Best engine mods for LS?
Pro
Joined: Jan 2001
Posts: 604
Likes: 299
From: San Jose CA
HP/$ the supercharger is (and always has been) the winner. But it's more dollars and more power than most expect.
Just the supercharger kit is $6000-$7000 before tax / install. You need to make sure you have one that is NY legal - which probably means a CARB number. Emissions legal kits tend to be a little more expensive
https://aacorvette.com/shop/product/c5-supercharger/
https://www.procharger.com/automotiv...rvette-c5-ls1/
TPS is having a black friday sale on superchargers right now
Probably budget more like $8-$9000 for a professional shop installed system.
For a street car with a sound motor, that doesn't need to meet any race classing - it's probably the way to go
Just the supercharger kit is $6000-$7000 before tax / install. You need to make sure you have one that is NY legal - which probably means a CARB number. Emissions legal kits tend to be a little more expensive
https://aacorvette.com/shop/product/c5-supercharger/
https://www.procharger.com/automotiv...rvette-c5-ls1/
TPS is having a black friday sale on superchargers right now
Probably budget more like $8-$9000 for a professional shop installed system.
For a street car with a sound motor, that doesn't need to meet any race classing - it's probably the way to go
Running Guns & Moonshine
Joined: Aug 2001
Posts: 12,370
Likes: 7,078
From: CT
I have literally gone price for price in posts before on this question. The blower sounds more expensive because it comes in one lump sum. But doing everything for a H/C kit which most do end up doing while it is cracked open adds up to be on par. Or it has within the last 3 to 5 years. I wager both options have similarly gained in expense in the current market. I should note that the cost of labor is presumed to be significantly higher for a H/C kit in the instance that an owner does not do the work themselves and pays a shop but I have never included labor in my comparisons.
Race Director
Joined: Oct 2004
Posts: 12,828
Likes: 4,635
To me, this is a no brainer. If I had it to do over again I'd go supercharger every time. Stock LS bottom ends are pretty stout. A good tuner is very important in any build, whether NA OR FI. But in a FI engine, especially with a stock bottom end, a really good tuner is absolutely essential to reliability. The stock rods and crank are fine. The stock hypereutectic pistons will also handle a lot of power. What they wont handle well is detonation. Forged pistons are much stronger and are able to withstand less than ideal tunes. I have a friend who has an '02 C5 Z06 with the A&A kit. Totally stock internals in the motor. He's had it on his Z06 for over 15 years with absolutely no problems. A few years ago he did install a performance cam, and it now makes over 600whp. Still no problems. Find a really good tuner and your stock internals will live a long time......
Racer
Joined: Nov 2004
Posts: 418
Likes: 74
From: Oshawa
I would recommend a well valve event timed camshaft to get more horsepower and torque.
This does not have to exhibit bad driveability with excessive overlap, however the stock camshaft is weak and it holds back all these cars.
If it is a decent camshaft you will not see too much degradation of fuel economy or range, it will sound better at idle and will not cause heat issues under the hood.
This does not have to exhibit bad driveability with excessive overlap, however the stock camshaft is weak and it holds back all these cars.
If it is a decent camshaft you will not see too much degradation of fuel economy or range, it will sound better at idle and will not cause heat issues under the hood.
Intermediate
Joined: Dec 2024
Posts: 28
Likes: 26
I’ve had mine for a full year and only did a full exhaust no tune yet. To be honest I say stay in this area The car is 25-26 years old. If you start tossing a lot of power at it your wallet will feel it. The car is light relatively quick. Doo full bolt ons. So intake manifold intake and full exhaust with a tune and it will be more then enough. If you want a fast *** car to race b58s and hell cats parts will break and cost you money
Instructor
Joined: Jun 2009
Posts: 155
Likes: 20
From: Brentwood Tn
If the 1999 is not fast enough, sell it and buy a 2003-04 ZO6. Look for one with headers and a tune. You will have more power and stock reliability.
Or you can put an LS6 in your car add headers and a tune and have a reliable car that is dependable and mostly stock. If you do not have access to
a lift and cannot do at least some of your own work you can dig a deep hole in your pocket before you know it.
Or you can put an LS6 in your car add headers and a tune and have a reliable car that is dependable and mostly stock. If you do not have access to
a lift and cannot do at least some of your own work you can dig a deep hole in your pocket before you know it.
Burning Brakes
Joined: Nov 2013
Posts: 1,049
Likes: 418
If you're going thru the trouble of engine swapping a C5 (not an easy or cheap task), many other engines are a better option
I do not suggest engine swapping. You can make lots of power on an LS1 bottom end
I do not suggest engine swapping. You can make lots of power on an LS1 bottom end
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
10 Things C8 Corvette Owners Hate (But Won't Tell You)
Joe Kucinski
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!
Brett Foote
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)
Joe Kucinski
Drifting
Joined: Aug 2017
Posts: 1,789
Likes: 331
From: Dayton, OH
For $6kish put a supercharger on it and call it a day.
Running Guns & Moonshine
Joined: Aug 2001
Posts: 12,370
Likes: 7,078
From: CT
Drifting
Joined: Mar 2000
Posts: 1,956
Likes: 135
From: Maryland
Probably depends on what you're going to do with the car.
I really wanted a centrifugal. Had a long talk with A&A and it was going to be a crap-shoot as to how the motor would hold up. It might be good or it might not. But, my car is almost exclusively used for HPDE. Was told it really needs forged pistons and properly gapped rings for reliability during extended WOT on the track.
I ended up doing cam, headers, springs, pushrods (larger Manton w/restricted flow), trunnions (CHE), timing chain, chain damper, injectors, and tune by Doug at ECS. Did it all myself except for the tune. Did not replace the heads or lifters. That was back in 2012. Car still runs great after all these years and many hours on the track. When / if this motor gets toasted, it will be replaced with LS7.
I really wanted a centrifugal. Had a long talk with A&A and it was going to be a crap-shoot as to how the motor would hold up. It might be good or it might not. But, my car is almost exclusively used for HPDE. Was told it really needs forged pistons and properly gapped rings for reliability during extended WOT on the track.
I ended up doing cam, headers, springs, pushrods (larger Manton w/restricted flow), trunnions (CHE), timing chain, chain damper, injectors, and tune by Doug at ECS. Did it all myself except for the tune. Did not replace the heads or lifters. That was back in 2012. Car still runs great after all these years and many hours on the track. When / if this motor gets toasted, it will be replaced with LS7.
Running Guns & Moonshine
Joined: Aug 2001
Posts: 12,370
Likes: 7,078
From: CT
LS7? Or an LS based 427? I think people often mix the terms but mean the latter. I'd be on an LS2 or LS3 block base and use the rec port LS3 heads if it were an HPDE car vs LS7 or LSx build. I can vouch the machine work to clearance for a CCW crank is a low investment and per those who run them competitively earns you more years between bearing replacements.
Drifting
Joined: Nov 2017
Posts: 1,373
Likes: 293
If I wasn't doing track-day stuff with my car, I would have gone with a centri supercharger like A&A's kit. It's the best bang for the buck. But most people who try that seem to run into cooling issues, because power creates heat, and the intercooler reduces the effectiveness of the already-marginal radiator. And tracks give a lot more opportunity to use power than streets.
For naturally aspirated upgrades, you basically have a choice between a bunch of outside-the-engine upgrades that each add a little bit of power (headers, intake manifold, throttle body, air filter, air bridge, etc, etc), or a cam that gives a lot more potential, plus all those little upgrades. I mostly depends on your budget. And the cam choice depends on how much low-speed roughness/surging/weakness you're willing to sacrifice in order to get more power at higher RPM.
This setup got me 450whp on one dyno and 475 on another: https://legacynsfw.github.io/450-recipe.html
I'd probably do the same setup again.
For naturally aspirated upgrades, you basically have a choice between a bunch of outside-the-engine upgrades that each add a little bit of power (headers, intake manifold, throttle body, air filter, air bridge, etc, etc), or a cam that gives a lot more potential, plus all those little upgrades. I mostly depends on your budget. And the cam choice depends on how much low-speed roughness/surging/weakness you're willing to sacrifice in order to get more power at higher RPM.
This setup got me 450whp on one dyno and 475 on another: https://legacynsfw.github.io/450-recipe.html
I'd probably do the same setup again.
Running Guns & Moonshine
Joined: Aug 2001
Posts: 12,370
Likes: 7,078
From: CT
For HPDE... I figure 400 rear wheel to 500 is about perfection and probably more than most can use fully. I know I can't. I just drive like a bay out of hell on summer Sunday mornings out through the hills. I agree that 20 minute sessions of wot would pack a lot of heat into your system and add about 4k in cooling upgrades between oil and coolant, let alone any aero mods to move heat from under the hood.
Race Director
Joined: Oct 2004
Posts: 12,828
Likes: 4,635
Drifting
Joined: Nov 2017
Posts: 1,373
Likes: 293
There's a couple slower corners where even lower-powered cars can get sideways if you use 2nd gear and stomp it, and that's kinda fun since it's at 30-40 mph. But I am not at a level when I can take pleasure in getting sideways at 75+.
Instructor
Joined: Jan 2015
Posts: 196
Likes: 53
From: Sun City AZ
ilter, but since I wasn't worried about dirt so much I used what you see.
Last edited by PapaFred; Jan 3, 2026 at 10:32 AM. Reason: inserted image
