Ls3 aftermarket intake worth the money?

[Kingkong]

Hey everyone I'm sure someone with knowledge on this will chime in but basically I've been told to basically keep my factory intake and that the after market ones are not worth the money for the little Gaines. Can anyone agree to this or show me the difference between the ls3 and say a fast or the high rise ones. Thanks

 

[Dunelover]

I seem to remember either car craft or Motortrend did a dyno comparison article with several  stock an aftermarket manifolds. 

 

[L.R.S.]

Depends on the application.  Talk to whoever built the engine and get their input.  Intakes aren't crazy expensive so if the engine builder didn't add one when it was built there probably wasn't a lot to gain, other then a cool look.  Years ago my stroker LS2 had a pro charger and I removed it and installed a cheap sheet metal intake.  Danzio tuned the car and said a stock intake would be better and give me a little more HP because it was a low compression engine built for boost.

 

[Lambro]

I did some chassis dyno testing with my Ls3 416.  The stock intake was way better in ever part of the curve then the sheet metal.  Richard holder did a much more through test with similar results

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[2dasand]

I had one of the big LS engine builders call it like this -  "They are just like a boob job!  They don't really do much, but everyone loves to look at them!!"  That has always stuck with me!

 

[Rockwood]

Fast is either tied or worth a couple of horsepower (like 1-2) everywhere compared to stock LS3.  For $1000, meh. 

Sheetmetal is only really worth it if you're doing forced induction and want to run a built-in air to water intercooler.

 

[J Alper]

It just depends on what you are trying to do,  they work like camshaft profiles,  are they worth the money? depends on what you are trying to do,  

At the end of the days where is the bottle neck, 

For a Factory LS3, I would say do not do a intake you will have pretty much very little or no gain,   when you add heads a after market intake will gain HP, but any time you gain HP you will loose torque, it just about runner speed and how the air is condensed into the runner, 

When doing a big inch motor a intake is really a must, but then where do you want the power,   stock profile intake will give more torque and keep power where we use it,   Hi rams really give a better overall HP number but it is way up in the range that is typically not used in a sand car,  

For me i went with a Hi-Ram,  i did the same test in a Fast Stock style intake and the Fast on a 440+ engine really out beat the Hi-Ram but the Hp loss was worth the look for me,  

At the end of the day, if you are a 416 or smaller, the LS3 intake is a hard one to beat,    

 

[Fullthrottleguy]

It just depends on what you are trying to do,  they work like camshaft profiles,  are they worth the money? depends on what you are trying to do,  

At the end of the days where is the bottle neck, 

For a Factory LS3, I would say do not do a intake you will have pretty much very little or no gain,   when you add heads a after market intake will gain HP, but any time you gain HP you will loose torque, it just about runner speed and how the air is condensed into the runner, 

When doing a big inch motor a intake is really a must, but then where do you want the power,   stock profile intake will give more torque and keep power where we use it,   Hi rams really give a better overall HP number but it is way up in the range that is typically not used in a sand car,  

For me i went with a Hi-Ram,  i did the same test in a Fast Stock style intake and the Fast on a 440+ engine really out beat the Hi-Ram but the Hp loss was worth the look for me,  

At the end of the day, if you are a 416 or smaller, the LS3 intake is a hard one to beat,    

JAlper is right on the money here - I would add that Every aftermarket intake with the exception of a few poorly designed Chinese intakes do a great job of improving power across a certain RPM range and with few exceptions that range is Always higher than stock redline.  If you look at 99% of the intakes they usuallu make Less TQ and usually HP under 5000 than the stock ls3 - and thats easy to explain they all are shorter runner.  The LS3 Intake is deceiving because the runner X-over the intake so they are pretty long and that build TQ across the RPM range and Usually HP across the range. 

Where the LS3 falls down is in Throttle body size.   This is especially true  Big Cube engines . Every aftermarket intake that makes more power TQ+HP over the LS3 under 5500 RPM on a Big Cube engine has a Bigger Throttle body.  The Intake is biggest enough to feed a 502, but the TB is the restriction at higher RPM.  Tests where they use and adapter or better yet hone the Intake to accept a 105mm Tjrottle show the Intake stretch the useable HP +TQ out to about 6200RPM 

For the Dunes its all abiut power under the curve  - that is to say the powerband you drive in  - Up to a 463cu with over 11:1 Compression the LS3  manifold with a 102mm TB (stock is 90mm) will hands down outperform anything  from 2500 - 5500 where most of us Dune. we like to think we are putting the car on the Rev limiter all day long  - but thats not smart or practical. Have the TQ not to have to downshift at 2500 is a better experience. 

But of course the Cam is the brain of the engine and most of us  always go too big and kill the Low end  so no matter waht manifold you use its not helping ...

The port dimension and angle of the GM LS3 head fits really well with the manifold.  Some aftermarket heads have a taller intake port floor and I have seen the MSD airforce pick up 15HP over 3500 on an LS3 Manifold on those heads, but they usually lose 30Ft lbs TQ, so driver feel IMO is worse.

I recently did an LSX 454 with custom cam  - a little more dune friendly  and it had a Holley Hi ram and a Holley 102 TB On the Dyno  -   We swapped the manifold for an LS7 with a Ported TB it lost almost 30HP at 6500  but made 50FT more TQ 2100 RPM to 5500  and was definitely more fun to drive  - then we swapped the LS7 intake for an MSD and the car picked up almost 35HP at 4000RPM to 6500PRM (the redline) it was the overall best.  at a 6500RPM redline that engine will outlast the car  - RPM kills engines 

So like everything else CAM, COMPRESSION, HEADS, MANIFOLD, FUEL, GEARING - the right combo and the right tune are really the key and how you drive it IMO

 

[Kingkong]

Thats what I was.looking for thanks full throttle and alper I'm definitely sticking with what I got and that's about what I figured haha...