Asking for a LSXr intake manifold for christmas, but I have to buy all other parts

Is the 102mm throttle body to much for the 5.3L? will I gain more hp tq from a 102 vs 90 with the manifold?

do yall recommend getting the fast billet rails as well or can I buy the adapter parts for the 5.3L rail to save a lil$$$$$

I can find used/newish Ls2 cable throttle bodys online around $200 but you know the expensive 450-550 price of the 102

 

Is this going into your 01? I would recommend the 90mm as it won't be a restriction for a long time short of major upgrades. I have a 90mm DBC if you want it $215 shipped.

 

Get the biggest you can afford and will fit! Keep in mind velocity into the plenum is not a factor that affects performance on this platform...you want and need as much volume available in the plenum as possible! There are numerous threads on tech about this where all the "experts" agree on this!

 

Thanks Matt 102 it is!!!
Quick question What cam and heads did yall run on you fastest N/A LS1
Thats insane to be a 9 sec car with 5.7L N/A Great job yall definitely know what you are doing

 

I'm thinkin that's going to be a secret! if everyone knew then everyone would have mid 9 sec NA stock bottom end LS1 cars...a lot more than power goes into making a 9 sec car though, weight, tires, suspension, etc

 

The question in your case that you need to ask yourself is the 102mm going to warrant the extra 200-250$? Money that could be spent elsewhere. For example let's say a cammed 5.3 will gain 6hp by going from 90to102. Not worth it IMO. Now let's say a boosted 6.2 will gain 25hp by going from 90 to 102 completely worth every penny. Now if the 5.3 is only a stepping stone to bigger cubes and boost you don't want to buy a throttlebody twice if you dont have to. Go 102 for sure. The law of diminishing return is important here. Just because something is better doesn't mean it is right for your build.

 

I'm thinkin that's going to be a secret! if everyone knew then everyone would have mid 9 sec NA stock bottom end LS1 cars...a lot more than power goes into making a 9 sec car though, weight, tires, suspension, etc

Hahahaha I had the secret thought go through my head after I posted it. Why would they give up their record braking car so somebody else could steel there design and make an 8 sec car...... I just have to know lol 9s N/A ls1 is insane

The question in your case that you need to ask yourself is the 102mm going to warrant the extra 200-250$? Money that could be spent elsewhere. For example let's say a cammed 5.3 will gain 6hp by going from 90to102. Not worth it IMO. Now let's say a boosted 6.2 will gain 25hp by going from 90 to 102 completely worth every penny. Now if the 5.3 is only a stepping stone to bigger cubes and boost you don't want to buy a throttlebody twice if you dont have to. Go 102 for sure. The law of diminishing return is important here. Just because something is better doesn't mean it is right for your build.

Great point!!! That $250 could be applied to a dyno tune. Of course this is my last option for N/A performance be sides ported heads and bumping compression up. I don't think i'm going to do that since its $1300. I am building this motor for tq and hp just tags along. I have a vinci 210/218 .584/.584 < with 1.8 rockers on 116Lsa

Do yall have any idea around how much tq difference one would see from a 90mm vs 102mm. I plan on wayyyyyy wayyyyyy wayyyyyy later down the road installing an intercooled turbo kit around 5-7psi

I was guessing the 102mm would make around 5-10 more hp vs. 90mm

 

When we went 9.62@132 it was our MS4 and PRC 227cc heads. Of course we had flycut pistons and milled the heck out of the heads to get compression. it's no secret that the car weighs about 2900lbs with the driver in it. Every component on the car are readily available for sell...other than a little prototype head work, it is all off the shelf stuff. It has every lightweight component known to man in it to achieve that weight. It does however have a decent looking interior and does not appear gutted. It has all interior panels and dash...minus the passenger and rear seats.

The newer setup has more cam and more head work, as well as the ET 2-piece CNC intake, different convertor, etc. The same old tranny was tired though so the 60' suffered....it ran 9.65@138 with that combo....so we know it's making the power we want, we just need time to install the new trans and converter that are sitting here, and a weekend to go race! We'll be looking for 9.3x@140ish next time out

 

ive got a 2012 rcsb work truck 5.3 i had the stock 90mm throttle body ported and polished. it made power gains with stock intake and works nicely with the fast lsxrt102mm intake on it now. i did have problems with the injector orings fitting on the 2012 5.3 injectors though. comp was no help at all with this problem! my mechanic fabricated some ac orings and shrink wrap too make them work. comps customer service didnt seem too give a crap about my problem and left me with twitching eye that i get rite before i kick somebodys ***!

 

Go with the 102mm if it is possible. Then you are done with it, and will never look back and regret it.