Intake, exhaust and tune HP numbers

Discussion on fuel delivery & intake/exhaust tech & mods.
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79sevillecoupe
Posts: 35
Joined: Mon Feb 13, 2017 10:43 pm

Intake, exhaust and tune HP numbers

Post by 79sevillecoupe »

What kind of power gains could I expect if I were to install the following:
1. VCM OTR cold air intake
2. FAST LSXR™ 102MM black intake manifold and 102MM throttle body(called FAST and they say the model with cathedral ports will work on our cars)
3. Kooks long tube headers(1 7/8") and green catted x-pipes
4. HPTuners tune

Im going to guestimate a 100 hp gain(roughly putting me around 400 to the wheels). Hopefully I'm not smoking dope with this number. I already have the intake on order. Kooks LT headers and cats are next(hooked up to stock muffler). Im looking to get a ballpark figure on the performance improvement I can expect to see with these mods.
Btw, car just hit 2000 miles today :D
Anyone else have any gains with these parts? If so, which parts and how much gains?
CrashTestDummy
Posts: 2300
Joined: Sat Feb 07, 2015 2:31 pm
Location: Pearland, Texas

Re: Intake, exhaust and tune HP numbers

Post by CrashTestDummy »

That intake will probably 'fit', but there will be a port mismatch. Since that's just about where the fuel is squirted into the air stream, I'd expect the extra turbulence might affect any gains made by the larger TB port opening.

You should probably have a look around the LS1Tech forum to see if anyone has actually seen what a cathedral-port intake does with square port heads.
Gene Beaird,
Pearland, Texas
2012 Caprice 9C1
1992 B4C 1LE Camaro
2018 Tahoe PPV (her car)
1995 DGGM Impala SS
1985 Firebird - 310 LS1 C Prepared autocross car.
1980 Bluebird Wanderlodge
And some others
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xcidmigs
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Location: SE PA

Re: Intake, exhaust and tune HP numbers

Post by xcidmigs »

I agree that the intake and TB is a waste of $$ for the rest of what you are doing. Both are nice parts but you don't need them at all for the rest of your combo. You are completely limited by the use of the stock cam.
There are multiple threads here showing how small diameter pipe is used in several parts of factory piping. You would be going from 3" x pipe to less than 2" at the trunk mid muffler and rear muffler joints.
For the money you are spending on the green x pipe alone you could replace entire exhaust with custom bent 2.5" which has been repeatedly shown to max HP and TQ in a true dual exhaust system up to something like 500HP. Factory LSA motor is still using the stock LS cast iron manifolds and 2.5" pipes.
Using dual 3" is just making it louder and more expensive. If you want the stealth sound of stock mufflers what about a set of remote cut outs installed right behind your X pipe? Then pick the cam of your desired power band and you have addressed pre, post and internal air flow.
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kevink
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Re: Intake, exhaust and tune HP numbers

Post by kevink »

A FAST intake is completely unnecessary and you are completely smoking dope thinking you're going to gain 100 HP... Sorry. Maybe half that, but with the stock mufflers, maybe even less.
2011 9C3: 11.48 @118.
79sevillecoupe
Posts: 35
Joined: Mon Feb 13, 2017 10:43 pm

Re: Intake, exhaust and tune HP numbers

Post by 79sevillecoupe »

CrashTestDummy wrote:That intake will probably 'fit', but there will be a port mismatch. Since that's just about where the fuel is squirted into the air stream, I'd expect the extra turbulence might affect any gains made by the larger TB port opening.

You should probably have a look around the LS1Tech forum to see if anyone has actually seen what a cathedral-port intake does with square port heads.
So this engine has square ports? From what I have found on other forums and info provided, I have gathered that they were cathedral ports. But hey, I wont know for sure until I open that bad boy up and see for myself. Can someone who has worked on these cars confirm if they are cathedral or rectangular ports. Thanks
79sevillecoupe
Posts: 35
Joined: Mon Feb 13, 2017 10:43 pm

Re: Intake, exhaust and tune HP numbers

Post by 79sevillecoupe »

kevink wrote:A FAST intake is completely unnecessary and you are completely smoking dope thinking you're going to gain 100 HP... Sorry. Maybe half that, but with the stock mufflers, maybe even less.
https://youtu.be/jpv8rRx_VlQ" onclick="window.open(this.href);return false;

This tuner is claiming 30hp gain without tune and 55hp gain with a tune. I have also read a set of kooks headers and green catted x pipe(going to go with the solo axle back system in there too) will give gains of 25-30hp. Adding a tune in there sounds like 60hp can be reached just with these parts. TB and intake manifold are saying 10-15 hp gains. Do these numbers not add out with anyone who has actually installed them into their car? :?: (TB and manifold are on the back burner for now, probably going to spend the money on a cam in a couple months.)
jackleg
Posts: 99
Joined: Wed May 04, 2016 9:25 pm
Location: SW MI

Re: Intake, exhaust and tune HP numbers

Post by jackleg »

Stock already has square port heads and better intake. Basically ls3 heads and intake on a ls2. Plus already has bigger injectors due to flex fuel.
79sevillecoupe wrote:
So this engine has square ports? From what I have found on other forums and info provided, I have gathered that they were cathedral ports. But hey, I wont know for sure until I open that bad boy up and see for myself. Can someone who has worked on these cars confirm if they are cathedral or rectangular ports. Thanks
2011 9C1 6.0
RCR "Little Lunati" 219/223 .625/.625 112+0
Kooks headers, hi flow cats, Dynomax Super Turbos
Flex fuel tune
CrashTestDummy
Posts: 2300
Joined: Sat Feb 07, 2015 2:31 pm
Location: Pearland, Texas

Re: Intake, exhaust and tune HP numbers

Post by CrashTestDummy »

There are a couple of guys who will port your intake manifold, and some claim pretty good gains with that. You might want to look into that instead of a new intake.

I think you'd gain far more from that new cam than an intake. You'll also get to use more of those headers. You'll also want to look into a better exhaust system. Even something that's 2.5" front to back is better than what comes on the things stock.

Another nice gain can be had from a better rear gear. Heck, even a 3.27 will really wake the car up, without actually adding any more HP. The car will feel much lighter.
Gene Beaird,
Pearland, Texas
2012 Caprice 9C1
1992 B4C 1LE Camaro
2018 Tahoe PPV (her car)
1995 DGGM Impala SS
1985 Firebird - 310 LS1 C Prepared autocross car.
1980 Bluebird Wanderlodge
And some others
Do YOU have my SPID?
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