesnt rob HP to make HP.
anything else you need to open up your motor and get good flowing heads appropriate for your build, higher compression pistons, and a good cam.
Really expensive in the end is an LS which is very over rated becasue the cheap ones still only make 320 to 350 hp. The only plus side is a better machined block, maybe main bearing oil priority , decent flowing stock heads. You still need very expensive swap headers, a computer system, tuning, new cam, expensive pan, expensive fuel pumps and filters....theres so many hidden costs that add up but these guys wont tell you about that...BECAUSE ITS A LS SWAP DUDE!!!! IT SO AWESOME!!!
you need to be more specific as to where you want power
cheap off the line power is torque
for cheap torque you want to get your distributor set so you are all in by 3000 rpm, you want a lower rear gear, you want a lower first gear in your transmission so either a newer 5 speed with a low first gear or an M20 or turbo350, get a good breathing dual plane intake that fits under your hood and headers with 2.5 to 3 inch exhaust and good mufflers.
more money but cheap is a turbo setup which will give you upper end HP as well. Much better than a blower as it doesnt rob HP to make HP.
anything else you need to open up your motor and get good flowing heads appropriate for your build, higher compression pistons, and a good cam.
Really expensive in the end is an LS which is very over rated becasue the cheap ones still only make 320 to 350 hp. The only plus side is a better machined block, maybe main bearing oil priority , decent flowing stock heads. You still need very expensive swap headers, a computer system, tuning, new cam, expensive pan, expensive fuel pumps and filters....theres so many hidden costs that add up but these guys wont tell you about that...BECAUSE ITS A LS SWAP DUDE!!!! IT SO AWESOME!!!
Hopefully the OP's original L82 is worth rebuilding. Neither of my L48s was. Both were totally spent, even the one with only 60K miles. So, for $700-, I have a complete, running LM7. Add in a few nice to haves, and I hope to get the swap done for about $2K. That's LESS than the cost of just a Sniper EFI install, and it doubles my horsepower! Or that's less than a nice pair of aluminum heads and an intake. I will caveat that by saying electronics are my hobby, so electrical stuff, programming, even 3D printing and machining parts, none of that scares me. YMMV.
My point was, before you do literally anything to your 40 year old engine, consider a crate engine. And for half the price of a crate engine, you might be able to do an LS swap. You WILL come out ahead in the long run. What do you do when you get to 400 hp in your SBC and stiill want more? If you started with an LS, you can boost to 700+ before stock stuff starts to break. Or you could (for example) spend $20K on two SBC rebuilds and still not have a working engine. So play to your strengths, but also consider the long-term goal for the car, assuming you will keep it long term. I figure I'll play with LS engines for a while, then EV swap one or both cars when battery energy density improves. But never having to rebuild an SBC or carburetor ever again? Priceless! At least to me.
And the best bang for your buck? Following @lars timing instructions. Spend $40- on distributor springs, adjustable vac advance (or vac advance limiter), and shim the endplay, and your car will feel transformed from the stock specs.
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
But you want to open up the rings for the nitrous to make the engine and pistons live longer, plus MSD controller that can retard the timing when the nitrous kicks in, thats why I didnt mention it...
But you want to open up the rings for the nitrous to make the engine and pistons live longer, plus MSD controller that can retard the timing when the nitrous kicks in, thats why I didnt mention it...
Eh, pull 6 degrees for a 125 WET shot and stock gap is fine for 125 on sbc v8. Run 30 degrees total vice 36.
My opinion that is, and my experience lol. Experiences may vary.
100 shot if wanted to be extra safe.
This is also sorta jest. OP would be better off with something that gives power all the time vice just at WOT. Cam/blower all more useful options.
but nitrous sure is fun.
easy power
