Ls1 intake vs ls6
Thread Starter
Drifting
Joined: Mar 2012
Posts: 1,959
Likes: 217
From: Victoria tx
Ls1 intake vs ls6
Does changing from an ls1 intake manifold to an ls6 make a huge difference? I know there is a flow difference and performance but how much? I cannot afford one of those high tech expensive ones such an a F.A.S.T or something else and I've found some used lay ones. To those who've done it, what were y'all's performance number differences? I ask because I'm most likely going to do high flow cats, vararam and a tune and that's why I ask
Le Mans Master
Joined: Jul 2010
Posts: 6,013
Likes: 726
Does changing from an ls1 intake manifold to an ls6 make a huge difference? I know there is a flow difference and performance but how much? I cannot afford one of those high tech expensive ones such an a F.A.S.T or something else and I've found some used lay ones. To those who've done it, what were y'all's performance number differences? I ask because I'm most likely going to do high flow cats, vararam and a tune and that's why I ask
Melting Slicks
Joined: Feb 2001
Posts: 2,804
Likes: 358
From: Northville, MI
On a stock engine it may make up to 5 more hp and 10-25lb more torque. The 01-04 C5 all used that intake. In a quarter mile, you would cut 0.1 sec in a 6 speed. If you are going to do other engine mods that is when it make sense.
Drifting
Joined: Nov 2005
Posts: 1,320
Likes: 242
From: NW Chicago
St. Jude Donor '12-'13-'14-'15
If one had a custom tune and a ls1 intake and then installed a ls6 intake, would the tune have to be updated? Or would the computer self adjust to the better air flow.
Racer
Joined: Jan 2017
Posts: 344
Likes: 114
From: Dawsonville Ga
Most guys report 10hp gains but more importantly driveability around town is much improved due to under the curve increases everywhere. It’s not going to turn your car into a race car, but if you can pick one up cheap…which is hard to do nowadays…I’d grab it. Like any mod you’d do to the LS, you’d want a really good tune afterward to maximize the potential here.
Thread Starter
Drifting
Joined: Mar 2012
Posts: 1,959
Likes: 217
From: Victoria tx
Most guys report 10hp gains but more importantly driveability around town is much improved due to under the curve increases everywhere. It’s not going to turn your car into a race car, but if you can pick one up cheap…which is hard to do nowadays…I’d grab it. Like any mod you’d do to the LS, you’d want a really good tune afterward to maximize the potential here.
What I'd like to do is high flow cats to go with my flowmaster outlaws, vararam, ls6 intake man and a tune
Running Guns & Moonshine
Joined: Aug 2001
Posts: 12,650
Likes: 7,292
From: CT
Not a worthy mod. And the "gains" are armchair general worthy, not street worthy. If you can score one for free or just 200.... OK very cool. But for what some folks or shops charge for an LS6 style intake I say it is typically not worth it.
Shop the used areas. If you're patient you'll find good prices.
If you don't already have a freer flowing Cai, look to that as well. But in neither case should you expect notable power gains.
Shop the used areas. If you're patient you'll find good prices.
If you don't already have a freer flowing Cai, look to that as well. But in neither case should you expect notable power gains.
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Thread Starter
Drifting
Joined: Mar 2012
Posts: 1,959
Likes: 217
From: Victoria tx
Not a worthy mod. And the "gains" are armchair general worthy, not street worthy. If you can score one for free or just 200.... OK very cool. But for what some folks or shops charge for an LS6 style intake I say it is typically not worth it.
Shop the used areas. If you're patient you'll find good prices.
If you don't already have a freer flowing Cai, look to that as well. But in neither case should you expect notable power gains.
Shop the used areas. If you're patient you'll find good prices.
If you don't already have a freer flowing Cai, look to that as well. But in neither case should you expect notable power gains.
Race Director
Joined: Oct 2004
Posts: 12,864
Likes: 4,667
Not a worthy mod. And the "gains" are armchair general worthy, not street worthy. If you can score one for free or just 200.... OK very cool. But for what some folks or shops charge for an LS6 style intake I say it is typically not worth it.
Shop the used areas. If you're patient you'll find good prices.
If you don't already have a freer flowing Cai, look to that as well. But in neither case should you expect notable power gains.
Shop the used areas. If you're patient you'll find good prices.
If you don't already have a freer flowing Cai, look to that as well. But in neither case should you expect notable power gains.
Thread Starter
Drifting
Joined: Mar 2012
Posts: 1,959
Likes: 217
From: Victoria tx
The LS6 intake DOES add power, but you usually need other small, supporting mods, before it can really make a noticeable difference. I doubt very seriously the OP will find a $200 LS6 intake, much less a free one! The LS6 intake was part of my high12s@110mph 1/4 mile runs, with completely stock internals. Hell, I didnt even know what sparkplugs were in it, lol!!
Le Mans Master
Joined: Feb 2021
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From: Florida
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Lets say $200 for LS6 intake, $400 for SDPC LS6 Power Max cam and GM beehive springs, and $400 for SE headers and x-pipe; total $1,000 (plus tax).
Thats a lot of power for a grand, probably in the 70 hp range at 5500 rpm.
Last edited by vette4fl; Feb 12, 2022 at 04:44 PM.
Le Mans Master
Joined: Feb 2021
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From: Florida
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Thread Starter
Drifting
Joined: Mar 2012
Posts: 1,959
Likes: 217
From: Victoria tx
Gosh it seems the ls6 manifold juice ain't worth the squeeze...
I simply was curious because I'm wanting to do high flows, vararam, fix oil pan gasket and get a tune and I figured if I'm going to get a tune then what else could I do...but no I can't/won't do headers. Can't afford them
Le Mans Master
Joined: Feb 2021
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From: Florida
2025 Corvette of the Year Finalist - Unmodified
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Gosh it seems the ls6 manifold juice ain't worth the squeeze...
I simply was curious because I'm wanting to do high flows, vararam, fix oil pan gasket and get a tune and I figured if I'm going to get a tune then what else could I do...but no I can't/won't do headers. Can't afford them
I simply was curious because I'm wanting to do high flows, vararam, fix oil pan gasket and get a tune and I figured if I'm going to get a tune then what else could I do...but no I can't/won't do headers. Can't afford them
Your current intake manifold and exhaust will work with a midrange cam, like the LS6 based cam I mentioned, and it’s very affordable and a nice driver. Just some options…
Good luck!
Thread Starter
Drifting
Joined: Mar 2012
Posts: 1,959
Likes: 217
From: Victoria tx
I get it. I’m always looking for improvements on a budget. These cold air intakes are a waste of money, though. A tune, a cam, heads, headers, those all make power. You can get a Z06 air box lid that has a larger opening cheap, and that with a tune will be an improvement.
Your current intake manifold and exhaust will work with a midrange cam, like the LS6 based cam I mentioned, and it’s very affordable and a nice driver. Just some options…
Good luck!
Your current intake manifold and exhaust will work with a midrange cam, like the LS6 based cam I mentioned, and it’s very affordable and a nice driver. Just some options…
Good luck!
Safety Car
Joined: Mar 2017
Posts: 3,771
Likes: 940
From: Orlando Florida
The LS6 is rated at 405 HP. Since you have a 99 (as do I) your motor was rated at 345. The LS6 has higher compression, better flowing heads, better flowing intake manifold, better flowing exhaust manifolds (that one may be arguable), a better cam shaft, and a tune setup for them. With all of the physical differences, there is a grand total of 55 HP difference. The heads are purported to be 20 HP. The cam has to be 25 or more -- that's only two features, and we've accounted for 45 out of 55 HP. I don't mean to discount the idea of the 5 extra HP, or more importantly more lower end torque across the board it may provide, but I will note I haven't seen an actual LS6 manifold go for less than $350 in a long, long time.
Melting Slicks
Joined: Dec 2004
Posts: 2,847
Likes: 1,144
From: Sleepy Hollow- NJ
The LS6 is rated at 405 HP. Since you have a 99 (as do I) your motor was rated at 345. The LS6 has higher compression, better flowing heads, better flowing intake manifold, better flowing exhaust manifolds (that one may be arguable), a better cam shaft, and a tune setup for them. With all of the physical differences, there is a grand total of 55 HP difference. The heads are purported to be 20 HP. The cam has to be 25 or more -- that's only two features, and we've accounted for 45 out of 55 HP. I don't mean to discount the idea of the 5 extra HP, or more importantly more lower end torque across the board it may provide, but I will note I haven't seen an actual LS6 manifold go for less than $350 in a long, long time.
and break it down one step further.The 2001 and up LS1s had a slightly different cam spec than the 00, and the 97-99's. But the "LS6" intake was added.
The net HP gain as reported from GM was 5hp. From 345hp in 97-00. To 350hp in 01-04.
Yes I do have the "LS6" intake on my 99 coupe. I put it on myself in 2003 and paid $175 for it on eBay. At that time I knew very little and apparently really wanted 5hp for $175.
However, it does factor in better with future upgrades. As I've not moved to a FAST intake and have had pretty fast cars with that "LS6" intake..
Last edited by Johnny Hardcore; Feb 13, 2022 at 09:00 PM.